AArch64ISelLowering.cpp

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//===-- AArch64ISelLowering.cpp - AArch64 DAG Lowering Implementation  ----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the AArch64TargetLowering class.
//
//===----------------------------------------------------------------------===//
 
#include "AArch64ISelLowering.h"
#include "AArch64CallingConvention.h"
#include "AArch64ExpandImm.h"
#include "AArch64MachineFunctionInfo.h"
#include "AArch64PerfectShuffle.h"
#include "AArch64RegisterInfo.h"
#include "AArch64SMEAttributes.h"
#include "AArch64Subtarget.h"
#include "AArch64TargetMachine.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "Utils/AArch64BaseInfo.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/SmallVectorExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/ObjCARCUtil.h"
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/ComplexDeinterleavingPass.h"
#include "llvm/CodeGen/GlobalISel/Utils.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SDPatternMatch.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/TargetCallingConv.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGenTypes/MachineValueType.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/IntrinsicsAArch64.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/Use.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/InstructionCost.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/SipHash.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/TargetParser/Triple.h"
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cstdint>
#include <cstdlib>
#include <iterator>
#include <limits>
#include <optional>
#include <tuple>
#include <utility>
#include <vector>
 
using namespace llvm;
 
#define DEBUG_TYPE "aarch64-lower"
 
STATISTIC(NumTailCalls, "Number of tail calls");
STATISTIC(NumOptimizedImms, "Number of times immediates were optimized");
 
// FIXME: The necessary dtprel relocations don't seem to be supported
// well in the GNU bfd and gold linkers at the moment. Therefore, by
// default, for now, fall back to GeneralDynamic code generation.
cl::opt<bool> EnableAArch64ELFLocalDynamicTLSGeneration(
    "aarch64-elf-ldtls-generation", cl::Hidden,
    cl::desc("Allow AArch64 Local Dynamic TLS code generation"),
    cl::init(false));
 
static cl::opt<bool>
EnableOptimizeLogicalImm("aarch64-enable-logical-imm", cl::Hidden,
                         cl::desc("Enable AArch64 logical imm instruction "
                                  "optimization"),
                         cl::init(true));
 
// Temporary option added for the purpose of testing functionality added
// to DAGCombiner.cpp in D92230. It is expected that this can be removed
// in future when both implementations will be based off MGATHER rather
// than the GLD1 nodes added for the SVE gather load intrinsics.
static cl::opt<bool>
EnableCombineMGatherIntrinsics("aarch64-enable-mgather-combine", cl::Hidden,
                                cl::desc("Combine extends of AArch64 masked "
                                         "gather intrinsics"),
                                cl::init(true));
 
static cl::opt<bool> EnableExtToTBL("aarch64-enable-ext-to-tbl", cl::Hidden,
                                    cl::desc("Combine ext and trunc to TBL"),
                                    cl::init(true));
 
// All of the XOR, OR and CMP use ALU ports, and data dependency will become the
// bottleneck after this transform on high end CPU. So this max leaf node
// limitation is guard cmp+ccmp will be profitable.
static cl::opt<unsigned> MaxXors("aarch64-max-xors", cl::init(16), cl::Hidden,
                                 cl::desc("Maximum of xors"));
 
// By turning this on, we will not fallback to DAG ISel when encountering
// scalable vector types for all instruction, even if SVE is not yet supported
// with some instructions.
// See [AArch64TargetLowering::fallbackToDAGISel] for implementation details.
cl::opt<bool> EnableSVEGISel(
    "aarch64-enable-gisel-sve", cl::Hidden,
    cl::desc("Enable / disable SVE scalable vectors in Global ISel"),
    cl::init(false));
 
// TODO: This option should be removed once we switch to always using PTRADD in
// the SelectionDAG.
static cl::opt<bool> UseFEATCPACodegen(
    "aarch64-use-featcpa-codegen", cl::Hidden,
    cl::desc("Generate ISD::PTRADD nodes for pointer arithmetic in "
             "SelectionDAG for FEAT_CPA"),
    cl::init(false));
 
/// Value type used for condition codes.
constexpr MVT CondCodeVT = MVT::i32;
 
/// Value type used for NZCV flags.
constexpr MVT FlagsVT = MVT::i32;
 
static const MCPhysReg GPRArgRegs[] = {AArch64::X0, AArch64::X1, AArch64::X2,
                                       AArch64::X3, AArch64::X4, AArch64::X5,
                                       AArch64::X6, AArch64::X7};
static const MCPhysReg FPRArgRegs[] = {AArch64::Q0, AArch64::Q1, AArch64::Q2,
                                       AArch64::Q3, AArch64::Q4, AArch64::Q5,
                                       AArch64::Q6, AArch64::Q7};
 
ArrayRef<MCPhysReg> llvm::AArch64::getGPRArgRegs() { return GPRArgRegs; }
 
ArrayRef<MCPhysReg> llvm::AArch64::getFPRArgRegs() { return FPRArgRegs; }
 
static inline EVT getPackedSVEVectorVT(EVT VT) {
  switch (VT.getSimpleVT().SimpleTy) {
  default:
    llvm_unreachable("unexpected element type for vector");
  case MVT::i8:
    return MVT::nxv16i8;
  case MVT::i16:
    return MVT::nxv8i16;
  case MVT::i32:
    return MVT::nxv4i32;
  case MVT::i64:
    return MVT::nxv2i64;
  case MVT::f16:
    return MVT::nxv8f16;
  case MVT::f32:
    return MVT::nxv4f32;
  case MVT::f64:
    return MVT::nxv2f64;
  case MVT::bf16:
    return MVT::nxv8bf16;
  }
}
 
// NOTE: Currently there's only a need to return integer vector types. If this
// changes then just add an extra "type" parameter.
static inline EVT getPackedSVEVectorVT(ElementCount EC) {
  switch (EC.getKnownMinValue()) {
  default:
    llvm_unreachable("unexpected element count for vector");
  case 16:
    return MVT::nxv16i8;
  case 8:
    return MVT::nxv8i16;
  case 4:
    return MVT::nxv4i32;
  case 2:
    return MVT::nxv2i64;
  }
}
 
static inline EVT getPromotedVTForPredicate(EVT VT) {
  assert(VT.isScalableVector() && (VT.getVectorElementType() == MVT::i1) &&
         "Expected scalable predicate vector type!");
  switch (VT.getVectorMinNumElements()) {
  default:
    llvm_unreachable("unexpected element count for vector");
  case 2:
    return MVT::nxv2i64;
  case 4:
    return MVT::nxv4i32;
  case 8:
    return MVT::nxv8i16;
  case 16:
    return MVT::nxv16i8;
  }
}
 
/// Returns true if VT's elements occupy the lowest bit positions of its
/// associated register class without any intervening space.
///
/// For example, nxv2f16, nxv4f16 and nxv8f16 are legal types that belong to the
/// same register class, but only nxv8f16 can be treated as a packed vector.
static inline bool isPackedVectorType(EVT VT, SelectionDAG &DAG) {
  assert(VT.isVector() && DAG.getTargetLoweringInfo().isTypeLegal(VT) &&
         "Expected legal vector type!");
  return VT.isFixedLengthVector() ||
         VT.getSizeInBits().getKnownMinValue() == AArch64::SVEBitsPerBlock;
}
 
static inline bool isPackedPredicateType(EVT VT, SelectionDAG &DAG) {
  assert(VT.isVector() && DAG.getTargetLoweringInfo().isTypeLegal(VT) &&
         "Expected legal type!");
  return VT == MVT::nxv16i1;
}
 
/// Returns true if the conceptual representation for \p VT does not map
/// directly to its physical register representation, meaning there are gaps
/// between elements in the register. In practice, the vector elements will be
/// strided by a power of two and placed starting from lane 0. For example,
/// nxv8i1 or nxv2f32 are unpacked types.
///
///\pre VT is a legal type.
static inline bool isUnpackedType(EVT VT, SelectionDAG &DAG) {
  bool Res = !isPackedVectorType(VT, DAG) && !isPackedPredicateType(VT, DAG);
  assert((!Res || VT.isScalableVector()) &&
         "Unexpected fixed-size unpacked type.");
  return Res;
}
 
// Returns true for ####_MERGE_PASSTHRU opcodes, whose operands have a leading
// predicate and end with a passthru value matching the result type.
static bool isMergePassthruOpcode(unsigned Opc) {
  switch (Opc) {
  default:
    return false;
  case AArch64ISD::BITREVERSE_MERGE_PASSTHRU:
  case AArch64ISD::BSWAP_MERGE_PASSTHRU:
  case AArch64ISD::REVH_MERGE_PASSTHRU:
  case AArch64ISD::REVW_MERGE_PASSTHRU:
  case AArch64ISD::REVD_MERGE_PASSTHRU:
  case AArch64ISD::CTLZ_MERGE_PASSTHRU:
  case AArch64ISD::CTPOP_MERGE_PASSTHRU:
  case AArch64ISD::DUP_MERGE_PASSTHRU:
  case AArch64ISD::ABS_MERGE_PASSTHRU:
  case AArch64ISD::NEG_MERGE_PASSTHRU:
  case AArch64ISD::FNEG_MERGE_PASSTHRU:
  case AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU:
  case AArch64ISD::ZERO_EXTEND_INREG_MERGE_PASSTHRU:
  case AArch64ISD::FCEIL_MERGE_PASSTHRU:
  case AArch64ISD::FFLOOR_MERGE_PASSTHRU:
  case AArch64ISD::FNEARBYINT_MERGE_PASSTHRU:
  case AArch64ISD::FRINT_MERGE_PASSTHRU:
  case AArch64ISD::FRINT32_MERGE_PASSTHRU:
  case AArch64ISD::FRINT64_MERGE_PASSTHRU:
  case AArch64ISD::FROUND_MERGE_PASSTHRU:
  case AArch64ISD::FROUNDEVEN_MERGE_PASSTHRU:
  case AArch64ISD::FTRUNC_MERGE_PASSTHRU:
  case AArch64ISD::FTRUNC32_MERGE_PASSTHRU:
  case AArch64ISD::FTRUNC64_MERGE_PASSTHRU:
  case AArch64ISD::FP_ROUND_MERGE_PASSTHRU:
  case AArch64ISD::FP_EXTEND_MERGE_PASSTHRU:
  case AArch64ISD::SINT_TO_FP_MERGE_PASSTHRU:
  case AArch64ISD::UINT_TO_FP_MERGE_PASSTHRU:
  case AArch64ISD::FCVTX_MERGE_PASSTHRU:
  case AArch64ISD::FCVTZU_MERGE_PASSTHRU:
  case AArch64ISD::FCVTZS_MERGE_PASSTHRU:
  case AArch64ISD::FSQRT_MERGE_PASSTHRU:
  case AArch64ISD::FRECPX_MERGE_PASSTHRU:
  case AArch64ISD::FABS_MERGE_PASSTHRU:
    return true;
  }
}
 
// Returns true if inactive lanes are known to be zeroed by construction.
static bool isZeroingInactiveLanes(SDValue Op) {
  switch (Op.getOpcode()) {
  default:
    return false;
  // We guarantee i1 splat_vectors to zero the other lanes
  case ISD::SPLAT_VECTOR:
  case ISD::GET_ACTIVE_LANE_MASK:
  case AArch64ISD::PTRUE:
  case AArch64ISD::SETCC_MERGE_ZERO:
    return true;
  case ISD::INTRINSIC_WO_CHAIN:
    switch (Op.getConstantOperandVal(0)) {
    default:
      return false;
    case Intrinsic::aarch64_sve_ptrue:
    case Intrinsic::aarch64_sve_pnext:
    case Intrinsic::aarch64_sve_cmpeq:
    case Intrinsic::aarch64_sve_cmpne:
    case Intrinsic::aarch64_sve_cmpge:
    case Intrinsic::aarch64_sve_cmpgt:
    case Intrinsic::aarch64_sve_cmphs:
    case Intrinsic::aarch64_sve_cmphi:
    case Intrinsic::aarch64_sve_cmpeq_wide:
    case Intrinsic::aarch64_sve_cmpne_wide:
    case Intrinsic::aarch64_sve_cmpge_wide:
    case Intrinsic::aarch64_sve_cmpgt_wide:
    case Intrinsic::aarch64_sve_cmplt_wide:
    case Intrinsic::aarch64_sve_cmple_wide:
    case Intrinsic::aarch64_sve_cmphs_wide:
    case Intrinsic::aarch64_sve_cmphi_wide:
    case Intrinsic::aarch64_sve_cmplo_wide:
    case Intrinsic::aarch64_sve_cmpls_wide:
    case Intrinsic::aarch64_sve_fcmpeq:
    case Intrinsic::aarch64_sve_fcmpne:
    case Intrinsic::aarch64_sve_fcmpge:
    case Intrinsic::aarch64_sve_fcmpgt:
    case Intrinsic::aarch64_sve_fcmpuo:
    case Intrinsic::aarch64_sve_facgt:
    case Intrinsic::aarch64_sve_facge:
    case Intrinsic::aarch64_sve_whilege:
    case Intrinsic::aarch64_sve_whilegt:
    case Intrinsic::aarch64_sve_whilehi:
    case Intrinsic::aarch64_sve_whilehs:
    case Intrinsic::aarch64_sve_whilele:
    case Intrinsic::aarch64_sve_whilelo:
    case Intrinsic::aarch64_sve_whilels:
    case Intrinsic::aarch64_sve_whilelt:
    case Intrinsic::aarch64_sve_match:
    case Intrinsic::aarch64_sve_nmatch:
    case Intrinsic::aarch64_sve_whilege_x2:
    case Intrinsic::aarch64_sve_whilegt_x2:
    case Intrinsic::aarch64_sve_whilehi_x2:
    case Intrinsic::aarch64_sve_whilehs_x2:
    case Intrinsic::aarch64_sve_whilele_x2:
    case Intrinsic::aarch64_sve_whilelo_x2:
    case Intrinsic::aarch64_sve_whilels_x2:
    case Intrinsic::aarch64_sve_whilelt_x2:
      return true;
    }
  }
}
 
static std::tuple<SDValue, SDValue>
extractPtrauthBlendDiscriminators(SDValue Disc, SelectionDAG *DAG) {
  SDLoc DL(Disc);
  SDValue AddrDisc;
  SDValue ConstDisc;
 
  // If this is a blend, remember the constant and address discriminators.
  // Otherwise, it's either a constant discriminator, or a non-blended
  // address discriminator.
  if (Disc->getOpcode() == ISD::INTRINSIC_WO_CHAIN &&
      Disc->getConstantOperandVal(0) == Intrinsic::ptrauth_blend) {
    AddrDisc = Disc->getOperand(1);
    ConstDisc = Disc->getOperand(2);
  } else {
    ConstDisc = Disc;
  }
 
  // If the constant discriminator (either the blend RHS, or the entire
  // discriminator value) isn't a 16-bit constant, bail out, and let the
  // discriminator be computed separately.
  const auto *ConstDiscN = dyn_cast<ConstantSDNode>(ConstDisc);
  if (!ConstDiscN || !isUInt<16>(ConstDiscN->getZExtValue()))
    return std::make_tuple(DAG->getTargetConstant(0, DL, MVT::i64), Disc);
 
  // If there's no address discriminator, use NoRegister, which we'll later
  // replace with XZR, or directly use a Z variant of the inst. when available.
  if (!AddrDisc)
    AddrDisc = DAG->getRegister(AArch64::NoRegister, MVT::i64);
 
  return std::make_tuple(
      DAG->getTargetConstant(ConstDiscN->getZExtValue(), DL, MVT::i64),
      AddrDisc);
}
 
AArch64TargetLowering::AArch64TargetLowering(const TargetMachine &TM,
                                             const AArch64Subtarget &STI)
    : TargetLowering(TM, STI), Subtarget(&STI) {
  // AArch64 doesn't have comparisons which set GPRs or setcc instructions, so
  // we have to make something up. Arbitrarily, choose ZeroOrOne.
  setBooleanContents(ZeroOrOneBooleanContent);
  // When comparing vectors the result sets the different elements in the
  // vector to all-one or all-zero.
  setBooleanVectorContents(ZeroOrNegativeOneBooleanContent);
 
  // Set up the register classes.
  addRegisterClass(MVT::i32, &AArch64::GPR32allRegClass);
  addRegisterClass(MVT::i64, &AArch64::GPR64allRegClass);
 
  if (Subtarget->hasLS64()) {
    addRegisterClass(MVT::i64x8, &AArch64::GPR64x8ClassRegClass);
    setOperationAction(ISD::LOAD, MVT::i64x8, Custom);
    setOperationAction(ISD::STORE, MVT::i64x8, Custom);
  }
 
  if (Subtarget->hasFPARMv8()) {
    addRegisterClass(MVT::aarch64mfp8, &AArch64::FPR8RegClass);
    addRegisterClass(MVT::f16, &AArch64::FPR16RegClass);
    addRegisterClass(MVT::bf16, &AArch64::FPR16RegClass);
    addRegisterClass(MVT::f32, &AArch64::FPR32RegClass);
    addRegisterClass(MVT::f64, &AArch64::FPR64RegClass);
    addRegisterClass(MVT::f128, &AArch64::FPR128RegClass);
  }
 
  if (Subtarget->hasNEON()) {
    addRegisterClass(MVT::v16i8, &AArch64::FPR8RegClass);
    addRegisterClass(MVT::v8i16, &AArch64::FPR16RegClass);
 
    addDRType(MVT::v2f32);
    addDRType(MVT::v8i8);
    addDRType(MVT::v4i16);
    addDRType(MVT::v2i32);
    addDRType(MVT::v1i64);
    addDRType(MVT::v1f64);
    addDRType(MVT::v4f16);
    addDRType(MVT::v4bf16);
 
    addQRType(MVT::v4f32);
    addQRType(MVT::v2f64);
    addQRType(MVT::v16i8);
    addQRType(MVT::v8i16);
    addQRType(MVT::v4i32);
    addQRType(MVT::v2i64);
    addQRType(MVT::v8f16);
    addQRType(MVT::v8bf16);
  }
 
  if (Subtarget->isSVEorStreamingSVEAvailable()) {
    // Add legal sve predicate types
    addRegisterClass(MVT::nxv1i1, &AArch64::PPRRegClass);
    addRegisterClass(MVT::nxv2i1, &AArch64::PPRRegClass);
    addRegisterClass(MVT::nxv4i1, &AArch64::PPRRegClass);
    addRegisterClass(MVT::nxv8i1, &AArch64::PPRRegClass);
    addRegisterClass(MVT::nxv16i1, &AArch64::PPRRegClass);
 
    // Add sve predicate as counter type
    addRegisterClass(MVT::aarch64svcount, &AArch64::PPRRegClass);
 
    // Add legal sve data types
    addRegisterClass(MVT::nxv16i8, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv8i16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv4i32, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv2i64, &AArch64::ZPRRegClass);
 
    addRegisterClass(MVT::nxv2f16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv4f16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv8f16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv2f32, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv4f32, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv2f64, &AArch64::ZPRRegClass);
 
    addRegisterClass(MVT::nxv2bf16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv4bf16, &AArch64::ZPRRegClass);
    addRegisterClass(MVT::nxv8bf16, &AArch64::ZPRRegClass);
 
    if (Subtarget->useSVEForFixedLengthVectors()) {
      for (MVT VT : MVT::integer_fixedlen_vector_valuetypes())
        if (useSVEForFixedLengthVectorVT(VT))
          addRegisterClass(VT, &AArch64::ZPRRegClass);
 
      for (MVT VT : MVT::fp_fixedlen_vector_valuetypes())
        if (useSVEForFixedLengthVectorVT(VT))
          addRegisterClass(VT, &AArch64::ZPRRegClass);
    }
  }
 
  // Compute derived properties from the register classes
  computeRegisterProperties(Subtarget->getRegisterInfo());
 
  // Provide all sorts of operation actions
  setOperationAction(ISD::GlobalAddress, MVT::i64, Custom);
  setOperationAction(ISD::GlobalTLSAddress, MVT::i64, Custom);
  setOperationAction(ISD::SETCC, MVT::i32, Custom);
  setOperationAction(ISD::SETCC, MVT::i64, Custom);
  setOperationAction(ISD::SETCC, MVT::bf16, Custom);
  setOperationAction(ISD::SETCC, MVT::f16, Custom);
  setOperationAction(ISD::SETCC, MVT::f32, Custom);
  setOperationAction(ISD::SETCC, MVT::f64, Custom);
  setOperationAction(ISD::STRICT_FSETCC, MVT::bf16, Custom);
  setOperationAction(ISD::STRICT_FSETCC, MVT::f16, Custom);
  setOperationAction(ISD::STRICT_FSETCC, MVT::f32, Custom);
  setOperationAction(ISD::STRICT_FSETCC, MVT::f64, Custom);
  setOperationAction(ISD::STRICT_FSETCCS, MVT::f16, Custom);
  setOperationAction(ISD::STRICT_FSETCCS, MVT::f32, Custom);
  setOperationAction(ISD::STRICT_FSETCCS, MVT::f64, Custom);
  setOperationAction(ISD::BITREVERSE, MVT::i32, Legal);
  setOperationAction(ISD::BITREVERSE, MVT::i64, Legal);
  setOperationAction(ISD::CTLS, MVT::i32, Legal);
  setOperationAction(ISD::CTLS, MVT::i64, Legal);
  setOperationAction(ISD::BRCOND, MVT::Other, Custom);
  setOperationAction(ISD::BR_CC, MVT::i32, Custom);
  setOperationAction(ISD::BR_CC, MVT::i64, Custom);
  setOperationAction(ISD::BR_CC, MVT::f16, Custom);
  setOperationAction(ISD::BR_CC, MVT::f32, Custom);
  setOperationAction(ISD::BR_CC, MVT::f64, Custom);
  setOperationAction(ISD::SELECT, MVT::i32, Custom);
  setOperationAction(ISD::SELECT, MVT::i64, Custom);
  if (Subtarget->hasFPARMv8()) {
    setOperationAction(ISD::SELECT, MVT::f16, Custom);
    setOperationAction(ISD::SELECT, MVT::bf16, Custom);
  }
  setOperationAction(ISD::SELECT, MVT::f32, Custom);
  setOperationAction(ISD::SELECT, MVT::f64, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::i32, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::i64, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::f16, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::bf16, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::f32, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::f64, Custom);
  setOperationAction(ISD::BR_JT, MVT::Other, Custom);
  setOperationAction(ISD::JumpTable, MVT::i64, Custom);
  setOperationAction(ISD::BRIND, MVT::Other, Custom);
  setOperationAction(ISD::SETCCCARRY, MVT::i64, Custom);
 
  setOperationAction(ISD::PtrAuthGlobalAddress, MVT::i64, Custom);
 
  setOperationAction(ISD::SHL_PARTS, MVT::i64, Custom);
  setOperationAction(ISD::SRA_PARTS, MVT::i64, Custom);
  setOperationAction(ISD::SRL_PARTS, MVT::i64, Custom);
 
  setOperationAction(ISD::FREM, MVT::f32, LibCall);
  setOperationAction(ISD::FREM, MVT::f64, LibCall);
 
  setOperationAction(ISD::BUILD_PAIR, MVT::i64, Expand);
 
  // Custom lowering hooks are needed for XOR
  // to fold it into CSINC/CSINV.
  setOperationAction(ISD::XOR, MVT::i32, Custom);
  setOperationAction(ISD::XOR, MVT::i64, Custom);
 
  setOperationAction(ISD::ADDRSPACECAST, MVT::i32, Custom);
  setOperationAction(ISD::ADDRSPACECAST, MVT::i64, Custom);
 
  // Virtually no operation on f128 is legal, but LLVM can't expand them when
  // there's a valid register class, so we need custom operations in most cases.
  setOperationAction(ISD::FABS, MVT::f128, Expand);
  setOperationAction(ISD::FADD, MVT::f128, LibCall);
  setOperationAction(ISD::FCOPYSIGN, MVT::f128, Expand);
  setOperationAction(ISD::FCOS, MVT::f128, Expand);
  setOperationAction(ISD::FDIV, MVT::f128, LibCall);
  setOperationAction(ISD::FMA, MVT::f128, Expand);
  setOperationAction(ISD::FMUL, MVT::f128, LibCall);
  setOperationAction(ISD::FNEG, MVT::f128, Expand);
  setOperationAction(ISD::FPOW, MVT::f128, Expand);
  setOperationAction(ISD::FREM, MVT::f128, LibCall);
  setOperationAction(ISD::FRINT, MVT::f128, Expand);
  setOperationAction(ISD::FSIN, MVT::f128, Expand);
  setOperationAction(ISD::FSINCOS, MVT::f128, Expand);
  setOperationAction(ISD::FSQRT, MVT::f128, Expand);
  setOperationAction(ISD::FSUB, MVT::f128, LibCall);
  setOperationAction(ISD::FTAN, MVT::f128, Expand);
  setOperationAction(ISD::FTRUNC, MVT::f128, Expand);
  setOperationAction(ISD::SETCC, MVT::f128, Custom);
  setOperationAction(ISD::STRICT_FSETCC, MVT::f128, Custom);
  setOperationAction(ISD::STRICT_FSETCCS, MVT::f128, Custom);
  setOperationAction(ISD::BR_CC, MVT::f128, Custom);
  setOperationAction(ISD::SELECT, MVT::f128, Custom);
  setOperationAction(ISD::SELECT_CC, MVT::f128, Custom);
  setOperationAction(ISD::FP_EXTEND, MVT::f128, Custom);
  // FIXME: f128 FMINIMUM and FMAXIMUM (including STRICT versions) currently
  // aren't handled.
 
  // Lowering for many of the conversions is actually specified by the non-f128
  // type. The LowerXXX function will be trivial when f128 isn't involved.
  setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
  setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
  setOperationAction(ISD::FP_TO_SINT, MVT::i128, Custom);
  setOperationAction(ISD::STRICT_FP_TO_SINT, MVT::i32, Custom);
  setOperationAction(ISD::STRICT_FP_TO_SINT, MVT::i64, Custom);
  setOperationAction(ISD::STRICT_FP_TO_SINT, MVT::i128, Custom);
  setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
  setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
  setOperationAction(ISD::FP_TO_UINT, MVT::i128, Custom);
  setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::i32, Custom);
  setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::i64, Custom);
  setOperationAction(ISD::STRICT_FP_TO_UINT, MVT::i128, Custom);
  setOperationAction(ISD::SINT_TO_FP, MVT::i32, Custom);
  setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
  setOperationAction(ISD::SINT_TO_FP, MVT::i128, Custom);
  setOperationAction(ISD::STRICT_SINT_TO_FP, MVT::i32, Custom);
  setOperationAction(ISD::STRICT_SINT_TO_FP, MVT::i64, Custom);
  setOperationAction(ISD::STRICT_SINT_TO_FP, MVT::i128, Custom);
  setOperationAction(ISD::UINT_TO_FP, MVT::i32, Custom);
  setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
  setOperationAction(ISD::UINT_TO_FP, MVT::i128, Custom);
  setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i32, Custom);
  setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i64, Custom);
  setOperationAction(ISD::STRICT_UINT_TO_FP, MVT::i128, Custom);
  if (Subtarget->hasFPARMv8()) {
    setOperationAction(ISD::FP_ROUND, MVT::f16, Custom);
    setOperationAction(ISD::FP_ROUND, MVT::bf16, Custom);
  }
  setOperationAction(ISD::FP_ROUND, MVT::f32, Custom);
  setOperationAction(ISD::FP_ROUND, MVT::f64, Custom);
  if (Subtarget->hasFPARMv8()) {
    setOperationAction(ISD::STRICT_FP_ROUND, MVT::f16, Custom);
    setOperationAction(ISD::STRICT_FP_ROUND, MVT::bf16, Custom);
  }
  setOperationAction(ISD::STRICT_FP_ROUND, MVT::f32, Custom);
  setOperationAction(ISD::STRICT_FP_ROUND, MVT::f64, Custom);
 
  setOperationAction(ISD::FP_TO_UINT_SAT, MVT::i32, Custom);
  setOperationAction(ISD::FP_TO_UINT_SAT, MVT::i64, Custom);
  setOperationAction(ISD::FP_TO_SINT_SAT, MVT::i32, Custom);
  setOperationAction(ISD::FP_TO_SINT_SAT, MVT::i64, Custom);
 
  // Variable arguments.
  setOperationAction(ISD::VASTART, MVT::Other, Custom);
  setOperationAction(ISD::VAARG, MVT::Other, Custom);
  setOperationAction(ISD::VACOPY, MVT::Other, Custom);
  setOperationAction(ISD::VAEND, MVT::Other, Expand);
 
  // Variable-sized objects.
  setOperationAction(ISD::STACKSAVE, MVT::Other, Expand);
  setOperationAction(ISD::STACKRESTORE, MVT::Other, Expand);
 
  // Lowering Funnel Shifts to EXTR
  setOperationAction(ISD::FSHR, MVT::i32, Custom);
  setOperationAction(ISD::FSHR, MVT::i64, Custom);
  setOperationAction(ISD::FSHL, MVT::i32, Custom);
  setOperationAction(ISD::FSHL, MVT::i64, Custom);
 
  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i64, Custom);
 
  // Constant pool entries
  setOperationAction(ISD::ConstantPool, MVT::i64, Custom);
 
  // BlockAddress
  setOperationAction(ISD::BlockAddress, MVT::i64, Custom);
 
  // AArch64 lacks both left-rotate and popcount instructions.
  setOperationAction(ISD::ROTL, MVT::i32, Expand);
  setOperationAction(ISD::ROTL, MVT::i64, Expand);
  for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
    setOperationAction(ISD::ROTL, VT, Expand);
    setOperationAction(ISD::ROTR, VT, Expand);
  }
 
  // AArch64 doesn't have i32 MULH{S|U}.
  setOperationAction(ISD::MULHU, MVT::i32, Expand);
  setOperationAction(ISD::MULHS, MVT::i32, Expand);
 
  // AArch64 doesn't have {U|S}MUL_LOHI.
  setOperationAction(ISD::UMUL_LOHI, MVT::i32, Expand);
  setOperationAction(ISD::SMUL_LOHI, MVT::i32, Expand);
  setOperationAction(ISD::UMUL_LOHI, MVT::i64, Expand);
  setOperationAction(ISD::SMUL_LOHI, MVT::i64, Expand);
 
  if (Subtarget->hasCSSC()) {
    setOperationAction(ISD::CTPOP, MVT::i32, Legal);
    setOperationAction(ISD::CTPOP, MVT::i64, Legal);
    setOperationAction(ISD::CTPOP, MVT::i128, Expand);
 
    setOperationAction(ISD::PARITY, MVT::i128, Expand);
 
    setOperationAction(ISD::CTTZ, MVT::i32, Legal);
    setOperationAction(ISD::CTTZ, MVT::i64, Legal);
    setOperationAction(ISD::CTTZ, MVT::i128, Expand);
 
    setOperationAction(ISD::ABS, MVT::i32, Legal);
    setOperationAction(ISD::ABS, MVT::i64, Legal);
 
    setOperationAction(ISD::SMAX, MVT::i32, Legal);
    setOperationAction(ISD::SMAX, MVT::i64, Legal);
    setOperationAction(ISD::UMAX, MVT::i32, Legal);
    setOperationAction(ISD::UMAX, MVT::i64, Legal);
 
    setOperationAction(ISD::SMIN, MVT::i32, Legal);
    setOperationAction(ISD::SMIN, MVT::i64, Legal);
    setOperationAction(ISD::UMIN, MVT::i32, Legal);
    setOperationAction(ISD::UMIN, MVT::i64, Legal);
  } else {
    setOperationAction(ISD::CTPOP, MVT::i32, Custom);
    setOperationAction(ISD::CTPOP, MVT::i64, Custom);
    setOperationAction(ISD::CTPOP, MVT::i128, Custom);
 
    setOperationAction(ISD::PARITY, MVT::i64, Custom);
    setOperationAction(ISD::PARITY, MVT::i128, Custom);
 
    setOperationAction(ISD::ABS, MVT::i32, Custom);
    setOperationAction(ISD::ABS, MVT::i64, Custom);
  }
 
  setOperationAction(ISD::SDIVREM, MVT::i32, Expand);
  setOperationAction(ISD::SDIVREM, MVT::i64, Expand);
  for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
    setOperationAction(ISD::SDIVREM, VT, Expand);
    setOperationAction(ISD::UDIVREM, VT, Expand);
  }
  setOperationAction(ISD::SREM, MVT::i32, Expand);
  setOperationAction(ISD::SREM, MVT::i64, Expand);
  setOperationAction(ISD::UDIVREM, MVT::i32, Expand);
  setOperationAction(ISD::UDIVREM, MVT::i64, Expand);
  setOperationAction(ISD::UREM, MVT::i32, Expand);
  setOperationAction(ISD::UREM, MVT::i64, Expand);
 
  // Custom lower Add/Sub/Mul with overflow.
  setOperationAction(ISD::SADDO, MVT::i32, Custom);
  setOperationAction(ISD::SADDO, MVT::i64, Custom);
  setOperationAction(ISD::UADDO, MVT::i32, Custom);
  setOperationAction(ISD::UADDO, MVT::i64, Custom);
  setOperationAction(ISD::SSUBO, MVT::i32, Custom);
  setOperationAction(ISD::SSUBO, MVT::i64, Custom);
  setOperationAction(ISD::USUBO, MVT::i32, Custom);
  setOperationAction(ISD::USUBO, MVT::i64, Custom);
  setOperationAction(ISD::SMULO, MVT::i32, Custom);
  setOperationAction(ISD::SMULO, MVT::i64, Custom);
  setOperationAction(ISD::UMULO, MVT::i32, Custom);
  setOperationAction(ISD::UMULO, MVT::i64, Custom);
 
  setOperationAction(ISD::UADDO_CARRY, MVT::i32, Custom);
  setOperationAction(ISD::UADDO_CARRY, MVT::i64, Custom);
  setOperationAction(ISD::USUBO_CARRY, MVT::i32, Custom);
  setOperationAction(ISD::USUBO_CARRY, MVT::i64, Custom);
  setOperationAction(ISD::SADDO_CARRY, MVT::i32, Custom);
  setOperationAction(ISD::SADDO_CARRY, MVT::i64, Custom);
  setOperationAction(ISD::SSUBO_CARRY, MVT::i32, Custom);
  setOperationAction(ISD::SSUBO_CARRY, MVT::i64, Custom);
 
  setOperationAction(ISD::FSIN, MVT::f64, Expand);
  setOperationAction(ISD::FSIN, MVT::f32, Expand);
  setOperationAction(ISD::FCOS, MVT::f32, Expand);
  setOperationAction(ISD::FCOS, MVT::f64, Expand);
  setOperationAction(ISD::FPOW, MVT::f32, Expand);
  setOperationAction(ISD::FPOW, MVT::f64, Expand);
  setOperationAction(ISD::FCOPYSIGN, MVT::f64, Custom);
  setOperationAction(ISD::FCOPYSIGN, MVT::f32, Custom);
  if (Subtarget->hasFullFP16()) {
    setOperationAction(ISD::FCOPYSIGN, MVT::f16, Custom);
    setOperationAction(ISD::FCOPYSIGN, MVT::bf16, Custom);
  } else {
    setOperationAction(ISD::FCOPYSIGN, MVT::f16, Promote);
    setOperationAction(ISD::FCOPYSIGN, MVT::bf16, Promote);
  }
 
  for (auto Op : {ISD::FREM,          ISD::FPOW,         ISD::FPOWI,
                  ISD::FCOS,          ISD::FSIN,         ISD::FSINCOS,
                  ISD::FSINCOSPI,     ISD::FMODF,        ISD::FACOS,
                  ISD::FASIN,         ISD::FATAN,        ISD::FATAN2,
                  ISD::FCOSH,         ISD::FSINH,        ISD::FTANH,
                  ISD::FTAN,          ISD::FEXP,         ISD::FEXP2,
                  ISD::FEXP10,        ISD::FLOG,         ISD::FLOG2,
                  ISD::FLOG10,        ISD::STRICT_FREM,  ISD::STRICT_FPOW,
                  ISD::STRICT_FPOWI,  ISD::STRICT_FCOS,  ISD::STRICT_FSIN,
                  ISD::STRICT_FACOS,  ISD::STRICT_FASIN, ISD::STRICT_FATAN,
                  ISD::STRICT_FATAN2, ISD::STRICT_FCOSH, ISD::STRICT_FSINH,
                  ISD::STRICT_FTANH,  ISD::STRICT_FEXP,  ISD::STRICT_FEXP2,
                  ISD::STRICT_FLOG,   ISD::STRICT_FLOG2, ISD::STRICT_FLOG10,
                  ISD::STRICT_FTAN}) {
    setOperationAction(Op, MVT::f16, Promote);
    setOperationAction(Op, MVT::v4f16, Expand);
    setOperationAction(Op, MVT::v8f16, Expand);
    setOperationAction(Op, MVT::bf16, Promote);
    setOperationAction(Op, MVT::v4bf16, Expand);
    setOperationAction(Op, MVT::v8bf16, Expand);
  }
 
  // Legalize fcanonicalize to circumvent default expansion
  setOperationAction(ISD::FCANONICALIZE, {MVT::f32, MVT::f64}, Legal);
  if (Subtarget->hasFullFP16()) {
    setOperationAction(ISD::FCANONICALIZE, MVT::f16, Legal);
  }
 
  // fpextend from f16 or bf16 to f32 is legal
  setOperationAction(ISD::FP_EXTEND, MVT::f32, Legal);
  setOperationAction(ISD::FP_EXTEND, MVT::v4f32, Legal);
  setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f32, Legal);
  setOperationAction(ISD::STRICT_FP_EXTEND, MVT::v4f32, Legal);
  // fpextend from bf16 to f64 needs to be split into two fpextends
  setOperationAction(ISD::FP_EXTEND, MVT::f64, Custom);
  setOperationAction(ISD::STRICT_FP_EXTEND, MVT::f64, Custom);
 
  auto LegalizeNarrowFP = [this](MVT ScalarVT) {
    for (auto Op : {
             ISD::SETCC,
             ISD::SELECT_CC,
             ISD::BR_CC,
             ISD::FADD,
             ISD::FSUB,
             ISD::FMUL,
             ISD::FDIV,
             ISD::FMA,
             ISD::FCEIL,
             ISD::FSQRT,
             ISD::FFLOOR,
             ISD::FNEARBYINT,
             ISD::FRINT,
             ISD::FROUND,
             ISD::FROUNDEVEN,
             ISD::FTRUNC,
             ISD::FMINNUM,
             ISD::FMAXNUM,
             ISD::FMINIMUM,
             ISD::FMAXIMUM,
             ISD::FMINIMUMNUM,
             ISD::FMAXIMUMNUM,
             ISD::FCANONICALIZE,
             ISD::STRICT_FADD,
             ISD::STRICT_FSUB,
             ISD::STRICT_FMUL,
             ISD::STRICT_FDIV,
             ISD::STRICT_FMA,
             ISD::STRICT_FCEIL,
             ISD::STRICT_FFLOOR,
             ISD::STRICT_FSQRT,
             ISD::STRICT_FRINT,
             ISD::STRICT_FNEARBYINT,
             ISD::STRICT_FROUND,
             ISD::STRICT_FTRUNC,
             ISD::STRICT_FROUNDEVEN,
             ISD::STRICT_FMINNUM,
             ISD::STRICT_FMAXNUM,
             ISD::STRICT_FMINIMUM,
             ISD::STRICT_FMAXIMUM,
         })
      setOperationAction(Op, ScalarVT, Promote);
 
    for (auto Op : {ISD::FNEG, ISD::FABS})
      setOperationAction(Op, ScalarVT, Legal);
 
    // Round-to-integer need custom lowering for fp16, as Promote doesn't work
    // because the result type is integer.
    for (auto Op : {ISD::LROUND, ISD::LLROUND, ISD::LRINT, ISD::LLRINT,
                    ISD::STRICT_LROUND, ISD::STRICT_LLROUND, ISD::STRICT_LRINT,
                    ISD::STRICT_LLRINT})
      setOperationAction(Op, ScalarVT, Custom);
 
    // promote v4f16 to v4f32 when that is known to be safe.
    auto V4Narrow = MVT::getVectorVT(ScalarVT, 4);
    setOperationPromotedToType(ISD::FADD,       V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FSUB,       V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FMUL,       V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FDIV,       V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FCEIL,      V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FFLOOR,     V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FROUND,     V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FTRUNC,     V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FROUNDEVEN, V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FRINT,      V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FNEARBYINT, V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::FCANONICALIZE, V4Narrow, MVT::v4f32);
    setOperationPromotedToType(ISD::SETCC,         V4Narrow, MVT::v4f32);
 
    setOperationAction(ISD::FABS,        V4Narrow, Legal);
    setOperationAction(ISD::FNEG,        V4Narrow, Legal);
    setOperationAction(ISD::FMA,         V4Narrow, Expand);
    setOperationAction(ISD::BR_CC,       V4Narrow, Expand);
    setOperationAction(ISD::SELECT,      V4Narrow, Expand);
    setOperationAction(ISD::SELECT_CC,   V4Narrow, Expand);
    setOperationAction(ISD::FCOPYSIGN,   V4Narrow, Custom);
    setOperationAction(ISD::FSQRT,       V4Narrow, Expand);
 
    auto V8Narrow = MVT::getVectorVT(ScalarVT, 8);
    setOperationPromotedToType(ISD::FCANONICALIZE, V8Narrow, MVT::v8f32);
    setOperationPromotedToType(ISD::SETCC,         V8Narrow, MVT::v8f32);
    setOperationPromotedToType(ISD::VECREDUCE_FADD, V8Narrow, MVT::v8f32);
    setOperationPromotedToType(ISD::VECREDUCE_FMUL, V8Narrow, MVT::v8f32);
 
    setOperationAction(ISD::FABS,        V8Narrow, Legal);
    setOperationAction(ISD::FADD,        V8Narrow, Expand);
    setOperationAction(ISD::FCEIL,       V8Narrow, Expand);
    setOperationAction(ISD::FCOPYSIGN,   V8Narrow, Custom);
    setOperationAction(ISD::FDIV,        V8Narrow, Expand);
    setOperationAction(ISD::FFLOOR,      V8Narrow, Expand);
    setOperationAction(ISD::FMA,         V8Narrow, Expand);
    setOperationAction(ISD::FMUL,        V8Narrow, Expand);
    setOperationAction(ISD::FNEARBYINT,  V8Narrow, Expand);
    setOperationAction(ISD::FNEG,        V8Narrow, Legal);
    setOperationAction(ISD::FROUND,      V8Narrow, Expand);
    setOperationAction(ISD::FROUNDEVEN,  V8Narrow, Expand);
    setOperationAction(ISD::FRINT,       V8Narrow, Expand);
    setOperationAction(ISD::FSQRT,       V8Narrow, Expand);
    setOperationAction(ISD::FSUB,        V8Narrow, Expand);
    setOperationAction(ISD::FTRUNC,      V8Narrow, Expand);
    setOperationAction(ISD::BR_CC,       V8Narrow, Expand);
    setOperationAction(ISD::SELECT,      V8Narrow, Expand);
    setOperationAction(ISD::SELECT_CC,   V8Narrow, Expand);
    setOperationAction(ISD::FP_EXTEND,   V8Narrow, Expand);
  };
 
  if (!Subtarget->hasFullFP16()) {
    LegalizeNarrowFP(MVT::f16);
  }
  LegalizeNarrowFP(MVT::bf16);
  setOperationAction(ISD::FP_ROUND, MVT::v4f32, Custom);
  setOperationAction(ISD::FP_ROUND, MVT::v4bf16, Custom);
 
  // AArch64 has implementations of a lot of rounding-like FP operations.
  // clang-format off
  for (auto Op :
       {ISD::FFLOOR,          ISD::FNEARBYINT,      ISD::FCEIL,
        ISD::FRINT,           ISD::FTRUNC,          ISD::FROUND,
        ISD::FROUNDEVEN,      ISD::FMINNUM,         ISD::FMAXNUM,
        ISD::FMINIMUM,        ISD::FMAXIMUM,        ISD::LROUND,
        ISD::LLROUND,         ISD::LRINT,           ISD::LLRINT,
        ISD::FMINNUM_IEEE,    ISD::FMAXNUM_IEEE,
        ISD::STRICT_FFLOOR,   ISD::STRICT_FCEIL,    ISD::STRICT_FNEARBYINT,
        ISD::STRICT_FRINT,    ISD::STRICT_FTRUNC,   ISD::STRICT_FROUNDEVEN,
        ISD::STRICT_FROUND,   ISD::STRICT_FMINNUM,  ISD::STRICT_FMAXNUM,
        ISD::STRICT_FMINIMUM, ISD::STRICT_FMAXIMUM, ISD::STRICT_LROUND,
        ISD::STRICT_LLROUND,  ISD::STRICT_LRINT,    ISD::STRICT_LLRINT}) {
    for (MVT Ty : {MVT::f32, MVT::f64})
      setOperationAction(Op, Ty, Legal);
    if (Subtarget->hasFullFP16())
      setOperationAction(Op, MVT::f16, Legal);
  }
  // clang-format on
 
  // Basic strict FP operations are legal
  for (auto Op : {ISD::STRICT_FADD, ISD::STRICT_FSUB, ISD::STRICT_FMUL,
                  ISD::STRICT_FDIV, ISD::STRICT_FMA, ISD::STRICT_FSQRT}) {
    for (MVT Ty : {MVT::f32, MVT::f64})
      setOperationAction(Op, Ty, Legal);
    if (Subtarget->hasFullFP16())
      setOperationAction(Op, MVT::f16, Legal);
  }
 
  setOperationAction(ISD::PREFETCH, MVT::Other, Custom);
 
  setOperationAction(ISD::GET_ROUNDING, MVT::i32, Custom);
  setOperationAction(ISD::SET_ROUNDING, MVT::Other, Custom);
  setOperationAction(ISD::GET_FPMODE, MVT::i32, Custom);
  setOperationAction(ISD::SET_FPMODE, MVT::i32, Custom);
  setOperationAction(ISD::RESET_FPMODE, MVT::Other, Custom);
 
  setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i128, Custom);
  if (!Subtarget->hasLSE() && !Subtarget->outlineAtomics()) {
    setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i64, LibCall);
  } else {
    setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i32, Expand);
    setOperationAction(ISD::ATOMIC_LOAD_SUB, MVT::i64, Expand);
  }
  setOperationAction(ISD::ATOMIC_LOAD_AND, MVT::i32, Custom);
  setOperationAction(ISD::ATOMIC_LOAD_AND, MVT::i64, Custom);
 
  // Generate outline atomics library calls only if LSE was not specified for
  // subtarget
  if (Subtarget->outlineAtomics() && !Subtarget->hasLSE()) {
    setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i64, LibCall);
    setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i128, LibCall);
    setOperationAction(ISD::ATOMIC_SWAP, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_SWAP, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_SWAP, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_SWAP, MVT::i64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_ADD, MVT::i64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_CLR, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_CLR, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_CLR, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_CLR, MVT::i64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i8, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_XOR, MVT::i64, LibCall);
  }
 
  if (Subtarget->outlineAtomics() && !Subtarget->hasLSFE()) {
    setOperationAction(ISD::ATOMIC_LOAD_FADD, MVT::f16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FADD, MVT::f32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FADD, MVT::f64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FADD, MVT::bf16, LibCall);
 
    setOperationAction(ISD::ATOMIC_LOAD_FMAX, MVT::f16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAX, MVT::f32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAX, MVT::f64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAX, MVT::bf16, LibCall);
 
    setOperationAction(ISD::ATOMIC_LOAD_FMIN, MVT::f16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMIN, MVT::f32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMIN, MVT::f64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMIN, MVT::bf16, LibCall);
 
    setOperationAction(ISD::ATOMIC_LOAD_FMAXIMUM, MVT::f16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAXIMUM, MVT::f32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAXIMUM, MVT::f64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMAXIMUM, MVT::bf16, LibCall);
 
    setOperationAction(ISD::ATOMIC_LOAD_FMINIMUM, MVT::f16, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMINIMUM, MVT::f32, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMINIMUM, MVT::f64, LibCall);
    setOperationAction(ISD::ATOMIC_LOAD_FMINIMUM, MVT::bf16, LibCall);
  }
 
  if (Subtarget->hasLSE128()) {
    // Custom lowering because i128 is not legal. Must be replaced by 2x64
    // values. ATOMIC_LOAD_AND also needs op legalisation to emit LDCLRP.
    setOperationAction(ISD::ATOMIC_LOAD_AND, MVT::i128, Custom);
    setOperationAction(ISD::ATOMIC_LOAD_OR, MVT::i128, Custom);
    setOperationAction(ISD::ATOMIC_SWAP, MVT::i128, Custom);
  }
 
  // 128-bit loads and stores can be done without expanding
  setOperationAction(ISD::LOAD, MVT::i128, Custom);
  setOperationAction(ISD::STORE, MVT::i128, Custom);
 
  // Aligned 128-bit loads and stores are single-copy atomic according to the
  // v8.4a spec. LRCPC3 introduces 128-bit STILP/LDIAPP but still requires LSE2.
  if (Subtarget->hasLSE2()) {
    setOperationAction(ISD::ATOMIC_LOAD, MVT::i128, Custom);
    setOperationAction(ISD::ATOMIC_STORE, MVT::i128, Custom);
  }
 
  // 256 bit non-temporal stores can be lowered to STNP. Do this as part of the
  // custom lowering, as there are no un-paired non-temporal stores and
  // legalization will break up 256 bit inputs.
  setOperationAction(ISD::STORE, MVT::v32i8, Custom);
  setOperationAction(ISD::STORE, MVT::v16i16, Custom);
  setOperationAction(ISD::STORE, MVT::v16f16, Custom);
  setOperationAction(ISD::STORE, MVT::v16bf16, Custom);
  setOperationAction(ISD::STORE, MVT::v8i32, Custom);
  setOperationAction(ISD::STORE, MVT::v8f32, Custom);
  setOperationAction(ISD::STORE, MVT::v4f64, Custom);
  setOperationAction(ISD::STORE, MVT::v4i64, Custom);
 
  // 256 bit non-temporal loads can be lowered to LDNP. This is done using
  // custom lowering, as there are no un-paired non-temporal loads legalization
  // will break up 256 bit inputs.
  setOperationAction(ISD::LOAD, MVT::v32i8, Custom);
  setOperationAction(ISD::LOAD, MVT::v16i16, Custom);
  setOperationAction(ISD::LOAD, MVT::v16f16, Custom);
  setOperationAction(ISD::LOAD, MVT::v16bf16, Custom);
  setOperationAction(ISD::LOAD, MVT::v8i32, Custom);
  setOperationAction(ISD::LOAD, MVT::v8f32, Custom);
  setOperationAction(ISD::LOAD, MVT::v4f64, Custom);
  setOperationAction(ISD::LOAD, MVT::v4i64, Custom);
 
  // Lower READCYCLECOUNTER using an mrs from CNTVCT_EL0.
  setOperationAction(ISD::READCYCLECOUNTER, MVT::i64, Legal);
 
  // Issue __sincos_stret if available.
  setOperationAction(ISD::FSINCOS, MVT::f64, Expand);
  setOperationAction(ISD::FSINCOS, MVT::f32, Expand);
 
  // Make floating-point constants legal for the large code model, so they don't
  // become loads from the constant pool.
  if (Subtarget->isTargetMachO() && TM.getCodeModel() == CodeModel::Large) {
    setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
    setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
  }
 
  // AArch64 does not have floating-point extending loads, i1 sign-extending
  // load, floating-point truncating stores, or v2i32->v2i16 truncating store.
  for (MVT VT : MVT::fp_valuetypes()) {
    setLoadExtAction(ISD::EXTLOAD, VT, MVT::bf16, Expand);
    setLoadExtAction(ISD::EXTLOAD, VT, MVT::f16, Expand);
    setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);
    setLoadExtAction(ISD::EXTLOAD, VT, MVT::f64, Expand);
    setLoadExtAction(ISD::EXTLOAD, VT, MVT::f80, Expand);
  }
  for (MVT VT : MVT::integer_valuetypes())
    setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Expand);
 
  for (MVT WideVT : MVT::fp_valuetypes()) {
    for (MVT NarrowVT : MVT::fp_valuetypes()) {
      if (WideVT.getScalarSizeInBits() > NarrowVT.getScalarSizeInBits()) {
        setTruncStoreAction(WideVT, NarrowVT, Expand);
      }
    }
  }
 
  if (Subtarget->hasFPARMv8()) {
    setOperationAction(ISD::BITCAST, MVT::i16, Custom);
    setOperationAction(ISD::BITCAST, MVT::f16, Custom);
    setOperationAction(ISD::BITCAST, MVT::bf16, Custom);
  }
 
  // Indexed loads and stores are supported.
  for (unsigned im = (unsigned)ISD::PRE_INC;
       im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
    setIndexedLoadAction(im, MVT::i8, Legal);
    setIndexedLoadAction(im, MVT::i16, Legal);
    setIndexedLoadAction(im, MVT::i32, Legal);
    setIndexedLoadAction(im, MVT::i64, Legal);
    setIndexedLoadAction(im, MVT::f64, Legal);
    setIndexedLoadAction(im, MVT::f32, Legal);
    setIndexedLoadAction(im, MVT::f16, Legal);
    setIndexedLoadAction(im, MVT::bf16, Legal);
    setIndexedStoreAction(im, MVT::i8, Legal);
    setIndexedStoreAction(im, MVT::i16, Legal);
    setIndexedStoreAction(im, MVT::i32, Legal);
    setIndexedStoreAction(im, MVT::i64, Legal);
    setIndexedStoreAction(im, MVT::f64, Legal);
    setIndexedStoreAction(im, MVT::f32, Legal);
    setIndexedStoreAction(im, MVT::f16, Legal);
    setIndexedStoreAction(im, MVT::bf16, Legal);
  }
 
  // Trap.
  setOperationAction(ISD::TRAP, MVT::Other, Legal);
  setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
  setOperationAction(ISD::UBSANTRAP, MVT::Other, Legal);
 
  // We combine OR nodes for ccmp operations.
  setTargetDAGCombine(ISD::OR);
  // Try to create BICs for vector ANDs.
  setTargetDAGCombine(ISD::AND);
 
  // llvm.init.trampoline and llvm.adjust.trampoline
  setOperationAction(ISD::INIT_TRAMPOLINE, MVT::Other, Custom);
  setOperationAction(ISD::ADJUST_TRAMPOLINE, MVT::Other, Custom);
 
  // Vector add and sub nodes may conceal a high-half opportunity.
  // Also, try to fold ADD into CSINC/CSINV..
  setTargetDAGCombine({ISD::ADD, ISD::ABS, ISD::SUB, ISD::XOR, ISD::SINT_TO_FP,
                       ISD::UINT_TO_FP});
 
  setTargetDAGCombine({ISD::FP_TO_SINT, ISD::FP_TO_UINT, ISD::FP_TO_SINT_SAT,
                       ISD::FP_TO_UINT_SAT, ISD::FADD});
 
  // Try and combine setcc/select_cc with csel and bool-vector bitcasts.
  setTargetDAGCombine(ISD::SETCC);
  setTargetDAGCombine(ISD::SELECT_CC);
 
  setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
 
  setTargetDAGCombine({ISD::ANY_EXTEND, ISD::ZERO_EXTEND, ISD::SIGN_EXTEND,
                       ISD::SIGN_EXTEND_INREG, ISD::CONCAT_VECTORS,
                       ISD::EXTRACT_SUBVECTOR, ISD::INSERT_SUBVECTOR,
                       ISD::STORE, ISD::BUILD_VECTOR});
  setTargetDAGCombine({ISD::SMIN, ISD::SMAX, ISD::UMIN, ISD::UMAX});
  setTargetDAGCombine(ISD::TRUNCATE);
  setTargetDAGCombine(ISD::LOAD);
 
  setTargetDAGCombine(ISD::MSTORE);
 
  setTargetDAGCombine(ISD::MUL);
 
  setTargetDAGCombine({ISD::SELECT, ISD::VSELECT});
 
  setTargetDAGCombine({ISD::INTRINSIC_VOID, ISD::INTRINSIC_W_CHAIN,
                       ISD::INSERT_VECTOR_ELT, ISD::EXTRACT_VECTOR_ELT,
                       ISD::VECREDUCE_ADD, ISD::STEP_VECTOR});
 
  setTargetDAGCombine(
      {ISD::MGATHER, ISD::MSCATTER, ISD::EXPERIMENTAL_VECTOR_HISTOGRAM});
 
  setTargetDAGCombine(ISD::FP_EXTEND);
 
  setTargetDAGCombine(ISD::GlobalAddress);
 
  setTargetDAGCombine(ISD::CTLZ);
 
  setTargetDAGCombine(ISD::GET_ACTIVE_LANE_MASK);
 
  setTargetDAGCombine(ISD::VECREDUCE_AND);
  setTargetDAGCombine(ISD::VECREDUCE_OR);
  setTargetDAGCombine(ISD::VECREDUCE_XOR);
  setTargetDAGCombine(ISD::VECREDUCE_FADD);
  setTargetDAGCombine(ISD::VECREDUCE_SEQ_FADD);
 
  setTargetDAGCombine(ISD::SCALAR_TO_VECTOR);
 
  setTargetDAGCombine(ISD::SHL);
  setTargetDAGCombine(ISD::VECTOR_DEINTERLEAVE);
  setTargetDAGCombine(ISD::CTPOP);
 
  // In case of strict alignment, avoid an excessive number of byte wide stores.
  MaxStoresPerMemsetOptSize = 8;
  MaxStoresPerMemset =
      Subtarget->requiresStrictAlign() ? MaxStoresPerMemsetOptSize : 32;
 
  MaxGluedStoresPerMemcpy = 4;
  MaxStoresPerMemcpyOptSize = 4;
  MaxStoresPerMemcpy =
      Subtarget->requiresStrictAlign() ? MaxStoresPerMemcpyOptSize : 16;
 
  MaxStoresPerMemmoveOptSize = 4;
  MaxStoresPerMemmove =
      Subtarget->requiresStrictAlign() ? MaxStoresPerMemmoveOptSize : 16;
 
  MaxLoadsPerMemcmpOptSize = 4;
  MaxLoadsPerMemcmp =
      Subtarget->requiresStrictAlign() ? MaxLoadsPerMemcmpOptSize : 8;
 
  setStackPointerRegisterToSaveRestore(AArch64::SP);
 
  setSchedulingPreference(Sched::Hybrid);
 
  EnableExtLdPromotion = true;
 
  // Set required alignment.
  setMinFunctionAlignment(Align(4));
  // Set preferred alignments.
 
  // Don't align loops on Windows. The SEH unwind info generation needs to
  // know the exact length of functions before the alignments have been
  // expanded.
  if (!Subtarget->isTargetWindows())
    setPrefLoopAlignment(STI.getPrefLoopAlignment());
  setMaxBytesForAlignment(STI.getMaxBytesForLoopAlignment());
  setPrefFunctionAlignment(STI.getPrefFunctionAlignment());
 
  // Only change the limit for entries in a jump table if specified by
  // the sub target, but not at the command line.
  unsigned MaxJT = STI.getMaximumJumpTableSize();
  if (MaxJT && getMaximumJumpTableSize() == UINT_MAX)
    setMaximumJumpTableSize(MaxJT);
 
  setHasExtractBitsInsn(true);
 
  setMaxDivRemBitWidthSupported(128);
 
  setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
  if (Subtarget->hasSME())
    setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i1, Custom);
 
  if (Subtarget->isNeonAvailable()) {
    // FIXME: v1f64 shouldn't be legal if we can avoid it, because it leads to
    // silliness like this:
    // clang-format off
    for (auto Op :
         {ISD::SELECT,            ISD::SELECT_CC,      ISD::FATAN2,
          ISD::BR_CC,             ISD::FADD,           ISD::FSUB,
          ISD::FMUL,              ISD::FDIV,           ISD::FMA,
          ISD::FNEG,              ISD::FABS,           ISD::FCEIL,
          ISD::FSQRT,             ISD::FFLOOR,         ISD::FNEARBYINT,
          ISD::FSIN,              ISD::FCOS,           ISD::FTAN,
          ISD::FASIN,             ISD::FACOS,          ISD::FATAN,
          ISD::FSINH,             ISD::FCOSH,          ISD::FTANH,
          ISD::FPOW,              ISD::FLOG,           ISD::FLOG2,
          ISD::FLOG10,            ISD::FEXP,           ISD::FEXP2,
          ISD::FEXP10,            ISD::FRINT,          ISD::FROUND,
          ISD::FROUNDEVEN,        ISD::FTRUNC,         ISD::FMINNUM,
          ISD::FMAXNUM,           ISD::FMINIMUM,       ISD::FMAXIMUM,
          ISD::FMAXNUM_IEEE,      ISD::FMINNUM_IEEE,
          ISD::STRICT_FADD,       ISD::STRICT_FSUB,    ISD::STRICT_FMUL,
          ISD::STRICT_FDIV,       ISD::STRICT_FMA,     ISD::STRICT_FCEIL,
          ISD::STRICT_FFLOOR,     ISD::STRICT_FSQRT,   ISD::STRICT_FRINT,
          ISD::STRICT_FNEARBYINT, ISD::STRICT_FROUND,  ISD::STRICT_FTRUNC,
          ISD::STRICT_FROUNDEVEN, ISD::STRICT_FMINNUM, ISD::STRICT_FMAXNUM,
          ISD::STRICT_FMINIMUM,   ISD::STRICT_FMAXIMUM})
      setOperationAction(Op, MVT::v1f64, Expand);
    // clang-format on
 
    for (auto Op :
         {ISD::FP_TO_SINT, ISD::FP_TO_UINT, ISD::SINT_TO_FP, ISD::UINT_TO_FP,
          ISD::FP_ROUND, ISD::FP_TO_SINT_SAT, ISD::FP_TO_UINT_SAT, ISD::MUL,
          ISD::STRICT_FP_TO_SINT, ISD::STRICT_FP_TO_UINT,
          ISD::STRICT_SINT_TO_FP, ISD::STRICT_UINT_TO_FP, ISD::STRICT_FP_ROUND})
      setOperationAction(Op, MVT::v1i64, Expand);
 
    // AArch64 doesn't have a direct vector ->f32 conversion instructions for
    // elements smaller than i32, so promote the input to i32 first.
    setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v4i8, MVT::v4i32);
    setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v4i8, MVT::v4i32);
 
    // Similarly, there is no direct i32 -> f64 vector conversion instruction.
    // Or, direct i32 -> f16 vector conversion.  Set it so custom, so the
    // conversion happens in two steps: v4i32 -> v4f32 -> v4f16
    for (auto Op : {ISD::SINT_TO_FP, ISD::UINT_TO_FP, ISD::STRICT_SINT_TO_FP,
                    ISD::STRICT_UINT_TO_FP})
      for (auto VT : {MVT::v2i32, MVT::v2i64, MVT::v4i32})
        setOperationAction(Op, VT, Custom);
 
    if (Subtarget->hasFullFP16()) {
      setOperationAction(ISD::ConstantFP, MVT::f16, Legal);
      setOperationAction(ISD::ConstantFP, MVT::bf16, Legal);
 
      setOperationAction(ISD::SINT_TO_FP, MVT::v8i8, Custom);
      setOperationAction(ISD::UINT_TO_FP, MVT::v8i8, Custom);
      setOperationAction(ISD::SINT_TO_FP, MVT::v16i8, Custom);
      setOperationAction(ISD::UINT_TO_FP, MVT::v16i8, Custom);
      setOperationAction(ISD::SINT_TO_FP, MVT::v4i16, Custom);
      setOperationAction(ISD::UINT_TO_FP, MVT::v4i16, Custom);
      setOperationAction(ISD::SINT_TO_FP, MVT::v8i16, Custom);
      setOperationAction(ISD::UINT_TO_FP, MVT::v8i16, Custom);
    } else {
      // when AArch64 doesn't have fullfp16 support, promote the input
      // to i32 first.
      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v8i8, MVT::v8i32);
      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v8i8, MVT::v8i32);
      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v16i8, MVT::v16i32);
      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v16i8, MVT::v16i32);
      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v4i16, MVT::v4i32);
      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v4i16, MVT::v4i32);
      setOperationPromotedToType(ISD::SINT_TO_FP, MVT::v8i16, MVT::v8i32);
      setOperationPromotedToType(ISD::UINT_TO_FP, MVT::v8i16, MVT::v8i32);
    }
 
    setOperationAction(ISD::CTLZ,       MVT::v1i64, Expand);
    setOperationAction(ISD::CTLZ,       MVT::v2i64, Expand);
    // CTLS (Count Leading Sign bits) - Legal for BHS types (8/16/32-bit
    // elements) No hardware support for 64-bit element vectors
    for (auto VT : {MVT::v8i8, MVT::v16i8, MVT::v4i16, MVT::v8i16, MVT::v2i32,
                    MVT::v4i32})
      setOperationAction(ISD::CTLS, VT, Legal);
    setOperationAction(ISD::BITREVERSE, MVT::v8i8, Legal);
    setOperationAction(ISD::BITREVERSE, MVT::v16i8, Legal);
    setOperationAction(ISD::BITREVERSE, MVT::v2i32, Custom);
    setOperationAction(ISD::BITREVERSE, MVT::v4i32, Custom);
    setOperationAction(ISD::BITREVERSE, MVT::v1i64, Custom);
    setOperationAction(ISD::BITREVERSE, MVT::v2i64, Custom);
    for (auto VT : {MVT::v1i64, MVT::v2i64}) {
      setOperationAction(ISD::UMAX, VT, Custom);
      setOperationAction(ISD::SMAX, VT, Custom);
      setOperationAction(ISD::UMIN, VT, Custom);
      setOperationAction(ISD::SMIN, VT, Custom);
    }
 
    // Custom handling for some quad-vector types to detect MULL.
    setOperationAction(ISD::MUL, MVT::v8i16, Custom);
    setOperationAction(ISD::MUL, MVT::v4i32, Custom);
    setOperationAction(ISD::MUL, MVT::v2i64, Custom);
    setOperationAction(ISD::MUL, MVT::v4i16, Custom);
    setOperationAction(ISD::MUL, MVT::v2i32, Custom);
    setOperationAction(ISD::MUL, MVT::v1i64, Custom);
 
    // Saturates
    for (MVT VT : { MVT::v8i8, MVT::v4i16, MVT::v2i32, MVT::v1i64,
                    MVT::v16i8, MVT::v8i16, MVT::v4i32, MVT::v2i64 }) {
      setOperationAction(ISD::SADDSAT, VT, Legal);
      setOperationAction(ISD::UADDSAT, VT, Legal);
      setOperationAction(ISD::SSUBSAT, VT, Legal);
      setOperationAction(ISD::USUBSAT, VT, Legal);
    }
 
    for (MVT VT : {MVT::v8i8, MVT::v4i16, MVT::v2i32, MVT::v16i8, MVT::v8i16,
                   MVT::v4i32}) {
      setOperationAction(ISD::AVGFLOORS, VT, Legal);
      setOperationAction(ISD::AVGFLOORU, VT, Legal);
      setOperationAction(ISD::AVGCEILS, VT, Legal);
      setOperationAction(ISD::AVGCEILU, VT, Legal);
      setOperationAction(ISD::ABDS, VT, Legal);
      setOperationAction(ISD::ABDU, VT, Legal);
    }
 
    // Vector reductions
    for (MVT VT : { MVT::v4f16, MVT::v2f32,
                    MVT::v8f16, MVT::v4f32, MVT::v2f64 }) {
      if (VT.getVectorElementType() != MVT::f16 || Subtarget->hasFullFP16()) {
        setOperationAction(ISD::VECREDUCE_FMAX, VT, Legal);
        setOperationAction(ISD::VECREDUCE_FMIN, VT, Legal);
        setOperationAction(ISD::VECREDUCE_FMAXIMUM, VT, Legal);
        setOperationAction(ISD::VECREDUCE_FMINIMUM, VT, Legal);
 
        setOperationAction(ISD::VECREDUCE_FADD, VT, Legal);
      }
    }
    if (Subtarget->hasFullFP16())
      setOperationAction(ISD::VECREDUCE_FADD, MVT::v2f16, Custom);
 
    for (MVT VT : { MVT::v8i8, MVT::v4i16, MVT::v2i32,
                    MVT::v16i8, MVT::v8i16, MVT::v4i32 }) {
      setOperationAction(ISD::VECREDUCE_ADD, VT, Custom);
      setOperationAction(ISD::VECREDUCE_SMAX, VT, Custom);
      setOperationAction(ISD::VECREDUCE_SMIN, VT, Custom);
      setOperationAction(ISD::VECREDUCE_UMAX, VT, Custom);
      setOperationAction(ISD::VECREDUCE_UMIN, VT, Custom);
      setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
      setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
      setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
    }
    setOperationAction(ISD::VECREDUCE_ADD, MVT::v2i64, Custom);
    setOperationAction(ISD::VECREDUCE_AND, MVT::v2i64, Custom);
    setOperationAction(ISD::VECREDUCE_OR, MVT::v2i64, Custom);
    setOperationAction(ISD::VECREDUCE_XOR, MVT::v2i64, Custom);
 
    setOperationAction(ISD::ANY_EXTEND, MVT::v4i32, Legal);
    setTruncStoreAction(MVT::v2i32, MVT::v2i16, Expand);
    // Likewise, narrowing and extending vector loads/stores aren't handled
    // directly.
    for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
      setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Expand);
 
      if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32) {
        setOperationAction(ISD::MULHS, VT, Legal);
        setOperationAction(ISD::MULHU, VT, Legal);
      } else {
        setOperationAction(ISD::MULHS, VT, Expand);
        setOperationAction(ISD::MULHU, VT, Expand);
      }
      setOperationAction(ISD::SMUL_LOHI, VT, Expand);
      setOperationAction(ISD::UMUL_LOHI, VT, Expand);
 
      if (VT == MVT::v4i16 || VT == MVT::v8i16 || VT == MVT::v2i32 ||
          VT == MVT::v4i32 || VT == MVT::v2i64)
        setOperationAction(ISD::BSWAP, VT, Legal);
      else
        setOperationAction(ISD::BSWAP, VT, Expand);
 
      if (VT == MVT::v8i8 || VT == MVT::v16i8 || VT == MVT::v8i16 ||
          VT == MVT::v4i16 || VT == MVT::v2i32 || VT == MVT::v4i32)
        setOperationAction(ISD::CTTZ, VT, Custom);
      else
        setOperationAction(ISD::CTTZ, VT, Expand);
 
      for (MVT InnerVT : MVT::fixedlen_vector_valuetypes()) {
        setTruncStoreAction(VT, InnerVT, Expand);
        setLoadExtAction(ISD::SEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::ZEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::EXTLOAD, VT, InnerVT, Expand);
      }
    }
 
    for (auto Op :
         {ISD::FFLOOR, ISD::FNEARBYINT, ISD::FCEIL, ISD::FRINT, ISD::FTRUNC,
          ISD::FROUND, ISD::FROUNDEVEN, ISD::FMAXNUM_IEEE, ISD::FMINNUM_IEEE,
          ISD::STRICT_FFLOOR, ISD::STRICT_FNEARBYINT, ISD::STRICT_FCEIL,
          ISD::STRICT_FRINT, ISD::STRICT_FTRUNC, ISD::STRICT_FROUND,
          ISD::STRICT_FROUNDEVEN}) {
      for (MVT Ty : {MVT::v2f32, MVT::v4f32, MVT::v2f64})
        setOperationAction(Op, Ty, Legal);
      if (Subtarget->hasFullFP16())
        for (MVT Ty : {MVT::v4f16, MVT::v8f16})
          setOperationAction(Op, Ty, Legal);
    }
 
    // LRINT and LLRINT.
    for (auto Op : {ISD::LRINT, ISD::LLRINT}) {
      for (MVT Ty : {MVT::v2f32, MVT::v4f32, MVT::v2f64})
        setOperationAction(Op, Ty, Custom);
      if (Subtarget->hasFullFP16())
        for (MVT Ty : {MVT::v4f16, MVT::v8f16})
          setOperationAction(Op, Ty, Custom);
    }
 
    setTruncStoreAction(MVT::v4i16, MVT::v4i8, Custom);
 
    setOperationAction(ISD::BITCAST, MVT::i2, Custom);
    setOperationAction(ISD::BITCAST, MVT::i4, Custom);
    setOperationAction(ISD::BITCAST, MVT::i8, Custom);
    setOperationAction(ISD::BITCAST, MVT::i16, Custom);
 
    setOperationAction(ISD::BITCAST, MVT::v2i8, Custom);
    setOperationAction(ISD::BITCAST, MVT::v2i16, Custom);
    setOperationAction(ISD::BITCAST, MVT::v4i8, Custom);
 
    setLoadExtAction(ISD::EXTLOAD, MVT::v2i32, MVT::v2i8, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i32, MVT::v2i8, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i32, MVT::v2i8, Custom);
    setLoadExtAction(ISD::EXTLOAD, MVT::v2i64, MVT::v2i8, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i64, MVT::v2i8, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i64, MVT::v2i8, Custom);
    setLoadExtAction(ISD::EXTLOAD, MVT::v4i16, MVT::v4i8, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v4i16, MVT::v4i8, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i16, MVT::v4i8, Custom);
    setLoadExtAction(ISD::EXTLOAD, MVT::v4i32, MVT::v4i8, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v4i32, MVT::v4i8, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v4i32, MVT::v4i8, Custom);
    setLoadExtAction(ISD::EXTLOAD, MVT::v2i32, MVT::v2i16, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i32, MVT::v2i16, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i32, MVT::v2i16, Custom);
    setLoadExtAction(ISD::EXTLOAD, MVT::v2i64, MVT::v2i16, Custom);
    setLoadExtAction(ISD::SEXTLOAD, MVT::v2i64, MVT::v2i16, Custom);
    setLoadExtAction(ISD::ZEXTLOAD, MVT::v2i64, MVT::v2i16, Custom);
 
    // ADDP custom lowering
    for (MVT VT : { MVT::v32i8, MVT::v16i16, MVT::v8i32, MVT::v4i64 })
      setOperationAction(ISD::ADD, VT, Custom);
    // FADDP custom lowering
    for (MVT VT : { MVT::v16f16, MVT::v8f32, MVT::v4f64 })
      setOperationAction(ISD::FADD, VT, Custom);
 
    if (Subtarget->hasDotProd()) {
      static const unsigned MLAOps[] = {ISD::PARTIAL_REDUCE_SMLA,
                                        ISD::PARTIAL_REDUCE_UMLA};
 
      setPartialReduceMLAAction(MLAOps, MVT::v4i32, MVT::v16i8, Legal);
      setPartialReduceMLAAction(MLAOps, MVT::v2i32, MVT::v8i8, Legal);
      setPartialReduceMLAAction(MLAOps, MVT::v2i32, MVT::v16i8, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v2i64, MVT::v16i8, Custom);
 
      if (Subtarget->hasMatMulInt8()) {
        setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, MVT::v4i32,
                                  MVT::v16i8, Legal);
        setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, MVT::v2i64,
                                  MVT::v16i8, Custom);
 
        setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, MVT::v2i32,
                                  MVT::v8i8, Legal);
      }
    }
 
    if (Subtarget->hasF16F32DOT() || Subtarget->hasFP16FML()) {
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::v2f32,
                                MVT::v4f16, Legal);
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::v4f32,
                                MVT::v8f16, Legal);
    }
 
    if (Subtarget->hasBF16())
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::v4f32,
                                MVT::v8bf16, Legal);
 
    setOperationAction(ISD::CLMUL, MVT::i8, Custom);
    setOperationAction(ISD::CLMUL, {MVT::v8i8, MVT::v16i8}, Legal);
    if (Subtarget->hasAES()) {
      setOperationAction(ISD::CLMUL, {MVT::i16, MVT::i32, MVT::i64}, Custom);
      setOperationAction(ISD::CLMUL, {MVT::v1i64, MVT::v2i64}, Legal);
    }
 
  } else /* !isNeonAvailable */ {
    for (MVT VT : MVT::fixedlen_vector_valuetypes()) {
      for (unsigned Op = 0; Op < ISD::BUILTIN_OP_END; ++Op)
        setOperationAction(Op, VT, Expand);
 
      if (VT.is128BitVector() || VT.is64BitVector()) {
        setOperationAction(ISD::LOAD, VT, Legal);
        setOperationAction(ISD::STORE, VT, Legal);
        setOperationAction(ISD::BITCAST, VT,
                           Subtarget->isLittleEndian() ? Legal : Expand);
      }
      for (MVT InnerVT : MVT::fixedlen_vector_valuetypes()) {
        setTruncStoreAction(VT, InnerVT, Expand);
        setLoadExtAction(ISD::SEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::ZEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::EXTLOAD, VT, InnerVT, Expand);
      }
    }
  }
 
  for (MVT VT : {MVT::v8i16, MVT::v4i32, MVT::v2i64}) {
    setOperationAction(ISD::TRUNCATE_SSAT_S, VT, Legal);
    setOperationAction(ISD::TRUNCATE_SSAT_U, VT, Legal);
    setOperationAction(ISD::TRUNCATE_USAT_U, VT, Legal);
  }
 
  if (Subtarget->hasSME()) {
    setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::Other, Custom);
  }
 
  // FIXME: Move lowering for more nodes here if those are common between
  // SVE and SME.
  if (Subtarget->isSVEorStreamingSVEAvailable()) {
    for (auto VT :
         {MVT::nxv16i1, MVT::nxv8i1, MVT::nxv4i1, MVT::nxv2i1, MVT::nxv1i1}) {
      setOperationAction(ISD::SPLAT_VECTOR, VT, Custom);
      setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
      setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
      setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
    }
    for (auto VT : {MVT::nxv16i1, MVT::nxv8i1, MVT::nxv4i1, MVT::nxv2i1}) {
      setOperationAction({ISD::CTTZ_ELTS, ISD::CTTZ_ELTS_ZERO_POISON}, VT,
                         Custom);
      setOperationAction(ISD::VECTOR_FIND_LAST_ACTIVE, VT, Legal);
      setOperationAction(ISD::GET_ACTIVE_LANE_MASK, VT, Legal);
    }
 
    if (Subtarget->isSVEorStreamingSVEAvailable() &&
        (Subtarget->hasSVE2p1() || Subtarget->hasSME2()))
      setOperationAction(ISD::GET_ACTIVE_LANE_MASK, MVT::nxv32i1, Custom);
 
    for (auto VT : {MVT::v16i8, MVT::v8i8, MVT::v4i16, MVT::v2i32})
      setOperationAction(ISD::GET_ACTIVE_LANE_MASK, VT, Custom);
 
    for (auto VT : {MVT::v8f16, MVT::v4f32, MVT::v2f64})
      setOperationAction(ISD::FMA, VT, Custom);
  }
 
  if (Subtarget->isSVEorStreamingSVEAvailable()) {
    for (auto VT : {MVT::nxv16i8, MVT::nxv8i16, MVT::nxv4i32, MVT::nxv2i64}) {
      setOperationAction(ISD::BITREVERSE, VT, Custom);
      setOperationAction(ISD::BSWAP, VT, Custom);
      setOperationAction(ISD::CTLZ, VT, Custom);
      setOperationAction(ISD::CTPOP, VT, Custom);
      setOperationAction(ISD::CTTZ, VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR, VT, Custom);
      setOperationAction(ISD::UINT_TO_FP, VT, Custom);
      setOperationAction(ISD::SINT_TO_FP, VT, Custom);
      setOperationAction(ISD::FP_TO_UINT, VT, Custom);
      setOperationAction(ISD::FP_TO_SINT, VT, Custom);
      setOperationAction(ISD::MLOAD, VT, Custom);
      setOperationAction(ISD::MSTORE, VT, Legal);
      setOperationAction(ISD::MUL, VT, Custom);
      setOperationAction(ISD::MULHS, VT, Custom);
      setOperationAction(ISD::MULHU, VT, Custom);
      setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
      setOperationAction(ISD::VECTOR_SPLICE_LEFT, VT, Custom);
      setOperationAction(ISD::VECTOR_SPLICE_RIGHT, VT, Custom);
      setOperationAction(ISD::SELECT, VT, Custom);
      setOperationAction(ISD::SETCC, VT, Custom);
      setOperationAction(ISD::SDIV, VT, Custom);
      setOperationAction(ISD::UDIV, VT, Custom);
      setOperationAction(ISD::SMIN, VT, Custom);
      setOperationAction(ISD::UMIN, VT, Custom);
      setOperationAction(ISD::SMAX, VT, Custom);
      setOperationAction(ISD::UMAX, VT, Custom);
      setOperationAction(ISD::SHL, VT, Custom);
      setOperationAction(ISD::SRL, VT, Custom);
      setOperationAction(ISD::SRA, VT, Custom);
      setOperationAction(ISD::ABS, VT, Custom);
      setOperationAction(ISD::ABDS, VT, Custom);
      setOperationAction(ISD::ABDU, VT, Custom);
      setOperationAction(ISD::VECREDUCE_ADD, VT, Custom);
      setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
      setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
      setOperationAction(ISD::VECREDUCE_MUL, VT, Custom);
      setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
      setOperationAction(ISD::VECREDUCE_UMIN, VT, Custom);
      setOperationAction(ISD::VECREDUCE_UMAX, VT, Custom);
      setOperationAction(ISD::VECREDUCE_SMIN, VT, Custom);
      setOperationAction(ISD::VECREDUCE_SMAX, VT, Custom);
      setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
      setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
 
      setOperationAction(ISD::UMUL_LOHI, VT, Expand);
      setOperationAction(ISD::SMUL_LOHI, VT, Expand);
      setOperationAction(ISD::SELECT_CC, VT, Expand);
      setOperationAction(ISD::ROTL, VT, Expand);
      setOperationAction(ISD::ROTR, VT, Expand);
 
      setOperationAction(ISD::SADDSAT, VT, Legal);
      setOperationAction(ISD::UADDSAT, VT, Legal);
      setOperationAction(ISD::SSUBSAT, VT, Legal);
      setOperationAction(ISD::USUBSAT, VT, Legal);
      setOperationAction(ISD::UREM, VT, Expand);
      setOperationAction(ISD::SREM, VT, Expand);
      setOperationAction(ISD::SDIVREM, VT, Expand);
      setOperationAction(ISD::UDIVREM, VT, Expand);
 
      setOperationAction(ISD::AVGFLOORS, VT, Custom);
      setOperationAction(ISD::AVGFLOORU, VT, Custom);
      setOperationAction(ISD::AVGCEILS, VT, Custom);
      setOperationAction(ISD::AVGCEILU, VT, Custom);
 
      setOperationAction(ISD::ANY_EXTEND_VECTOR_INREG, VT, Custom);
      setOperationAction(ISD::SIGN_EXTEND_VECTOR_INREG, VT, Custom);
      setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Custom);
 
      if (!Subtarget->isLittleEndian())
        setOperationAction(ISD::BITCAST, VT, Custom);
 
      if (Subtarget->hasSVE2() ||
          (Subtarget->hasSME() && Subtarget->isStreaming()))
        // For SLI/SRI.
        setOperationAction(ISD::OR, VT, Custom);
    }
 
    for (auto VT : {MVT::nxv4i32, MVT::nxv2i64}) {
      setOperationAction(ISD::MASKED_UDIV, VT, Legal);
      setOperationAction(ISD::MASKED_SDIV, VT, Legal);
    }
 
    // Illegal unpacked integer vector types.
    for (auto VT : {MVT::nxv8i8, MVT::nxv4i16, MVT::nxv2i32}) {
      setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR, VT, Custom);
    }
 
    // Type legalize unpacked bitcasts.
    for (auto VT : {MVT::nxv2i16, MVT::nxv4i16, MVT::nxv2i32})
      setOperationAction(ISD::BITCAST, VT, Custom);
 
    for (auto VT :
         { MVT::nxv2i8, MVT::nxv2i16, MVT::nxv2i32, MVT::nxv2i64, MVT::nxv4i8,
           MVT::nxv4i16, MVT::nxv4i32, MVT::nxv8i8, MVT::nxv8i16 })
      setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Legal);
 
    // Promote predicate as counter load/stores to standard predicates.
    setOperationPromotedToType(ISD::LOAD, MVT::aarch64svcount, MVT::nxv16i1);
    setOperationPromotedToType(ISD::STORE, MVT::aarch64svcount, MVT::nxv16i1);
 
    // Predicate as counter legalization actions.
    setOperationAction(ISD::SELECT, MVT::aarch64svcount, Custom);
    setOperationAction(ISD::SELECT_CC, MVT::aarch64svcount, Expand);
 
    for (auto VT :
         {MVT::nxv16i1, MVT::nxv8i1, MVT::nxv4i1, MVT::nxv2i1, MVT::nxv1i1}) {
      setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
      setOperationAction(ISD::SELECT, VT, Custom);
      setOperationAction(ISD::SETCC, VT, Custom);
      setOperationAction(ISD::TRUNCATE, VT, Custom);
      setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
      setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
      setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
 
      setOperationAction(ISD::SELECT_CC, VT, Expand);
      setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR, VT, Custom);
 
      // There are no legal MVT::nxv16f## based types.
      if (VT != MVT::nxv16i1) {
        setOperationAction(ISD::FP_TO_SINT, VT, Custom);
        setOperationAction(ISD::FP_TO_UINT, VT, Custom);
        setOperationAction(ISD::SINT_TO_FP, VT, Custom);
        setOperationAction(ISD::UINT_TO_FP, VT, Custom);
      }
    }
 
    // NEON doesn't support masked loads/stores, but SME and SVE do.
    for (auto VT :
         {MVT::v4f16, MVT::v8f16, MVT::v2f32, MVT::v4f32, MVT::v1f64,
          MVT::v2f64, MVT::v8i8, MVT::v16i8, MVT::v4i16, MVT::v8i16,
          MVT::v2i32, MVT::v4i32, MVT::v1i64, MVT::v2i64}) {
      setOperationAction(ISD::MLOAD, VT, Custom);
      setOperationAction(ISD::MSTORE, VT, Custom);
    }
 
    // Firstly, exclude all scalable vector extending loads/truncating stores,
    // include both integer and floating scalable vector.
    for (MVT VT : MVT::scalable_vector_valuetypes()) {
      for (MVT InnerVT : MVT::scalable_vector_valuetypes()) {
        setTruncStoreAction(VT, InnerVT, Expand);
        setLoadExtAction(ISD::SEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::ZEXTLOAD, VT, InnerVT, Expand);
        setLoadExtAction(ISD::EXTLOAD, VT, InnerVT, Expand);
      }
    }
 
    // Then, selectively enable those which we directly support.
    setTruncStoreAction(MVT::nxv2i64, MVT::nxv2i8, Legal);
    setTruncStoreAction(MVT::nxv2i64, MVT::nxv2i16, Legal);
    setTruncStoreAction(MVT::nxv2i64, MVT::nxv2i32, Legal);
    setTruncStoreAction(MVT::nxv4i32, MVT::nxv4i8, Legal);
    setTruncStoreAction(MVT::nxv4i32, MVT::nxv4i16, Legal);
    setTruncStoreAction(MVT::nxv8i16, MVT::nxv8i8, Legal);
    for (auto Op : {ISD::ZEXTLOAD, ISD::SEXTLOAD, ISD::EXTLOAD}) {
      setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i8, Legal);
      setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i16, Legal);
      setLoadExtAction(Op, MVT::nxv2i64, MVT::nxv2i32, Legal);
      setLoadExtAction(Op, MVT::nxv4i32, MVT::nxv4i8, Legal);
      setLoadExtAction(Op, MVT::nxv4i32, MVT::nxv4i16, Legal);
      setLoadExtAction(Op, MVT::nxv8i16, MVT::nxv8i8, Legal);
    }
 
    // SVE supports truncating stores of 64 and 128-bit vectors
    setTruncStoreAction(MVT::v2i64, MVT::v2i8, Custom);
    setTruncStoreAction(MVT::v2i64, MVT::v2i16, Custom);
    setTruncStoreAction(MVT::v2i64, MVT::v2i32, Custom);
    setTruncStoreAction(MVT::v2i32, MVT::v2i8, Custom);
    setTruncStoreAction(MVT::v2i32, MVT::v2i16, Custom);
 
    for (auto VT : {MVT::nxv2f16, MVT::nxv4f16, MVT::nxv8f16, MVT::nxv2f32,
                    MVT::nxv4f32, MVT::nxv2f64}) {
      setOperationAction(ISD::BITCAST, VT, Custom);
      setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR, VT, Custom);
      setOperationAction(ISD::MLOAD, VT, Custom);
      setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
      setOperationAction(ISD::SELECT, VT, Custom);
      setOperationAction(ISD::SETCC, VT, Custom);
      setOperationAction(ISD::FADD, VT, Custom);
      setOperationAction(ISD::FCANONICALIZE, VT, Custom);
      setOperationAction(ISD::FCOPYSIGN, VT, Custom);
      setOperationAction(ISD::FDIV, VT, Custom);
      setOperationAction(ISD::FMA, VT, Custom);
      setOperationAction(ISD::FMAXIMUM, VT, Custom);
      setOperationAction(ISD::FMAXNUM, VT, Custom);
      setOperationAction(ISD::FMAXNUM_IEEE, VT, Custom);
      setOperationAction(ISD::FMINIMUM, VT, Custom);
      setOperationAction(ISD::FMINNUM, VT, Custom);
      setOperationAction(ISD::FMINNUM_IEEE, VT, Custom);
      setOperationAction(ISD::FMUL, VT, Custom);
      setOperationAction(ISD::FNEG, VT, Custom);
      setOperationAction(ISD::FSUB, VT, Custom);
      setOperationAction(ISD::FCEIL, VT, Custom);
      setOperationAction(ISD::FFLOOR, VT, Custom);
      setOperationAction(ISD::FNEARBYINT, VT, Custom);
      setOperationAction(ISD::FRINT, VT, Custom);
      setOperationAction(ISD::LRINT, VT, Custom);
      setOperationAction(ISD::LLRINT, VT, Custom);
      setOperationAction(ISD::FROUND, VT, Custom);
      setOperationAction(ISD::FROUNDEVEN, VT, Custom);
      setOperationAction(ISD::FTRUNC, VT, Custom);
      setOperationAction(ISD::FSQRT, VT, Custom);
      setOperationAction(ISD::FABS, VT, Custom);
      setOperationAction(ISD::FP_EXTEND, VT, Custom);
      setOperationAction(ISD::FP_ROUND, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FADD, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FMAX, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FMIN, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FMAXIMUM, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FMINIMUM, VT, Custom);
      setOperationAction(ISD::VECREDUCE_FMUL, VT, Custom);
      setOperationAction(ISD::VECTOR_SPLICE_LEFT, VT, Custom);
      setOperationAction(ISD::VECTOR_SPLICE_RIGHT, VT, Custom);
      setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
      setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
 
      setOperationAction(ISD::SELECT_CC, VT, Expand);
      setOperationAction(ISD::FREM, VT, Expand);
      setOperationAction(ISD::FPOW, VT, Expand);
      setOperationAction(ISD::FPOWI, VT, Expand);
      setOperationAction(ISD::FCBRT, VT, Expand);
      setOperationAction(ISD::FCOS, VT, Expand);
      setOperationAction(ISD::FSIN, VT, Expand);
      setOperationAction(ISD::FSINCOS, VT, Expand);
      setOperationAction(ISD::FTAN, VT, Expand);
      setOperationAction(ISD::FACOS, VT, Expand);
      setOperationAction(ISD::FASIN, VT, Expand);
      setOperationAction(ISD::FATAN, VT, Expand);
      setOperationAction(ISD::FATAN2, VT, Expand);
      setOperationAction(ISD::FCOSH, VT, Expand);
      setOperationAction(ISD::FSINH, VT, Expand);
      setOperationAction(ISD::FTANH, VT, Expand);
      setOperationAction(ISD::FEXP, VT, Expand);
      setOperationAction(ISD::FEXP2, VT, Expand);
      setOperationAction(ISD::FEXP10, VT, Expand);
      setOperationAction(ISD::FLOG, VT, Expand);
      setOperationAction(ISD::FLOG2, VT, Expand);
      setOperationAction(ISD::FLOG10, VT, Expand);
 
      setCondCodeAction(ISD::SETO, VT, Expand);
      setCondCodeAction(ISD::SETOLT, VT, Expand);
      setCondCodeAction(ISD::SETLT, VT, Expand);
      setCondCodeAction(ISD::SETOLE, VT, Expand);
      setCondCodeAction(ISD::SETLE, VT, Expand);
      setCondCodeAction(ISD::SETULT, VT, Expand);
      setCondCodeAction(ISD::SETULE, VT, Expand);
      setCondCodeAction(ISD::SETUGE, VT, Expand);
      setCondCodeAction(ISD::SETUGT, VT, Expand);
      setCondCodeAction(ISD::SETUEQ, VT, Expand);
      setCondCodeAction(ISD::SETONE, VT, Expand);
    }
 
    for (auto VT : {MVT::nxv2bf16, MVT::nxv4bf16, MVT::nxv8bf16}) {
      setOperationAction(ISD::BITCAST, VT, Custom);
      setOperationAction(ISD::CONCAT_VECTORS, VT, Custom);
      setOperationAction(ISD::FABS, VT, Custom);
      setOperationAction(ISD::FCOPYSIGN, VT, Custom);
      setOperationAction(ISD::FNEG, VT, Custom);
      setOperationAction(ISD::FP_EXTEND, VT, Custom);
      setOperationAction(ISD::FP_ROUND, VT, Custom);
      setOperationAction(ISD::MLOAD, VT, Custom);
      setOperationAction(ISD::INSERT_SUBVECTOR, VT, Custom);
      setOperationAction(ISD::SELECT, VT, Custom);
      setOperationAction(ISD::SELECT_CC, VT, Expand);
      setOperationAction(ISD::SPLAT_VECTOR, VT, Legal);
      setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
      setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
      setOperationAction(ISD::VECTOR_SPLICE_LEFT, VT, Custom);
      setOperationAction(ISD::VECTOR_SPLICE_RIGHT, VT, Custom);
    }
 
    if (Subtarget->hasSVEB16B16() &&
        Subtarget->isNonStreamingSVEorSME2Available()) {
      // Note: Use SVE for bfloat16 operations when +sve-b16b16 is available.
      for (auto VT : {MVT::v4bf16, MVT::v8bf16, MVT::nxv2bf16, MVT::nxv4bf16,
                      MVT::nxv8bf16}) {
        setOperationAction(ISD::FADD, VT, Custom);
        setOperationAction(ISD::FMA, VT, Custom);
        setOperationAction(ISD::FMAXIMUM, VT, Custom);
        setOperationAction(ISD::FMAXNUM, VT, Custom);
        setOperationAction(ISD::FMINIMUM, VT, Custom);
        setOperationAction(ISD::FMINNUM, VT, Custom);
        setOperationAction(ISD::FMUL, VT, Custom);
        setOperationAction(ISD::FSUB, VT, Custom);
      }
    }
 
    for (auto Opcode :
         {ISD::FCEIL, ISD::FDIV, ISD::FFLOOR, ISD::FNEARBYINT, ISD::FRINT,
          ISD::FROUND, ISD::FROUNDEVEN, ISD::FSQRT, ISD::FTRUNC, ISD::SETCC,
          ISD::VECREDUCE_FADD, ISD::VECREDUCE_FMAX, ISD::VECREDUCE_FMAXIMUM,
          ISD::VECREDUCE_FMIN, ISD::VECREDUCE_FMINIMUM}) {
      setOperationPromotedToType(Opcode, MVT::nxv2bf16, MVT::nxv2f32);
      setOperationPromotedToType(Opcode, MVT::nxv4bf16, MVT::nxv4f32);
      setOperationPromotedToType(Opcode, MVT::nxv8bf16, MVT::nxv8f32);
    }
 
    if (!Subtarget->hasSVEB16B16() ||
        !Subtarget->isNonStreamingSVEorSME2Available()) {
      for (MVT VT : {MVT::nxv2bf16, MVT::nxv4bf16, MVT::nxv8bf16}) {
        MVT PromotedVT = VT.changeVectorElementType(MVT::f32);
        setOperationPromotedToType(ISD::FADD, VT, PromotedVT);
        setOperationPromotedToType(ISD::FMA, VT, PromotedVT);
        setOperationPromotedToType(ISD::FMAXIMUM, VT, PromotedVT);
        setOperationPromotedToType(ISD::FMAXNUM, VT, PromotedVT);
        setOperationPromotedToType(ISD::FMINIMUM, VT, PromotedVT);
        setOperationPromotedToType(ISD::FMINNUM, VT, PromotedVT);
        setOperationPromotedToType(ISD::FSUB, VT, PromotedVT);
 
        if (VT != MVT::nxv2bf16 && Subtarget->hasBF16())
          setOperationAction(ISD::FMUL, VT, Custom);
        else
          setOperationPromotedToType(ISD::FMUL, VT, PromotedVT);
      }
 
      if (Subtarget->hasBF16() && Subtarget->isNeonAvailable())
        setOperationAction(ISD::FMUL, MVT::v8bf16, Custom);
    }
 
    setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i8, Custom);
    setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::i16, Custom);
 
    // A number of operations like MULH and integer divides are not supported by
    // NEON but are available in SVE.
    for (auto VT : {MVT::v8i8, MVT::v16i8, MVT::v4i16, MVT::v8i16, MVT::v2i32,
                    MVT::v4i32, MVT::v1i64, MVT::v2i64}) {
      setOperationAction(ISD::MASKED_SDIV, VT, Custom);
      setOperationAction(ISD::MASKED_UDIV, VT, Custom);
      setOperationAction(ISD::SDIV, VT, Custom);
      setOperationAction(ISD::UDIV, VT, Custom);
      setOperationAction(ISD::MULHS, VT, Custom);
      setOperationAction(ISD::MULHU, VT, Custom);
    }
 
    // NEON doesn't support 64-bit vector integer muls, but SVE does.
    setOperationAction(ISD::MUL, MVT::v1i64, Custom);
    setOperationAction(ISD::MUL, MVT::v2i64, Custom);
 
    // With SVE2 we can try lowering these to pairwise operations (e.g. smaxp).
    if (Subtarget->hasSVE2() || Subtarget->isStreamingSVEAvailable()) {
      setOperationAction(ISD::VECREDUCE_SMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_SMIN, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_UMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_UMIN, MVT::v2i64, Custom);
    }
 
    // NOTE: Currently this has to happen after computeRegisterProperties rather
    // than the preferred option of combining it with the addRegisterClass call.
    if (Subtarget->useSVEForFixedLengthVectors()) {
      for (MVT VT : MVT::integer_fixedlen_vector_valuetypes()) {
        if (useSVEForFixedLengthVectorVT(
                VT, /*OverrideNEON=*/!Subtarget->isNeonAvailable()))
          addTypeForFixedLengthSVE(VT);
      }
      for (MVT VT : MVT::fp_fixedlen_vector_valuetypes()) {
        if (useSVEForFixedLengthVectorVT(
                VT, /*OverrideNEON=*/!Subtarget->isNeonAvailable()))
          addTypeForFixedLengthSVE(VT);
      }
 
      // 64bit results can mean a bigger than NEON input.
      for (auto VT : {MVT::v8i8, MVT::v4i16})
        setOperationAction(ISD::TRUNCATE, VT, Custom);
      setOperationAction(ISD::FP_ROUND, MVT::v4f16, Custom);
 
      // 128bit results imply a bigger than NEON input.
      for (auto VT : {MVT::v16i8, MVT::v8i16, MVT::v4i32})
        setOperationAction(ISD::TRUNCATE, VT, Custom);
      for (auto VT : {MVT::v8f16, MVT::v4f32, MVT::v8bf16})
        setOperationAction(ISD::FP_ROUND, VT, Custom);
 
      // These operations are not supported on NEON but SVE can do them.
      setOperationAction(ISD::BITREVERSE, MVT::v1i64, Custom);
      setOperationAction(ISD::CTLZ, MVT::v1i64, Custom);
      setOperationAction(ISD::CTLZ, MVT::v2i64, Custom);
      setOperationAction(ISD::CTTZ, MVT::v1i64, Custom);
      setOperationAction(ISD::SMAX, MVT::v1i64, Custom);
      setOperationAction(ISD::SMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::SMIN, MVT::v1i64, Custom);
      setOperationAction(ISD::SMIN, MVT::v2i64, Custom);
      setOperationAction(ISD::UMAX, MVT::v1i64, Custom);
      setOperationAction(ISD::UMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::UMIN, MVT::v1i64, Custom);
      setOperationAction(ISD::UMIN, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_SMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_SMIN, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_UMAX, MVT::v2i64, Custom);
      setOperationAction(ISD::VECREDUCE_UMIN, MVT::v2i64, Custom);
 
      // Int operations with no NEON support.
      for (auto VT : {MVT::v8i8, MVT::v16i8, MVT::v4i16, MVT::v8i16,
                      MVT::v2i32, MVT::v4i32, MVT::v2i64}) {
        setOperationAction(ISD::BITREVERSE, VT, Custom);
        setOperationAction(ISD::CTTZ, VT, Custom);
        setOperationAction(ISD::VECREDUCE_AND, VT, Custom);
        setOperationAction(ISD::VECREDUCE_OR, VT, Custom);
        setOperationAction(ISD::VECREDUCE_XOR, VT, Custom);
      }
 
      // Use SVE for vectors with more than 2 elements.
      for (auto VT : {MVT::v4f16, MVT::v8f16, MVT::v4f32})
        setOperationAction(ISD::VECREDUCE_FADD, VT, Custom);
    }
 
    setOperationPromotedToType(ISD::VECTOR_SPLICE_LEFT, MVT::nxv2i1,
                               MVT::nxv2i64);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_RIGHT, MVT::nxv2i1,
                               MVT::nxv2i64);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_LEFT, MVT::nxv4i1,
                               MVT::nxv4i32);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_RIGHT, MVT::nxv4i1,
                               MVT::nxv4i32);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_LEFT, MVT::nxv8i1,
                               MVT::nxv8i16);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_RIGHT, MVT::nxv8i1,
                               MVT::nxv8i16);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_LEFT, MVT::nxv16i1,
                               MVT::nxv16i8);
    setOperationPromotedToType(ISD::VECTOR_SPLICE_RIGHT, MVT::nxv16i1,
                               MVT::nxv16i8);
 
    setOperationAction(ISD::VSCALE, MVT::i32, Custom);
 
    for (auto VT : {MVT::v16i1, MVT::v8i1, MVT::v4i1, MVT::v2i1})
      setOperationAction(
          {ISD::INTRINSIC_WO_CHAIN, ISD::CTTZ_ELTS, ISD::CTTZ_ELTS_ZERO_POISON},
          VT, Custom);
  }
 
  // Handle partial reduction operations
  if (Subtarget->isSVEorStreamingSVEAvailable()) {
    // Mark known legal pairs as 'Legal' (these will expand to UDOT or SDOT).
    // Other pairs will default to 'Expand'.
    static const unsigned MLAOps[] = {ISD::PARTIAL_REDUCE_SMLA,
                                      ISD::PARTIAL_REDUCE_UMLA};
    setPartialReduceMLAAction(MLAOps, MVT::nxv2i64, MVT::nxv8i16, Legal);
    setPartialReduceMLAAction(MLAOps, MVT::nxv4i32, MVT::nxv16i8, Legal);
 
    setPartialReduceMLAAction(MLAOps, MVT::nxv2i64, MVT::nxv16i8, Custom);
 
    if (Subtarget->hasMatMulInt8()) {
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, MVT::nxv4i32,
                                MVT::nxv16i8, Legal);
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, MVT::nxv2i64,
                                MVT::nxv16i8, Custom);
    }
 
    if (Subtarget->hasSVE2() || Subtarget->hasSME()) {
      // Wide add types
      setPartialReduceMLAAction(MLAOps, MVT::nxv2i64, MVT::nxv4i32, Legal);
      setPartialReduceMLAAction(MLAOps, MVT::nxv4i32, MVT::nxv8i16, Legal);
      setPartialReduceMLAAction(MLAOps, MVT::nxv8i16, MVT::nxv16i8, Legal);
 
      setOperationAction(ISD::CLMUL, {MVT::nxv16i8, MVT::nxv4i32}, Legal);
 
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::nxv4f32,
                                MVT::nxv8f16, Legal);
 
      // We can use SVE2p1 fdot or SVE2 fmlalb/t to emulate the fixed-length
      // variant (unless NEON fdot is natively available).
      if (!Subtarget->isNeonAvailable() ||
          (!Subtarget->hasF16F32DOT() && !Subtarget->hasFP16FML())) {
        setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::v4f32,
                                  MVT::v8f16, Custom);
        setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::v2f32,
                                  MVT::v4f16, Custom);
      }
    }
 
    if (Subtarget->hasBF16())
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, MVT::nxv4f32,
                                MVT::nxv8bf16, Legal);
  }
 
  if (Subtarget->hasSVEAES() &&
      (Subtarget->isSVEAvailable() || Subtarget->hasSSVE_AES()))
    setOperationAction(ISD::CLMUL, MVT::nxv2i64, Legal);
 
  // Handle non-aliasing elements mask
  if (Subtarget->hasSVE2() ||
      (Subtarget->hasSME() && Subtarget->isStreaming())) {
    // FIXME: Support wider fixed-length types when msve-vector-bits is used.
    for (auto VT : {MVT::v2i32, MVT::v4i16, MVT::v8i8, MVT::v16i8}) {
      setOperationAction(ISD::LOOP_DEPENDENCE_RAW_MASK, VT, Custom);
      setOperationAction(ISD::LOOP_DEPENDENCE_WAR_MASK, VT, Custom);
    }
    for (auto VT : {MVT::nxv2i1, MVT::nxv4i1, MVT::nxv8i1, MVT::nxv16i1}) {
      setOperationAction(ISD::LOOP_DEPENDENCE_RAW_MASK, VT, Custom);
      setOperationAction(ISD::LOOP_DEPENDENCE_WAR_MASK, VT, Custom);
    }
  }
 
  // Handle operations that are only available in non-streaming SVE mode.
  if (Subtarget->isSVEAvailable()) {
    for (auto VT : {MVT::nxv16i8,  MVT::nxv8i16, MVT::nxv4i32,  MVT::nxv2i64,
                    MVT::nxv2f16,  MVT::nxv4f16, MVT::nxv8f16,  MVT::nxv2f32,
                    MVT::nxv4f32,  MVT::nxv2f64, MVT::nxv2bf16, MVT::nxv4bf16,
                    MVT::nxv8bf16, MVT::v4f16,   MVT::v8f16,    MVT::v2f32,
                    MVT::v4f32,    MVT::v1f64,   MVT::v2f64,    MVT::v8i8,
                    MVT::v16i8,    MVT::v4i16,   MVT::v8i16,    MVT::v2i32,
                    MVT::v4i32,    MVT::v1i64,   MVT::v2i64}) {
      setOperationAction(ISD::MGATHER, VT, Custom);
      setOperationAction(ISD::MSCATTER, VT, Custom);
    }
 
    for (auto VT : {MVT::nxv2f16, MVT::nxv4f16, MVT::nxv8f16, MVT::nxv2f32,
                    MVT::nxv4f32, MVT::nxv2f64, MVT::v4f16, MVT::v8f16,
                    MVT::v2f32, MVT::v4f32, MVT::v2f64})
      setOperationAction(ISD::VECREDUCE_SEQ_FADD, VT, Custom);
 
    // We can lower types that have <vscale x {2|4}> elements to compact.
    for (auto VT :
         {MVT::nxv4i32, MVT::nxv2i64, MVT::nxv2f32, MVT::nxv4f32, MVT::nxv2f64})
      setOperationAction(ISD::VECTOR_COMPRESS, VT, Custom);
 
    // If we have SVE, we can use SVE logic for legal NEON vectors in the lowest
    // bits of the SVE register.
    for (auto VT : {MVT::v2i32, MVT::v4i32, MVT::v2i64, MVT::v2f32, MVT::v4f32,
                    MVT::v2f64})
      setOperationAction(ISD::VECTOR_COMPRESS, VT, Custom);
 
    // Promote v4i16/f16 to v4i32/f32 as the SVE container for v4i16 is nxv8,
    // which is not supported with for compact (with only +sve).
    setOperationPromotedToType(ISD::VECTOR_COMPRESS, MVT::v4bf16, MVT::v4i16);
    setOperationPromotedToType(ISD::VECTOR_COMPRESS, MVT::v4f16, MVT::v4i16);
    setOperationPromotedToType(ISD::VECTOR_COMPRESS, MVT::v4i16, MVT::v4i32);
 
    for (auto VT : {MVT::nxv2i8, MVT::nxv2i16, MVT::nxv2i32, MVT::nxv2i64,
                    MVT::nxv2f32, MVT::nxv2f64, MVT::nxv4i8, MVT::nxv4i16,
                    MVT::nxv4i32, MVT::nxv4f32}) {
      // Use a custom lowering for masked stores that could be a supported
      // compressing store. Note: These types still use the normal (Legal)
      // lowering for non-compressing masked stores.
      setOperationAction(ISD::MSTORE, VT, Custom);
    }
 
    // Histcnt is SVE2 only
    if (Subtarget->hasSVE2()) {
      setOperationAction(ISD::EXPERIMENTAL_VECTOR_HISTOGRAM, MVT::nxv4i32,
                         Custom);
      setOperationAction(ISD::EXPERIMENTAL_VECTOR_HISTOGRAM, MVT::nxv2i64,
                         Custom);
 
      static const unsigned MLAOps[] = {ISD::PARTIAL_REDUCE_SMLA,
                                        ISD::PARTIAL_REDUCE_UMLA};
      // Must be lowered to SVE instructions.
      setPartialReduceMLAAction(MLAOps, MVT::v2i64, MVT::v4i32, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v2i64, MVT::v8i16, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v2i64, MVT::v16i8, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v4i32, MVT::v8i16, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v4i32, MVT::v16i8, Custom);
      setPartialReduceMLAAction(MLAOps, MVT::v8i16, MVT::v16i8, Custom);
    }
  }
 
  if (Subtarget->hasMOPS() && Subtarget->hasMTE()) {
    // Only required for llvm.aarch64.mops.memset.tag
    setOperationAction(ISD::INTRINSIC_W_CHAIN, MVT::i8, Custom);
  }
 
  setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
 
  if (Subtarget->hasSVE()) {
    setOperationAction(ISD::FLDEXP, MVT::f64, Custom);
    setOperationAction(ISD::FLDEXP, MVT::f32, Custom);
    setOperationAction(ISD::FLDEXP, MVT::f16, Custom);
    setOperationAction(ISD::FLDEXP, MVT::bf16, Custom);
  }
 
  PredictableSelectIsExpensive = Subtarget->predictableSelectIsExpensive();
 
  IsStrictFPEnabled = true;
  setMaxAtomicSizeInBitsSupported(128);
 
  // On MSVC, both 32-bit and 64-bit, ldexpf(f32) is not defined.  MinGW has
  // it, but it's just a wrapper around ldexp.
  if (Subtarget->isTargetWindows()) {
    for (ISD::NodeType Op : {ISD::FLDEXP, ISD::STRICT_FLDEXP, ISD::FFREXP})
      if (isOperationExpand(Op, MVT::f32))
        setOperationAction(Op, MVT::f32, Promote);
  }
 
  // LegalizeDAG currently can't expand fp16/bf16 LDEXP/FREXP on targets where
  // i16 isn't legal.
  for (ISD::NodeType Op : {ISD::FLDEXP, ISD::STRICT_FLDEXP, ISD::FFREXP}) {
    if (isOperationExpand(Op, MVT::f16))
      setOperationAction(Op, MVT::f16, Promote);
    if (isOperationExpand(Op, MVT::bf16))
      setOperationAction(Op, MVT::bf16, Promote);
  }
}
 
const AArch64TargetMachine &AArch64TargetLowering::getTM() const {
  return static_cast<const AArch64TargetMachine &>(getTargetMachine());
}
 
void AArch64TargetLowering::addTypeForNEON(MVT VT) {
  assert(VT.isVector() && "VT should be a vector type");
 
  if (VT.isFloatingPoint()) {
    MVT PromoteTo = EVT(VT).changeVectorElementTypeToInteger().getSimpleVT();
    setOperationPromotedToType(ISD::LOAD, VT, PromoteTo);
    setOperationPromotedToType(ISD::STORE, VT, PromoteTo);
  }
 
  // Mark vector float intrinsics as expand.
  if (VT == MVT::v2f32 || VT == MVT::v4f32 || VT == MVT::v2f64) {
    setOperationAction(ISD::FSIN, VT, Expand);
    setOperationAction(ISD::FCOS, VT, Expand);
    setOperationAction(ISD::FTAN, VT, Expand);
    setOperationAction(ISD::FASIN, VT, Expand);
    setOperationAction(ISD::FACOS, VT, Expand);
    setOperationAction(ISD::FATAN, VT, Expand);
    setOperationAction(ISD::FATAN2, VT, Expand);
    setOperationAction(ISD::FSINH, VT, Expand);
    setOperationAction(ISD::FCOSH, VT, Expand);
    setOperationAction(ISD::FTANH, VT, Expand);
    setOperationAction(ISD::FPOW, VT, Expand);
    setOperationAction(ISD::FCBRT, VT, Expand);
    setOperationAction(ISD::FLOG, VT, Expand);
    setOperationAction(ISD::FLOG2, VT, Expand);
    setOperationAction(ISD::FLOG10, VT, Expand);
    setOperationAction(ISD::FEXP, VT, Expand);
    setOperationAction(ISD::FEXP2, VT, Expand);
    setOperationAction(ISD::FEXP10, VT, Expand);
  }
 
  // But we do support custom-lowering for FCOPYSIGN.
  if (VT == MVT::v2f32 || VT == MVT::v4f32 || VT == MVT::v2f64 ||
      ((VT == MVT::v4bf16 || VT == MVT::v8bf16 || VT == MVT::v4f16 ||
        VT == MVT::v8f16) &&
       Subtarget->hasFullFP16()))
    setOperationAction(ISD::FCOPYSIGN, VT, Custom);
 
  setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Custom);
  setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Custom);
  setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
  setOperationAction(ISD::ZERO_EXTEND_VECTOR_INREG, VT, Custom);
  setOperationAction(ISD::VECTOR_DEINTERLEAVE, VT, Custom);
  setOperationAction(ISD::VECTOR_INTERLEAVE, VT, Custom);
  setOperationAction(ISD::VECTOR_SHUFFLE, VT, Custom);
  setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Custom);
  setOperationAction(ISD::SRA, VT, Custom);
  setOperationAction(ISD::SRL, VT, Custom);
  setOperationAction(ISD::SHL, VT, Custom);
  setOperationAction(ISD::OR, VT, Custom);
  setOperationAction(ISD::SETCC, VT, Custom);
  setOperationAction(ISD::CONCAT_VECTORS, VT, Legal);
 
  setOperationAction(ISD::SELECT, VT, Expand);
  setOperationAction(ISD::SELECT_CC, VT, Expand);
  setOperationAction(ISD::VSELECT, VT, Expand);
  for (MVT InnerVT : MVT::all_valuetypes())
    setLoadExtAction(ISD::EXTLOAD, InnerVT, VT, Expand);
 
  // CNT supports only B element sizes, then use UADDLP to widen.
  if (VT != MVT::v8i8 && VT != MVT::v16i8)
    setOperationAction(ISD::CTPOP, VT, Custom);
 
  setOperationAction(ISD::UDIV, VT, Expand);
  setOperationAction(ISD::SDIV, VT, Expand);
  setOperationAction(ISD::UREM, VT, Expand);
  setOperationAction(ISD::SREM, VT, Expand);
  setOperationAction(ISD::FREM, VT, Expand);
 
  for (unsigned Opcode :
       {ISD::FP_TO_SINT, ISD::FP_TO_UINT, ISD::FP_TO_SINT_SAT,
        ISD::FP_TO_UINT_SAT, ISD::STRICT_FP_TO_SINT, ISD::STRICT_FP_TO_UINT})
    setOperationAction(Opcode, VT, Custom);
 
  if (!VT.isFloatingPoint())
    setOperationAction(ISD::ABS, VT, Legal);
 
  // [SU][MIN|MAX] are available for all NEON types apart from i64.
  if (!VT.isFloatingPoint() && VT != MVT::v2i64 && VT != MVT::v1i64)
    for (unsigned Opcode : {ISD::SMIN, ISD::SMAX, ISD::UMIN, ISD::UMAX})
      setOperationAction(Opcode, VT, Legal);
 
  // F[MIN|MAX][NUM|NAN] and simple strict operations are available for all FP
  // NEON types.
  if (VT.isFloatingPoint() &&
      VT.getVectorElementType() != MVT::bf16 &&
      (VT.getVectorElementType() != MVT::f16 || Subtarget->hasFullFP16()))
    for (unsigned Opcode :
         {ISD::FMINIMUM, ISD::FMAXIMUM, ISD::FMINNUM, ISD::FMAXNUM,
          ISD::FMINNUM_IEEE, ISD::FMAXNUM_IEEE, ISD::STRICT_FMINIMUM,
          ISD::STRICT_FMAXIMUM, ISD::STRICT_FMINNUM, ISD::STRICT_FMAXNUM,
          ISD::STRICT_FADD, ISD::STRICT_FSUB, ISD::STRICT_FMUL,
          ISD::STRICT_FDIV, ISD::STRICT_FMA, ISD::STRICT_FSQRT})
      setOperationAction(Opcode, VT, Legal);
 
  // Strict fp extend and trunc are legal
  if (VT.isFloatingPoint() && VT.getScalarSizeInBits() != 16)
    setOperationAction(ISD::STRICT_FP_EXTEND, VT, Legal);
  if (VT.isFloatingPoint() && VT.getScalarSizeInBits() != 64)
    setOperationAction(ISD::STRICT_FP_ROUND, VT, Legal);
 
  // FIXME: We could potentially make use of the vector comparison instructions
  // for STRICT_FSETCC and STRICT_FSETCSS, but there's a number of
  // complications:
  //  * FCMPEQ/NE are quiet comparisons, the rest are signalling comparisons,
  //    so we would need to expand when the condition code doesn't match the
  //    kind of comparison.
  //  * Some kinds of comparison require more than one FCMXY instruction so
  //    would need to be expanded instead.
  //  * The lowering of the non-strict versions involves target-specific ISD
  //    nodes so we would likely need to add strict versions of all of them and
  //    handle them appropriately.
  setOperationAction(ISD::STRICT_FSETCC, VT, Expand);
  setOperationAction(ISD::STRICT_FSETCCS, VT, Expand);
 
  // When little-endian we can use ordinary d and q register loads/stores for
  // vector types, but when big-endian we need to use structure load/store which
  // only allow post-index addressing.
  if (Subtarget->isLittleEndian()) {
    for (unsigned im = (unsigned)ISD::PRE_INC;
         im != (unsigned)ISD::LAST_INDEXED_MODE; ++im) {
      setIndexedLoadAction(im, VT, Legal);
      setIndexedStoreAction(im, VT, Legal);
    }
  } else {
    setIndexedLoadAction(ISD::POST_INC, VT, Legal);
    setIndexedStoreAction(ISD::POST_INC, VT, Legal);
  }
 
  if (Subtarget->hasD128()) {
    setOperationAction(ISD::READ_REGISTER, MVT::i128, Custom);
    setOperationAction(ISD::WRITE_REGISTER, MVT::i128, Custom);
  }
 
  if (VT.isInteger()) {
    // Let common code emit inverted variants of compares we do support.
    setCondCodeAction(ISD::SETNE, VT, Expand);
    setCondCodeAction(ISD::SETLE, VT, Expand);
    setCondCodeAction(ISD::SETLT, VT, Expand);
    setCondCodeAction(ISD::SETULE, VT, Expand);
    setCondCodeAction(ISD::SETULT, VT, Expand);
  }
}
 
bool AArch64TargetLowering::shouldExpandGetActiveLaneMask(EVT ResVT,
                                                          EVT OpVT) const {
  // Only SVE has a 1:1 mapping from intrinsic -> instruction (whilelo).
  if (!Subtarget->isSVEorStreamingSVEAvailable() ||
      ResVT.getVectorElementType() != MVT::i1)
    return true;
 
  // Only support illegal types if the result is scalable and min elements > 1.
  if (ResVT.getVectorMinNumElements() == 1 ||
      (ResVT.isFixedLengthVector() && (ResVT.getVectorNumElements() > 16 ||
                                       (OpVT != MVT::i32 && OpVT != MVT::i64))))
    return true;
 
  // 32 & 64 bit operands are supported. We can promote anything < 64 bits,
  // but anything larger should be expanded.
  if (OpVT.getFixedSizeInBits() > 64)
    return true;
 
  return false;
}
 
bool AArch64TargetLowering::shouldExpandCttzElements(EVT VT) const {
  if (!Subtarget->isSVEorStreamingSVEAvailable())
    return true;
 
  // We can only use the BRKB + CNTP sequence with legal predicate types. We can
  // also support fixed-width predicates.
  return VT != MVT::nxv16i1 && VT != MVT::nxv8i1 && VT != MVT::nxv4i1 &&
         VT != MVT::nxv2i1 && VT != MVT::v16i1 && VT != MVT::v8i1 &&
         VT != MVT::v4i1 && VT != MVT::v2i1;
}
 
bool AArch64TargetLowering::shouldExpandVectorMatch(EVT VT,
                                                    unsigned SearchSize) const {
  // MATCH is SVE2 and only available in non-streaming mode.
  if (!Subtarget->hasSVE2() || !Subtarget->isSVEAvailable())
    return true;
  // Furthermore, we can only use it for 8-bit or 16-bit elements.
  if (VT == MVT::nxv8i16 || VT == MVT::v8i16)
    return SearchSize != 8;
  if (VT == MVT::nxv16i8 || VT == MVT::v16i8 || VT == MVT::v8i8)
    return SearchSize != 8 && SearchSize != 16;
  return true;
}
 
void AArch64TargetLowering::addTypeForFixedLengthSVE(MVT VT) {
  assert(VT.isFixedLengthVector() && "Expected fixed length vector type!");
 
  // By default everything must be expanded.
  for (unsigned Op = 0; Op < ISD::BUILTIN_OP_END; ++Op)
    setOperationAction(Op, VT, Expand);
 
  if (VT.isFloatingPoint()) {
    setCondCodeAction(ISD::SETO, VT, Expand);
    setCondCodeAction(ISD::SETOLT, VT, Expand);
    setCondCodeAction(ISD::SETOLE, VT, Expand);
    setCondCodeAction(ISD::SETULT, VT, Expand);
    setCondCodeAction(ISD::SETULE, VT, Expand);
    setCondCodeAction(ISD::SETUGE, VT, Expand);
    setCondCodeAction(ISD::SETUGT, VT, Expand);
    setCondCodeAction(ISD::SETUEQ, VT, Expand);
    setCondCodeAction(ISD::SETONE, VT, Expand);
  }
 
  TargetLoweringBase::LegalizeAction Default =
      VT == MVT::v1f64 ? Expand : Custom;
 
  // Mark integer truncating stores/extending loads as having custom lowering
  if (VT.isInteger()) {
    MVT InnerVT = VT.changeVectorElementType(MVT::i8);
    while (InnerVT != VT) {
      setTruncStoreAction(VT, InnerVT, Default);
      setLoadExtAction(ISD::ZEXTLOAD, VT, InnerVT, Default);
      setLoadExtAction(ISD::SEXTLOAD, VT, InnerVT, Default);
      setLoadExtAction(ISD::EXTLOAD, VT, InnerVT, Default);
      InnerVT = InnerVT.changeVectorElementType(
          MVT::getIntegerVT(2 * InnerVT.getScalarSizeInBits()));
    }
  }
 
  // Mark floating-point truncating stores/extending loads as having custom
  // lowering
  if (VT.isFloatingPoint()) {
    MVT InnerVT = VT.changeVectorElementType(MVT::f16);
    while (InnerVT != VT) {
      setTruncStoreAction(VT, InnerVT, Custom);
      setLoadExtAction(ISD::EXTLOAD, VT, InnerVT, Default);
      InnerVT = InnerVT.changeVectorElementType(
          MVT::getFloatingPointVT(2 * InnerVT.getScalarSizeInBits()));
    }
  }
 
  bool PreferNEON = VT.is64BitVector() || VT.is128BitVector();
  bool PreferSVE = !PreferNEON && Subtarget->isSVEAvailable();
 
  static const unsigned MLAOps[] = {ISD::PARTIAL_REDUCE_SMLA,
                                    ISD::PARTIAL_REDUCE_UMLA};
  unsigned NumElts = VT.getVectorNumElements();
  if (VT.getVectorElementType() == MVT::i64) {
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i8, NumElts * 8), Custom);
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i16, NumElts * 4), Custom);
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i32, NumElts * 2), Custom);
  } else if (VT.getVectorElementType() == MVT::i32) {
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i8, NumElts * 4), Custom);
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i16, NumElts * 2), Custom);
  } else if (VT.getVectorElementType() == MVT::i16) {
    setPartialReduceMLAAction(MLAOps, VT,
                              MVT::getVectorVT(MVT::i8, NumElts * 2), Custom);
  }
  if (Subtarget->hasMatMulInt8()) {
    if (VT.getVectorElementType() == MVT::i32)
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, VT,
                                MVT::getVectorVT(MVT::i8, NumElts * 4), Custom);
    else if (VT.getVectorElementType() == MVT::i64)
      setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_SUMLA, VT,
                                MVT::getVectorVT(MVT::i8, NumElts * 8), Custom);
  }
 
  if (Subtarget->hasSVE2p1() && VT.getVectorElementType() == MVT::f32) {
    setPartialReduceMLAAction(ISD::PARTIAL_REDUCE_FMLA, VT,
                              MVT::getVectorVT(MVT::f16, NumElts * 2), Custom);
  }
 
  // Lower fixed length vector operations to scalable equivalents.
  setOperationAction(ISD::ABDS, VT, Default);
  setOperationAction(ISD::ABDU, VT, Default);
  setOperationAction(ISD::ABS, VT, Default);
  setOperationAction(ISD::ADD, VT, Default);
  setOperationAction(ISD::AND, VT, Default);
  setOperationAction(ISD::ANY_EXTEND, VT, Default);
  setOperationAction(ISD::BITCAST, VT, PreferNEON ? Legal : Default);
  setOperationAction(ISD::BITREVERSE, VT, Default);
  setOperationAction(ISD::BSWAP, VT, Default);
  setOperationAction(ISD::BUILD_VECTOR, VT, Custom);
  setOperationAction(ISD::CONCAT_VECTORS, VT, Default);
  setOperationAction(ISD::CTLZ, VT, Default);
  setOperationAction(ISD::CTPOP, VT, Default);
  setOperationAction(ISD::CTTZ, VT, Default);
  setOperationAction(ISD::EXTRACT_SUBVECTOR, VT, Default);
  setOperationAction(ISD::EXTRACT_VECTOR_ELT, VT, Default);
  setOperationAction(ISD::FABS, VT, Default);
  setOperationAction(ISD::FADD, VT, Default);
  setOperationAction(ISD::FCANONICALIZE, VT, Default);
  setOperationAction(ISD::FCEIL, VT, Default);
  setOperationAction(ISD::FCOPYSIGN, VT, Default);
  setOperationAction(ISD::FDIV, VT, Default);
  setOperationAction(ISD::FFLOOR, VT, Default);
  setOperationAction(ISD::FMA, VT, Default);
  setOperationAction(ISD::FMAXIMUM, VT, Default);
  setOperationAction(ISD::FMAXNUM, VT, Default);
  setOperationAction(ISD::FMAXNUM_IEEE, VT, Default);
  setOperationAction(ISD::FMINIMUM, VT, Default);
  setOperationAction(ISD::FMINNUM, VT, Default);
  setOperationAction(ISD::FMINNUM_IEEE, VT, Default);
  setOperationAction(ISD::FMUL, VT, Default);
  setOperationAction(ISD::FNEARBYINT, VT, Default);
  setOperationAction(ISD::FNEG, VT, Default);
  setOperationAction(ISD::FP_EXTEND, VT, Default);
  setOperationAction(ISD::FP_ROUND, VT, Default);
  setOperationAction(ISD::FP_TO_SINT, VT, Default);
  setOperationAction(ISD::FP_TO_UINT, VT, Default);
  setOperationAction(ISD::FRINT, VT, Default);
  setOperationAction(ISD::LRINT, VT, Default);
  setOperationAction(ISD::LLRINT, VT, Default);
  setOperationAction(ISD::FROUND, VT, Default);
  setOperationAction(ISD::FROUNDEVEN, VT, Default);
  setOperationAction(ISD::FSQRT, VT, Default);
  setOperationAction(ISD::FSUB, VT, Default);
  setOperationAction(ISD::FTRUNC, VT, Default);
  setOperationAction(ISD::GET_ACTIVE_LANE_MASK, VT, Default);
  setOperationAction(ISD::INSERT_VECTOR_ELT, VT, Default);
  setOperationAction(ISD::LOAD, VT, PreferNEON ? Legal : Default);
  setOperationAction(ISD::MASKED_UDIV, VT, Default);
  setOperationAction(ISD::MASKED_SDIV, VT, Default);
  setOperationAction(ISD::MGATHER, VT, PreferSVE ? Default : Expand);
  setOperationAction(ISD::MLOAD, VT, Default);
  setOperationAction(ISD::MSCATTER, VT, PreferSVE ? Default : Expand);
  setOperationAction(ISD::MSTORE, VT, Default);
  setOperationAction(ISD::MUL, VT, Default);
  setOperationAction(ISD::MULHS, VT, Default);
  setOperationAction(ISD::MULHU, VT, Default);
  setOperationAction(ISD::OR, VT, Default);
  setOperationAction(ISD::SCALAR_TO_VECTOR, VT, PreferNEON ? Legal : Expand);
  setOperationAction(ISD::SDIV, VT, Default);
  setOperationAction(ISD::SELECT, VT, Default);
  setOperationAction(ISD::SETCC, VT, Default);
  setOperationAction(ISD::SHL, VT, Default);
  setOperationAction(ISD::SIGN_EXTEND, VT, Default);
  setOperationAction(ISD::SIGN_EXTEND_INREG, VT, Default);
  setOperationAction(ISD::SINT_TO_FP, VT, Default);
  setOperationAction(ISD::SMAX, VT, Default);
  setOperationAction(ISD::SMIN, VT, Default);
  setOperationAction(ISD::SPLAT_VECTOR, VT, Default);
  setOperationAction(ISD::SRA, VT, Default);
  setOperationAction(ISD::SRL, VT, Default);
  setOperationAction(ISD::STORE, VT, PreferNEON ? Legal : Default);
  setOperationAction(ISD::SUB, VT, Default);
  setOperationAction(ISD::TRUNCATE, VT, Default);
  setOperationAction(ISD::UDIV, VT, Default);
  setOperationAction(ISD::UINT_TO_FP, VT, Default);
  setOperationAction(ISD::UMAX, VT, Default);
  setOperationAction(ISD::UMIN, VT, Default);
  setOperationAction(ISD::VECREDUCE_ADD, VT, Default);
  setOperationAction(ISD::VECREDUCE_AND, VT, Default);
  setOperationAction(ISD::VECREDUCE_FADD, VT, Default);
  setOperationAction(ISD::VECREDUCE_FMAX, VT, Default);
  setOperationAction(ISD::VECREDUCE_FMIN, VT, Default);
  setOperationAction(ISD::VECREDUCE_FMAXIMUM, VT, Default);
  setOperationAction(ISD::VECREDUCE_FMINIMUM, VT, Default);
  setOperationAction(ISD::VECREDUCE_OR, VT, Default);
  setOperationAction(ISD::VECREDUCE_SEQ_FADD, VT, PreferSVE ? Default : Expand);
  setOperationAction(ISD::VECREDUCE_SMAX, VT, Default);
  setOperationAction(ISD::VECREDUCE_SMIN, VT, Default);
  setOperationAction(ISD::VECREDUCE_UMAX, VT, Default);
  setOperationAction(ISD::VECREDUCE_UMIN, VT, Default);
  setOperationAction(ISD::VECREDUCE_XOR, VT, Default);
  setOperationAction(ISD::VECTOR_SHUFFLE, VT, Default);
  setOperationAction(ISD::VECTOR_SPLICE_LEFT, VT, Default);
  setOperationAction(ISD::VECTOR_SPLICE_RIGHT, VT, Default);
  setOperationAction(ISD::VSELECT, VT, Default);
  setOperationAction(ISD::XOR, VT, Default);
  setOperationAction(ISD::ZERO_EXTEND, VT, Default);
}
 
void AArch64TargetLowering::addDRType(MVT VT) {
  addRegisterClass(VT, &AArch64::FPR64RegClass);
  if (Subtarget->isNeonAvailable())
    addTypeForNEON(VT);
}
 
void AArch64TargetLowering::addQRType(MVT VT) {
  addRegisterClass(VT, &AArch64::FPR128RegClass);
  if (Subtarget->isNeonAvailable())
    addTypeForNEON(VT);
}
 
EVT AArch64TargetLowering::getSetCCResultType(const DataLayout &,
                                              LLVMContext &C, EVT VT) const {
  if (!VT.isVector())
    return MVT::i32;
  if (VT.isScalableVector())
    return EVT::getVectorVT(C, MVT::i1, VT.getVectorElementCount());
  return VT.changeVectorElementTypeToInteger();
}
 
// isIntImmediate - This method tests to see if the node is a constant
// operand. If so Imm will receive the value.
static bool isIntImmediate(const SDNode *N, uint64_t &Imm) {
  if (const ConstantSDNode *C = dyn_cast<const ConstantSDNode>(N)) {
    Imm = C->getZExtValue();
    return true;
  }
  return false;
}
 
bool isVectorizedBinOp(unsigned Opcode) {
  switch (Opcode) {
  case AArch64ISD::SQDMULH:
    return true;
  default:
    return false;
  }
}
 
// isOpcWithIntImmediate - This method tests to see if the node is a specific
// opcode and that it has a immediate integer right operand.
// If so Imm will receive the value.
static bool isOpcWithIntImmediate(const SDNode *N, unsigned Opc,
                                  uint64_t &Imm) {
  return N->getOpcode() == Opc &&
         isIntImmediate(N->getOperand(1).getNode(), Imm);
}
 
static bool optimizeLogicalImm(SDValue Op, unsigned Size, uint64_t Imm,
                               const APInt &Demanded,
                               TargetLowering::TargetLoweringOpt &TLO,
                               unsigned NewOpc) {
  uint64_t OldImm = Imm, NewImm, Enc;
  uint64_t Mask = ((uint64_t)(-1LL) >> (64 - Size)), OrigMask = Mask;
 
  // Return if the immediate is already all zeros, all ones, a bimm32 or a
  // bimm64.
  if (Imm == 0 || Imm == Mask ||
      AArch64_AM::isLogicalImmediate(Imm & Mask, Size))
    return false;
 
  unsigned EltSize = Size;
  uint64_t DemandedBits = Demanded.getZExtValue();
 
  // Clear bits that are not demanded.
  Imm &= DemandedBits;
 
  while (true) {
    // The goal here is to set the non-demanded bits in a way that minimizes
    // the number of switching between 0 and 1. In order to achieve this goal,
    // we set the non-demanded bits to the value of the preceding demanded bits.
    // For example, if we have an immediate 0bx10xx0x1 ('x' indicates a
    // non-demanded bit), we copy bit0 (1) to the least significant 'x',
    // bit2 (0) to 'xx', and bit6 (1) to the most significant 'x'.
    // The final result is 0b11000011.
    uint64_t NonDemandedBits = ~DemandedBits;
    uint64_t InvertedImm = ~Imm & DemandedBits;
    uint64_t RotatedImm =
        ((InvertedImm << 1) | (InvertedImm >> (EltSize - 1) & 1)) &
        NonDemandedBits;
    uint64_t Sum = RotatedImm + NonDemandedBits;
    bool Carry = NonDemandedBits & ~Sum & (1ULL << (EltSize - 1));
    uint64_t Ones = (Sum + Carry) & NonDemandedBits;
    NewImm = (Imm | Ones) & Mask;
 
    // If NewImm or its bitwise NOT is a shifted mask, it is a bitmask immediate
    // or all-ones or all-zeros, in which case we can stop searching. Otherwise,
    // we halve the element size and continue the search.
    if (isShiftedMask_64(NewImm) || isShiftedMask_64(~(NewImm | ~Mask)))
      break;
 
    // We cannot shrink the element size any further if it is 2-bits.
    if (EltSize == 2)
      return false;
 
    EltSize /= 2;
    Mask >>= EltSize;
    uint64_t Hi = Imm >> EltSize, DemandedBitsHi = DemandedBits >> EltSize;
 
    // Return if there is mismatch in any of the demanded bits of Imm and Hi.
    if (((Imm ^ Hi) & (DemandedBits & DemandedBitsHi) & Mask) != 0)
      return false;
 
    // Merge the upper and lower halves of Imm and DemandedBits.
    Imm |= Hi;
    DemandedBits |= DemandedBitsHi;
  }
 
  ++NumOptimizedImms;
 
  // Replicate the element across the register width.
  while (EltSize < Size) {
    NewImm |= NewImm << EltSize;
    EltSize *= 2;
  }
 
  (void)OldImm;
  assert(((OldImm ^ NewImm) & Demanded.getZExtValue()) == 0 &&
         "demanded bits should never be altered");
  assert(OldImm != NewImm && "the new imm shouldn't be equal to the old imm");
 
  // Create the new constant immediate node.
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  SDValue New;
 
  // If the new constant immediate is all-zeros or all-ones, let the target
  // independent DAG combine optimize this node.
  if (NewImm == 0 || NewImm == OrigMask) {
    New = TLO.DAG.getNode(Op.getOpcode(), DL, VT, Op.getOperand(0),
                          TLO.DAG.getConstant(NewImm, DL, VT));
  // Otherwise, create a machine node so that target independent DAG combine
  // doesn't undo this optimization.
  } else {
    Enc = AArch64_AM::encodeLogicalImmediate(NewImm, Size);
    SDValue EncConst = TLO.DAG.getTargetConstant(Enc, DL, VT);
    New = SDValue(
        TLO.DAG.getMachineNode(NewOpc, DL, VT, Op.getOperand(0), EncConst), 0);
  }
 
  return TLO.CombineTo(Op, New);
}
 
bool AArch64TargetLowering::targetShrinkDemandedConstant(
    SDValue Op, const APInt &DemandedBits, const APInt &DemandedElts,
    TargetLoweringOpt &TLO) const {
  // Delay this optimization to as late as possible.
  if (!TLO.LegalOps)
    return false;
 
  if (!EnableOptimizeLogicalImm)
    return false;
 
  EVT VT = Op.getValueType();
  if (VT.isVector())
    return false;
 
  unsigned Size = VT.getSizeInBits();
 
  if (Size != 32 && Size != 64)
    return false;
 
  // Exit early if we demand all bits.
  if (DemandedBits.isAllOnes())
    return false;
 
  unsigned NewOpc;
  switch (Op.getOpcode()) {
  default:
    return false;
  case ISD::AND:
    NewOpc = Size == 32 ? AArch64::ANDWri : AArch64::ANDXri;
    break;
  case ISD::OR:
    NewOpc = Size == 32 ? AArch64::ORRWri : AArch64::ORRXri;
    break;
  case ISD::XOR:
    NewOpc = Size == 32 ? AArch64::EORWri : AArch64::EORXri;
    break;
  }
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op.getOperand(1));
  if (!C)
    return false;
  uint64_t Imm = C->getZExtValue();
  return optimizeLogicalImm(Op, Size, Imm, DemandedBits, TLO, NewOpc);
}
 
/// computeKnownBitsForTargetNode - Determine which of the bits specified in
/// Mask are known to be either zero or one and return them Known.
void AArch64TargetLowering::computeKnownBitsForTargetNode(
    const SDValue Op, KnownBits &Known, const APInt &DemandedElts,
    const SelectionDAG &DAG, unsigned Depth) const {
  switch (Op.getOpcode()) {
  default:
    break;
  case AArch64ISD::DUP: {
    SDValue SrcOp = Op.getOperand(0);
    Known = DAG.computeKnownBits(SrcOp, Depth + 1);
    if (SrcOp.getValueSizeInBits() != Op.getScalarValueSizeInBits()) {
      assert(SrcOp.getValueSizeInBits() > Op.getScalarValueSizeInBits() &&
             "Expected DUP implicit truncation");
      Known = Known.trunc(Op.getScalarValueSizeInBits());
    }
    break;
  }
  case AArch64ISD::CSEL: {
    KnownBits Known2;
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
    Known = Known.intersectWith(Known2);
    break;
  }
  case AArch64ISD::CSNEG:
  case AArch64ISD::CSINC:
  case AArch64ISD::CSINV: {
    KnownBits KnownOp0 = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    KnownBits KnownOp1 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
 
    // The result is either:
    // CSINC: KnownOp0 or KnownOp1 + 1
    // CSINV: KnownOp0 or ~KnownOp1
    // CSNEG: KnownOp0 or KnownOp1 * -1
    if (Op.getOpcode() == AArch64ISD::CSINC)
      KnownOp1 = KnownBits::add(
          KnownOp1,
          KnownBits::makeConstant(APInt(Op.getScalarValueSizeInBits(), 1)));
    else if (Op.getOpcode() == AArch64ISD::CSINV)
      std::swap(KnownOp1.Zero, KnownOp1.One);
    else if (Op.getOpcode() == AArch64ISD::CSNEG)
      KnownOp1 =
          KnownBits::mul(KnownOp1, KnownBits::makeConstant(APInt::getAllOnes(
                                       Op.getScalarValueSizeInBits())));
 
    Known = KnownOp0.intersectWith(KnownOp1);
    break;
  }
  case AArch64ISD::BICi: {
    // Compute the bit cleared value.
    APInt Mask =
        ~(Op->getConstantOperandAPInt(1) << Op->getConstantOperandAPInt(2))
             .trunc(Known.getBitWidth());
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known &= KnownBits::makeConstant(Mask);
    break;
  }
  case AArch64ISD::VLSHR: {
    KnownBits Known2;
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
    Known = KnownBits::lshr(Known, Known2);
    break;
  }
  case AArch64ISD::VASHR: {
    KnownBits Known2;
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
    Known = KnownBits::ashr(Known, Known2);
    break;
  }
  case AArch64ISD::VSHL: {
    KnownBits Known2;
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known2 = DAG.computeKnownBits(Op->getOperand(1), Depth + 1);
    Known = KnownBits::shl(Known, Known2);
    break;
  }
  case AArch64ISD::MOVI: {
    Known = KnownBits::makeConstant(
        APInt(Known.getBitWidth(), Op->getConstantOperandVal(0)));
    break;
  }
  case AArch64ISD::MOVIshift: {
    Known = KnownBits::makeConstant(
        APInt(Known.getBitWidth(), Op->getConstantOperandVal(0)
                                       << Op->getConstantOperandVal(1)));
    break;
  }
  case AArch64ISD::MOVImsl: {
    unsigned ShiftAmt = AArch64_AM::getShiftValue(Op->getConstantOperandVal(1));
    Known = KnownBits::makeConstant(APInt(
        Known.getBitWidth(), ~(~Op->getConstantOperandVal(0) << ShiftAmt)));
    break;
  }
  case AArch64ISD::MOVIedit: {
    Known = KnownBits::makeConstant(APInt(
        Known.getBitWidth(),
        AArch64_AM::decodeAdvSIMDModImmType10(Op->getConstantOperandVal(0))));
    break;
  }
  case AArch64ISD::MVNIshift: {
    Known = KnownBits::makeConstant(
        APInt(Known.getBitWidth(),
              ~(Op->getConstantOperandVal(0) << Op->getConstantOperandVal(1)),
              /*isSigned*/ false, /*implicitTrunc*/ true));
    break;
  }
  case AArch64ISD::MVNImsl: {
    unsigned ShiftAmt = AArch64_AM::getShiftValue(Op->getConstantOperandVal(1));
    Known = KnownBits::makeConstant(
        APInt(Known.getBitWidth(), (~Op->getConstantOperandVal(0) << ShiftAmt),
              /*isSigned*/ false, /*implicitTrunc*/ true));
    break;
  }
  case AArch64ISD::LOADgot:
  case AArch64ISD::ADDlow: {
    if (!Subtarget->isTargetILP32())
      break;
    // In ILP32 mode all valid pointers are in the low 4GB of the address-space.
    Known.Zero = APInt::getHighBitsSet(64, 32);
    break;
  }
  case AArch64ISD::ASSERT_ZEXT_BOOL: {
    Known = DAG.computeKnownBits(Op->getOperand(0), Depth + 1);
    Known.Zero |= APInt(Known.getBitWidth(), 0xFE);
    break;
  }
  case ISD::INTRINSIC_W_CHAIN: {
    Intrinsic::ID IntID =
        static_cast<Intrinsic::ID>(Op->getConstantOperandVal(1));
    switch (IntID) {
    default: return;
    case Intrinsic::aarch64_ldaxr:
    case Intrinsic::aarch64_ldxr: {
      unsigned BitWidth = Known.getBitWidth();
      EVT VT = cast<MemIntrinsicSDNode>(Op)->getMemoryVT();
      unsigned MemBits = VT.getScalarSizeInBits();
      Known.Zero |= APInt::getHighBitsSet(BitWidth, BitWidth - MemBits);
      return;
    }
    }
    break;
  }
  case ISD::INTRINSIC_WO_CHAIN:
  case ISD::INTRINSIC_VOID: {
    unsigned IntNo = Op.getConstantOperandVal(0);
    switch (IntNo) {
    default:
      break;
    case Intrinsic::aarch64_neon_uaddlv: {
      MVT VT = Op.getOperand(1).getValueType().getSimpleVT();
      unsigned BitWidth = Known.getBitWidth();
      if (VT == MVT::v8i8 || VT == MVT::v16i8) {
        unsigned Bound = (VT == MVT::v8i8) ?  11 : 12;
        assert(BitWidth >= Bound && "Unexpected width!");
        APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - Bound);
        Known.Zero |= Mask;
      }
      break;
    }
    case Intrinsic::aarch64_neon_umaxv:
    case Intrinsic::aarch64_neon_uminv: {
      // Figure out the datatype of the vector operand. The UMINV instruction
      // will zero extend the result, so we can mark as known zero all the
      // bits larger than the element datatype. 32-bit or larget doesn't need
      // this as those are legal types and will be handled by isel directly.
      MVT VT = Op.getOperand(1).getValueType().getSimpleVT();
      unsigned BitWidth = Known.getBitWidth();
      if (VT == MVT::v8i8 || VT == MVT::v16i8) {
        assert(BitWidth >= 8 && "Unexpected width!");
        APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 8);
        Known.Zero |= Mask;
      } else if (VT == MVT::v4i16 || VT == MVT::v8i16) {
        assert(BitWidth >= 16 && "Unexpected width!");
        APInt Mask = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
        Known.Zero |= Mask;
      }
      break;
    } break;
    }
  }
  }
}
 
unsigned AArch64TargetLowering::ComputeNumSignBitsForTargetNode(
    SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
    unsigned Depth) const {
  EVT VT = Op.getValueType();
  unsigned VTBits = VT.getScalarSizeInBits();
  unsigned Opcode = Op.getOpcode();
  switch (Opcode) {
  case AArch64ISD::FCMEQ:
  case AArch64ISD::FCMGE:
  case AArch64ISD::FCMGT:
    // Compares return either 0 or all-ones
    return VTBits;
  case AArch64ISD::VASHR: {
    unsigned Tmp =
        DAG.ComputeNumSignBits(Op.getOperand(0), DemandedElts, Depth + 1);
    return std::min<uint64_t>(Tmp + Op.getConstantOperandVal(1), VTBits);
  }
  }
 
  return 1;
}
 
MVT AArch64TargetLowering::getScalarShiftAmountTy(const DataLayout &DL,
                                                  EVT) const {
  return MVT::i64;
}
 
bool AArch64TargetLowering::allowsMisalignedMemoryAccesses(
    EVT VT, unsigned AddrSpace, Align Alignment, MachineMemOperand::Flags Flags,
    unsigned *Fast) const {
 
  // Allow SVE loads/stores where the alignment >= the size of the element type,
  // even with +strict-align. Predicated SVE loads/stores (e.g. ld1/st1), used
  // for stores that come from IR, only require element-size alignment (even if
  // unaligned accesses are disabled). Without this, these will be forced to
  // have 16-byte alignment with +strict-align (and fail to lower as we don't
  // yet support TLI.expandUnalignedLoad() and TLI.expandUnalignedStore()).
  if (VT.isScalableVector()) {
    unsigned ElementSizeBits = VT.getScalarSizeInBits();
    if (ElementSizeBits % 8 == 0 && Alignment >= Align(ElementSizeBits / 8))
      return true;
  }
 
  if (Subtarget->requiresStrictAlign())
    return false;
 
  if (Fast) {
    // Some CPUs are fine with unaligned stores except for 128-bit ones.
    *Fast = !Subtarget->isMisaligned128StoreSlow() || VT.getStoreSize() != 16 ||
            // See comments in performSTORECombine() for more details about
            // these conditions.
 
            // Code that uses clang vector extensions can mark that it
            // wants unaligned accesses to be treated as fast by
            // underspecifying alignment to be 1 or 2.
            Alignment <= 2 ||
 
            // Disregard v2i64. Memcpy lowering produces those and splitting
            // them regresses performance on micro-benchmarks and olden/bh.
            VT == MVT::v2i64;
  }
  return true;
}
 
// Same as above but handling LLTs instead.
bool AArch64TargetLowering::allowsMisalignedMemoryAccesses(
    LLT Ty, unsigned AddrSpace, Align Alignment, MachineMemOperand::Flags Flags,
    unsigned *Fast) const {
  if (Subtarget->requiresStrictAlign())
    return false;
 
  if (Fast) {
    // Some CPUs are fine with unaligned stores except for 128-bit ones.
    *Fast = !Subtarget->isMisaligned128StoreSlow() ||
            Ty.getSizeInBytes() != 16 ||
            // See comments in performSTORECombine() for more details about
            // these conditions.
 
            // Code that uses clang vector extensions can mark that it
            // wants unaligned accesses to be treated as fast by
            // underspecifying alignment to be 1 or 2.
            Alignment <= 2 ||
 
            // Disregard v2i64. Memcpy lowering produces those and splitting
            // them regresses performance on micro-benchmarks and olden/bh.
            Ty == LLT::fixed_vector(2, 64);
  }
  return true;
}
 
FastISel *AArch64TargetLowering::createFastISel(
    FunctionLoweringInfo &funcInfo, const TargetLibraryInfo *libInfo,
    const LibcallLoweringInfo *libcallLowering) const {
  return AArch64::createFastISel(funcInfo, libInfo, libcallLowering);
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitF128CSEL(MachineInstr &MI,
                                    MachineBasicBlock *MBB) const {
  // We materialise the F128CSEL pseudo-instruction as some control flow and a
  // phi node:
 
  // OrigBB:
  //     [... previous instrs leading to comparison ...]
  //     b.ne TrueBB
  //     b EndBB
  // TrueBB:
  //     ; Fallthrough
  // EndBB:
  //     Dest = PHI [IfTrue, TrueBB], [IfFalse, OrigBB]
 
  MachineFunction *MF = MBB->getParent();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  const BasicBlock *LLVM_BB = MBB->getBasicBlock();
  DebugLoc DL = MI.getDebugLoc();
  MachineFunction::iterator It = ++MBB->getIterator();
 
  Register DestReg = MI.getOperand(0).getReg();
  Register IfTrueReg = MI.getOperand(1).getReg();
  Register IfFalseReg = MI.getOperand(2).getReg();
  unsigned CondCode = MI.getOperand(3).getImm();
  bool NZCVKilled = MI.getOperand(4).isKill();
 
  MachineBasicBlock *TrueBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *EndBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MF->insert(It, TrueBB);
  MF->insert(It, EndBB);
 
  // Transfer rest of current basic-block to EndBB
  EndBB->splice(EndBB->begin(), MBB, std::next(MachineBasicBlock::iterator(MI)),
                MBB->end());
  EndBB->transferSuccessorsAndUpdatePHIs(MBB);
 
  BuildMI(MBB, DL, TII->get(AArch64::Bcc)).addImm(CondCode).addMBB(TrueBB);
  BuildMI(MBB, DL, TII->get(AArch64::B)).addMBB(EndBB);
  MBB->addSuccessor(TrueBB);
  MBB->addSuccessor(EndBB);
 
  // TrueBB falls through to the end.
  TrueBB->addSuccessor(EndBB);
 
  if (!NZCVKilled) {
    TrueBB->addLiveIn(AArch64::NZCV);
    EndBB->addLiveIn(AArch64::NZCV);
  }
 
  BuildMI(*EndBB, EndBB->begin(), DL, TII->get(AArch64::PHI), DestReg)
      .addReg(IfTrueReg)
      .addMBB(TrueBB)
      .addReg(IfFalseReg)
      .addMBB(MBB);
 
  MI.eraseFromParent();
  return EndBB;
}
 
MachineBasicBlock *AArch64TargetLowering::EmitLoweredCatchRet(
       MachineInstr &MI, MachineBasicBlock *BB) const {
  assert(!isAsynchronousEHPersonality(classifyEHPersonality(
             BB->getParent()->getFunction().getPersonalityFn())) &&
         "SEH does not use catchret!");
  return BB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitDynamicProbedAlloc(MachineInstr &MI,
                                              MachineBasicBlock *MBB) const {
  MachineFunction &MF = *MBB->getParent();
  MachineBasicBlock::iterator MBBI = MI.getIterator();
  const AArch64InstrInfo &TII =
      *MF.getSubtarget<AArch64Subtarget>().getInstrInfo();
  Register TargetReg = MI.getOperand(0).getReg();
  MachineBasicBlock::iterator NextInst =
      TII.probedStackAlloc(MBBI, TargetReg, false);
 
  MI.eraseFromParent();
  return NextInst->getParent();
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitCheckMatchingVL(MachineInstr &MI,
                                           MachineBasicBlock *MBB) const {
  MachineFunction *MF = MBB->getParent();
  MachineRegisterInfo &MRI = MF->getRegInfo();
 
  const TargetRegisterClass *RC_GPR = &AArch64::GPR64RegClass;
  const TargetRegisterClass *RC_GPRsp = &AArch64::GPR64spRegClass;
 
  Register RegVL_GPR = MRI.createVirtualRegister(RC_GPR);
  Register RegVL_GPRsp = MRI.createVirtualRegister(RC_GPRsp); // for ADDSVL src
  Register RegSVL_GPR = MRI.createVirtualRegister(RC_GPR);
  Register RegSVL_GPRsp = MRI.createVirtualRegister(RC_GPRsp); // for ADDSVL dst
 
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  DebugLoc DL = MI.getDebugLoc();
 
  // RDVL requires GPR64, ADDSVL requires GPR64sp
  // We need to insert COPY instructions, these will later be removed by the
  // RegisterCoalescer
  BuildMI(*MBB, MI, DL, TII->get(AArch64::RDVLI_XI), RegVL_GPR).addImm(1);
  BuildMI(*MBB, MI, DL, TII->get(TargetOpcode::COPY), RegVL_GPRsp)
      .addReg(RegVL_GPR);
 
  BuildMI(*MBB, MI, DL, TII->get(AArch64::ADDSVL_XXI), RegSVL_GPRsp)
      .addReg(RegVL_GPRsp)
      .addImm(-1);
  BuildMI(*MBB, MI, DL, TII->get(TargetOpcode::COPY), RegSVL_GPR)
      .addReg(RegSVL_GPRsp);
 
  const BasicBlock *LLVM_BB = MBB->getBasicBlock();
  MachineFunction::iterator It = ++MBB->getIterator();
  MachineBasicBlock *TrapBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MachineBasicBlock *PassBB = MF->CreateMachineBasicBlock(LLVM_BB);
  MF->insert(It, TrapBB);
  MF->insert(It, PassBB);
 
  // Continue if vector lengths match
  BuildMI(*MBB, MI, DL, TII->get(AArch64::CBZX))
      .addReg(RegSVL_GPR)
      .addMBB(PassBB);
 
  // Transfer rest of current BB to PassBB
  PassBB->splice(PassBB->begin(), MBB,
                 std::next(MachineBasicBlock::iterator(MI)), MBB->end());
  PassBB->transferSuccessorsAndUpdatePHIs(MBB);
 
  // Trap if vector lengths mismatch
  BuildMI(TrapBB, DL, TII->get(AArch64::BRK)).addImm(1);
 
  MBB->addSuccessor(TrapBB);
  MBB->addSuccessor(PassBB);
 
  MI.eraseFromParent();
  return PassBB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitTileLoad(unsigned Opc, unsigned BaseReg,
                                    MachineInstr &MI,
                                    MachineBasicBlock *BB) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineInstrBuilder MIB = BuildMI(*BB, MI, MI.getDebugLoc(), TII->get(Opc));
 
  MIB.addReg(BaseReg + MI.getOperand(0).getImm(), RegState::Define);
  MIB.add(MI.getOperand(1)); // slice index register
  MIB.add(MI.getOperand(2)); // slice index offset
  MIB.add(MI.getOperand(3)); // pg
  MIB.add(MI.getOperand(4)); // base
  MIB.add(MI.getOperand(5)); // offset
 
  MI.eraseFromParent(); // The pseudo is gone now.
  return BB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitFill(MachineInstr &MI, MachineBasicBlock *BB) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineInstrBuilder MIB =
      BuildMI(*BB, MI, MI.getDebugLoc(), TII->get(AArch64::LDR_ZA));
 
  MIB.addReg(AArch64::ZA, RegState::Define);
  MIB.add(MI.getOperand(0)); // Vector select register
  MIB.add(MI.getOperand(1)); // Vector select offset
  MIB.add(MI.getOperand(2)); // Base
  MIB.add(MI.getOperand(1)); // Offset, same as vector select offset
 
  MI.eraseFromParent(); // The pseudo is gone now.
  return BB;
}
 
MachineBasicBlock *AArch64TargetLowering::EmitZTInstr(MachineInstr &MI,
                                                      MachineBasicBlock *BB,
                                                      unsigned Opcode,
                                                      bool Op0IsDef) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineInstrBuilder MIB;
 
  MIB = BuildMI(*BB, MI, MI.getDebugLoc(), TII->get(Opcode))
            .addReg(MI.getOperand(0).getReg(), getDefRegState(Op0IsDef));
  for (unsigned I = 1; I < MI.getNumOperands(); ++I)
    MIB.add(MI.getOperand(I));
 
  MI.eraseFromParent(); // The pseudo is gone now.
  return BB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitZAInstr(unsigned Opc, unsigned BaseReg,
                                   MachineInstr &MI,
                                   MachineBasicBlock *BB) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineInstrBuilder MIB = BuildMI(*BB, MI, MI.getDebugLoc(), TII->get(Opc));
  unsigned StartIdx = 0;
 
  bool HasTile = BaseReg != AArch64::ZA;
  bool HasZPROut = HasTile && MI.getOperand(0).isReg();
  if (HasZPROut) {
    MIB.add(MI.getOperand(StartIdx)); // Output ZPR
    ++StartIdx;
  }
  if (HasTile) {
    MIB.addReg(BaseReg + MI.getOperand(StartIdx).getImm(),
               RegState::Define);                           // Output ZA Tile
    MIB.addReg(BaseReg + MI.getOperand(StartIdx).getImm()); // Input Za Tile
    StartIdx++;
  } else {
    // Avoids all instructions with mnemonic za.<sz>[Reg, Imm,
    if (MI.getOperand(0).isReg() && !MI.getOperand(1).isImm()) {
      MIB.add(MI.getOperand(StartIdx)); // Output ZPR
      ++StartIdx;
    }
    MIB.addReg(BaseReg, RegState::Define).addReg(BaseReg);
  }
  for (unsigned I = StartIdx; I < MI.getNumOperands(); ++I)
    MIB.add(MI.getOperand(I));
 
  MI.eraseFromParent(); // The pseudo is gone now.
  return BB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitZero(MachineInstr &MI, MachineBasicBlock *BB) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineInstrBuilder MIB =
      BuildMI(*BB, MI, MI.getDebugLoc(), TII->get(AArch64::ZERO_M));
  MIB.add(MI.getOperand(0)); // Mask
 
  unsigned Mask = MI.getOperand(0).getImm();
  for (unsigned I = 0; I < 8; I++) {
    if (Mask & (1 << I))
      MIB.addDef(AArch64::ZAD0 + I, RegState::ImplicitDefine);
  }
 
  MI.eraseFromParent(); // The pseudo is gone now.
  return BB;
}
 
MachineBasicBlock *
AArch64TargetLowering::EmitEntryPStateSM(MachineInstr &MI,
                                         MachineBasicBlock *BB) const {
  MachineFunction *MF = BB->getParent();
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  const DebugLoc &DL = MI.getDebugLoc();
  Register ResultReg = MI.getOperand(0).getReg();
  if (MF->getRegInfo().use_empty(ResultReg)) {
    // Nothing to do. Pseudo erased below.
  } else if (Subtarget->hasSME()) {
    BuildMI(*BB, MI, DL, TII->get(AArch64::MRS), ResultReg)
        .addImm(AArch64SysReg::SVCR)
        .addReg(AArch64::VG, RegState::Implicit);
  } else {
    RTLIB::Libcall LC = RTLIB::SMEABI_SME_STATE;
    const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
    BuildMI(*BB, MI, DL, TII->get(AArch64::BL))
        .addExternalSymbol(getLibcallName(LC))
        .addReg(AArch64::X0, RegState::ImplicitDefine)
        .addRegMask(TRI->getCallPreservedMask(*MF, getLibcallCallingConv(LC)));
    BuildMI(*BB, MI, DL, TII->get(TargetOpcode::COPY), ResultReg)
        .addReg(AArch64::X0);
  }
  MI.eraseFromParent();
  return BB;
}
 
// Helper function to find the instruction that defined a virtual register.
// If unable to find such instruction, returns nullptr.
static const MachineInstr *stripVRegCopies(const MachineRegisterInfo &MRI,
                                           Register Reg) {
  while (Reg.isVirtual()) {
    MachineInstr *DefMI = MRI.getVRegDef(Reg);
    assert(DefMI && "Virtual register definition not found");
    unsigned Opcode = DefMI->getOpcode();
 
    if (Opcode == AArch64::COPY) {
      Reg = DefMI->getOperand(1).getReg();
      // Vreg is defined by copying from physreg.
      if (Reg.isPhysical())
        return DefMI;
      continue;
    }
    if (Opcode == AArch64::SUBREG_TO_REG) {
      Reg = DefMI->getOperand(1).getReg();
      continue;
    }
 
    return DefMI;
  }
  return nullptr;
}
 
void AArch64TargetLowering::fixupPtrauthDiscriminator(
    MachineInstr &MI, MachineBasicBlock *BB, MachineOperand &IntDiscOp,
    MachineOperand &AddrDiscOp, const TargetRegisterClass *AddrDiscRC) const {
  const TargetInstrInfo *TII = Subtarget->getInstrInfo();
  MachineRegisterInfo &MRI = MI.getMF()->getRegInfo();
  const DebugLoc &DL = MI.getDebugLoc();
 
  Register AddrDisc = AddrDiscOp.getReg();
  int64_t IntDisc = IntDiscOp.getImm();
  assert(IntDisc == 0 && "Blend components are already expanded");
 
  const MachineInstr *DiscMI = stripVRegCopies(MRI, AddrDisc);
  if (DiscMI) {
    switch (DiscMI->getOpcode()) {
    case AArch64::MOVKXi:
      // blend(addr, imm) which is lowered as "MOVK addr, #imm, #48".
      // #imm should be an immediate and not a global symbol, for example.
      if (DiscMI->getOperand(2).isImm() &&
          DiscMI->getOperand(3).getImm() == 48) {
        AddrDisc = DiscMI->getOperand(1).getReg();
        IntDisc = DiscMI->getOperand(2).getImm();
      }
      break;
    case AArch64::MOVi32imm:
    case AArch64::MOVi64imm:
      // Small immediate integer constant passed via VReg.
      if (DiscMI->getOperand(1).isImm() &&
          isUInt<16>(DiscMI->getOperand(1).getImm())) {
        AddrDisc = AArch64::NoRegister;
        IntDisc = DiscMI->getOperand(1).getImm();
      }
      break;
    }
  }
 
  // For uniformity, always use NoRegister, as XZR is not necessarily contained
  // in the requested register class.
  if (AddrDisc == AArch64::XZR)
    AddrDisc = AArch64::NoRegister;
 
  // Make sure AddrDisc operand respects the register class imposed by MI.
  if (AddrDisc && MRI.getRegClass(AddrDisc) != AddrDiscRC) {
    Register TmpReg = MRI.createVirtualRegister(AddrDiscRC);
    BuildMI(*BB, MI, DL, TII->get(AArch64::COPY), TmpReg).addReg(AddrDisc);
    AddrDisc = TmpReg;
  }
 
  AddrDiscOp.setReg(AddrDisc);
  IntDiscOp.setImm(IntDisc);
}
 
MachineBasicBlock *AArch64TargetLowering::EmitInstrWithCustomInserter(
    MachineInstr &MI, MachineBasicBlock *BB) const {
 
  int SMEOrigInstr = AArch64::getSMEPseudoMap(MI.getOpcode());
  if (SMEOrigInstr != -1) {
    const TargetInstrInfo *TII = Subtarget->getInstrInfo();
    uint64_t SMEMatrixType =
        TII->get(MI.getOpcode()).TSFlags & AArch64::SMEMatrixTypeMask;
    switch (SMEMatrixType) {
    case (AArch64::SMEMatrixArray):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZA, MI, BB);
    case (AArch64::SMEMatrixTileB):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZAB0, MI, BB);
    case (AArch64::SMEMatrixTileH):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZAH0, MI, BB);
    case (AArch64::SMEMatrixTileS):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZAS0, MI, BB);
    case (AArch64::SMEMatrixTileD):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZAD0, MI, BB);
    case (AArch64::SMEMatrixTileQ):
      return EmitZAInstr(SMEOrigInstr, AArch64::ZAQ0, MI, BB);
    }
  }
 
  switch (MI.getOpcode()) {
  default:
#ifndef NDEBUG
    MI.dump();
#endif
    llvm_unreachable("Unexpected instruction for custom inserter!");
  case AArch64::EntryPStateSM:
    return EmitEntryPStateSM(MI, BB);
  case AArch64::F128CSEL:
    return EmitF128CSEL(MI, BB);
  case TargetOpcode::STATEPOINT:
    // STATEPOINT is a pseudo instruction which has no implicit defs/uses
    // while bl call instruction (where statepoint will be lowered at the end)
    // has implicit def. This def is early-clobber as it will be set at
    // the moment of the call and earlier than any use is read.
    // Add this implicit dead def here as a workaround.
    MI.addOperand(*MI.getMF(),
                  MachineOperand::CreateReg(
                      AArch64::LR, /*isDef*/ true,
                      /*isImp*/ true, /*isKill*/ false, /*isDead*/ true,
                      /*isUndef*/ false, /*isEarlyClobber*/ true));
    [[fallthrough]];
  case TargetOpcode::STACKMAP:
  case TargetOpcode::PATCHPOINT:
    return emitPatchPoint(MI, BB);
 
  case TargetOpcode::PATCHABLE_EVENT_CALL:
  case TargetOpcode::PATCHABLE_TYPED_EVENT_CALL:
    return BB;
 
  case AArch64::CATCHRET:
    return EmitLoweredCatchRet(MI, BB);
 
  case AArch64::PROBED_STACKALLOC_DYN:
    return EmitDynamicProbedAlloc(MI, BB);
 
  case AArch64::CHECK_MATCHING_VL_PSEUDO:
    return EmitCheckMatchingVL(MI, BB);
 
  case AArch64::LD1_MXIPXX_H_PSEUDO_B:
    return EmitTileLoad(AArch64::LD1_MXIPXX_H_B, AArch64::ZAB0, MI, BB);
  case AArch64::LD1_MXIPXX_H_PSEUDO_H:
    return EmitTileLoad(AArch64::LD1_MXIPXX_H_H, AArch64::ZAH0, MI, BB);
  case AArch64::LD1_MXIPXX_H_PSEUDO_S:
    return EmitTileLoad(AArch64::LD1_MXIPXX_H_S, AArch64::ZAS0, MI, BB);
  case AArch64::LD1_MXIPXX_H_PSEUDO_D:
    return EmitTileLoad(AArch64::LD1_MXIPXX_H_D, AArch64::ZAD0, MI, BB);
  case AArch64::LD1_MXIPXX_H_PSEUDO_Q:
    return EmitTileLoad(AArch64::LD1_MXIPXX_H_Q, AArch64::ZAQ0, MI, BB);
  case AArch64::LD1_MXIPXX_V_PSEUDO_B:
    return EmitTileLoad(AArch64::LD1_MXIPXX_V_B, AArch64::ZAB0, MI, BB);
  case AArch64::LD1_MXIPXX_V_PSEUDO_H:
    return EmitTileLoad(AArch64::LD1_MXIPXX_V_H, AArch64::ZAH0, MI, BB);
  case AArch64::LD1_MXIPXX_V_PSEUDO_S:
    return EmitTileLoad(AArch64::LD1_MXIPXX_V_S, AArch64::ZAS0, MI, BB);
  case AArch64::LD1_MXIPXX_V_PSEUDO_D:
    return EmitTileLoad(AArch64::LD1_MXIPXX_V_D, AArch64::ZAD0, MI, BB);
  case AArch64::LD1_MXIPXX_V_PSEUDO_Q:
    return EmitTileLoad(AArch64::LD1_MXIPXX_V_Q, AArch64::ZAQ0, MI, BB);
  case AArch64::LDR_ZA_PSEUDO:
    return EmitFill(MI, BB);
  case AArch64::LDR_TX_PSEUDO:
    return EmitZTInstr(MI, BB, AArch64::LDR_TX, /*Op0IsDef=*/true);
  case AArch64::STR_TX_PSEUDO:
    return EmitZTInstr(MI, BB, AArch64::STR_TX, /*Op0IsDef=*/false);
  case AArch64::ZERO_M_PSEUDO:
    return EmitZero(MI, BB);
  case AArch64::ZERO_T_PSEUDO:
    return EmitZTInstr(MI, BB, AArch64::ZERO_T, /*Op0IsDef=*/true);
  case AArch64::MOVT_TIZ_PSEUDO:
    return EmitZTInstr(MI, BB, AArch64::MOVT_TIZ, /*Op0IsDef=*/true);
 
  case AArch64::PAC:
    fixupPtrauthDiscriminator(MI, BB, MI.getOperand(3), MI.getOperand(4),
                              &AArch64::GPR64noipRegClass);
    return BB;
  }
}
 
//===----------------------------------------------------------------------===//
// AArch64 Lowering private implementation.
//===----------------------------------------------------------------------===//
 
//===----------------------------------------------------------------------===//
// Lowering Code
//===----------------------------------------------------------------------===//
 
// Forward declarations of SVE fixed length lowering helpers
static EVT getContainerForFixedLengthVector(SelectionDAG &DAG, EVT VT);
static SDValue convertToScalableVector(SelectionDAG &DAG, EVT VT, SDValue V);
static SDValue convertFromScalableVector(SelectionDAG &DAG, EVT VT, SDValue V);
static SDValue convertFixedMaskToScalableVector(SDValue Mask,
                                                SelectionDAG &DAG);
static SDValue getPredicateForVector(SelectionDAG &DAG, SDLoc &DL, EVT VT);
static SDValue getPredicateForScalableVector(SelectionDAG &DAG, SDLoc &DL,
                                             EVT VT);
static SDValue getSVEPredicateBitCast(EVT VT, SDValue Op, SelectionDAG &DAG);
 
/// isZerosVector - Check whether SDNode N is a zero-filled vector.
static bool isZerosVector(const SDNode *N) {
  // Look through a bit convert.
  while (N->getOpcode() == ISD::BITCAST)
    N = N->getOperand(0).getNode();
 
  if (ISD::isConstantSplatVectorAllZeros(N))
    return true;
 
  if (N->getOpcode() != AArch64ISD::DUP)
    return false;
 
  auto Opnd0 = N->getOperand(0);
  return isNullConstant(Opnd0) || isNullFPConstant(Opnd0);
}
 
static bool isOneVector(SDValue V) {
  return isOneOrOneSplat(V) ||
         (V.getOpcode() == AArch64ISD::DUP && isOneConstant(V.getOperand(0)));
}
 
/// changeIntCCToAArch64CC - Convert a DAG integer condition code to an AArch64
/// CC
static AArch64CC::CondCode changeIntCCToAArch64CC(ISD::CondCode CC,
                                                  SDValue RHS = {}) {
  switch (CC) {
  default:
    llvm_unreachable("Unknown condition code!");
  case ISD::SETNE:
    return AArch64CC::NE;
  case ISD::SETEQ:
    return AArch64CC::EQ;
  case ISD::SETGT:
    return AArch64CC::GT;
  case ISD::SETGE:
    return (RHS && isNullConstant(RHS)) ? AArch64CC::PL : AArch64CC::GE;
  case ISD::SETLT:
    return (RHS && isNullConstant(RHS)) ? AArch64CC::MI : AArch64CC::LT;
  case ISD::SETLE:
    return AArch64CC::LE;
  case ISD::SETUGT:
    return AArch64CC::HI;
  case ISD::SETUGE:
    return AArch64CC::HS;
  case ISD::SETULT:
    return AArch64CC::LO;
  case ISD::SETULE:
    return AArch64CC::LS;
  }
}
 
/// changeFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64 CC.
static void changeFPCCToAArch64CC(ISD::CondCode CC,
                                  AArch64CC::CondCode &CondCode,
                                  AArch64CC::CondCode &CondCode2) {
  CondCode2 = AArch64CC::AL;
  switch (CC) {
  default:
    llvm_unreachable("Unknown FP condition!");
  case ISD::SETEQ:
  case ISD::SETOEQ:
    CondCode = AArch64CC::EQ;
    break;
  case ISD::SETGT:
  case ISD::SETOGT:
    CondCode = AArch64CC::GT;
    break;
  case ISD::SETGE:
  case ISD::SETOGE:
    CondCode = AArch64CC::GE;
    break;
  case ISD::SETOLT:
    CondCode = AArch64CC::MI;
    break;
  case ISD::SETOLE:
    CondCode = AArch64CC::LS;
    break;
  case ISD::SETONE:
    CondCode = AArch64CC::MI;
    CondCode2 = AArch64CC::GT;
    break;
  case ISD::SETO:
    CondCode = AArch64CC::VC;
    break;
  case ISD::SETUO:
    CondCode = AArch64CC::VS;
    break;
  case ISD::SETUEQ:
    CondCode = AArch64CC::EQ;
    CondCode2 = AArch64CC::VS;
    break;
  case ISD::SETUGT:
    CondCode = AArch64CC::HI;
    break;
  case ISD::SETUGE:
    CondCode = AArch64CC::PL;
    break;
  case ISD::SETLT:
  case ISD::SETULT:
    CondCode = AArch64CC::LT;
    break;
  case ISD::SETLE:
  case ISD::SETULE:
    CondCode = AArch64CC::LE;
    break;
  case ISD::SETNE:
  case ISD::SETUNE:
    CondCode = AArch64CC::NE;
    break;
  }
}
 
/// Convert a DAG fp condition code to an AArch64 CC.
/// This differs from changeFPCCToAArch64CC in that it returns cond codes that
/// should be AND'ed instead of OR'ed.
static void changeFPCCToANDAArch64CC(ISD::CondCode CC,
                                     AArch64CC::CondCode &CondCode,
                                     AArch64CC::CondCode &CondCode2) {
  CondCode2 = AArch64CC::AL;
  switch (CC) {
  default:
    changeFPCCToAArch64CC(CC, CondCode, CondCode2);
    assert(CondCode2 == AArch64CC::AL);
    break;
  case ISD::SETONE:
    // (a one b)
    // == ((a olt b) || (a ogt b))
    // == ((a ord b) && (a une b))
    CondCode = AArch64CC::VC;
    CondCode2 = AArch64CC::NE;
    break;
  case ISD::SETUEQ:
    // (a ueq b)
    // == ((a uno b) || (a oeq b))
    // == ((a ule b) && (a uge b))
    CondCode = AArch64CC::PL;
    CondCode2 = AArch64CC::LE;
    break;
  }
}
 
/// changeVectorFPCCToAArch64CC - Convert a DAG fp condition code to an AArch64
/// CC usable with the vector instructions. Fewer operations are available
/// without a real NZCV register, so we have to use less efficient combinations
/// to get the same effect.
static void changeVectorFPCCToAArch64CC(ISD::CondCode CC,
                                        AArch64CC::CondCode &CondCode,
                                        AArch64CC::CondCode &CondCode2,
                                        bool &Invert) {
  Invert = false;
  switch (CC) {
  default:
    // Mostly the scalar mappings work fine.
    changeFPCCToAArch64CC(CC, CondCode, CondCode2);
    break;
  case ISD::SETUO:
    Invert = true;
    [[fallthrough]];
  case ISD::SETO:
    CondCode = AArch64CC::MI;
    CondCode2 = AArch64CC::GE;
    break;
  case ISD::SETLE:
    CondCode = AArch64CC::LS;
    CondCode2 = AArch64CC::AL;
    break;
  case ISD::SETLT:
    CondCode = AArch64CC::MI;
    CondCode2 = AArch64CC::AL;
    break;
  case ISD::SETUEQ:
  case ISD::SETULT:
  case ISD::SETULE:
  case ISD::SETUGT:
  case ISD::SETUGE:
    // All of the compare-mask comparisons are ordered, but we can switch
    // between the two by a double inversion. E.g. ULE == !OGT.
    Invert = true;
    changeFPCCToAArch64CC(getSetCCInverse(CC, /* FP inverse */ MVT::f32),
                          CondCode, CondCode2);
    break;
  }
}
 
/// Like SelectionDAG::getCondCode(), but for AArch64 condition codes.
static SDValue getCondCode(SelectionDAG &DAG, AArch64CC::CondCode CC) {
  // TODO: Should be TargetConstant (need to s/imm/timm in patterns).
  return DAG.getConstant(CC, SDLoc(), CondCodeVT);
}
 
static bool isLegalArithImmed(uint64_t C) {
  // Matches AArch64DAGToDAGISel::SelectArithImmed().
  bool IsLegal = (C >> 12 == 0) || ((C & 0xFFFULL) == 0 && C >> 24 == 0);
  LLVM_DEBUG(dbgs() << "Is imm " << C
                    << " legal: " << (IsLegal ? "yes\n" : "no\n"));
  return IsLegal;
}
 
bool isLegalCmpImmed(APInt C) {
  // Works for negative immediates too, as it can be written as an ADDS
  // instruction with a negated immediate.
  return isLegalArithImmed(C.abs().getZExtValue());
}
 
unsigned numberOfInstrToLoadImm(APInt C) {
  uint64_t Imm = C.getZExtValue();
  SmallVector<AArch64_IMM::ImmInsnModel> Insn;
  AArch64_IMM::expandMOVImm(Imm, 32, Insn);
  return Insn.size();
}
 
static bool isSafeSignedCMN(SDValue Op, SelectionDAG &DAG) {
  // 0 - INT_MIN sign wraps, so no signed wrap means cmn is safe.
  if (Op->getFlags().hasNoSignedWrap())
    return true;
 
  // We can still figure out if the second operand is safe to use
  // in a CMN instruction by checking if it is known to be not the minimum
  // signed value. If it is not, then we can safely use CMN.
  // Note: We can eventually remove this check and simply rely on
  // Op->getFlags().hasNoSignedWrap() once SelectionDAG/ISelLowering
  // consistently sets them appropriately when making said nodes.
 
  KnownBits KnownSrc = DAG.computeKnownBits(Op.getOperand(1));
  return !KnownSrc.getSignedMinValue().isMinSignedValue();
}
 
// Can a (CMP op1, (sub 0, op2) be turned into a CMN instruction on
// the grounds that "op1 - (-op2) == op1 + op2" ? Not always, the C and V flags
// can be set differently by this operation. It comes down to whether
// "SInt(~op2)+1 == SInt(~op2+1)" (and the same for UInt). If they are then
// everything is fine. If not then the optimization is wrong. Thus general
// comparisons are only valid if op2 != 0 and op2 != INT_MIN.
//
// So, finally, the only LLVM-native comparisons that don't mention C or V
// are the ones that aren't unsigned comparisons. They're the only ones we can
// safely use CMN for in the absence of information about op2.
static bool isCMN(SDValue Op, ISD::CondCode CC, SelectionDAG &DAG) {
  return Op.getOpcode() == ISD::SUB && isNullConstant(Op.getOperand(0)) &&
         (isIntEqualitySetCC(CC) ||
          (isUnsignedIntSetCC(CC) && DAG.isKnownNeverZero(Op.getOperand(1))) ||
          (isSignedIntSetCC(CC) && isSafeSignedCMN(Op, DAG)));
}
 
static SDValue emitStrictFPComparison(SDValue LHS, SDValue RHS, const SDLoc &DL,
                                      SelectionDAG &DAG, SDValue Chain,
                                      bool IsSignaling) {
  EVT VT = LHS.getValueType();
  assert(VT != MVT::f128);
 
  const bool FullFP16 = DAG.getSubtarget<AArch64Subtarget>().hasFullFP16();
 
  if ((VT == MVT::f16 && !FullFP16) || VT == MVT::bf16) {
    LHS = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {MVT::f32, MVT::Other},
                      {Chain, LHS});
    RHS = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {MVT::f32, MVT::Other},
                      {LHS.getValue(1), RHS});
    Chain = RHS.getValue(1);
  }
  unsigned Opcode =
      IsSignaling ? AArch64ISD::STRICT_FCMPE : AArch64ISD::STRICT_FCMP;
  return DAG.getNode(Opcode, DL, {FlagsVT, MVT::Other}, {Chain, LHS, RHS});
}
 
static SDValue emitComparison(SDValue LHS, SDValue RHS, ISD::CondCode CC,
                              const SDLoc &DL, SelectionDAG &DAG) {
  EVT VT = LHS.getValueType();
  const bool FullFP16 = DAG.getSubtarget<AArch64Subtarget>().hasFullFP16();
 
  if (VT.isFloatingPoint()) {
    assert(VT != MVT::f128);
    if ((VT == MVT::f16 && !FullFP16) || VT == MVT::bf16) {
      LHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, LHS);
      RHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, RHS);
    }
    return DAG.getNode(AArch64ISD::FCMP, DL, FlagsVT, LHS, RHS);
  }
 
  // The CMP instruction is just an alias for SUBS, and representing it as
  // SUBS means that it's possible to get CSE with subtract operations.
  // A later phase can perform the optimization of setting the destination
  // register to WZR/XZR if it ends up being unused.
  unsigned Opcode = AArch64ISD::SUBS;
 
  if (isCMN(RHS, CC, DAG)) {
    // Can we combine a (CMP op1, (sub 0, op2) into a CMN instruction ?
    Opcode = AArch64ISD::ADDS;
    RHS = RHS.getOperand(1);
  } else if (LHS.getOpcode() == ISD::SUB && isNullConstant(LHS.getOperand(0)) &&
             isIntEqualitySetCC(CC)) {
    // As we are looking for EQ/NE compares, the operands can be commuted ; can
    // we combine a (CMP (sub 0, op1), op2) into a CMN instruction ?
    Opcode = AArch64ISD::ADDS;
    LHS = LHS.getOperand(1);
  } else if (isNullConstant(RHS) && !isUnsignedIntSetCC(CC)) {
    if (LHS.getOpcode() == ISD::AND) {
      // Similarly, (CMP (and X, Y), 0) can be implemented with a TST
      // (a.k.a. ANDS) except that the flags are only guaranteed to work for one
      // of the signed comparisons.
      const SDValue ANDSNode =
          DAG.getNode(AArch64ISD::ANDS, DL, DAG.getVTList(VT, FlagsVT),
                      LHS.getOperand(0), LHS.getOperand(1));
      // Replace all users of (and X, Y) with newly generated (ands X, Y)
      DAG.ReplaceAllUsesWith(LHS, ANDSNode);
      return ANDSNode.getValue(1);
    } else if (LHS.getOpcode() == AArch64ISD::ANDS) {
      // Use result of ANDS
      return LHS.getValue(1);
    }
  }
 
  return DAG.getNode(Opcode, DL, DAG.getVTList(VT, FlagsVT), LHS, RHS)
      .getValue(1);
}
 
/// \defgroup AArch64CCMP CMP;CCMP matching
///
/// These functions deal with the formation of CMP;CCMP;... sequences.
/// The CCMP/CCMN/FCCMP/FCCMPE instructions allow the conditional execution of
/// a comparison. They set the NZCV flags to a predefined value if their
/// predicate is false. This allows to express arbitrary conjunctions, for
/// example "cmp 0 (and (setCA (cmp A)) (setCB (cmp B)))"
/// expressed as:
///   cmp A
///   ccmp B, inv(CB), CA
///   check for CB flags
///
/// This naturally lets us implement chains of AND operations with SETCC
/// operands. And we can even implement some other situations by transforming
/// them:
///   - We can implement (NEG SETCC) i.e. negating a single comparison by
///     negating the flags used in a CCMP/FCCMP operations.
///   - We can negate the result of a whole chain of CMP/CCMP/FCCMP operations
///     by negating the flags we test for afterwards. i.e.
///     NEG (CMP CCMP CCCMP ...) can be implemented.
///   - Note that we can only ever negate all previously processed results.
///     What we can not implement by flipping the flags to test is a negation
///     of two sub-trees (because the negation affects all sub-trees emitted so
///     far, so the 2nd sub-tree we emit would also affect the first).
/// With those tools we can implement some OR operations:
///   - (OR (SETCC A) (SETCC B)) can be implemented via:
///     NEG (AND (NEG (SETCC A)) (NEG (SETCC B)))
///   - After transforming OR to NEG/AND combinations we may be able to use NEG
///     elimination rules from earlier to implement the whole thing as a
///     CCMP/FCCMP chain.
///
/// As complete example:
///     or (or (setCA (cmp A)) (setCB (cmp B)))
///        (and (setCC (cmp C)) (setCD (cmp D)))"
/// can be reassociated to:
///     or (and (setCC (cmp C)) setCD (cmp D))
//         (or (setCA (cmp A)) (setCB (cmp B)))
/// can be transformed to:
///     not (and (not (and (setCC (cmp C)) (setCD (cmp D))))
///              (and (not (setCA (cmp A)) (not (setCB (cmp B))))))"
/// which can be implemented as:
///   cmp C
///   ccmp D, inv(CD), CC
///   ccmp A, CA, inv(CD)
///   ccmp B, CB, inv(CA)
///   check for CB flags
///
/// A counterexample is "or (and A B) (and C D)" which translates to
/// not (and (not (and (not A) (not B))) (not (and (not C) (not D)))), we
/// can only implement 1 of the inner (not) operations, but not both!
/// @{
 
/// Create a conditional comparison; Use CCMP, CCMN or FCCMP as appropriate.
static SDValue emitConditionalComparison(SDValue LHS, SDValue RHS,
                                         ISD::CondCode CC, SDValue CCOp,
                                         AArch64CC::CondCode Predicate,
                                         AArch64CC::CondCode OutCC,
                                         const SDLoc &DL, SelectionDAG &DAG) {
  unsigned Opcode = 0;
  const bool FullFP16 = DAG.getSubtarget<AArch64Subtarget>().hasFullFP16();
 
  if (LHS.getValueType().isFloatingPoint()) {
    assert(LHS.getValueType() != MVT::f128);
    if ((LHS.getValueType() == MVT::f16 && !FullFP16) ||
        LHS.getValueType() == MVT::bf16) {
      LHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, LHS);
      RHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, RHS);
    }
    Opcode = AArch64ISD::FCCMP;
  } else if (ConstantSDNode *Const = dyn_cast<ConstantSDNode>(RHS)) {
    APInt Imm = Const->getAPIntValue();
    if (Imm.isNegative() && Imm.sgt(-32)) {
      Opcode = AArch64ISD::CCMN;
      RHS = DAG.getConstant(Imm.abs(), DL, Const->getValueType(0));
    }
  } else if (isCMN(RHS, CC, DAG)) {
    Opcode = AArch64ISD::CCMN;
    RHS = RHS.getOperand(1);
  } else if (LHS.getOpcode() == ISD::SUB && isNullConstant(LHS.getOperand(0)) &&
             isIntEqualitySetCC(CC)) {
    // As we are looking for EQ/NE compares, the operands can be commuted ; can
    // we combine a (CCMP (sub 0, op1), op2) into a CCMN instruction ?
    Opcode = AArch64ISD::CCMN;
    LHS = LHS.getOperand(1);
  }
  if (Opcode == 0)
    Opcode = AArch64ISD::CCMP;
 
  SDValue Condition = getCondCode(DAG, Predicate);
  AArch64CC::CondCode InvOutCC = AArch64CC::getInvertedCondCode(OutCC);
  unsigned NZCV = AArch64CC::getNZCVToSatisfyCondCode(InvOutCC);
  SDValue NZCVOp = DAG.getConstant(NZCV, DL, MVT::i32);
  return DAG.getNode(Opcode, DL, FlagsVT, LHS, RHS, NZCVOp, Condition, CCOp);
}
 
/// Returns true if @p Val is a tree of AND/OR/SETCC operations that can be
/// expressed as a conjunction. See \ref AArch64CCMP.
/// \param CanNegate    Set to true if we can negate the whole sub-tree just by
///                     changing the conditions on the SETCC tests.
///                     (this means we can call emitConjunctionRec() with
///                      Negate==true on this sub-tree)
/// \param MustBeFirst  Set to true if this subtree needs to be negated and we
///                     cannot do the negation naturally. We are required to
///                     emit the subtree first in this case.
/// \param PreferFirst  Set to true if processing this subtree first may
///                     result in more efficient code.
/// \param WillNegate   Is true if are called when the result of this
///                     subexpression must be negated. This happens when the
///                     outer expression is an OR. We can use this fact to know
///                     that we have a double negation (or (or ...) ...) that
///                     can be implemented for free.
static bool canEmitConjunction(SelectionDAG &DAG, const SDValue Val,
                               bool &CanNegate, bool &MustBeFirst,
                               bool &PreferFirst, bool WillNegate,
                               unsigned Depth = 0) {
  if (!Val.hasOneUse())
    return false;
  unsigned Opcode = Val->getOpcode();
  if (Opcode == ISD::SETCC) {
    EVT VT = Val->getOperand(0).getValueType();
    if (VT == MVT::f128)
      return false;
    CanNegate = true;
    MustBeFirst = false;
    // Designate this operation as a preferred first operation if the result
    // of a SUB operation can be reused.
    PreferFirst = DAG.doesNodeExist(ISD::SUB, DAG.getVTList(VT),
                                    {Val->getOperand(0), Val->getOperand(1)});
    return true;
  }
  // Protect against exponential runtime and stack overflow.
  if (Depth > 6)
    return false;
  if (Opcode == ISD::AND || Opcode == ISD::OR) {
    bool IsOR = Opcode == ISD::OR;
    SDValue O0 = Val->getOperand(0);
    SDValue O1 = Val->getOperand(1);
    bool CanNegateL;
    bool MustBeFirstL;
    bool PreferFirstL;
    if (!canEmitConjunction(DAG, O0, CanNegateL, MustBeFirstL, PreferFirstL,
                            IsOR, Depth + 1))
      return false;
    bool CanNegateR;
    bool MustBeFirstR;
    bool PreferFirstR;
    if (!canEmitConjunction(DAG, O1, CanNegateR, MustBeFirstR, PreferFirstR,
                            IsOR, Depth + 1))
      return false;
 
    if (MustBeFirstL && MustBeFirstR)
      return false;
 
    if (IsOR) {
      // For an OR expression we need to be able to naturally negate at least
      // one side or we cannot do the transformation at all.
      if (!CanNegateL && !CanNegateR)
        return false;
      // If we the result of the OR will be negated and we can naturally negate
      // the leaves, then this sub-tree as a whole negates naturally.
      CanNegate = WillNegate && CanNegateL && CanNegateR;
      // If we cannot naturally negate the whole sub-tree, then this must be
      // emitted first.
      MustBeFirst = !CanNegate;
    } else {
      assert(Opcode == ISD::AND && "Must be OR or AND");
      // We cannot naturally negate an AND operation.
      CanNegate = false;
      MustBeFirst = MustBeFirstL || MustBeFirstR;
    }
    PreferFirst = PreferFirstL || PreferFirstR;
    return true;
  }
  return false;
}
 
/// Emit conjunction or disjunction tree with the CMP/FCMP followed by a chain
/// of CCMP/CFCMP ops. See @ref AArch64CCMP.
/// Tries to transform the given i1 producing node @p Val to a series compare
/// and conditional compare operations. @returns an NZCV flags producing node
/// and sets @p OutCC to the flags that should be tested or returns SDValue() if
/// transformation was not possible.
/// \p Negate is true if we want this sub-tree being negated just by changing
/// SETCC conditions.
static SDValue emitConjunctionRec(SelectionDAG &DAG, SDValue Val,
    AArch64CC::CondCode &OutCC, bool Negate, SDValue CCOp,
    AArch64CC::CondCode Predicate) {
  // We're at a tree leaf, produce a conditional comparison operation.
  unsigned Opcode = Val->getOpcode();
  if (Opcode == ISD::SETCC) {
    SDValue LHS = Val->getOperand(0);
    SDValue RHS = Val->getOperand(1);
    ISD::CondCode CC = cast<CondCodeSDNode>(Val->getOperand(2))->get();
    bool isInteger = LHS.getValueType().isInteger();
    if (Negate)
      CC = getSetCCInverse(CC, LHS.getValueType());
    SDLoc DL(Val);
    // Determine OutCC and handle FP special case.
    if (isInteger) {
      OutCC = changeIntCCToAArch64CC(CC, RHS);
    } else {
      assert(LHS.getValueType().isFloatingPoint());
      AArch64CC::CondCode ExtraCC;
      changeFPCCToANDAArch64CC(CC, OutCC, ExtraCC);
      // Some floating point conditions can't be tested with a single condition
      // code. Construct an additional comparison in this case.
      if (ExtraCC != AArch64CC::AL) {
        SDValue ExtraCmp;
        if (!CCOp.getNode())
          ExtraCmp = emitComparison(LHS, RHS, CC, DL, DAG);
        else
          ExtraCmp = emitConditionalComparison(LHS, RHS, CC, CCOp, Predicate,
                                               ExtraCC, DL, DAG);
        CCOp = ExtraCmp;
        Predicate = ExtraCC;
      }
    }
 
    // Produce a normal comparison if we are first in the chain
    if (!CCOp)
      return emitComparison(LHS, RHS, CC, DL, DAG);
    // Otherwise produce a ccmp.
    return emitConditionalComparison(LHS, RHS, CC, CCOp, Predicate, OutCC, DL,
                                     DAG);
  }
  assert(Val->hasOneUse() && "Valid conjunction/disjunction tree");
 
  bool IsOR = Opcode == ISD::OR;
 
  SDValue LHS = Val->getOperand(0);
  bool CanNegateL;
  bool MustBeFirstL;
  bool PreferFirstL;
  bool ValidL = canEmitConjunction(DAG, LHS, CanNegateL, MustBeFirstL,
                                   PreferFirstL, IsOR);
  assert(ValidL && "Valid conjunction/disjunction tree");
  (void)ValidL;
 
  SDValue RHS = Val->getOperand(1);
  bool CanNegateR;
  bool MustBeFirstR;
  bool PreferFirstR;
  bool ValidR = canEmitConjunction(DAG, RHS, CanNegateR, MustBeFirstR,
                                   PreferFirstR, IsOR);
  assert(ValidR && "Valid conjunction/disjunction tree");
  (void)ValidR;
 
  bool ShouldFirstL = PreferFirstL && !PreferFirstR && !MustBeFirstR;
 
  // Swap sub-tree that must or should come first to the right side.
  if (MustBeFirstL || ShouldFirstL) {
    assert(!MustBeFirstR && "Valid conjunction/disjunction tree");
    std::swap(LHS, RHS);
    std::swap(CanNegateL, CanNegateR);
    std::swap(MustBeFirstL, MustBeFirstR);
  }
 
  bool NegateR;
  bool NegateAfterR;
  bool NegateL;
  bool NegateAfterAll;
  if (Opcode == ISD::OR) {
    // Swap the sub-tree that we can negate naturally to the left.
    if (!CanNegateL) {
      assert(CanNegateR && "at least one side must be negatable");
      assert(!MustBeFirstR && "invalid conjunction/disjunction tree");
      assert(!Negate);
      std::swap(LHS, RHS);
      NegateR = false;
      NegateAfterR = true;
    } else {
      // Negate the left sub-tree if possible, otherwise negate the result.
      NegateR = CanNegateR;
      NegateAfterR = !CanNegateR;
    }
    NegateL = true;
    NegateAfterAll = !Negate;
  } else {
    assert(Opcode == ISD::AND && "Valid conjunction/disjunction tree");
    assert(!Negate && "Valid conjunction/disjunction tree");
 
    NegateL = false;
    NegateR = false;
    NegateAfterR = false;
    NegateAfterAll = false;
  }
 
  // Emit sub-trees.
  AArch64CC::CondCode RHSCC;
  SDValue CmpR = emitConjunctionRec(DAG, RHS, RHSCC, NegateR, CCOp, Predicate);
  if (NegateAfterR)
    RHSCC = AArch64CC::getInvertedCondCode(RHSCC);
  SDValue CmpL = emitConjunctionRec(DAG, LHS, OutCC, NegateL, CmpR, RHSCC);
  if (NegateAfterAll)
    OutCC = AArch64CC::getInvertedCondCode(OutCC);
  return CmpL;
}
 
/// Emit expression as a conjunction (a series of CCMP/CFCMP ops).
/// In some cases this is even possible with OR operations in the expression.
/// See \ref AArch64CCMP.
/// \see emitConjunctionRec().
static SDValue emitConjunction(SelectionDAG &DAG, SDValue Val,
                               AArch64CC::CondCode &OutCC) {
  bool DummyCanNegate;
  bool DummyMustBeFirst;
  bool DummyPreferFirst;
  if (!canEmitConjunction(DAG, Val, DummyCanNegate, DummyMustBeFirst,
                          DummyPreferFirst, false))
    return SDValue();
 
  return emitConjunctionRec(DAG, Val, OutCC, false, SDValue(), AArch64CC::AL);
}
 
/// @}
 
/// Returns how profitable it is to fold a comparison's operand's shift and/or
/// extension operations.
static unsigned getCmpOperandFoldingProfit(SDValue Op) {
  auto isSupportedExtend = [&](SDValue V) {
    if (V.getOpcode() == ISD::SIGN_EXTEND_INREG)
      return true;
 
    if (V.getOpcode() == ISD::AND)
      if (ConstantSDNode *MaskCst = dyn_cast<ConstantSDNode>(V.getOperand(1))) {
        uint64_t Mask = MaskCst->getZExtValue();
        return (Mask == 0xFF || Mask == 0xFFFF || Mask == 0xFFFFFFFF);
      }
 
    return false;
  };
 
  if (!Op.hasOneUse())
    return 0;
 
  if (isSupportedExtend(Op))
    return 1;
 
  unsigned Opc = Op.getOpcode();
  if (Opc == ISD::SHL || Opc == ISD::SRL || Opc == ISD::SRA)
    if (ConstantSDNode *ShiftCst = dyn_cast<ConstantSDNode>(Op.getOperand(1))) {
      uint64_t Shift = ShiftCst->getZExtValue();
      if (isSupportedExtend(Op.getOperand(0)))
        return (Shift <= 4) ? 2 : 1;
      EVT VT = Op.getValueType();
      if ((VT == MVT::i32 && Shift <= 31) || (VT == MVT::i64 && Shift <= 63))
        return 1;
    }
 
  return 0;
}
 
// emitComparison() converts comparison with one or negative one to comparison
// with 0. Note that this only works for signed comparisons because of how ANDS
// works.
static bool shouldBeAdjustedToZero(SDValue LHS, APInt C, ISD::CondCode &CC) {
  // Only works for ANDS and AND.
  if (LHS.getOpcode() != ISD::AND && LHS.getOpcode() != AArch64ISD::ANDS)
    return false;
 
  if (C.isOne() && (CC == ISD::SETLT || CC == ISD::SETGE)) {
    CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
    return true;
  }
 
  if (C.isAllOnes() && (CC == ISD::SETLE || CC == ISD::SETGT)) {
    CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
    return true;
  }
 
  return false;
}
 
static SDValue getAArch64Cmp(SDValue LHS, SDValue RHS, ISD::CondCode CC,
                             SDValue &AArch64cc, SelectionDAG &DAG,
                             const SDLoc &DL) {
  if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS.getNode())) {
    EVT VT = RHS.getValueType();
    APInt C = RHSC->getAPIntValue();
    // shouldBeAdjustedToZero is a special case to better fold with
    // emitComparison().
    if (shouldBeAdjustedToZero(LHS, C, CC)) {
      // Adjust the constant to zero.
      // CC has already been adjusted.
      RHS = DAG.getConstant(0, DL, VT);
    } else if (!isLegalCmpImmed(C)) {
      unsigned NumImmForC = numberOfInstrToLoadImm(C);
      // Constant does not fit, try adjusting it by one?
      switch (CC) {
      default:
        break;
      case ISD::SETLT:
      case ISD::SETGE:
        if (!C.isMinSignedValue()) {
          APInt CMinusOne = C - 1;
          if (isLegalCmpImmed(CMinusOne) ||
              (NumImmForC > numberOfInstrToLoadImm(CMinusOne))) {
            CC = (CC == ISD::SETLT) ? ISD::SETLE : ISD::SETGT;
            RHS = DAG.getConstant(CMinusOne, DL, VT);
          }
        }
        break;
      case ISD::SETULT:
      case ISD::SETUGE: {
        // C is not 0 because it is a legal immediate.
        assert(!C.isZero() && "C should not be zero here");
        APInt CMinusOne = C - 1;
        if (isLegalCmpImmed(CMinusOne) ||
            (NumImmForC > numberOfInstrToLoadImm(CMinusOne))) {
          CC = (CC == ISD::SETULT) ? ISD::SETULE : ISD::SETUGT;
          RHS = DAG.getConstant(CMinusOne, DL, VT);
        }
        break;
      }
      case ISD::SETLE:
      case ISD::SETGT:
        if (!C.isMaxSignedValue()) {
          APInt CPlusOne = C + 1;
          if (isLegalCmpImmed(CPlusOne) ||
              (NumImmForC > numberOfInstrToLoadImm(CPlusOne))) {
            CC = (CC == ISD::SETLE) ? ISD::SETLT : ISD::SETGE;
            RHS = DAG.getConstant(CPlusOne, DL, VT);
          }
        }
        break;
      case ISD::SETULE:
      case ISD::SETUGT: {
        if (!C.isAllOnes()) {
          APInt CPlusOne = C + 1;
          if (isLegalCmpImmed(CPlusOne) ||
              (NumImmForC > numberOfInstrToLoadImm(CPlusOne))) {
            CC = (CC == ISD::SETULE) ? ISD::SETULT : ISD::SETUGE;
            RHS = DAG.getConstant(CPlusOne, DL, VT);
          }
        }
        break;
      }
      }
    }
  }
 
  // Comparisons are canonicalized so that the RHS operand is simpler than the
  // LHS one, the extreme case being when RHS is an immediate. However, AArch64
  // can fold some shift+extend operations on the RHS operand, so swap the
  // operands if that can be done.
  //
  // For example:
  //    lsl     w13, w11, #1
  //    cmp     w13, w12
  // can be turned into:
  //    cmp     w12, w11, lsl #1
  if (!isa<ConstantSDNode>(RHS) || !isLegalCmpImmed(RHS->getAsAPIntVal())) {
    bool LHSIsCMN = isCMN(LHS, CC, DAG);
    bool RHSIsCMN = isCMN(RHS, CC, DAG);
    SDValue TheLHS = LHSIsCMN ? LHS.getOperand(1) : LHS;
    SDValue TheRHS = RHSIsCMN ? RHS.getOperand(1) : RHS;
 
    if (getCmpOperandFoldingProfit(TheLHS) + (LHSIsCMN ? 1 : 0) >
        getCmpOperandFoldingProfit(TheRHS) + (RHSIsCMN ? 1 : 0)) {
      std::swap(LHS, RHS);
      CC = ISD::getSetCCSwappedOperands(CC);
    }
  }
 
  SDValue Cmp;
  AArch64CC::CondCode AArch64CC;
  if (isIntEqualitySetCC(CC) && isa<ConstantSDNode>(RHS)) {
    const ConstantSDNode *RHSC = cast<ConstantSDNode>(RHS);
 
    // The imm operand of ADDS is an unsigned immediate, in the range 0 to 4095.
    // For the i8 operand, the largest immediate is 255, so this can be easily
    // encoded in the compare instruction. For the i16 operand, however, the
    // largest immediate cannot be encoded in the compare.
    // Therefore, use a sign extending load and cmn to avoid materializing the
    // -1 constant. For example,
    // movz w1, #65535
    // ldrh w0, [x0, #0]
    // cmp w0, w1
    // >
    // ldrsh w0, [x0, #0]
    // cmn w0, #1
    // Fundamental, we're relying on the property that (zext LHS) == (zext RHS)
    // if and only if (sext LHS) == (sext RHS). The checks are in place to
    // ensure both the LHS and RHS are truly zero extended and to make sure the
    // transformation is profitable.
    if ((RHSC->getZExtValue() >> 16 == 0) && isa<LoadSDNode>(LHS) &&
        cast<LoadSDNode>(LHS)->getExtensionType() == ISD::ZEXTLOAD &&
        cast<LoadSDNode>(LHS)->getMemoryVT() == MVT::i16 &&
        LHS.getNode()->hasNUsesOfValue(1, 0)) {
      int16_t ValueofRHS = RHS->getAsZExtVal();
      if (ValueofRHS < 0 && isLegalArithImmed(-ValueofRHS)) {
        SDValue SExt =
            DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, LHS.getValueType(), LHS,
                        DAG.getValueType(MVT::i16));
        Cmp = emitComparison(
            SExt, DAG.getSignedConstant(ValueofRHS, DL, RHS.getValueType()), CC,
            DL, DAG);
        AArch64CC = changeIntCCToAArch64CC(CC);
      }
    }
 
    if (!Cmp && (RHSC->isZero() || RHSC->isOne())) {
      if ((Cmp = emitConjunction(DAG, LHS, AArch64CC))) {
        if ((CC == ISD::SETNE) ^ RHSC->isZero())
          AArch64CC = AArch64CC::getInvertedCondCode(AArch64CC);
      }
    }
  }
 
  if (!Cmp) {
    Cmp = emitComparison(LHS, RHS, CC, DL, DAG);
    AArch64CC = changeIntCCToAArch64CC(CC, RHS);
  }
  AArch64cc = getCondCode(DAG, AArch64CC);
  return Cmp;
}
 
static std::pair<SDValue, SDValue>
getAArch64XALUOOp(AArch64CC::CondCode &CC, SDValue Op, SelectionDAG &DAG) {
  assert((Op.getValueType() == MVT::i32 || Op.getValueType() == MVT::i64) &&
         "Unsupported value type");
  SDValue Value, Overflow;
  SDLoc DL(Op);
  SDValue LHS = Op.getOperand(0);
  SDValue RHS = Op.getOperand(1);
  unsigned Opc = 0;
  switch (Op.getOpcode()) {
  default:
    llvm_unreachable("Unknown overflow instruction!");
  case ISD::SADDO:
    Opc = AArch64ISD::ADDS;
    CC = AArch64CC::VS;
    break;
  case ISD::UADDO:
    Opc = AArch64ISD::ADDS;
    CC = AArch64CC::HS;
    break;
  case ISD::SSUBO:
    Opc = AArch64ISD::SUBS;
    CC = AArch64CC::VS;
    break;
  case ISD::USUBO:
    Opc = AArch64ISD::SUBS;
    CC = AArch64CC::LO;
    break;
  // Multiply needs a little bit extra work.
  case ISD::SMULO:
  case ISD::UMULO: {
    CC = AArch64CC::NE;
    bool IsSigned = Op.getOpcode() == ISD::SMULO;
    if (Op.getValueType() == MVT::i32) {
      // Extend to 64-bits, then perform a 64-bit multiply.
      unsigned ExtendOpc = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
      LHS = DAG.getNode(ExtendOpc, DL, MVT::i64, LHS);
      RHS = DAG.getNode(ExtendOpc, DL, MVT::i64, RHS);
      SDValue Mul = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
      Value = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, Mul);
 
      // Check that the result fits into a 32-bit integer.
      SDVTList VTs = DAG.getVTList(MVT::i64, FlagsVT);
      if (IsSigned) {
        // cmp xreg, wreg, sxtw
        SDValue SExtMul = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, Value);
        Overflow =
            DAG.getNode(AArch64ISD::SUBS, DL, VTs, Mul, SExtMul).getValue(1);
      } else {
        // tst xreg, #0xffffffff00000000
        SDValue UpperBits = DAG.getConstant(0xFFFFFFFF00000000, DL, MVT::i64);
        Overflow =
            DAG.getNode(AArch64ISD::ANDS, DL, VTs, Mul, UpperBits).getValue(1);
      }
      break;
    }
    assert(Op.getValueType() == MVT::i64 && "Expected an i64 value type");
    // For the 64 bit multiply
    Value = DAG.getNode(ISD::MUL, DL, MVT::i64, LHS, RHS);
    if (IsSigned) {
      SDValue UpperBits = DAG.getNode(ISD::MULHS, DL, MVT::i64, LHS, RHS);
      SDValue LowerBits = DAG.getNode(ISD::SRA, DL, MVT::i64, Value,
                                      DAG.getConstant(63, DL, MVT::i64));
      // It is important that LowerBits is last, otherwise the arithmetic
      // shift will not be folded into the compare (SUBS).
      SDVTList VTs = DAG.getVTList(MVT::i64, FlagsVT);
      Overflow = DAG.getNode(AArch64ISD::SUBS, DL, VTs, UpperBits, LowerBits)
                     .getValue(1);
    } else {
      SDValue UpperBits = DAG.getNode(ISD::MULHU, DL, MVT::i64, LHS, RHS);
      SDVTList VTs = DAG.getVTList(MVT::i64, FlagsVT);
      Overflow =
          DAG.getNode(AArch64ISD::SUBS, DL, VTs,
                      DAG.getConstant(0, DL, MVT::i64),
                      UpperBits).getValue(1);
    }
    break;
  }
  } // switch (...)
 
  if (Opc) {
    SDVTList VTs = DAG.getVTList(Op->getValueType(0), FlagsVT);
 
    // Emit the AArch64 operation with overflow check.
    Value = DAG.getNode(Opc, DL, VTs, LHS, RHS);
    Overflow = Value.getValue(1);
  }
  return std::make_pair(Value, Overflow);
}
 
SDValue AArch64TargetLowering::LowerXOR(SDValue Op, SelectionDAG &DAG) const {
  if (useSVEForFixedLengthVectorVT(Op.getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerToScalableOp(Op, DAG);
 
  SDValue Sel = Op.getOperand(0);
  SDValue Other = Op.getOperand(1);
  SDLoc DL(Sel);
 
  // If the operand is an overflow checking operation, invert the condition
  // code and kill the Not operation. I.e., transform:
  // (xor (overflow_op_bool, 1))
  //   -->
  // (csel 1, 0, invert(cc), overflow_op_bool)
  // ... which later gets transformed to just a cset instruction with an
  // inverted condition code, rather than a cset + eor sequence.
  if (isOneConstant(Other) && ISD::isOverflowIntrOpRes(Sel)) {
    // Only lower legal XALUO ops.
    if (!DAG.getTargetLoweringInfo().isTypeLegal(Sel->getValueType(0)))
      return SDValue();
 
    SDValue TVal = DAG.getConstant(1, DL, MVT::i32);
    SDValue FVal = DAG.getConstant(0, DL, MVT::i32);
    AArch64CC::CondCode CC;
    SDValue Value, Overflow;
    std::tie(Value, Overflow) = getAArch64XALUOOp(CC, Sel.getValue(0), DAG);
    SDValue CCVal = getCondCode(DAG, getInvertedCondCode(CC));
    return DAG.getNode(AArch64ISD::CSEL, DL, Op.getValueType(), TVal, FVal,
                       CCVal, Overflow);
  }
  // If neither operand is a SELECT_CC, give up.
  if (Sel.getOpcode() != ISD::SELECT_CC)
    std::swap(Sel, Other);
  if (Sel.getOpcode() != ISD::SELECT_CC)
    return Op;
 
  // The folding we want to perform is:
  // (xor x, (select_cc a, b, cc, 0, -1) )
  //   -->
  // (csel x, (xor x, -1), cc ...)
  //
  // The latter will get matched to a CSINV instruction.
 
  ISD::CondCode CC = cast<CondCodeSDNode>(Sel.getOperand(4))->get();
  SDValue LHS = Sel.getOperand(0);
  SDValue RHS = Sel.getOperand(1);
  SDValue TVal = Sel.getOperand(2);
  SDValue FVal = Sel.getOperand(3);
 
  // FIXME: This could be generalized to non-integer comparisons.
  if (LHS.getValueType() != MVT::i32 && LHS.getValueType() != MVT::i64)
    return Op;
 
  ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
  ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
 
  // The values aren't constants, this isn't the pattern we're looking for.
  if (!CFVal || !CTVal)
    return Op;
 
  // We can commute the SELECT_CC by inverting the condition.  This
  // might be needed to make this fit into a CSINV pattern.
  if (CTVal->isAllOnes() && CFVal->isZero()) {
    std::swap(TVal, FVal);
    std::swap(CTVal, CFVal);
    CC = ISD::getSetCCInverse(CC, LHS.getValueType());
  }
 
  // If the constants line up, perform the transform!
  if (CTVal->isZero() && CFVal->isAllOnes()) {
    SDValue CCVal;
    SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, DL);
 
    FVal = Other;
    TVal = DAG.getNode(ISD::XOR, DL, Other.getValueType(), Other,
                       DAG.getAllOnesConstant(DL, Other.getValueType()));
 
    return DAG.getNode(AArch64ISD::CSEL, DL, Sel.getValueType(), FVal, TVal,
                       CCVal, Cmp);
  }
 
  return Op;
}
 
// If Invert is false, sets 'C' bit of NZCV to 0 if value is 0, else sets 'C'
// bit to 1. If Invert is true, sets 'C' bit of NZCV to 1 if value is 0, else
// sets 'C' bit to 0.
static SDValue valueToCarryFlag(SDValue Value, SelectionDAG &DAG, bool Invert) {
  SDLoc DL(Value);
  EVT VT = Value.getValueType();
  SDValue Op0 = Invert ? DAG.getConstant(0, DL, VT) : Value;
  SDValue Op1 = Invert ? Value : DAG.getConstant(1, DL, VT);
  SDValue Cmp =
      DAG.getNode(AArch64ISD::SUBS, DL, DAG.getVTList(VT, FlagsVT), Op0, Op1);
  return Cmp.getValue(1);
}
 
// If Invert is false, value is 1 if 'C' bit of NZCV is 1, else 0.
// If Invert is true, value is 0 if 'C' bit of NZCV is 1, else 1.
static SDValue carryFlagToValue(SDValue Glue, EVT VT, SelectionDAG &DAG,
                                bool Invert) {
  assert(Glue.getResNo() == 1);
  SDLoc DL(Glue);
  SDValue Zero = DAG.getConstant(0, DL, VT);
  SDValue One = DAG.getConstant(1, DL, VT);
  AArch64CC::CondCode Cond = Invert ? AArch64CC::LO : AArch64CC::HS;
  SDValue CC = getCondCode(DAG, Cond);
  return DAG.getNode(AArch64ISD::CSEL, DL, VT, One, Zero, CC, Glue);
}
 
// Value is 1 if 'V' bit of NZCV is 1, else 0
static SDValue overflowFlagToValue(SDValue Glue, EVT VT, SelectionDAG &DAG) {
  assert(Glue.getResNo() == 1);
  SDLoc DL(Glue);
  SDValue Zero = DAG.getConstant(0, DL, VT);
  SDValue One = DAG.getConstant(1, DL, VT);
  SDValue CC = getCondCode(DAG, AArch64CC::VS);
  return DAG.getNode(AArch64ISD::CSEL, DL, VT, One, Zero, CC, Glue);
}
 
// This lowering is inefficient, but it will get cleaned up by
// `foldOverflowCheck`
static SDValue lowerADDSUBO_CARRY(SDValue Op, SelectionDAG &DAG,
                                  unsigned Opcode, bool IsSigned) {
  EVT VT0 = Op.getValue(0).getValueType();
  EVT VT1 = Op.getValue(1).getValueType();
 
  if (VT0 != MVT::i32 && VT0 != MVT::i64)
    return SDValue();
 
  bool InvertCarry = Opcode == AArch64ISD::SBCS;
  SDValue OpLHS = Op.getOperand(0);
  SDValue OpRHS = Op.getOperand(1);
  SDValue OpCarryIn = valueToCarryFlag(Op.getOperand(2), DAG, InvertCarry);
 
  SDLoc DL(Op);
 
  SDValue Sum = DAG.getNode(Opcode, DL, DAG.getVTList(VT0, FlagsVT), OpLHS,
                            OpRHS, OpCarryIn);
 
  SDValue OutFlag =
      IsSigned ? overflowFlagToValue(Sum.getValue(1), VT1, DAG)
               : carryFlagToValue(Sum.getValue(1), VT1, DAG, InvertCarry);
 
  return DAG.getMergeValues({Sum, OutFlag}, DL);
}
 
static SDValue lowerIntNeonIntrinsic(SDValue Op, unsigned Opcode,
                                     SelectionDAG &DAG,
                                     bool LastOperandIsImm = false) {
  if (Op.getValueType().isVector())
    return SDValue();
 
  SDLoc DL(Op);
  SmallVector<SDValue, 2> NewOps;
  const unsigned NumOperands = Op.getNumOperands();
  auto getFloatVT = [](EVT VT) {
    assert((VT == MVT::i32 || VT == MVT::i64) && "Unexpected VT");
    return VT == MVT::i32 ? MVT::f32 : MVT::f64;
  };
  auto bitcastToFloat = [&](SDValue Val) {
    return DAG.getBitcast(getFloatVT(Val.getValueType()), Val);
  };
 
  // Skip first operand as it is intrinsic ID.
  for (unsigned I = 1; I < NumOperands; ++I) {
    SDValue Val = Op.getOperand(I);
    const bool KeepInt = LastOperandIsImm && (I == NumOperands - 1);
    NewOps.push_back(KeepInt ? Val : bitcastToFloat(Val));
  }
  EVT OrigVT = Op.getValueType();
  SDValue OpNode = DAG.getNode(Opcode, DL, getFloatVT(OrigVT), NewOps);
  return DAG.getBitcast(OrigVT, OpNode);
}
 
static SDValue LowerXALUO(SDValue Op, SelectionDAG &DAG) {
  // Let legalize expand this if it isn't a legal type yet.
  if (!DAG.getTargetLoweringInfo().isTypeLegal(Op.getValueType()))
    return SDValue();
 
  SDLoc DL(Op);
  AArch64CC::CondCode CC;
  // The actual operation that sets the overflow or carry flag.
  SDValue Value, Overflow;
  std::tie(Value, Overflow) = getAArch64XALUOOp(CC, Op, DAG);
 
  // We use 0 and 1 as false and true values.
  SDValue TVal = DAG.getConstant(1, DL, MVT::i32);
  SDValue FVal = DAG.getConstant(0, DL, MVT::i32);
 
  // We use an inverted condition, because the conditional select is inverted
  // too. This will allow it to be selected to a single instruction:
  // CSINC Wd, WZR, WZR, invert(cond).
  SDValue CCVal = getCondCode(DAG, getInvertedCondCode(CC));
  Overflow =
      DAG.getNode(AArch64ISD::CSEL, DL, MVT::i32, FVal, TVal, CCVal, Overflow);
 
  return DAG.getMergeValues({Value, Overflow}, DL);
}
 
// Prefetch operands are:
// 1: Address to prefetch
// 2: bool isWrite
// 3: int locality (0 = no locality ... 3 = extreme locality)
// 4: bool isDataCache
static SDValue LowerPREFETCH(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  unsigned IsWrite = Op.getConstantOperandVal(2);
  unsigned Locality = Op.getConstantOperandVal(3);
  unsigned IsData = Op.getConstantOperandVal(4);
 
  bool IsStream = !Locality;
  // When the locality number is set
  if (Locality) {
    // The front-end should have filtered out the out-of-range values
    assert(Locality <= 3 && "Prefetch locality out-of-range");
    // The locality degree is the opposite of the cache speed.
    // Put the number the other way around.
    // The encoding starts at 0 for level 1
    Locality = 3 - Locality;
  }
 
  // built the mask value encoding the expected behavior.
  unsigned PrfOp = (IsWrite << 4) |     // Load/Store bit
                   (!IsData << 3) |     // IsDataCache bit
                   (Locality << 1) |    // Cache level bits
                   (unsigned)IsStream;  // Stream bit
  return DAG.getNode(AArch64ISD::PREFETCH, DL, MVT::Other, Op.getOperand(0),
                     DAG.getTargetConstant(PrfOp, DL, MVT::i32),
                     Op.getOperand(1));
}
 
// Converts SETCC (AND X Y) Z ULT -> SETCC (AND X (Y & ~(Z - 1)) 0 EQ when Y is
// a power of 2. This is then lowered to ANDS X (Y & ~(Z - 1)) instead of SUBS
// (AND X Y) Z which produces a better opt with EmitComparison
static void simplifySetCCIntoEq(ISD::CondCode &CC, SDValue &LHS, SDValue &RHS,
                                SelectionDAG &DAG, const SDLoc DL) {
  if (CC == ISD::SETULT && LHS.getOpcode() == ISD::AND && LHS->hasOneUse()) {
    ConstantSDNode *LHSConstOp = dyn_cast<ConstantSDNode>(LHS.getOperand(1));
    ConstantSDNode *RHSConst = dyn_cast<ConstantSDNode>(RHS);
    if (LHSConstOp && RHSConst) {
      uint64_t LHSConstValue = LHSConstOp->getZExtValue();
      uint64_t RHSConstant = RHSConst->getZExtValue();
      if (isPowerOf2_64(RHSConstant)) {
        uint64_t NewMaskValue = LHSConstValue & ~(RHSConstant - 1);
        LHS =
            DAG.getNode(ISD::AND, DL, LHS.getValueType(), LHS.getOperand(0),
                        DAG.getConstant(NewMaskValue, DL, LHS.getValueType()));
        RHS = DAG.getConstant(0, DL, RHS.getValueType());
        CC = ISD::SETEQ;
      }
    }
  }
}
 
SDValue AArch64TargetLowering::LowerFP_EXTEND(SDValue Op,
                                              SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  if (VT.isScalableVector()) {
    SDValue SrcVal = Op.getOperand(0);
 
    if (VT == MVT::nxv2f64 && SrcVal.getValueType() == MVT::nxv2bf16) {
      // Break conversion in two with the first part converting to f32 and the
      // second using native f32->VT instructions.
      SDLoc DL(Op);
      return DAG.getNode(ISD::FP_EXTEND, DL, VT,
                         DAG.getNode(ISD::FP_EXTEND, DL, MVT::nxv2f32, SrcVal));
    }
 
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FP_EXTEND_MERGE_PASSTHRU);
  }
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthFPExtendToSVE(Op, DAG);
 
  bool IsStrict = Op->isStrictFPOpcode();
  SDValue Op0 = Op.getOperand(IsStrict ? 1 : 0);
  EVT Op0VT = Op0.getValueType();
  if (VT == MVT::f64) {
    // FP16->FP32 extends are legal for v32 and v4f32.
    if (Op0VT == MVT::f32 || Op0VT == MVT::f16)
      return Op;
    // Split bf16->f64 extends into two fpextends.
    if (Op0VT == MVT::bf16 && IsStrict) {
      SDValue Ext1 =
          DAG.getNode(ISD::STRICT_FP_EXTEND, SDLoc(Op), {MVT::f32, MVT::Other},
                      {Op0, Op.getOperand(0)});
      return DAG.getNode(ISD::STRICT_FP_EXTEND, SDLoc(Op), {VT, MVT::Other},
                         {Ext1, Ext1.getValue(1)});
    }
    if (Op0VT == MVT::bf16)
      return DAG.getNode(ISD::FP_EXTEND, SDLoc(Op), VT,
                         DAG.getNode(ISD::FP_EXTEND, SDLoc(Op), MVT::f32, Op0));
    return SDValue();
  }
 
  assert(Op.getValueType() == MVT::f128 && "Unexpected lowering");
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerFP_ROUND(SDValue Op,
                                             SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  bool IsStrict = Op->isStrictFPOpcode();
  SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
  EVT SrcVT = SrcVal.getValueType();
  bool Trunc = Op.getConstantOperandVal(IsStrict ? 2 : 1) == 1;
  SDNodeFlags Flags = Op->getFlags();
 
  if (VT.isScalableVector()) {
    // Let common code split the operation.
    if (SrcVT == MVT::nxv8f32)
      return Op;
 
    if (VT.getScalarType() != MVT::bf16)
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::FP_ROUND_MERGE_PASSTHRU);
 
    SDLoc DL(Op);
    constexpr EVT I32 = MVT::nxv4i32;
    auto ImmV = [&](int I) -> SDValue { return DAG.getConstant(I, DL, I32); };
 
    SDValue NaN;
    SDValue Narrow;
 
    if (SrcVT == MVT::nxv2f32 || SrcVT == MVT::nxv4f32) {
      if (Subtarget->hasBF16())
        return LowerToPredicatedOp(Op, DAG,
                                   AArch64ISD::FP_ROUND_MERGE_PASSTHRU);
 
      Narrow = getSVESafeBitCast(I32, SrcVal, DAG);
 
      // Set the quiet bit.
      if (!DAG.isKnownNeverSNaN(SrcVal) && !Flags.hasNoNaNs())
        NaN = DAG.getNode(ISD::OR, DL, I32, Narrow, ImmV(0x400000));
    } else if (SrcVT == MVT::nxv2f64 &&
               (Subtarget->hasSVE2() || Subtarget->isStreamingSVEAvailable())) {
      // Round to float without introducing rounding errors and try again.
      SDValue Pg = getPredicateForVector(DAG, DL, MVT::nxv2f32);
      Narrow = DAG.getNode(AArch64ISD::FCVTX_MERGE_PASSTHRU, DL, MVT::nxv2f32,
                           Pg, SrcVal, DAG.getPOISON(MVT::nxv2f32));
 
      SmallVector<SDValue, 3> NewOps;
      if (IsStrict)
        NewOps.push_back(Op.getOperand(0));
      NewOps.push_back(Narrow);
      NewOps.push_back(Op.getOperand(IsStrict ? 2 : 1));
      return DAG.getNode(Op.getOpcode(), DL, VT, NewOps, Op->getFlags());
    } else
      return SDValue();
 
    if (!Trunc) {
      SDValue Lsb = DAG.getNode(ISD::SRL, DL, I32, Narrow, ImmV(16));
      Lsb = DAG.getNode(ISD::AND, DL, I32, Lsb, ImmV(1));
      SDValue RoundingBias = DAG.getNode(ISD::ADD, DL, I32, Lsb, ImmV(0x7fff));
      Narrow = DAG.getNode(ISD::ADD, DL, I32, Narrow, RoundingBias);
    }
 
    // Don't round if we had a NaN, we don't want to turn 0x7fffffff into
    // 0x80000000.
    if (NaN) {
      EVT I1 = I32.changeElementType(*DAG.getContext(), MVT::i1);
      EVT CondVT = VT.changeElementType(*DAG.getContext(), MVT::i1);
      SDValue IsNaN = DAG.getSetCC(DL, CondVT, SrcVal, SrcVal, ISD::SETUO);
      IsNaN = DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, I1, IsNaN);
      Narrow = DAG.getSelect(DL, I32, IsNaN, NaN, Narrow);
    }
 
    // Now that we have rounded, shift the bits into position.
    Narrow = DAG.getNode(ISD::SRL, DL, I32, Narrow, ImmV(16));
    return getSVESafeBitCast(VT, Narrow, DAG);
  }
 
  if (useSVEForFixedLengthVectorVT(SrcVT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthFPRoundToSVE(Op, DAG);
 
  // Expand cases where the result type is BF16 but we don't have hardware
  // instructions to lower it.
  if (VT.getScalarType() == MVT::bf16 &&
      !((Subtarget->hasNEON() || Subtarget->hasSME()) &&
        Subtarget->hasBF16())) {
    SDLoc DL(Op);
    SDValue Narrow = SrcVal;
    SDValue NaN;
    EVT I32 = SrcVT.changeElementType(*DAG.getContext(), MVT::i32);
    EVT F32 = SrcVT.changeElementType(*DAG.getContext(), MVT::f32);
    if (SrcVT.getScalarType() == MVT::f32) {
      bool NeverSNaN = DAG.isKnownNeverSNaN(Narrow);
      Narrow = DAG.getNode(ISD::BITCAST, DL, I32, Narrow);
      if (!NeverSNaN) {
        // Set the quiet bit.
        NaN = DAG.getNode(ISD::OR, DL, I32, Narrow,
                          DAG.getConstant(0x400000, DL, I32));
      }
    } else if (SrcVT.getScalarType() == MVT::f64) {
      Narrow = DAG.getNode(AArch64ISD::FCVTXN, DL, F32, Narrow);
      Narrow = DAG.getNode(ISD::BITCAST, DL, I32, Narrow);
    } else {
      return SDValue();
    }
    if (!Trunc) {
      SDValue One = DAG.getConstant(1, DL, I32);
      SDValue Lsb = DAG.getNode(ISD::SRL, DL, I32, Narrow,
                                DAG.getShiftAmountConstant(16, I32, DL));
      Lsb = DAG.getNode(ISD::AND, DL, I32, Lsb, One);
      SDValue RoundingBias =
          DAG.getNode(ISD::ADD, DL, I32, DAG.getConstant(0x7fff, DL, I32), Lsb);
      Narrow = DAG.getNode(ISD::ADD, DL, I32, Narrow, RoundingBias);
    }
 
    // Don't round if we had a NaN, we don't want to turn 0x7fffffff into
    // 0x80000000.
    if (NaN) {
      SDValue IsNaN = DAG.getSetCC(
          DL, getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), SrcVT),
          SrcVal, SrcVal, ISD::SETUO);
      Narrow = DAG.getSelect(DL, I32, IsNaN, NaN, Narrow);
    }
 
    // Now that we have rounded, shift the bits into position.
    Narrow = DAG.getNode(ISD::SRL, DL, I32, Narrow,
                         DAG.getShiftAmountConstant(16, I32, DL));
    if (VT.isVector()) {
      EVT I16 = I32.changeVectorElementType(*DAG.getContext(), MVT::i16);
      Narrow = DAG.getNode(ISD::TRUNCATE, DL, I16, Narrow);
      return DAG.getNode(ISD::BITCAST, DL, VT, Narrow);
    }
    Narrow = DAG.getNode(ISD::BITCAST, DL, F32, Narrow);
    SDValue Result = DAG.getTargetExtractSubreg(AArch64::hsub, DL, VT, Narrow);
    return IsStrict ? DAG.getMergeValues({Result, Op.getOperand(0)}, DL)
                    : Result;
  }
 
  if (SrcVT != MVT::f128) {
    // Expand cases where the input is a vector bigger than NEON.
    if (useSVEForFixedLengthVectorVT(SrcVT))
      return SDValue();
 
    // It's legal except when f128 is involved
    return Op;
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerVectorFP_TO_INT(SDValue Op,
                                                    SelectionDAG &DAG) const {
  // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
  // Any additional optimization in this function should be recorded
  // in the cost tables.
  bool IsStrict = Op->isStrictFPOpcode();
  EVT InVT = Op.getOperand(IsStrict ? 1 : 0).getValueType();
  EVT VT = Op.getValueType();
 
  assert(!(IsStrict && VT.isScalableVector()) &&
         "Unimplemented SVE support for STRICT_FP_to_INT!");
 
  // f16 conversions are promoted to f32 when full fp16 is not supported.
  if ((InVT.getVectorElementType() == MVT::f16 && !Subtarget->hasFullFP16()) ||
      InVT.getVectorElementType() == MVT::bf16) {
    EVT NewVT = VT.changeElementType(*DAG.getContext(), MVT::f32);
    SDLoc DL(Op);
    if (IsStrict) {
      SDValue Ext = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {NewVT, MVT::Other},
                                {Op.getOperand(0), Op.getOperand(1)});
      return DAG.getNode(Op.getOpcode(), DL, {VT, MVT::Other},
                         {Ext.getValue(1), Ext.getValue(0)});
    }
    return DAG.getNode(
        Op.getOpcode(), DL, Op.getValueType(),
        DAG.getNode(ISD::FP_EXTEND, DL, NewVT, Op.getOperand(0)));
  }
 
  if (VT.isScalableVector()) {
    if (VT.getVectorElementType() == MVT::i1) {
      SDLoc DL(Op);
      EVT CvtVT = getPromotedVTForPredicate(VT);
      SDValue Cvt = DAG.getNode(Op.getOpcode(), DL, CvtVT, Op.getOperand(0));
      SDValue Zero = DAG.getConstant(0, DL, CvtVT);
      return DAG.getSetCC(DL, VT, Cvt, Zero, ISD::SETNE);
    }
 
    // Let common code split the operation.
    if (InVT == MVT::nxv8f32)
      return Op;
 
    unsigned Opcode = Op.getOpcode() == ISD::FP_TO_UINT
                          ? AArch64ISD::FCVTZU_MERGE_PASSTHRU
                          : AArch64ISD::FCVTZS_MERGE_PASSTHRU;
    return LowerToPredicatedOp(Op, DAG, Opcode);
  }
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()) ||
      useSVEForFixedLengthVectorVT(InVT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthFPToIntToSVE(Op, DAG);
 
  uint64_t VTSize = VT.getFixedSizeInBits();
  uint64_t InVTSize = InVT.getFixedSizeInBits();
  if (VTSize < InVTSize) {
    SDLoc DL(Op);
    if (IsStrict) {
      InVT = InVT.changeVectorElementTypeToInteger();
      SDValue Cv = DAG.getNode(Op.getOpcode(), DL, {InVT, MVT::Other},
                               {Op.getOperand(0), Op.getOperand(1)});
      SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, VT, Cv);
      return DAG.getMergeValues({Trunc, Cv.getValue(1)}, DL);
    }
    SDValue Cv =
        DAG.getNode(Op.getOpcode(), DL, InVT.changeVectorElementTypeToInteger(),
                    Op.getOperand(0));
    return DAG.getNode(ISD::TRUNCATE, DL, VT, Cv);
  }
 
  if (VTSize > InVTSize) {
    SDLoc DL(Op);
    MVT ExtVT =
        MVT::getVectorVT(MVT::getFloatingPointVT(VT.getScalarSizeInBits()),
                         VT.getVectorNumElements());
    if (IsStrict) {
      SDValue Ext = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {ExtVT, MVT::Other},
                                {Op.getOperand(0), Op.getOperand(1)});
      return DAG.getNode(Op.getOpcode(), DL, {VT, MVT::Other},
                         {Ext.getValue(1), Ext.getValue(0)});
    }
    SDValue Ext = DAG.getNode(ISD::FP_EXTEND, DL, ExtVT, Op.getOperand(0));
    return DAG.getNode(Op.getOpcode(), DL, VT, Ext);
  }
 
  // Use a scalar operation for conversions between single-element vectors of
  // the same size.
  if (InVT.getVectorNumElements() == 1) {
    SDLoc DL(Op);
    SDValue Extract = DAG.getNode(
        ISD::EXTRACT_VECTOR_ELT, DL, InVT.getScalarType(),
        Op.getOperand(IsStrict ? 1 : 0), DAG.getConstant(0, DL, MVT::i64));
    EVT ScalarVT = VT.getScalarType();
    if (IsStrict)
      return DAG.getNode(Op.getOpcode(), DL, {ScalarVT, MVT::Other},
                         {Op.getOperand(0), Extract});
    return DAG.getNode(Op.getOpcode(), DL, ScalarVT, Extract);
  }
 
  // Type changing conversions are illegal.
  return Op;
}
 
SDValue AArch64TargetLowering::LowerFP_TO_INT(SDValue Op,
                                              SelectionDAG &DAG) const {
  bool IsStrict = Op->isStrictFPOpcode();
  SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
 
  if (SrcVal.getValueType().isVector())
    return LowerVectorFP_TO_INT(Op, DAG);
 
  // f16 conversions are promoted to f32 when full fp16 is not supported.
  if ((SrcVal.getValueType() == MVT::f16 && !Subtarget->hasFullFP16()) ||
      SrcVal.getValueType() == MVT::bf16) {
    SDLoc DL(Op);
    if (IsStrict) {
      SDValue Ext =
          DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {MVT::f32, MVT::Other},
                      {Op.getOperand(0), SrcVal});
      return DAG.getNode(Op.getOpcode(), DL, {Op.getValueType(), MVT::Other},
                         {Ext.getValue(1), Ext.getValue(0)});
    }
    return DAG.getNode(Op.getOpcode(), DL, Op.getValueType(),
                       DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, SrcVal));
  }
 
  if (SrcVal.getValueType() != MVT::f128) {
    // It's legal except when f128 is involved
    return Op;
  }
 
  return SDValue();
}
 
SDValue
AArch64TargetLowering::LowerVectorFP_TO_INT_SAT(SDValue Op,
                                                SelectionDAG &DAG) const {
  // AArch64 FP-to-int conversions saturate to the destination element size, so
  // we can lower common saturating conversions to simple instructions.
  SDValue SrcVal = Op.getOperand(0);
  EVT SrcVT = SrcVal.getValueType();
  EVT DstVT = Op.getValueType();
  EVT SatVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
 
  uint64_t SrcElementWidth = SrcVT.getScalarSizeInBits();
  uint64_t DstElementWidth = DstVT.getScalarSizeInBits();
  uint64_t SatWidth = SatVT.getScalarSizeInBits();
  assert(SatWidth <= DstElementWidth &&
         "Saturation width cannot exceed result width");
 
  // TODO: Consider lowering to SVE operations, as in LowerVectorFP_TO_INT.
  // Currently, the `llvm.fpto[su]i.sat.*` intrinsics don't accept scalable
  // types, so this is hard to reach.
  if (DstVT.isScalableVector())
    return SDValue();
 
  EVT SrcElementVT = SrcVT.getVectorElementType();
 
  // In the absence of FP16 support, promote f16 to f32 and saturate the result.
  SDLoc DL(Op);
  SDValue SrcVal2;
  if ((SrcElementVT == MVT::f16 &&
       (!Subtarget->hasFullFP16() || DstElementWidth > 16)) ||
      SrcElementVT == MVT::bf16) {
    MVT F32VT = MVT::getVectorVT(MVT::f32, SrcVT.getVectorNumElements());
    SrcVal = DAG.getNode(ISD::FP_EXTEND, DL, F32VT, SrcVal);
    // If we are extending to a v8f32, split into two v4f32 to produce legal
    // types.
    if (F32VT.getSizeInBits() > 128) {
      std::tie(SrcVal, SrcVal2) = DAG.SplitVector(SrcVal, DL);
      F32VT = F32VT.getHalfNumVectorElementsVT();
    }
    SrcVT = F32VT;
    SrcElementVT = MVT::f32;
    SrcElementWidth = 32;
  } else if (SrcElementVT != MVT::f64 && SrcElementVT != MVT::f32 &&
             SrcElementVT != MVT::f16 && SrcElementVT != MVT::bf16)
    return SDValue();
 
  // Expand to f64 if we are saturating to i64, to help keep the lanes the same
  // width and produce a fcvtzu.
  if (SatWidth == 64 && SrcElementWidth < 64) {
    MVT F64VT = MVT::getVectorVT(MVT::f64, SrcVT.getVectorNumElements());
    SrcVal = DAG.getNode(ISD::FP_EXTEND, DL, F64VT, SrcVal);
    SrcVT = F64VT;
    SrcElementVT = MVT::f64;
    SrcElementWidth = 64;
  }
  // Cases that we can emit directly.
  if (SrcElementWidth == DstElementWidth && SrcElementWidth == SatWidth) {
    SDValue Res = DAG.getNode(Op.getOpcode(), DL, DstVT, SrcVal,
                              DAG.getValueType(DstVT.getScalarType()));
    if (SrcVal2) {
      SDValue Res2 = DAG.getNode(Op.getOpcode(), DL, DstVT, SrcVal2,
                                 DAG.getValueType(DstVT.getScalarType()));
      return DAG.getNode(ISD::CONCAT_VECTORS, DL, DstVT, Res, Res2);
    }
    return Res;
  }
 
  // Otherwise we emit a cvt that saturates to a higher BW, and saturate the
  // result. This is only valid if the legal cvt is larger than the saturate
  // width. For double, as we don't have MIN/MAX, it can be simpler to scalarize
  // (at least until sqxtn is selected).
  if (SrcElementWidth < SatWidth || SrcElementVT == MVT::f64)
    return SDValue();
 
  EVT IntVT = SrcVT.changeVectorElementTypeToInteger();
  SDValue NativeCvt = DAG.getNode(Op.getOpcode(), DL, IntVT, SrcVal,
                                  DAG.getValueType(IntVT.getScalarType()));
  SDValue NativeCvt2 =
      SrcVal2 ? DAG.getNode(Op.getOpcode(), DL, IntVT, SrcVal2,
                            DAG.getValueType(IntVT.getScalarType()))
              : SDValue();
  SDValue Sat, Sat2;
  if (Op.getOpcode() == ISD::FP_TO_SINT_SAT) {
    SDValue MinC = DAG.getConstant(
        APInt::getSignedMaxValue(SatWidth).sext(SrcElementWidth), DL, IntVT);
    SDValue Min = DAG.getNode(ISD::SMIN, DL, IntVT, NativeCvt, MinC);
    SDValue Min2 = SrcVal2 ? DAG.getNode(ISD::SMIN, DL, IntVT, NativeCvt2, MinC) : SDValue();
    SDValue MaxC = DAG.getConstant(
        APInt::getSignedMinValue(SatWidth).sext(SrcElementWidth), DL, IntVT);
    Sat = DAG.getNode(ISD::SMAX, DL, IntVT, Min, MaxC);
    Sat2 = SrcVal2 ? DAG.getNode(ISD::SMAX, DL, IntVT, Min2, MaxC) : SDValue();
  } else {
    SDValue MinC = DAG.getConstant(
        APInt::getAllOnes(SatWidth).zext(SrcElementWidth), DL, IntVT);
    Sat = DAG.getNode(ISD::UMIN, DL, IntVT, NativeCvt, MinC);
    Sat2 = SrcVal2 ? DAG.getNode(ISD::UMIN, DL, IntVT, NativeCvt2, MinC) : SDValue();
  }
 
  if (SrcVal2)
    Sat = DAG.getNode(ISD::CONCAT_VECTORS, DL,
                      IntVT.getDoubleNumVectorElementsVT(*DAG.getContext()),
                      Sat, Sat2);
 
  return DAG.getNode(ISD::TRUNCATE, DL, DstVT, Sat);
}
 
SDValue AArch64TargetLowering::LowerFP_TO_INT_SAT(SDValue Op,
                                                  SelectionDAG &DAG) const {
  // AArch64 FP-to-int conversions saturate to the destination register size, so
  // we can lower common saturating conversions to simple instructions.
  SDValue SrcVal = Op.getOperand(0);
  EVT SrcVT = SrcVal.getValueType();
 
  if (SrcVT.isVector())
    return LowerVectorFP_TO_INT_SAT(Op, DAG);
 
  EVT DstVT = Op.getValueType();
  EVT SatVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
  uint64_t SatWidth = SatVT.getScalarSizeInBits();
  uint64_t DstWidth = DstVT.getScalarSizeInBits();
  assert(SatWidth <= DstWidth && "Saturation width cannot exceed result width");
 
  // In the absence of FP16 support, promote f16 to f32 and saturate the result.
  if ((SrcVT == MVT::f16 && !Subtarget->hasFullFP16()) || SrcVT == MVT::bf16) {
    SrcVal = DAG.getNode(ISD::FP_EXTEND, SDLoc(Op), MVT::f32, SrcVal);
    SrcVT = MVT::f32;
  } else if (SrcVT != MVT::f64 && SrcVT != MVT::f32 && SrcVT != MVT::f16 &&
             SrcVT != MVT::bf16)
    return SDValue();
 
  SDLoc DL(Op);
  // Cases that we can emit directly.
  if ((SrcVT == MVT::f64 || SrcVT == MVT::f32 ||
       (SrcVT == MVT::f16 && Subtarget->hasFullFP16())) &&
      DstVT == SatVT && (DstVT == MVT::i64 || DstVT == MVT::i32))
    return DAG.getNode(Op.getOpcode(), DL, DstVT, SrcVal,
                       DAG.getValueType(DstVT));
 
  // Otherwise we emit a cvt that saturates to a higher BW, and saturate the
  // result. This is only valid if the legal cvt is larger than the saturate
  // width.
  if (DstWidth < SatWidth)
    return SDValue();
 
  if (SrcVT == MVT::f16 && SatVT == MVT::i16 && DstVT == MVT::i32) {
    if (Op.getOpcode() == ISD::FP_TO_SINT_SAT) {
      SDValue CVTf32 =
          DAG.getNode(AArch64ISD::FCVTZS_HALF, DL, MVT::f32, SrcVal);
      SDValue Bitcast = DAG.getBitcast(DstVT, CVTf32);
      return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, DstVT, Bitcast,
                         DAG.getValueType(SatVT));
    }
    SDValue CVTf32 = DAG.getNode(AArch64ISD::FCVTZU_HALF, DL, MVT::f32, SrcVal);
    return DAG.getBitcast(DstVT, CVTf32);
  }
 
  SDValue NativeCvt =
      DAG.getNode(Op.getOpcode(), DL, DstVT, SrcVal, DAG.getValueType(DstVT));
  SDValue Sat;
  if (Op.getOpcode() == ISD::FP_TO_SINT_SAT) {
    SDValue MinC = DAG.getConstant(
        APInt::getSignedMaxValue(SatWidth).sext(DstWidth), DL, DstVT);
    SDValue Min = DAG.getNode(ISD::SMIN, DL, DstVT, NativeCvt, MinC);
    SDValue MaxC = DAG.getConstant(
        APInt::getSignedMinValue(SatWidth).sext(DstWidth), DL, DstVT);
    Sat = DAG.getNode(ISD::SMAX, DL, DstVT, Min, MaxC);
  } else {
    SDValue MinC = DAG.getConstant(
        APInt::getAllOnes(SatWidth).zext(DstWidth), DL, DstVT);
    Sat = DAG.getNode(ISD::UMIN, DL, DstVT, NativeCvt, MinC);
  }
 
  return DAG.getNode(ISD::TRUNCATE, DL, DstVT, Sat);
}
 
SDValue AArch64TargetLowering::LowerVectorXRINT(SDValue Op,
                                                SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  SDValue Src = Op.getOperand(0);
  SDLoc DL(Op);
 
  assert(VT.isVector() && "Expected vector type");
 
  EVT CastVT = VT.changeVectorElementType(
      *DAG.getContext(), Src.getValueType().getVectorElementType());
 
  // Round the floating-point value into a floating-point register with the
  // current rounding mode.
  SDValue FOp = DAG.getNode(ISD::FRINT, DL, CastVT, Src);
 
  // Truncate the rounded floating point to an integer.
  return DAG.getNode(ISD::FP_TO_SINT_SAT, DL, VT, FOp,
                     DAG.getValueType(VT.getVectorElementType()));
}
 
SDValue AArch64TargetLowering::LowerVectorINT_TO_FP(SDValue Op,
                                                    SelectionDAG &DAG) const {
  // Warning: We maintain cost tables in AArch64TargetTransformInfo.cpp.
  // Any additional optimization in this function should be recorded
  // in the cost tables.
  bool IsStrict = Op->isStrictFPOpcode();
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  SDValue In = Op.getOperand(IsStrict ? 1 : 0);
  EVT InVT = In.getValueType();
  unsigned Opc = Op.getOpcode();
  bool IsSigned = Opc == ISD::SINT_TO_FP || Opc == ISD::STRICT_SINT_TO_FP;
 
  assert(!(IsStrict && VT.isScalableVector()) &&
         "Unimplemented SVE support for ISD:::STRICT_INT_TO_FP!");
 
  // NOTE: i1->bf16 does not require promotion to f32.
  if (VT.isScalableVector() && InVT.getVectorElementType() == MVT::i1) {
    SDValue FalseVal = DAG.getConstantFP(0.0, DL, VT);
    SDValue TrueVal = IsSigned ? DAG.getConstantFP(-1.0, DL, VT)
                               : DAG.getConstantFP(1.0, DL, VT);
    return DAG.getNode(ISD::VSELECT, DL, VT, In, TrueVal, FalseVal);
  }
 
  // Promote bf16 conversions to f32.
  if (VT.getVectorElementType() == MVT::bf16) {
    EVT F32 = VT.changeElementType(*DAG.getContext(), MVT::f32);
    if (IsStrict) {
      SDValue Val = DAG.getNode(Op.getOpcode(), DL, {F32, MVT::Other},
                                {Op.getOperand(0), In});
      return DAG.getNode(ISD::STRICT_FP_ROUND, DL,
                         {Op.getValueType(), MVT::Other},
                         {Val.getValue(1), Val.getValue(0),
                          DAG.getIntPtrConstant(0, DL, /*isTarget=*/true)});
    }
    return DAG.getNode(ISD::FP_ROUND, DL, Op.getValueType(),
                       DAG.getNode(Op.getOpcode(), DL, F32, In),
                       DAG.getIntPtrConstant(0, DL, /*isTarget=*/true));
  }
 
  if (VT.isScalableVector()) {
    // Let common code split the operation.
    if (VT == MVT::nxv8f32)
      return Op;
 
    unsigned Opcode = IsSigned ? AArch64ISD::SINT_TO_FP_MERGE_PASSTHRU
                               : AArch64ISD::UINT_TO_FP_MERGE_PASSTHRU;
    return LowerToPredicatedOp(Op, DAG, Opcode);
  }
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()) ||
      useSVEForFixedLengthVectorVT(InVT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthIntToFPToSVE(Op, DAG);
 
  uint64_t VTSize = VT.getFixedSizeInBits();
  uint64_t InVTSize = InVT.getFixedSizeInBits();
  if (VTSize < InVTSize) {
    // AArch64 doesn't have a direct vector instruction to convert
    // fixed point to floating point AND narrow it at the same time.
    // Additional rounding when the target is f32/f64 causes double
    // rounding issues. Conversion to f16 is fine due to narrow width.
    bool IsTargetf32 = VT.getVectorElementType() == MVT::f32;
    bool IsTargetf16 = false;
    if (Op.hasOneUse() &&
        Op->user_begin()->getOpcode() == ISD::CONCAT_VECTORS) {
      // Some vector types are split during legalization into half, followed by
      // concatenation, followed by rounding to the original vector type. If we
      // end up resolving to f16 type, we shouldn't worry about rounding errors.
      SDNode *U = *Op->user_begin();
      if (U->hasOneUse() && U->user_begin()->getOpcode() == ISD::FP_ROUND) {
        EVT TmpVT = U->user_begin()->getValueType(0);
        if (TmpVT.getScalarType() == MVT::f16)
          IsTargetf16 = true;
      }
    }
 
    if (IsTargetf32 && !IsTargetf16) {
      return !IsStrict ? DAG.UnrollVectorOp(Op.getNode()) : SDValue();
    }
 
    MVT CastVT =
        MVT::getVectorVT(MVT::getFloatingPointVT(InVT.getScalarSizeInBits()),
                         InVT.getVectorNumElements());
    if (IsStrict) {
      In = DAG.getNode(Opc, DL, {CastVT, MVT::Other}, {Op.getOperand(0), In});
      return DAG.getNode(ISD::STRICT_FP_ROUND, DL, {VT, MVT::Other},
                         {In.getValue(1), In.getValue(0),
                          DAG.getIntPtrConstant(0, DL, /*isTarget=*/true)});
    }
    In = DAG.getNode(Opc, DL, CastVT, In);
    return DAG.getNode(ISD::FP_ROUND, DL, VT, In,
                       DAG.getIntPtrConstant(0, DL, /*isTarget=*/true));
  }
 
  if (VTSize > InVTSize) {
    unsigned CastOpc = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
    EVT CastVT = VT.changeVectorElementTypeToInteger();
    In = DAG.getNode(CastOpc, DL, CastVT, In);
    if (IsStrict)
      return DAG.getNode(Opc, DL, {VT, MVT::Other}, {Op.getOperand(0), In});
    return DAG.getNode(Opc, DL, VT, In);
  }
 
  // Use a scalar operation for conversions between single-element vectors of
  // the same size.
  if (VT.getVectorNumElements() == 1) {
    SDValue Extract =
        DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, InVT.getScalarType(), In,
                    DAG.getConstant(0, DL, MVT::i64));
    EVT ScalarVT = VT.getScalarType();
    if (IsStrict)
      return DAG.getNode(Op.getOpcode(), DL, {ScalarVT, MVT::Other},
                         {Op.getOperand(0), Extract});
    return DAG.getNode(Op.getOpcode(), DL, ScalarVT, Extract);
  }
 
  return Op;
}
 
SDValue AArch64TargetLowering::LowerINT_TO_FP(SDValue Op,
                                            SelectionDAG &DAG) const {
  if (Op.getValueType().isVector())
    return LowerVectorINT_TO_FP(Op, DAG);
 
  bool IsStrict = Op->isStrictFPOpcode();
  SDValue SrcVal = Op.getOperand(IsStrict ? 1 : 0);
 
  bool IsSigned = Op->getOpcode() == ISD::STRICT_SINT_TO_FP ||
                  Op->getOpcode() == ISD::SINT_TO_FP;
 
  auto IntToFpViaPromotion = [&](EVT PromoteVT) {
    SDLoc DL(Op);
    if (IsStrict) {
      SDValue Val = DAG.getNode(Op.getOpcode(), DL, {PromoteVT, MVT::Other},
                                {Op.getOperand(0), SrcVal});
      return DAG.getNode(ISD::STRICT_FP_ROUND, DL,
                         {Op.getValueType(), MVT::Other},
                         {Val.getValue(1), Val.getValue(0),
                          DAG.getIntPtrConstant(0, DL, /*isTarget=*/true)});
    }
    return DAG.getNode(ISD::FP_ROUND, DL, Op.getValueType(),
                       DAG.getNode(Op.getOpcode(), DL, PromoteVT, SrcVal),
                       DAG.getIntPtrConstant(0, DL, /*isTarget=*/true));
  };
 
  if (Op.getValueType() == MVT::bf16) {
    unsigned MaxWidth = IsSigned
                            ? DAG.ComputeMaxSignificantBits(SrcVal)
                            : DAG.computeKnownBits(SrcVal).countMaxActiveBits();
    // bf16 conversions are promoted to f32 when converting from i16.
    if (MaxWidth <= 24) {
      return IntToFpViaPromotion(MVT::f32);
    }
 
    // bf16 conversions are promoted to f64 when converting from i32.
    if (MaxWidth <= 53) {
      return IntToFpViaPromotion(MVT::f64);
    }
 
    // We need to be careful about i64 -> bf16.
    // Consider an i32 22216703.
    // This number cannot be represented exactly as an f32 and so a itofp will
    // turn it into 22216704.0 fptrunc to bf16 will turn this into 22282240.0
    // However, the correct bf16 was supposed to be 22151168.0
    // We need to use sticky rounding to get this correct.
    if (SrcVal.getValueType() == MVT::i64) {
      SDLoc DL(Op);
      // This algorithm is equivalent to the following:
      // uint64_t SrcHi = SrcVal & ~0xfffull;
      // uint64_t SrcLo = SrcVal &  0xfffull;
      // uint64_t Highest = SrcVal >> 53;
      // bool HasHighest = Highest != 0;
      // uint64_t ToRound = HasHighest ? SrcHi : SrcVal;
      // double  Rounded = static_cast<double>(ToRound);
      // uint64_t RoundedBits = std::bit_cast<uint64_t>(Rounded);
      // uint64_t HasLo = SrcLo != 0;
      // bool NeedsAdjustment = HasHighest & HasLo;
      // uint64_t AdjustedBits = RoundedBits | uint64_t{NeedsAdjustment};
      // double Adjusted = std::bit_cast<double>(AdjustedBits);
      // return static_cast<__bf16>(Adjusted);
      //
      // Essentially, what happens is that SrcVal either fits perfectly in a
      // double-precision value or it is too big. If it is sufficiently small,
      // we should just go u64 -> double -> bf16 in a naive way. Otherwise, we
      // ensure that u64 -> double has no rounding error by only using the 52
      // MSB of the input. The low order bits will get merged into a sticky bit
      // which will avoid issues incurred by double rounding.
 
      // Signed conversion is more or less like so:
      // copysign((__bf16)abs(SrcVal), SrcVal)
      SDValue SignBit;
      if (IsSigned) {
        SignBit = DAG.getNode(ISD::AND, DL, MVT::i64, SrcVal,
                              DAG.getConstant(1ull << 63, DL, MVT::i64));
        SrcVal = DAG.getNode(ISD::ABS, DL, MVT::i64, SrcVal);
      }
      SDValue SrcHi = DAG.getNode(ISD::AND, DL, MVT::i64, SrcVal,
                                  DAG.getConstant(~0xfffull, DL, MVT::i64));
      SDValue SrcLo = DAG.getNode(ISD::AND, DL, MVT::i64, SrcVal,
                                  DAG.getConstant(0xfffull, DL, MVT::i64));
      SDValue Highest =
          DAG.getNode(ISD::SRL, DL, MVT::i64, SrcVal,
                      DAG.getShiftAmountConstant(53, MVT::i64, DL));
      SDValue Zero64 = DAG.getConstant(0, DL, MVT::i64);
      SDValue ToRound =
          DAG.getSelectCC(DL, Highest, Zero64, SrcHi, SrcVal, ISD::SETNE);
      SDValue Rounded =
          IsStrict ? DAG.getNode(Op.getOpcode(), DL, {MVT::f64, MVT::Other},
                                 {Op.getOperand(0), ToRound})
                   : DAG.getNode(Op.getOpcode(), DL, MVT::f64, ToRound);
 
      SDValue RoundedBits = DAG.getNode(ISD::BITCAST, DL, MVT::i64, Rounded);
      if (SignBit) {
        RoundedBits = DAG.getNode(ISD::OR, DL, MVT::i64, RoundedBits, SignBit);
      }
 
      SDValue HasHighest = DAG.getSetCC(
          DL,
          getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i64),
          Highest, Zero64, ISD::SETNE);
 
      SDValue HasLo = DAG.getSetCC(
          DL,
          getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i64),
          SrcLo, Zero64, ISD::SETNE);
 
      SDValue NeedsAdjustment =
          DAG.getNode(ISD::AND, DL, HasLo.getValueType(), HasHighest, HasLo);
      NeedsAdjustment = DAG.getZExtOrTrunc(NeedsAdjustment, DL, MVT::i64);
 
      SDValue AdjustedBits =
          DAG.getNode(ISD::OR, DL, MVT::i64, RoundedBits, NeedsAdjustment);
      SDValue Adjusted = DAG.getNode(ISD::BITCAST, DL, MVT::f64, AdjustedBits);
      return IsStrict
                 ? DAG.getNode(
                       ISD::STRICT_FP_ROUND, DL,
                       {Op.getValueType(), MVT::Other},
                       {Rounded.getValue(1), Adjusted,
                        DAG.getIntPtrConstant(0, DL, /*isTarget=*/true)})
                 : DAG.getNode(ISD::FP_ROUND, DL, Op.getValueType(), Adjusted,
                               DAG.getIntPtrConstant(0, DL, /*isTarget=*/true));
    }
  }
 
  // f16 conversions are promoted to f32 when full fp16 is not supported.
  if (Op.getValueType() == MVT::f16 && !Subtarget->hasFullFP16()) {
    return IntToFpViaPromotion(MVT::f32);
  }
 
  // i128 conversions are libcalls.
  if (SrcVal.getValueType() == MVT::i128)
    return SDValue();
 
  // Other conversions are legal, unless it's to the completely software-based
  // fp128.
  if (Op.getValueType() != MVT::f128)
    return Op;
  return SDValue();
}
 
static MVT getSVEContainerType(EVT ContentTy);
 
SDValue
AArch64TargetLowering::LowerLOOP_DEPENDENCE_MASK(SDValue Op,
                                                 SelectionDAG &DAG) const {
  assert((Subtarget->hasSVE2() ||
          (Subtarget->hasSME() && Subtarget->isStreaming())) &&
         "Lowering loop_dependence_raw_mask or loop_dependence_war_mask "
         "requires SVE or SME");
 
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  unsigned LaneOffset = Op.getConstantOperandVal(3);
  unsigned NumElements = VT.getVectorMinNumElements();
  uint64_t EltSizeInBytes = Op.getConstantOperandVal(2);
  EVT AddrTy = Op->getOperand(0).getValueType();
 
  // Lane offsets and other element sizes are not supported by whilewr/rw.
  if (LaneOffset != 0 || !is_contained({1u, 2u, 4u, 8u}, EltSizeInBytes))
    return SDValue();
 
  EVT EltVT = MVT::getIntegerVT(EltSizeInBytes * 8);
  EVT PredVT =
      getPackedSVEVectorVT(EltVT).changeElementType(*DAG.getContext(), MVT::i1);
 
  if (PredVT == VT) {
    // Legal whilewr/rw (lowered by tablegen matcher).
    if (AddrTy == MVT::i64)
      return Op;
 
    // Almost legal whilewr/rw (addresses must be promoted to i64).
    assert(AddrTy == MVT::i32 && "Only expected i32 to be legal!");
    return DAG.getNode(
        Op.getOpcode(), DL, VT,
        DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, Op->getOperand(0)),
        DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, Op->getOperand(1)),
        DAG.getConstant(EltSizeInBytes, DL, MVT::i64), Op->getOperand(3));
  }
 
  // Expand if this mask needs splitting (this will produce a whilelo).
  if (NumElements > PredVT.getVectorMinNumElements())
    return SDValue();
 
  SDValue Mask =
      DAG.getNode(Op.getOpcode(), DL, PredVT, to_vector(Op->op_values()));
 
  if (VT.isFixedLengthVector()) {
    EVT WidePredVT =
        PredVT.changeElementType(*DAG.getContext(), VT.getScalarType());
    SDValue MaskAsInt = DAG.getNode(ISD::SIGN_EXTEND, DL, WidePredVT, Mask);
    return convertFromScalableVector(DAG, VT, MaskAsInt);
  }
 
  return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, Mask,
                     DAG.getConstant(0, DL, MVT::i64));
}
 
SDValue AArch64TargetLowering::LowerBITCAST(SDValue Op,
                                            SelectionDAG &DAG) const {
  EVT OpVT = Op.getValueType();
  EVT ArgVT = Op.getOperand(0).getValueType();
 
  if (useSVEForFixedLengthVectorVT(OpVT))
    return LowerFixedLengthBitcastToSVE(Op, DAG);
 
  if (OpVT.isScalableVector()) {
    assert(isTypeLegal(OpVT) && "Unexpected result type!");
 
    // Handle type legalisation first.
    if (!isTypeLegal(ArgVT)) {
      assert(OpVT.isFloatingPoint() && !ArgVT.isFloatingPoint() &&
             "Expected int->fp bitcast!");
 
      // Bitcasting between unpacked vector types of different element counts is
      // not a NOP because the live elements are laid out differently.
      //                01234567
      // e.g. nxv2i32 = XX??XX??
      //      nxv4f16 = X?X?X?X?
      if (OpVT.getVectorElementCount() != ArgVT.getVectorElementCount())
        return SDValue();
 
      SDValue ExtResult =
          DAG.getNode(ISD::ANY_EXTEND, SDLoc(Op), getSVEContainerType(ArgVT),
                      Op.getOperand(0));
      return getSVESafeBitCast(OpVT, ExtResult, DAG);
    }
 
    // Bitcasts between legal types with the same element count are legal.
    if (OpVT.getVectorElementCount() == ArgVT.getVectorElementCount())
      return Op;
 
    // getSVESafeBitCast does not support casting between unpacked types.
    if (!isPackedVectorType(OpVT, DAG))
      return SDValue();
 
    return getSVESafeBitCast(OpVT, Op.getOperand(0), DAG);
  }
 
  if (OpVT != MVT::f16 && OpVT != MVT::bf16)
    return SDValue();
 
  // Bitcasts between f16 and bf16 are legal.
  if (ArgVT == MVT::f16 || ArgVT == MVT::bf16)
    return Op;
 
  SDValue Src = Op.getOperand(0);
  SDLoc DL(Op);
  if (ArgVT.isVector() && ArgVT.getSizeInBits() == 16) {
    Src = DAG.getNode(ISD::BITCAST, DL, MVT::i16, Src);
    ArgVT = MVT::i16;
  }
 
  assert(ArgVT == MVT::i16);
 
  Op = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i32, Src);
  Op = DAG.getNode(ISD::BITCAST, DL, MVT::f32, Op);
  return DAG.getTargetExtractSubreg(AArch64::hsub, DL, OpVT, Op);
}
 
// Returns lane if Op extracts from a two-element vector and lane is constant
// (i.e., extractelt(<2 x Ty> %v, ConstantLane)), and std::nullopt otherwise.
static std::optional<uint64_t>
getConstantLaneNumOfExtractHalfOperand(SDValue &Op) {
  SDNode *OpNode = Op.getNode();
  if (OpNode->getOpcode() != ISD::EXTRACT_VECTOR_ELT)
    return std::nullopt;
 
  EVT VT = OpNode->getOperand(0).getValueType();
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpNode->getOperand(1));
  if (!VT.isFixedLengthVector() || VT.getVectorNumElements() != 2 || !C)
    return std::nullopt;
 
  return C->getZExtValue();
}
 
static bool isExtendedBUILD_VECTOR(SDValue N, SelectionDAG &DAG,
                                   bool isSigned) {
  EVT VT = N.getValueType();
 
  if (N.getOpcode() != ISD::BUILD_VECTOR)
    return false;
 
  for (const SDValue &Elt : N->op_values()) {
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Elt)) {
      unsigned EltSize = VT.getScalarSizeInBits();
      unsigned HalfSize = EltSize / 2;
      if (isSigned) {
        if (!isIntN(HalfSize, C->getSExtValue()))
          return false;
      } else {
        if (!isUIntN(HalfSize, C->getZExtValue()))
          return false;
      }
      continue;
    }
    return false;
  }
 
  return true;
}
 
static SDValue skipExtensionForVectorMULL(SDValue N, SelectionDAG &DAG) {
  EVT VT = N.getValueType();
  assert(VT.is128BitVector() && "Unexpected vector MULL size");
  EVT HalfVT = EVT::getVectorVT(
      *DAG.getContext(),
      VT.getScalarType().getHalfSizedIntegerVT(*DAG.getContext()),
      VT.getVectorElementCount());
  return DAG.getNode(ISD::TRUNCATE, SDLoc(N), HalfVT, N);
}
 
static bool isSignExtended(SDValue N, SelectionDAG &DAG) {
  return N.getOpcode() == ISD::SIGN_EXTEND ||
         N.getOpcode() == ISD::ANY_EXTEND ||
         isExtendedBUILD_VECTOR(N, DAG, true);
}
 
static bool isZeroExtended(SDValue N, SelectionDAG &DAG) {
  return N.getOpcode() == ISD::ZERO_EXTEND ||
         N.getOpcode() == ISD::ANY_EXTEND ||
         isExtendedBUILD_VECTOR(N, DAG, false);
}
 
static bool isAddSubSExt(SDValue N, SelectionDAG &DAG) {
  unsigned Opcode = N.getOpcode();
  if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
    SDValue N0 = N.getOperand(0);
    SDValue N1 = N.getOperand(1);
    return N0->hasOneUse() && N1->hasOneUse() &&
      isSignExtended(N0, DAG) && isSignExtended(N1, DAG);
  }
  return false;
}
 
static bool isAddSubZExt(SDValue N, SelectionDAG &DAG) {
  unsigned Opcode = N.getOpcode();
  if (Opcode == ISD::ADD || Opcode == ISD::SUB) {
    SDValue N0 = N.getOperand(0);
    SDValue N1 = N.getOperand(1);
    return N0->hasOneUse() && N1->hasOneUse() &&
      isZeroExtended(N0, DAG) && isZeroExtended(N1, DAG);
  }
  return false;
}
 
SDValue AArch64TargetLowering::LowerGET_ROUNDING(SDValue Op,
                                                 SelectionDAG &DAG) const {
  // The rounding mode is in bits 23:22 of the FPSCR.
  // The ARM rounding mode value to FLT_ROUNDS mapping is 0->1, 1->2, 2->3, 3->0
  // The formula we use to implement this is (((FPSCR + 1 << 22) >> 22) & 3)
  // so that the shift + and get folded into a bitfield extract.
  SDLoc DL(Op);
 
  SDValue Chain = Op.getOperand(0);
  SDValue FPCR_64 =
      DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i64, MVT::Other},
                  {Chain, DAG.getTargetConstant(Intrinsic::aarch64_get_fpcr, DL,
                                                MVT::i64)});
  Chain = FPCR_64.getValue(1);
  SDValue FPCR_32 = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, FPCR_64);
  SDValue FltRounds = DAG.getNode(ISD::ADD, DL, MVT::i32, FPCR_32,
                                  DAG.getConstant(1U << 22, DL, MVT::i32));
  SDValue RMODE = DAG.getNode(ISD::SRL, DL, MVT::i32, FltRounds,
                              DAG.getConstant(22, DL, MVT::i32));
  SDValue AND = DAG.getNode(ISD::AND, DL, MVT::i32, RMODE,
                            DAG.getConstant(3, DL, MVT::i32));
  return DAG.getMergeValues({AND, Chain}, DL);
}
 
SDValue AArch64TargetLowering::LowerSET_ROUNDING(SDValue Op,
                                                 SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Chain = Op->getOperand(0);
  SDValue RMValue = Op->getOperand(1);
 
  // The rounding mode is in bits 23:22 of the FPCR.
  // The llvm.set.rounding argument value to the rounding mode in FPCR mapping
  // is 0->3, 1->0, 2->1, 3->2. The formula we use to implement this is
  // ((arg - 1) & 3) << 22).
  //
  // The argument of llvm.set.rounding must be within the segment [0, 3], so
  // NearestTiesToAway (4) is not handled here. It is responsibility of the code
  // generated llvm.set.rounding to ensure this condition.
 
  // Calculate new value of FPCR[23:22].
  RMValue = DAG.getNode(ISD::SUB, DL, MVT::i32, RMValue,
                        DAG.getConstant(1, DL, MVT::i32));
  RMValue = DAG.getNode(ISD::AND, DL, MVT::i32, RMValue,
                        DAG.getConstant(0x3, DL, MVT::i32));
  RMValue =
      DAG.getNode(ISD::SHL, DL, MVT::i32, RMValue,
                  DAG.getConstant(AArch64::RoundingBitsPos, DL, MVT::i32));
  RMValue = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, RMValue);
 
  // Get current value of FPCR.
  SDValue Ops[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_get_fpcr, DL, MVT::i64)};
  SDValue FPCR =
      DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i64, MVT::Other}, Ops);
  Chain = FPCR.getValue(1);
  FPCR = FPCR.getValue(0);
 
  // Put new rounding mode into FPSCR[23:22].
  const int RMMask = ~(AArch64::Rounding::rmMask << AArch64::RoundingBitsPos);
  FPCR = DAG.getNode(ISD::AND, DL, MVT::i64, FPCR,
                     DAG.getConstant(RMMask, DL, MVT::i64));
  FPCR = DAG.getNode(ISD::OR, DL, MVT::i64, FPCR, RMValue);
  SDValue Ops2[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_set_fpcr, DL, MVT::i64),
      FPCR};
  return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
}
 
SDValue AArch64TargetLowering::LowerGET_FPMODE(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Chain = Op->getOperand(0);
 
  // Get current value of FPCR.
  SDValue Ops[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_get_fpcr, DL, MVT::i64)};
  SDValue FPCR =
      DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i64, MVT::Other}, Ops);
  Chain = FPCR.getValue(1);
  FPCR = FPCR.getValue(0);
 
  // Truncate FPCR to 32 bits.
  SDValue Result = DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, FPCR);
 
  return DAG.getMergeValues({Result, Chain}, DL);
}
 
SDValue AArch64TargetLowering::LowerSET_FPMODE(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Chain = Op->getOperand(0);
  SDValue Mode = Op->getOperand(1);
 
  // Extend the specified value to 64 bits.
  SDValue FPCR = DAG.getZExtOrTrunc(Mode, DL, MVT::i64);
 
  // Set new value of FPCR.
  SDValue Ops2[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_set_fpcr, DL, MVT::i64),
      FPCR};
  return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
}
 
SDValue AArch64TargetLowering::LowerRESET_FPMODE(SDValue Op,
                                                 SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Chain = Op->getOperand(0);
 
  // Get current value of FPCR.
  SDValue Ops[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_get_fpcr, DL, MVT::i64)};
  SDValue FPCR =
      DAG.getNode(ISD::INTRINSIC_W_CHAIN, DL, {MVT::i64, MVT::Other}, Ops);
  Chain = FPCR.getValue(1);
  FPCR = FPCR.getValue(0);
 
  // Clear bits that are not reserved.
  SDValue FPSCRMasked = DAG.getNode(
      ISD::AND, DL, MVT::i64, FPCR,
      DAG.getConstant(AArch64::ReservedFPControlBits, DL, MVT::i64));
 
  // Set new value of FPCR.
  SDValue Ops2[] = {
      Chain, DAG.getTargetConstant(Intrinsic::aarch64_set_fpcr, DL, MVT::i64),
      FPSCRMasked};
  return DAG.getNode(ISD::INTRINSIC_VOID, DL, MVT::Other, Ops2);
}
 
static unsigned selectUmullSmull(SDValue &N0, SDValue &N1, SelectionDAG &DAG,
                                 SDLoc DL, bool &IsMLA) {
  bool IsN0SExt = isSignExtended(N0, DAG);
  bool IsN1SExt = isSignExtended(N1, DAG);
  if (IsN0SExt && IsN1SExt)
    return AArch64ISD::SMULL;
 
  bool IsN0ZExt = isZeroExtended(N0, DAG);
  bool IsN1ZExt = isZeroExtended(N1, DAG);
 
  if (IsN0ZExt && IsN1ZExt)
    return AArch64ISD::UMULL;
 
  // Select UMULL if we can replace the other operand with an extend.
  EVT VT = N0.getValueType();
  unsigned EltSize = VT.getScalarSizeInBits();
  APInt Mask = APInt::getHighBitsSet(EltSize, EltSize / 2);
  if (IsN0ZExt || IsN1ZExt) {
    if (DAG.MaskedValueIsZero(IsN0ZExt ? N1 : N0, Mask))
      return AArch64ISD::UMULL;
  } else if (VT == MVT::v2i64 && DAG.MaskedValueIsZero(N0, Mask) &&
             DAG.MaskedValueIsZero(N1, Mask)) {
    // For v2i64 we look more aggressively at both operands being zero, to avoid
    // scalarization.
    return AArch64ISD::UMULL;
  }
 
  if (IsN0SExt || IsN1SExt) {
    if (DAG.ComputeNumSignBits(IsN0SExt ? N1 : N0) > EltSize / 2)
      return AArch64ISD::SMULL;
  } else if (VT == MVT::v2i64 && DAG.ComputeNumSignBits(N0) > EltSize / 2 &&
             DAG.ComputeNumSignBits(N1) > EltSize / 2) {
    return AArch64ISD::SMULL;
  }
 
  if (!IsN1SExt && !IsN1ZExt)
    return 0;
 
  // Look for (s/zext A + s/zext B) * (s/zext C). We want to turn these
  // into (s/zext A * s/zext C) + (s/zext B * s/zext C)
  if (IsN1SExt && isAddSubSExt(N0, DAG)) {
    IsMLA = true;
    return AArch64ISD::SMULL;
  }
  if (IsN1ZExt && isAddSubZExt(N0, DAG)) {
    IsMLA = true;
    return AArch64ISD::UMULL;
  }
  if (IsN0ZExt && isAddSubZExt(N1, DAG)) {
    std::swap(N0, N1);
    IsMLA = true;
    return AArch64ISD::UMULL;
  }
  return 0;
}
 
// Transform mul<v2i64, splat(const)> into a SHL and ADD/SUB
// (1) multiply-by-(power-of-2 +/- 1) into shift and add/sub.
// mul x, (2^N + 1) --> add (shl x, N), x
// mul x, (2^N - 1) --> sub (shl x, N), x
// Examples: x * 33 --> (x << 5) + x
//           x * 15 --> (x << 4) - x
//           x * -33 --> -((x << 5) + x)
//           x * -15 --> -((x << 4) - x) ; this reduces --> x - (x << 4)
// (2) multiply-by-(power-of-2 +/- power-of-2) into shifts and add/sub.
// mul x, (2^N + 2^M) --> (add (shl x, N), (shl x, M))
// mul x, (2^N - 2^M) --> (sub (shl x, N), (shl x, M))
// Examples: x * 0x8800 --> (x << 15) + (x << 11)
//           x * 0xf800 --> (x << 16) - (x << 11)
//           x * -0x8800 --> -((x << 15) + (x << 11))
//           x * -0xf800 --> -((x << 16) - (x << 11)) ; (x << 11) - (x << 16)
static SDValue convertMulToShlAdd(SDNode *N, SelectionDAG &DAG) {
  const SDNode *Operand = N->getOperand(1).getNode();
  APInt SplatValue;
 
  // Not a constant splat so should just stay as a multiplication operation
  if (!ISD::isConstantSplatVector(Operand, SplatValue) ||
      !SplatValue.getBoolValue())
    return SDValue();
 
  bool IsNegative = SplatValue.isNegative();
  SplatValue = SplatValue.abs();
  // Placeholder for MathOp
  unsigned MathOp = ISD::DELETED_NODE;
  unsigned TZeros = SplatValue.countr_zero();
 
  // Shift the splat value by all the zeros, this won't affect the parity
  // this will help us find the first and second multiple to use.
  SplatValue.lshrInPlace(TZeros);
 
  if ((SplatValue - 1).isPowerOf2())
    MathOp = ISD::ADD;
  else if ((SplatValue + 1).isPowerOf2())
    MathOp = ISD::SUB;
 
  // If the constant is not (2^n + 1) or (2^n - 1), it would require
  // more than one addition/subtraction. For v2i64, the cost of
  // multiple vector adds/shifts often exceeds the cost of
  // scalarization (moving to GPRs to use a single MUL).
  if (MathOp != ISD::DELETED_NODE) {
    SDLoc DL(N);
    EVT VT = N->getValueType(0);
    SDValue LHS = N->getOperand(0);
 
    unsigned ShiftAmt = MathOp == ISD::ADD ? (SplatValue - 1).logBase2()
                                           : (SplatValue + 1).logBase2();
    ShiftAmt += TZeros;
 
    SDValue Shl =
        DAG.getNode(ISD::SHL, DL, VT, LHS, DAG.getConstant(ShiftAmt, DL, VT));
 
    SDValue NewLHS = TZeros ? DAG.getNode(ISD::SHL, DL, VT, LHS,
                                          DAG.getConstant(TZeros, DL, VT))
                            : LHS;
    SDValue Combined = DAG.getNode(MathOp, DL, VT, Shl, NewLHS);
    if (IsNegative)
      Combined = DAG.getNegative(Combined, DL, VT);
    return Combined;
  }
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerMUL(SDValue Op, SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
 
  bool OverrideNEON = !Subtarget->isNeonAvailable();
  if (VT.isScalableVector() || useSVEForFixedLengthVectorVT(VT, OverrideNEON))
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::MUL_PRED);
 
  // Multiplications are only custom-lowered for 128-bit and 64-bit vectors so
  // that VMULL can be detected.  Otherwise v2i64 multiplications are not legal.
  assert((VT.is128BitVector() || VT.is64BitVector()) && VT.isInteger() &&
         "unexpected type for custom-lowering ISD::MUL");
  SDValue N0 = Op.getOperand(0);
  SDValue N1 = Op.getOperand(1);
  bool isMLA = false;
  EVT OVT = VT;
  if (VT.is64BitVector()) {
    if (N0.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
        isNullConstant(N0.getOperand(1)) &&
        N0.getOperand(0).getValueType().is128BitVector() &&
        N1.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
        isNullConstant(N1.getOperand(1)) &&
        N1.getOperand(0).getValueType().is128BitVector()) {
      N0 = N0.getOperand(0);
      N1 = N1.getOperand(0);
      VT = N0.getValueType();
    } else {
      if (VT == MVT::v1i64) {
        if (Subtarget->hasSVE())
          return LowerToPredicatedOp(Op, DAG, AArch64ISD::MUL_PRED);
        // Fall through to expand this.  It is not legal.
        return SDValue();
      } else
        // Other vector multiplications are legal.
        return Op;
    }
  }
 
  SDLoc DL(Op);
  unsigned NewOpc = selectUmullSmull(N0, N1, DAG, DL, isMLA);
 
  if (!NewOpc) {
    if (VT.getVectorElementType() == MVT::i64) {
      // If SVE is available then i64 vector multiplications can also be made
      // legal.
      if (Subtarget->hasSVE())
        return LowerToPredicatedOp(Op, DAG, AArch64ISD::MUL_PRED);
      // Try to optimize the mul to a shift left and add instead of scalarizing.
      if (SDValue ShlAdd = convertMulToShlAdd(Op.getNode(), DAG))
        return ShlAdd;
      // Fall through to expanding as the mul is not legal.
      return SDValue();
    } else
      // Other vector multiplications are legal.
      return Op;
  }
 
  // Legalize to a S/UMULL instruction
  SDValue Op0;
  SDValue Op1 = skipExtensionForVectorMULL(N1, DAG);
  if (!isMLA) {
    Op0 = skipExtensionForVectorMULL(N0, DAG);
    assert(Op0.getValueType().is64BitVector() &&
           Op1.getValueType().is64BitVector() &&
           "unexpected types for extended operands to VMULL");
    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, OVT,
                       DAG.getNode(NewOpc, DL, VT, Op0, Op1),
                       DAG.getConstant(0, DL, MVT::i64));
  }
  // Optimizing (zext A + zext B) * C, to (S/UMULL A, C) + (S/UMULL B, C) during
  // isel lowering to take advantage of no-stall back to back s/umul + s/umla.
  // This is true for CPUs with accumulate forwarding such as Cortex-A53/A57
  SDValue N00 = skipExtensionForVectorMULL(N0.getOperand(0), DAG);
  SDValue N01 = skipExtensionForVectorMULL(N0.getOperand(1), DAG);
  EVT Op1VT = Op1.getValueType();
  return DAG.getNode(
      ISD::EXTRACT_SUBVECTOR, DL, OVT,
      DAG.getNode(N0.getOpcode(), DL, VT,
                  DAG.getNode(NewOpc, DL, VT,
                              DAG.getNode(ISD::BITCAST, DL, Op1VT, N00), Op1),
                  DAG.getNode(NewOpc, DL, VT,
                              DAG.getNode(ISD::BITCAST, DL, Op1VT, N01), Op1)),
      DAG.getConstant(0, DL, MVT::i64));
}
 
static inline SDValue getPTrue(SelectionDAG &DAG, SDLoc DL, EVT VT,
                               int Pattern) {
  if (Pattern == AArch64SVEPredPattern::all)
    return DAG.getConstant(1, DL, VT);
 
  // When the number of active elements of a pattern matches the scalable vector
  // length, we can upgrade the pattern to ALL and emit a splat instead.
  if (unsigned PatNumElts = getNumElementsFromSVEPredPattern(Pattern)) {
    const AArch64Subtarget &Subtarget = DAG.getSubtarget<AArch64Subtarget>();
    unsigned NumElts = VT.getVectorMinNumElements();
    unsigned VScale = Subtarget.getSVEVectorSizeInBits() / 128;
    if (PatNumElts == (NumElts * VScale))
      return DAG.getConstant(1, DL, VT);
  }
 
  return DAG.getNode(AArch64ISD::PTRUE, DL, VT,
                     DAG.getTargetConstant(Pattern, DL, MVT::i32));
}
 
static SDValue optimizeIncrementingWhile(SDNode *N, SelectionDAG &DAG,
                                         bool IsSigned, bool IsEqual) {
  unsigned Op0 = N->getOpcode() == ISD::INTRINSIC_WO_CHAIN ? 1 : 0;
  unsigned Op1 = N->getOpcode() == ISD::INTRINSIC_WO_CHAIN ? 2 : 1;
 
  if (!N->getValueType(0).isScalableVector() ||
      !isa<ConstantSDNode>(N->getOperand(Op1)))
    return SDValue();
 
  SDLoc DL(N);
  APInt Y = N->getConstantOperandAPInt(Op1);
 
  // When the second operand is the maximum value, comparisons that include
  // equality can never fail and thus we can return an all active predicate.
  if (IsEqual)
    if (IsSigned ? Y.isMaxSignedValue() : Y.isMaxValue())
      return DAG.getConstant(1, DL, N->getValueType(0));
 
  if (!isa<ConstantSDNode>(N->getOperand(Op0)))
    return SDValue();
 
  APInt X = N->getConstantOperandAPInt(Op0);
 
  bool Overflow;
  APInt NumActiveElems =
      IsSigned ? Y.ssub_ov(X, Overflow) : Y.usub_ov(X, Overflow);
 
  if (Overflow)
    return SDValue();
 
  if (IsEqual) {
    APInt One(NumActiveElems.getBitWidth(), 1, IsSigned);
    NumActiveElems = IsSigned ? NumActiveElems.sadd_ov(One, Overflow)
                              : NumActiveElems.uadd_ov(One, Overflow);
    if (Overflow)
      return SDValue();
  }
 
  std::optional<unsigned> PredPattern =
      getSVEPredPatternFromNumElements(NumActiveElems.getZExtValue());
  unsigned MinSVEVectorSize = std::max(
      DAG.getSubtarget<AArch64Subtarget>().getMinSVEVectorSizeInBits(), 128u);
  unsigned ElementSize = 128 / N->getValueType(0).getVectorMinNumElements();
  if (PredPattern != std::nullopt &&
      NumActiveElems.getZExtValue() <= (MinSVEVectorSize / ElementSize))
    return getPTrue(DAG, DL, N->getValueType(0), *PredPattern);
 
  return SDValue();
}
 
// Match get.active.lane.mask(0, cttz.elts(x)) -> brkb(x)
// Match get.active.lane.mask(0, add(cttz.elts(x), 1)) -> brka(x)
static SDValue optimizeBrk(SDNode *N, SelectionDAG &DAG) {
  SDLoc DL(N);
  EVT VT = N->getValueType(0);
  // Lower bound must be 0.
  if (!isZeroOrZeroSplat(N->getOperand(0)))
    return SDValue();
 
  SDValue Upper = N->getOperand(1);
 
  // Default to brkb, switch to brka if we find a +1.
  unsigned BrkID = Intrinsic::aarch64_sve_brkb_z;
  if (Upper->getOpcode() == ISD::ADD && isOneOrOneSplat(Upper.getOperand(1))) {
    Upper = Upper.getOperand(0);
    BrkID = Intrinsic::aarch64_sve_brka_z;
  }
 
  // We're looking for an upper bound based on CTTZ_ELTS; this would be selected
  // as a cntp(brk(Pg, Mask)), but if we're just going to make a whilelo based
  // on that then we just need the brk.
  if (Upper.getOpcode() != AArch64ISD::CTTZ_ELTS || !VT.isScalableVector() ||
      Upper.getOperand(0).getValueType() != VT)
    return SDValue();
 
  SDValue Pg = Upper->getOperand(0);
  SDValue Mask = Upper->getOperand(1);
 
  // brk{a,b} only support .b forms, so cast to make sure all our p regs match.
  Pg = getSVEPredicateBitCast(MVT::nxv16i1, Pg, DAG);
  SDValue MaskR =
      DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, MVT::nxv16i1, Mask);
  SDValue ID = DAG.getTargetConstant(BrkID, DL, MVT::i64);
  SDValue Brk =
      DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, MVT::nxv16i1, ID, Pg, MaskR);
  return DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, VT, Brk);
}
 
// Returns a safe bitcast between two scalable vector predicates, where
// any newly created lanes from a widening bitcast are defined as zero.
static SDValue getSVEPredicateBitCast(EVT VT, SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  EVT InVT = Op.getValueType();
 
  assert(InVT.getVectorElementType() == MVT::i1 &&
         VT.getVectorElementType() == MVT::i1 &&
         "Expected a predicate-to-predicate bitcast");
  assert(VT.isScalableVector() && DAG.getTargetLoweringInfo().isTypeLegal(VT) &&
         InVT.isScalableVector() &&
         DAG.getTargetLoweringInfo().isTypeLegal(InVT) &&
         "Only expect to cast between legal scalable predicate types!");
 
  // Return the operand if the cast isn't changing type,
  if (InVT == VT)
    return Op;
 
  // Look through casts to <vscale x 16 x i1> when their input has more lanes
  // than VT. This will increase the chances of removing casts that introduce
  // new lanes, which have to be explicitly zero'd.
  if (Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN &&
      Op.getConstantOperandVal(0) == Intrinsic::aarch64_sve_convert_to_svbool &&
      Op.getOperand(1).getValueType().bitsGT(VT))
    Op = Op.getOperand(1);
 
  SDValue Reinterpret = DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, VT, Op);
 
  // We only have to zero the lanes if new lanes are being defined, e.g. when
  // casting from <vscale x 2 x i1> to <vscale x 16 x i1>. If this is not the
  // case (e.g. when casting from <vscale x 16 x i1> -> <vscale x 2 x i1>) then
  // we can return here.
  if (InVT.bitsGT(VT))
    return Reinterpret;
 
  // Check if the other lanes are already known to be zeroed by
  // construction.
  if (isZeroingInactiveLanes(Op))
    return Reinterpret;
 
  // Zero the newly introduced lanes.
  SDValue Mask = DAG.getConstant(1, DL, InVT);
  Mask = DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, VT, Mask);
  return DAG.getNode(ISD::AND, DL, VT, Reinterpret, Mask);
}
 
SDValue AArch64TargetLowering::getRuntimePStateSM(SelectionDAG &DAG,
                                                  SDValue Chain, SDLoc DL,
                                                  EVT VT) const {
  RTLIB::Libcall LC = RTLIB::SMEABI_SME_STATE;
  RTLIB::LibcallImpl LCImpl = DAG.getLibcalls().getLibcallImpl(LC);
  SDValue Callee =
      DAG.getExternalSymbol(LCImpl, getPointerTy(DAG.getDataLayout()));
  Type *Int64Ty = Type::getInt64Ty(*DAG.getContext());
  Type *RetTy = StructType::get(Int64Ty, Int64Ty);
  TargetLowering::CallLoweringInfo CLI(DAG);
  ArgListTy Args;
  CLI.setDebugLoc(DL).setChain(Chain).setLibCallee(
      DAG.getLibcalls().getLibcallImplCallingConv(LCImpl), RetTy, Callee,
      std::move(Args));
  std::pair<SDValue, SDValue> CallResult = LowerCallTo(CLI);
  SDValue Mask = DAG.getConstant(/*PSTATE.SM*/ 1, DL, MVT::i64);
  return DAG.getNode(ISD::AND, DL, MVT::i64, CallResult.first.getOperand(0),
                     Mask);
}
 
// Lower an SME LDR/STR ZA intrinsic
// Case 1: If the vector number (vecnum) is an immediate in range, it gets
// folded into the instruction
//    ldr(%tileslice, %ptr, 11) -> ldr [%tileslice, 11], [%ptr, 11]
// Case 2: If the vecnum is not an immediate, then it is used to modify the base
// and tile slice registers
//    ldr(%tileslice, %ptr, %vecnum)
//    ->
//    %svl = rdsvl
//    %ptr2 = %ptr + %svl * %vecnum
//    %tileslice2 = %tileslice + %vecnum
//    ldr [%tileslice2, 0], [%ptr2, 0]
// Case 3: If the vecnum is an immediate out of range, then the same is done as
// case 2, but the base and slice registers are modified by the greatest
// multiple of 15 lower than the vecnum and the remainder is folded into the
// instruction. This means that successive loads and stores that are offset from
// each other can share the same base and slice register updates.
//    ldr(%tileslice, %ptr, 22)
//    ldr(%tileslice, %ptr, 23)
//    ->
//    %svl = rdsvl
//    %ptr2 = %ptr + %svl * 15
//    %tileslice2 = %tileslice + 15
//    ldr [%tileslice2, 7], [%ptr2, 7]
//    ldr [%tileslice2, 8], [%ptr2, 8]
// Case 4: If the vecnum is an add of an immediate, then the non-immediate
// operand and the immediate can be folded into the instruction, like case 2.
//    ldr(%tileslice, %ptr, %vecnum + 7)
//    ldr(%tileslice, %ptr, %vecnum + 8)
//    ->
//    %svl = rdsvl
//    %ptr2 = %ptr + %svl * %vecnum
//    %tileslice2 = %tileslice + %vecnum
//    ldr [%tileslice2, 7], [%ptr2, 7]
//    ldr [%tileslice2, 8], [%ptr2, 8]
// Case 5: The vecnum being an add of an immediate out of range is also handled,
// in which case the same remainder logic as case 3 is used.
SDValue LowerSMELdrStr(SDValue N, SelectionDAG &DAG, bool IsLoad) {
  SDLoc DL(N);
 
  SDValue TileSlice = N->getOperand(2);
  SDValue Base = N->getOperand(3);
  SDValue VecNum = N->getOperand(4);
  int32_t ConstAddend = 0;
  SDValue VarAddend = VecNum;
 
  // If the vnum is an add of an immediate, we can fold it into the instruction
  if (VecNum.getOpcode() == ISD::ADD &&
      isa<ConstantSDNode>(VecNum.getOperand(1))) {
    ConstAddend = cast<ConstantSDNode>(VecNum.getOperand(1))->getSExtValue();
    VarAddend = VecNum.getOperand(0);
  } else if (auto ImmNode = dyn_cast<ConstantSDNode>(VecNum)) {
    ConstAddend = ImmNode->getSExtValue();
    VarAddend = SDValue();
  }
 
  int32_t ImmAddend = ConstAddend % 16;
  if (int32_t C = (ConstAddend - ImmAddend)) {
    SDValue CVal = DAG.getTargetConstant(C, DL, MVT::i32);
    VarAddend = VarAddend
                    ? DAG.getNode(ISD::ADD, DL, MVT::i32, {VarAddend, CVal})
                    : CVal;
  }
 
  if (VarAddend) {
    // Get the vector length that will be multiplied by vnum
    auto SVL = DAG.getNode(AArch64ISD::RDSVL, DL, MVT::i64,
                           DAG.getConstant(1, DL, MVT::i32));
 
    // Multiply SVL and vnum then add it to the base
    SDValue Mul = DAG.getNode(
        ISD::MUL, DL, MVT::i64,
        {SVL, DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, VarAddend)});
    Base = DAG.getNode(ISD::ADD, DL, MVT::i64, {Base, Mul});
    // Just add vnum to the tileslice
    TileSlice = DAG.getNode(ISD::ADD, DL, MVT::i32, {TileSlice, VarAddend});
  }
 
  return DAG.getNode(IsLoad ? AArch64ISD::SME_ZA_LDR : AArch64ISD::SME_ZA_STR,
                     DL, MVT::Other,
                     {/*Chain=*/N.getOperand(0), TileSlice, Base,
                      DAG.getTargetConstant(ImmAddend, DL, MVT::i32)});
}
 
SDValue LowerVectorMatch(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  SDValue ID =
      DAG.getTargetConstant(Intrinsic::aarch64_sve_match, DL, MVT::i64);
 
  auto Op1 = Op.getOperand(1);
  auto Op2 = Op.getOperand(2);
  auto Mask = Op.getOperand(3);
 
  EVT Op1VT = Op1.getValueType();
  EVT Op2VT = Op2.getValueType();
  EVT ResVT = Op.getValueType();
 
  assert((Op1VT.getVectorElementType() == MVT::i8 ||
          Op1VT.getVectorElementType() == MVT::i16) &&
         "Expected 8-bit or 16-bit characters.");
 
  // Scalable vector type used to wrap operands.
  // A single container is enough for both operands because ultimately the
  // operands will have to be wrapped to the same type (nxv16i8 or nxv8i16).
  EVT OpContainerVT = Op1VT.isScalableVector()
                          ? Op1VT
                          : getContainerForFixedLengthVector(DAG, Op1VT);
 
  if (Op2VT.is128BitVector()) {
    // If Op2 is a full 128-bit vector, wrap it trivially in a scalable vector.
    Op2 = convertToScalableVector(DAG, OpContainerVT, Op2);
    // Further, if the result is scalable, broadcast Op2 to a full SVE register.
    if (ResVT.isScalableVector())
      Op2 = DAG.getNode(AArch64ISD::DUPLANE128, DL, OpContainerVT, Op2,
                        DAG.getTargetConstant(0, DL, MVT::i64));
  } else {
    // If Op2 is not a full 128-bit vector, we always need to broadcast it.
    unsigned Op2BitWidth = Op2VT.getFixedSizeInBits();
    MVT Op2IntVT = MVT::getIntegerVT(Op2BitWidth);
    EVT Op2PromotedVT = getPackedSVEVectorVT(Op2IntVT);
    Op2 = DAG.getBitcast(MVT::getVectorVT(Op2IntVT, 1), Op2);
    Op2 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, Op2IntVT, Op2,
                      DAG.getConstant(0, DL, MVT::i64));
    Op2 = DAG.getSplatVector(Op2PromotedVT, DL, Op2);
    Op2 = DAG.getBitcast(OpContainerVT, Op2);
  }
 
  // If the result is scalable, we just need to carry out the MATCH.
  if (ResVT.isScalableVector())
    return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, ResVT, ID, Mask, Op1, Op2);
 
  // If the result is fixed, we can still use MATCH but we need to wrap the
  // first operand and the mask in scalable vectors before doing so.
 
  // Wrap the operands.
  Op1 = convertToScalableVector(DAG, OpContainerVT, Op1);
  Mask = DAG.getNode(ISD::SIGN_EXTEND, DL, Op1VT, Mask);
  Mask = convertFixedMaskToScalableVector(Mask, DAG);
 
  // Carry out the match.
  SDValue Match = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, Mask.getValueType(),
                              ID, Mask, Op1, Op2);
 
  // Extract and promote the match result (nxv16i1/nxv8i1) to ResVT
  // (v16i8/v8i8).
  Match = DAG.getNode(ISD::SIGN_EXTEND, DL, OpContainerVT, Match);
  Match = convertFromScalableVector(DAG, Op1VT, Match);
  return DAG.getNode(ISD::TRUNCATE, DL, ResVT, Match);
}
 
SDValue AArch64TargetLowering::LowerINTRINSIC_VOID(SDValue Op,
                                                   SelectionDAG &DAG) const {
  unsigned IntNo = Op.getConstantOperandVal(1);
  SDLoc DL(Op);
  switch (IntNo) {
  default:
    return SDValue(); // Don't custom lower most intrinsics.
  case Intrinsic::aarch64_prefetch: {
    SDValue Chain = Op.getOperand(0);
    SDValue Addr = Op.getOperand(2);
 
    unsigned IsWrite = Op.getConstantOperandVal(3);
    unsigned Locality = Op.getConstantOperandVal(4);
    unsigned IsStream = Op.getConstantOperandVal(5);
    unsigned IsData = Op.getConstantOperandVal(6);
    unsigned PrfOp = (IsWrite << 4) |    // Load/Store bit
                     (!IsData << 3) |    // IsDataCache bit
                     (Locality << 1) |   // Cache level bits
                     (unsigned)IsStream; // Stream bit
 
    return DAG.getNode(AArch64ISD::PREFETCH, DL, MVT::Other, Chain,
                       DAG.getTargetConstant(PrfOp, DL, MVT::i32), Addr);
  }
  case Intrinsic::aarch64_range_prefetch: {
    SDValue Chain = Op.getOperand(0);
    SDValue Addr = Op.getOperand(2);
 
    unsigned IsWrite = Op.getConstantOperandVal(3);
    unsigned IsStream = Op.getConstantOperandVal(4);
    unsigned PrfOp = (IsStream << 2) | IsWrite;
 
    SDValue Metadata = Op.getOperand(5);
    return DAG.getNode(AArch64ISD::RANGE_PREFETCH, DL, MVT::Other, Chain,
                       DAG.getTargetConstant(PrfOp, DL, MVT::i32), Addr,
                       Metadata);
  }
  case Intrinsic::aarch64_prefetch_ir:
    return DAG.getNode(AArch64ISD::PREFETCH, DL, MVT::Other,
                       Op.getOperand(0),                        // Chain
                       DAG.getTargetConstant(24, DL, MVT::i32), // Rt
                       Op.getOperand(2));                       // Addr
  case Intrinsic::aarch64_sme_str:
  case Intrinsic::aarch64_sme_ldr: {
    return LowerSMELdrStr(Op, DAG, IntNo == Intrinsic::aarch64_sme_ldr);
  }
  case Intrinsic::aarch64_sme_za_enable:
    return DAG.getNode(
        AArch64ISD::SMSTART, DL, DAG.getVTList(MVT::Other, MVT::Glue),
        Op->getOperand(0), // Chain
        DAG.getTargetConstant((int32_t)(AArch64SVCR::SVCRZA), DL, MVT::i32));
  case Intrinsic::aarch64_sme_za_disable:
    return DAG.getNode(
        AArch64ISD::SMSTOP, DL, DAG.getVTList(MVT::Other, MVT::Glue),
        Op->getOperand(0), // Chain
        DAG.getTargetConstant((int32_t)(AArch64SVCR::SVCRZA), DL, MVT::i32));
  }
}
 
SDValue AArch64TargetLowering::LowerINTRINSIC_W_CHAIN(SDValue Op,
                                                      SelectionDAG &DAG) const {
  unsigned IntNo = Op.getConstantOperandVal(1);
  SDLoc DL(Op);
  switch (IntNo) {
  default:
    return SDValue(); // Don't custom lower most intrinsics.
  case Intrinsic::aarch64_mops_memset_tag: {
    auto Node = cast<MemIntrinsicSDNode>(Op.getNode());
    SDValue Chain = Node->getChain();
    SDValue Dst = Op.getOperand(2);
    SDValue Val = Op.getOperand(3);
    Val = DAG.getAnyExtOrTrunc(Val, DL, MVT::i64);
    SDValue Size = Op.getOperand(4);
    auto Alignment = Node->getMemOperand()->getAlign();
    bool IsVol = Node->isVolatile();
    auto DstPtrInfo = Node->getPointerInfo();
 
    const auto &SDI =
        static_cast<const AArch64SelectionDAGInfo &>(DAG.getSelectionDAGInfo());
    SDValue MS = SDI.EmitMOPS(AArch64::MOPSMemorySetTaggingPseudo, DAG, DL,
                              Chain, Dst, Val, Size, Alignment, IsVol,
                              DstPtrInfo, MachinePointerInfo{});
 
    // MOPS_MEMSET_TAGGING has 3 results (DstWb, SizeWb, Chain) whereas the
    // intrinsic has 2. So hide SizeWb using MERGE_VALUES. Otherwise
    // LowerOperationWrapper will complain that the number of results has
    // changed.
    return DAG.getMergeValues({MS.getValue(0), MS.getValue(2)}, DL);
  }
  }
}
 
SDValue AArch64TargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op,
                                                     SelectionDAG &DAG) const {
  unsigned IntNo = Op.getConstantOperandVal(0);
  SDLoc DL(Op);
  switch (IntNo) {
  default: return SDValue();    // Don't custom lower most intrinsics.
  case Intrinsic::thread_pointer: {
    EVT PtrVT = getPointerTy(DAG.getDataLayout());
    return DAG.getNode(AArch64ISD::THREAD_POINTER, DL, PtrVT);
  }
  case Intrinsic::aarch64_sve_whilewr_b:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_WAR_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(1, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilewr_h:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_WAR_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(2, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilewr_s:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_WAR_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(4, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilewr_d:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_WAR_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(8, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilerw_b:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_RAW_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(1, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilerw_h:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_RAW_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(2, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilerw_s:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_RAW_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(4, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_sve_whilerw_d:
    return DAG.getNode(ISD::LOOP_DEPENDENCE_RAW_MASK, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(8, DL, MVT::i64),
                       DAG.getConstant(0, DL, MVT::i64));
  case Intrinsic::aarch64_neon_abs: {
    EVT Ty = Op.getValueType();
    if (Ty == MVT::i64) {
      SDValue Result =
          DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v1i64, Op.getOperand(1));
      Result = DAG.getNode(ISD::ABS, DL, MVT::v1i64, Result);
      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::i64, Result,
                         DAG.getConstant(0, DL, MVT::i64));
    } else if (Ty.isVector() && Ty.isInteger() && isTypeLegal(Ty)) {
      return DAG.getNode(ISD::ABS, DL, Ty, Op.getOperand(1));
    } else {
      report_fatal_error("Unexpected type for AArch64 NEON intrinsic");
    }
  }
  case Intrinsic::aarch64_neon_pmull64: {
    SDValue LHS = Op.getOperand(1);
    SDValue RHS = Op.getOperand(2);
 
    std::optional<uint64_t> LHSLane =
        getConstantLaneNumOfExtractHalfOperand(LHS);
    std::optional<uint64_t> RHSLane =
        getConstantLaneNumOfExtractHalfOperand(RHS);
 
    assert((!LHSLane || *LHSLane < 2) && "Expect lane to be None or 0 or 1");
    assert((!RHSLane || *RHSLane < 2) && "Expect lane to be None or 0 or 1");
 
    // 'aarch64_neon_pmull64' takes i64 parameters; while pmull/pmull2
    // instructions execute on SIMD registers. So canonicalize i64 to v1i64,
    // which ISel recognizes better. For example, generate a ldr into d*
    // registers as opposed to a GPR load followed by a fmov.
    auto TryVectorizeOperand = [](SDValue N, std::optional<uint64_t> NLane,
                                  std::optional<uint64_t> OtherLane,
                                  const SDLoc &DL,
                                  SelectionDAG &DAG) -> SDValue {
      // If the operand is an higher half itself, rewrite it to
      // extract_high_v2i64; this way aarch64_neon_pmull64 could
      // re-use the dag-combiner function with aarch64_neon_{pmull,smull,umull}.
      if (NLane == 1)
        return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v1i64,
                           N.getOperand(0), DAG.getConstant(1, DL, MVT::i64));
 
      // Operand N is not a higher half but the other operand is.
      if (OtherLane == 1) {
        // If this operand is a lower half, rewrite it to
        // extract_high_v2i64(duplane(<2 x Ty>, 0)). This saves a roundtrip to
        // align lanes of two operands. A roundtrip sequence (to move from lane
        // 1 to lane 0) is like this:
        //   mov x8, v0.d[1]
        //   fmov d0, x8
        if (NLane == 0)
          return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v1i64,
                             DAG.getNode(AArch64ISD::DUPLANE64, DL, MVT::v2i64,
                                         N.getOperand(0),
                                         DAG.getConstant(0, DL, MVT::i64)),
                             DAG.getConstant(1, DL, MVT::i64));
 
        // Otherwise just dup from main to all lanes.
        return DAG.getNode(AArch64ISD::DUP, DL, MVT::v1i64, N);
      }
 
      // Neither operand is an extract of higher half, so codegen may just use
      // the non-high version of PMULL instruction. Use v1i64 to represent i64.
      assert(N.getValueType() == MVT::i64 &&
             "Intrinsic aarch64_neon_pmull64 requires i64 parameters");
      return DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, MVT::v1i64, N);
    };
 
    LHS = TryVectorizeOperand(LHS, LHSLane, RHSLane, DL, DAG);
    RHS = TryVectorizeOperand(RHS, RHSLane, LHSLane, DL, DAG);
 
    return DAG.getNode(AArch64ISD::PMULL, DL, Op.getValueType(), LHS, RHS);
  }
  case Intrinsic::aarch64_neon_smax:
    return DAG.getNode(ISD::SMAX, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  case Intrinsic::aarch64_neon_umax:
    return DAG.getNode(ISD::UMAX, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  case Intrinsic::aarch64_neon_smin:
    return DAG.getNode(ISD::SMIN, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  case Intrinsic::aarch64_neon_umin:
    return DAG.getNode(ISD::UMIN, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  case Intrinsic::aarch64_neon_scalar_sqxtn:
  case Intrinsic::aarch64_neon_scalar_sqxtun:
  case Intrinsic::aarch64_neon_scalar_uqxtn: {
    assert(Op.getValueType() == MVT::i32 || Op.getValueType() == MVT::f32);
    if (Op.getValueType() == MVT::i32)
      return DAG.getNode(ISD::BITCAST, DL, MVT::i32,
                         DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, MVT::f32,
                                     Op.getOperand(0),
                                     DAG.getNode(ISD::BITCAST, DL, MVT::f64,
                                                 Op.getOperand(1))));
    return SDValue();
  }
  case Intrinsic::aarch64_neon_sqxtn:
    return DAG.getNode(ISD::TRUNCATE_SSAT_S, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_neon_sqxtun:
    return DAG.getNode(ISD::TRUNCATE_SSAT_U, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_neon_uqxtn:
    return DAG.getNode(ISD::TRUNCATE_USAT_U, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_neon_sqshrn:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_SSAT_S, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::VASHR, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQSHRN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_sqshrun:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_SSAT_U, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::VASHR, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQSHRUN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_uqshrn:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_USAT_U, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::VLSHR, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQSHRN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_sqrshrn:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_SSAT_S, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::SRSHR_I, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRSHRN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_sqrshrun:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_SSAT_U, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::SRSHR_I, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRSHRUN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_uqrshrn:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::TRUNCATE_USAT_U, DL, Op.getValueType(),
                         DAG.getNode(AArch64ISD::URSHR_I, DL,
                                     Op.getOperand(1).getValueType(),
                                     Op.getOperand(1), Op.getOperand(2)));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQRSHRN, DAG,
                                 /*LastOperandIsImm=*/true);
  case Intrinsic::aarch64_neon_sqdmulh:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQDMULH, DAG);
  case Intrinsic::aarch64_neon_sqrdmulh:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRDMULH, DAG);
  case Intrinsic::aarch64_neon_sqrdmlah:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRDMLAH, DAG);
  case Intrinsic::aarch64_neon_sqrdmlsh:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRDMLSH, DAG);
  case Intrinsic::aarch64_neon_sqrshl:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQRSHL, DAG);
  case Intrinsic::aarch64_neon_sqshl:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQSHL, DAG);
  case Intrinsic::aarch64_neon_uqrshl:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQRSHL, DAG);
  case Intrinsic::aarch64_neon_uqshl:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQSHL, DAG);
  case Intrinsic::aarch64_neon_sqadd:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::SADDSAT, DL, Op.getValueType(), Op.getOperand(1),
                         Op.getOperand(2));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQADD, DAG);
 
  case Intrinsic::aarch64_neon_sqsub:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::SSUBSAT, DL, Op.getValueType(), Op.getOperand(1),
                         Op.getOperand(2));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQSUB, DAG);
 
  case Intrinsic::aarch64_neon_uqadd:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::UADDSAT, DL, Op.getValueType(), Op.getOperand(1),
                         Op.getOperand(2));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQADD, DAG);
  case Intrinsic::aarch64_neon_suqadd:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SUQADD, DAG);
  case Intrinsic::aarch64_neon_usqadd:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::USQADD, DAG);
  case Intrinsic::aarch64_neon_uqsub:
    if (Op.getValueType().isVector())
      return DAG.getNode(ISD::USUBSAT, DL, Op.getValueType(), Op.getOperand(1),
                         Op.getOperand(2));
    return lowerIntNeonIntrinsic(Op, AArch64ISD::UQSUB, DAG);
  case Intrinsic::aarch64_neon_sqdmulls_scalar:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQDMULL, DAG);
  case Intrinsic::aarch64_neon_sqabs:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQABS, DAG);
  case Intrinsic::aarch64_neon_sqneg:
    return lowerIntNeonIntrinsic(Op, AArch64ISD::SQNEG, DAG);
  case Intrinsic::aarch64_sve_whilelt:
    return optimizeIncrementingWhile(Op.getNode(), DAG, /*IsSigned=*/true,
                                     /*IsEqual=*/false);
  case Intrinsic::aarch64_sve_whilels:
    return optimizeIncrementingWhile(Op.getNode(), DAG, /*IsSigned=*/false,
                                     /*IsEqual=*/true);
  case Intrinsic::aarch64_sve_whilele:
    return optimizeIncrementingWhile(Op.getNode(), DAG, /*IsSigned=*/true,
                                     /*IsEqual=*/true);
  case Intrinsic::aarch64_sve_sunpkhi:
    return DAG.getNode(AArch64ISD::SUNPKHI, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_sunpklo:
    return DAG.getNode(AArch64ISD::SUNPKLO, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_uunpkhi:
    return DAG.getNode(AArch64ISD::UUNPKHI, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_uunpklo:
    return DAG.getNode(AArch64ISD::UUNPKLO, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_clasta_n:
    return DAG.getNode(AArch64ISD::CLASTA_N, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
  case Intrinsic::aarch64_sve_clastb_n:
    return DAG.getNode(AArch64ISD::CLASTB_N, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
  case Intrinsic::aarch64_sve_lasta:
    return DAG.getNode(AArch64ISD::LASTA, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_lastb:
    return DAG.getNode(AArch64ISD::LASTB, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_tbl:
    return DAG.getNode(AArch64ISD::TBL, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  case Intrinsic::aarch64_sve_trn1:
    return DAG.getNode(AArch64ISD::TRN1, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_trn2:
    return DAG.getNode(AArch64ISD::TRN2, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_uzp1:
    return DAG.getNode(AArch64ISD::UZP1, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_uzp2:
    return DAG.getNode(AArch64ISD::UZP2, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_zip1:
    return DAG.getNode(AArch64ISD::ZIP1, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_zip2:
    return DAG.getNode(AArch64ISD::ZIP2, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_splice:
    return DAG.getNode(AArch64ISD::SPLICE, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
  case Intrinsic::aarch64_sve_ptrue:
    return getPTrue(DAG, DL, Op.getValueType(), Op.getConstantOperandVal(1));
  case Intrinsic::aarch64_sve_clz:
    return DAG.getNode(AArch64ISD::CTLZ_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sme_cntsd: {
    SDValue Bytes = DAG.getNode(AArch64ISD::RDSVL, DL, Op.getValueType(),
                                DAG.getConstant(1, DL, MVT::i32));
    return DAG.getNode(ISD::SRL, DL, Op.getValueType(), Bytes,
                       DAG.getConstant(3, DL, MVT::i32), SDNodeFlags::Exact);
  }
  case Intrinsic::aarch64_sve_cnt: {
    SDValue Data = Op.getOperand(3);
    // CTPOP only supports integer operands.
    if (Data.getValueType().isFloatingPoint())
      Data = DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Data);
    return DAG.getNode(AArch64ISD::CTPOP_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Data, Op.getOperand(1));
  }
  case Intrinsic::aarch64_sve_dupq_lane:
    return LowerDUPQLane(Op, DAG);
  case Intrinsic::aarch64_sve_convert_from_svbool:
    if (Op.getValueType() == MVT::aarch64svcount)
      return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Op.getOperand(1));
    return getSVEPredicateBitCast(Op.getValueType(), Op.getOperand(1), DAG);
  case Intrinsic::aarch64_sve_convert_to_svbool:
    if (Op.getOperand(1).getValueType() == MVT::aarch64svcount)
      return DAG.getNode(ISD::BITCAST, DL, MVT::nxv16i1, Op.getOperand(1));
    return getSVEPredicateBitCast(MVT::nxv16i1, Op.getOperand(1), DAG);
  case Intrinsic::aarch64_sve_fneg:
    return DAG.getNode(AArch64ISD::FNEG_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frintp:
    return DAG.getNode(AArch64ISD::FCEIL_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frintm:
    return DAG.getNode(AArch64ISD::FFLOOR_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frinti:
    return DAG.getNode(AArch64ISD::FNEARBYINT_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frintx:
    return DAG.getNode(AArch64ISD::FRINT_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frint32x:
    return DAG.getNode(AArch64ISD::FRINT32_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frint64x:
    return DAG.getNode(AArch64ISD::FRINT64_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frinta:
    return DAG.getNode(AArch64ISD::FROUND_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frintn:
    return DAG.getNode(AArch64ISD::FROUNDEVEN_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frintz:
    return DAG.getNode(AArch64ISD::FTRUNC_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frint32z:
    return DAG.getNode(AArch64ISD::FTRUNC32_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frint64z:
    return DAG.getNode(AArch64ISD::FTRUNC64_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_ucvtf:
    return DAG.getNode(AArch64ISD::UINT_TO_FP_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_scvtf:
    return DAG.getNode(AArch64ISD::SINT_TO_FP_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_fcvtzu:
    return DAG.getNode(AArch64ISD::FCVTZU_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_fcvtzs:
    return DAG.getNode(AArch64ISD::FCVTZS_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_fsqrt:
    return DAG.getNode(AArch64ISD::FSQRT_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frecpx:
    return DAG.getNode(AArch64ISD::FRECPX_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_frecpe_x:
    return DAG.getNode(AArch64ISD::FRECPE, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frecps_x:
    return DAG.getNode(AArch64ISD::FRECPS, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_frsqrte_x:
    return DAG.getNode(AArch64ISD::FRSQRTE, DL, Op.getValueType(),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_frsqrts_x:
    return DAG.getNode(AArch64ISD::FRSQRTS, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2));
  case Intrinsic::aarch64_sve_fabs:
    return DAG.getNode(AArch64ISD::FABS_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_abs:
    return DAG.getNode(AArch64ISD::ABS_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_neg:
    return DAG.getNode(AArch64ISD::NEG_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_insr: {
    SDValue Scalar = Op.getOperand(2);
    EVT ScalarTy = Scalar.getValueType();
    if ((ScalarTy == MVT::i8) || (ScalarTy == MVT::i16))
      Scalar = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i32, Scalar);
 
    return DAG.getNode(AArch64ISD::INSR, DL, Op.getValueType(),
                       Op.getOperand(1), Scalar);
  }
  case Intrinsic::aarch64_sve_rbit:
    return DAG.getNode(AArch64ISD::BITREVERSE_MERGE_PASSTHRU, DL,
                       Op.getValueType(), Op.getOperand(2), Op.getOperand(3),
                       Op.getOperand(1));
  case Intrinsic::aarch64_sve_revb:
    return DAG.getNode(AArch64ISD::BSWAP_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_revh:
    return DAG.getNode(AArch64ISD::REVH_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_revw:
    return DAG.getNode(AArch64ISD::REVW_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_revd:
    return DAG.getNode(AArch64ISD::REVD_MERGE_PASSTHRU, DL, Op.getValueType(),
                       Op.getOperand(2), Op.getOperand(3), Op.getOperand(1));
  case Intrinsic::aarch64_sve_sxtb:
    return DAG.getNode(
        AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i8)),
        Op.getOperand(1));
  case Intrinsic::aarch64_sve_sxth:
    return DAG.getNode(
        AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i16)),
        Op.getOperand(1));
  case Intrinsic::aarch64_sve_sxtw:
    return DAG.getNode(
        AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i32)),
        Op.getOperand(1));
  case Intrinsic::aarch64_sve_uxtb:
    return DAG.getNode(
        AArch64ISD::ZERO_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i8)),
        Op.getOperand(1));
  case Intrinsic::aarch64_sve_uxth:
    return DAG.getNode(
        AArch64ISD::ZERO_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i16)),
        Op.getOperand(1));
  case Intrinsic::aarch64_sve_uxtw:
    return DAG.getNode(
        AArch64ISD::ZERO_EXTEND_INREG_MERGE_PASSTHRU, DL, Op.getValueType(),
        Op.getOperand(2), Op.getOperand(3),
        DAG.getValueType(Op.getValueType().changeVectorElementType(
            *DAG.getContext(), MVT::i32)),
        Op.getOperand(1));
  case Intrinsic::localaddress: {
    const auto &MF = DAG.getMachineFunction();
    const auto *RegInfo = Subtarget->getRegisterInfo();
    unsigned Reg = RegInfo->getLocalAddressRegister(MF);
    return DAG.getCopyFromReg(DAG.getEntryNode(), DL, Reg,
                              Op.getSimpleValueType());
  }
 
  case Intrinsic::eh_recoverfp: {
    // FIXME: This needs to be implemented to correctly handle highly aligned
    // stack objects. For now we simply return the incoming FP. Refer D53541
    // for more details.
    SDValue FnOp = Op.getOperand(1);
    SDValue IncomingFPOp = Op.getOperand(2);
    GlobalAddressSDNode *GSD = dyn_cast<GlobalAddressSDNode>(FnOp);
    auto *Fn = dyn_cast_or_null<Function>(GSD ? GSD->getGlobal() : nullptr);
    if (!Fn)
      report_fatal_error(
          "llvm.eh.recoverfp must take a function as the first argument");
    return IncomingFPOp;
  }
  case Intrinsic::aarch64_neon_vsri:
  case Intrinsic::aarch64_neon_vsli:
  case Intrinsic::aarch64_sve_sri:
  case Intrinsic::aarch64_sve_sli: {
    EVT Ty = Op.getValueType();
 
    if (!Ty.isVector())
      report_fatal_error("Unexpected type for aarch64_neon_vsli");
 
    assert(Op.getConstantOperandVal(3) <= Ty.getScalarSizeInBits());
 
    bool IsShiftRight = IntNo == Intrinsic::aarch64_neon_vsri ||
                        IntNo == Intrinsic::aarch64_sve_sri;
    unsigned Opcode = IsShiftRight ? AArch64ISD::VSRI : AArch64ISD::VSLI;
    return DAG.getNode(Opcode, DL, Ty, Op.getOperand(1), Op.getOperand(2),
                       Op.getOperand(3));
  }
 
  case Intrinsic::aarch64_neon_srhadd:
  case Intrinsic::aarch64_neon_urhadd:
  case Intrinsic::aarch64_neon_shadd:
  case Intrinsic::aarch64_neon_uhadd: {
    bool IsSignedAdd = (IntNo == Intrinsic::aarch64_neon_srhadd ||
                        IntNo == Intrinsic::aarch64_neon_shadd);
    bool IsRoundingAdd = (IntNo == Intrinsic::aarch64_neon_srhadd ||
                          IntNo == Intrinsic::aarch64_neon_urhadd);
    unsigned Opcode = IsSignedAdd
                          ? (IsRoundingAdd ? ISD::AVGCEILS : ISD::AVGFLOORS)
                          : (IsRoundingAdd ? ISD::AVGCEILU : ISD::AVGFLOORU);
    return DAG.getNode(Opcode, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  }
  case Intrinsic::aarch64_neon_saddlp:
  case Intrinsic::aarch64_neon_uaddlp: {
    unsigned Opcode = IntNo == Intrinsic::aarch64_neon_uaddlp
                          ? AArch64ISD::UADDLP
                          : AArch64ISD::SADDLP;
    return DAG.getNode(Opcode, DL, Op.getValueType(), Op.getOperand(1));
  }
  case Intrinsic::aarch64_neon_sdot:
  case Intrinsic::aarch64_neon_udot:
  case Intrinsic::aarch64_sve_sdot:
  case Intrinsic::aarch64_sve_udot: {
    unsigned Opcode = (IntNo == Intrinsic::aarch64_neon_udot ||
                       IntNo == Intrinsic::aarch64_sve_udot)
                          ? AArch64ISD::UDOT
                          : AArch64ISD::SDOT;
    return DAG.getNode(Opcode, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2), Op.getOperand(3));
  }
  case Intrinsic::aarch64_neon_usdot:
  case Intrinsic::aarch64_sve_usdot: {
    return DAG.getNode(AArch64ISD::USDOT, DL, Op.getValueType(),
                       Op.getOperand(1), Op.getOperand(2), Op.getOperand(3));
  }
  case Intrinsic::aarch64_neon_saddlv:
  case Intrinsic::aarch64_neon_uaddlv: {
    EVT OpVT = Op.getOperand(1).getValueType();
    EVT ResVT = Op.getValueType();
    assert(
        ((ResVT == MVT::i32 && (OpVT == MVT::v8i8 || OpVT == MVT::v16i8 ||
                                OpVT == MVT::v8i16 || OpVT == MVT::v4i16)) ||
         (ResVT == MVT::i64 && (OpVT == MVT::v4i32 || OpVT == MVT::v2i32))) &&
        "Unexpected aarch64_neon_u/saddlv type");
    (void)OpVT;
    // In order to avoid insert_subvector, use v4i32 rather than v2i32.
    SDValue ADDLV = DAG.getNode(
        IntNo == Intrinsic::aarch64_neon_uaddlv ? AArch64ISD::UADDLV
                                                : AArch64ISD::SADDLV,
        DL, ResVT == MVT::i32 ? MVT::v4i32 : MVT::v2i64, Op.getOperand(1));
    SDValue EXTRACT_VEC_ELT = DAG.getNode(
        ISD::EXTRACT_VECTOR_ELT, DL, ResVT == MVT::i32 ? MVT::i32 : MVT::i64,
        ADDLV, DAG.getConstant(0, DL, MVT::i64));
    return EXTRACT_VEC_ELT;
  }
  case Intrinsic::experimental_vector_match: {
    return LowerVectorMatch(Op, DAG);
  }
  case Intrinsic::aarch64_cls:
  case Intrinsic::aarch64_cls64: {
    SDValue Res = DAG.getNode(ISD::CTLS, DL, Op.getOperand(1).getValueType(),
                              Op.getOperand(1));
    return DAG.getNode(ISD::TRUNCATE, DL, Op.getValueType(), Res);
  }
  case Intrinsic::aarch64_neon_cls: {
    // Lower NEON CLS intrinsic to ISD::CTLS
    return DAG.getNode(ISD::CTLS, DL, Op.getValueType(), Op.getOperand(1));
  }
  case Intrinsic::aarch64_sve_pmul:
  case Intrinsic::aarch64_neon_pmul:
    return DAG.getNode(ISD::CLMUL, DL, Op.getValueType(), Op.getOperand(1),
                       Op.getOperand(2));
  }
}
 
bool AArch64TargetLowering::shouldExtendGSIndex(EVT VT, EVT &EltTy) const {
  if (VT.getVectorElementType() == MVT::i8 ||
      VT.getVectorElementType() == MVT::i16) {
    EltTy = MVT::i32;
    return true;
  }
  return false;
}
 
bool AArch64TargetLowering::shouldRemoveExtendFromGSIndex(SDValue Extend,
                                                          EVT DataVT) const {
  const EVT IndexVT = Extend.getOperand(0).getValueType();
  // SVE only supports implicit extension of 32-bit indices.
  if (!Subtarget->hasSVE() || IndexVT.getVectorElementType() != MVT::i32)
    return false;
 
  // Indices cannot be smaller than the main data type.
  if (IndexVT.getScalarSizeInBits() < DataVT.getScalarSizeInBits())
    return false;
 
  // Scalable vectors with "vscale * 2" or fewer elements sit within a 64-bit
  // element container type, which would violate the previous clause.
  return DataVT.isFixedLengthVector() || DataVT.getVectorMinNumElements() > 2;
}
 
/// Helper function to check if a small vector load can be optimized.
static bool isEligibleForSmallVectorLoadOpt(LoadSDNode *LD,
                                            const AArch64Subtarget &Subtarget) {
  if (!Subtarget.isNeonAvailable())
    return false;
  if (LD->isVolatile())
    return false;
 
  EVT MemVT = LD->getMemoryVT();
  if (MemVT != MVT::v2i8 && MemVT != MVT::v4i8 && MemVT != MVT::v2i16)
    return false;
 
  Align Alignment = LD->getAlign();
  Align RequiredAlignment = Align(MemVT.getStoreSize().getFixedValue());
  if (Subtarget.requiresStrictAlign() && Alignment < RequiredAlignment)
    return false;
 
  return true;
}
 
bool AArch64TargetLowering::isVectorLoadExtDesirable(SDValue ExtVal) const {
  EVT ExtVT = ExtVal.getValueType();
  // Small, illegal vectors can be extended inreg.
  if (auto *Load = dyn_cast<LoadSDNode>(ExtVal.getOperand(0))) {
    if (ExtVT.isFixedLengthVector() && ExtVT.getStoreSizeInBits() <= 128 &&
        isEligibleForSmallVectorLoadOpt(Load, *Subtarget))
      return true;
  }
  if (!ExtVT.isScalableVector() && !Subtarget->useSVEForFixedLengthVectors())
    return false;
 
  // It may be worth creating extending masked loads if there are multiple
  // masked loads using the same predicate. That way we'll end up creating
  // extending masked loads that may then get split by the legaliser. This
  // results in just one set of predicate unpacks at the start, instead of
  // multiple sets of vector unpacks after each load.
  if (auto *Ld = dyn_cast<MaskedLoadSDNode>(ExtVal->getOperand(0))) {
    if (!isLoadLegalOrCustom(ExtVT, Ld->getValueType(0), Ld->getAlign(),
                             Ld->getAddressSpace(), ISD::ZEXTLOAD, false)) {
      // Disable extending masked loads for fixed-width for now, since the code
      // quality doesn't look great.
      if (!ExtVT.isScalableVector())
        return false;
 
      unsigned NumExtMaskedLoads = 0;
      for (auto *U : Ld->getMask()->users())
        if (isa<MaskedLoadSDNode>(U))
          NumExtMaskedLoads++;
 
      if (NumExtMaskedLoads <= 1)
        return false;
    }
  }
 
  EVT PreExtScalarVT = ExtVal->getOperand(0).getValueType().getScalarType();
  return PreExtScalarVT == MVT::i8 || PreExtScalarVT == MVT::i16 ||
         PreExtScalarVT == MVT::i32 || PreExtScalarVT == MVT::i64;
}
 
unsigned getGatherVecOpcode(bool IsScaled, bool IsSigned, bool NeedsExtend) {
  std::map<std::tuple<bool, bool, bool>, unsigned> AddrModes = {
      {std::make_tuple(/*Scaled*/ false, /*Signed*/ false, /*Extend*/ false),
       AArch64ISD::GLD1_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ false, /*Signed*/ false, /*Extend*/ true),
       AArch64ISD::GLD1_UXTW_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ false, /*Signed*/ true, /*Extend*/ false),
       AArch64ISD::GLD1_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ false, /*Signed*/ true, /*Extend*/ true),
       AArch64ISD::GLD1_SXTW_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ true, /*Signed*/ false, /*Extend*/ false),
       AArch64ISD::GLD1_SCALED_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ true, /*Signed*/ false, /*Extend*/ true),
       AArch64ISD::GLD1_UXTW_SCALED_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ true, /*Signed*/ true, /*Extend*/ false),
       AArch64ISD::GLD1_SCALED_MERGE_ZERO},
      {std::make_tuple(/*Scaled*/ true, /*Signed*/ true, /*Extend*/ true),
       AArch64ISD::GLD1_SXTW_SCALED_MERGE_ZERO},
  };
  auto Key = std::make_tuple(IsScaled, IsSigned, NeedsExtend);
  return AddrModes.find(Key)->second;
}
 
unsigned getSignExtendedGatherOpcode(unsigned Opcode) {
  switch (Opcode) {
  default:
    llvm_unreachable("unimplemented opcode");
    return Opcode;
  case AArch64ISD::GLD1_MERGE_ZERO:
    return AArch64ISD::GLD1S_MERGE_ZERO;
  case AArch64ISD::GLD1_IMM_MERGE_ZERO:
    return AArch64ISD::GLD1S_IMM_MERGE_ZERO;
  case AArch64ISD::GLD1_UXTW_MERGE_ZERO:
    return AArch64ISD::GLD1S_UXTW_MERGE_ZERO;
  case AArch64ISD::GLD1_SXTW_MERGE_ZERO:
    return AArch64ISD::GLD1S_SXTW_MERGE_ZERO;
  case AArch64ISD::GLD1_SCALED_MERGE_ZERO:
    return AArch64ISD::GLD1S_SCALED_MERGE_ZERO;
  case AArch64ISD::GLD1_UXTW_SCALED_MERGE_ZERO:
    return AArch64ISD::GLD1S_UXTW_SCALED_MERGE_ZERO;
  case AArch64ISD::GLD1_SXTW_SCALED_MERGE_ZERO:
    return AArch64ISD::GLD1S_SXTW_SCALED_MERGE_ZERO;
  }
}
 
SDValue AArch64TargetLowering::LowerMGATHER(SDValue Op,
                                            SelectionDAG &DAG) const {
  MaskedGatherSDNode *MGT = cast<MaskedGatherSDNode>(Op);
 
  SDLoc DL(Op);
  SDValue Chain = MGT->getChain();
  SDValue PassThru = MGT->getPassThru();
  SDValue Mask = MGT->getMask();
  SDValue BasePtr = MGT->getBasePtr();
  SDValue Index = MGT->getIndex();
  SDValue Scale = MGT->getScale();
  EVT VT = Op.getValueType();
  EVT MemVT = MGT->getMemoryVT();
  ISD::LoadExtType ExtType = MGT->getExtensionType();
  ISD::MemIndexType IndexType = MGT->getIndexType();
 
  // SVE supports zero (and so undef) passthrough values only, everything else
  // must be handled manually by an explicit select on the load's output.
  if (!PassThru->isUndef() && !isZerosVector(PassThru.getNode())) {
    SDValue Ops[] = {Chain, DAG.getUNDEF(VT), Mask, BasePtr, Index, Scale};
    SDValue Load =
        DAG.getMaskedGather(MGT->getVTList(), MemVT, DL, Ops,
                            MGT->getMemOperand(), IndexType, ExtType);
    SDValue Select = DAG.getSelect(DL, VT, Mask, Load, PassThru);
    return DAG.getMergeValues({Select, Load.getValue(1)}, DL);
  }
 
  bool IsScaled = MGT->isIndexScaled();
  bool IsSigned = MGT->isIndexSigned();
 
  // SVE supports an index scaled by sizeof(MemVT.elt) only, everything else
  // must be calculated before hand.
  uint64_t ScaleVal = Scale->getAsZExtVal();
  if (IsScaled && ScaleVal != MemVT.getScalarStoreSize()) {
    assert(isPowerOf2_64(ScaleVal) && "Expecting power-of-two types");
    EVT IndexVT = Index.getValueType();
    Index = DAG.getNode(ISD::SHL, DL, IndexVT, Index,
                        DAG.getConstant(Log2_32(ScaleVal), DL, IndexVT));
    Scale = DAG.getTargetConstant(1, DL, Scale.getValueType());
 
    SDValue Ops[] = {Chain, PassThru, Mask, BasePtr, Index, Scale};
    return DAG.getMaskedGather(MGT->getVTList(), MemVT, DL, Ops,
                               MGT->getMemOperand(), IndexType, ExtType);
  }
 
  // Lower fixed length gather to a scalable equivalent.
  if (VT.isFixedLengthVector()) {
    assert(Subtarget->useSVEForFixedLengthVectors() &&
           "Cannot lower when not using SVE for fixed vectors!");
 
    // NOTE: Handle floating-point as if integer then bitcast the result.
    EVT DataVT = VT.changeVectorElementTypeToInteger();
    MemVT = MemVT.changeVectorElementTypeToInteger();
 
    // Find the smallest integer fixed length vector we can use for the gather.
    EVT PromotedVT = VT.changeVectorElementType(*DAG.getContext(), MVT::i32);
    if (DataVT.getVectorElementType() == MVT::i64 ||
        Index.getValueType().getVectorElementType() == MVT::i64 ||
        Mask.getValueType().getVectorElementType() == MVT::i64)
      PromotedVT = VT.changeVectorElementType(*DAG.getContext(), MVT::i64);
 
    // Promote vector operands except for passthrough, which we know is either
    // undef or zero, and thus best constructed directly.
    unsigned ExtOpcode = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
    Index = DAG.getNode(ExtOpcode, DL, PromotedVT, Index);
    Mask = DAG.getNode(ISD::SIGN_EXTEND, DL, PromotedVT, Mask);
 
    // A promoted result type forces the need for an extending load.
    if (PromotedVT != DataVT && ExtType == ISD::NON_EXTLOAD)
      ExtType = ISD::EXTLOAD;
 
    EVT ContainerVT = getContainerForFixedLengthVector(DAG, PromotedVT);
 
    // Convert fixed length vector operands to scalable.
    MemVT = ContainerVT.changeVectorElementType(*DAG.getContext(),
                                                MemVT.getVectorElementType());
    Index = convertToScalableVector(DAG, ContainerVT, Index);
    Mask = convertFixedMaskToScalableVector(Mask, DAG);
    PassThru = PassThru->isUndef() ? DAG.getUNDEF(ContainerVT)
                                   : DAG.getConstant(0, DL, ContainerVT);
 
    // Emit equivalent scalable vector gather.
    SDValue Ops[] = {Chain, PassThru, Mask, BasePtr, Index, Scale};
    SDValue Load =
        DAG.getMaskedGather(DAG.getVTList(ContainerVT, MVT::Other), MemVT, DL,
                            Ops, MGT->getMemOperand(), IndexType, ExtType);
 
    // Extract fixed length data then convert to the required result type.
    SDValue Result = convertFromScalableVector(DAG, PromotedVT, Load);
    Result = DAG.getNode(ISD::TRUNCATE, DL, DataVT, Result);
    if (VT.isFloatingPoint())
      Result = DAG.getNode(ISD::BITCAST, DL, VT, Result);
 
    return DAG.getMergeValues({Result, Load.getValue(1)}, DL);
  }
 
  // Everything else is legal.
  return Op;
}
 
SDValue AArch64TargetLowering::LowerMSCATTER(SDValue Op,
                                             SelectionDAG &DAG) const {
  MaskedScatterSDNode *MSC = cast<MaskedScatterSDNode>(Op);
 
  SDLoc DL(Op);
  SDValue Chain = MSC->getChain();
  SDValue StoreVal = MSC->getValue();
  SDValue Mask = MSC->getMask();
  SDValue BasePtr = MSC->getBasePtr();
  SDValue Index = MSC->getIndex();
  SDValue Scale = MSC->getScale();
  EVT VT = StoreVal.getValueType();
  EVT MemVT = MSC->getMemoryVT();
  ISD::MemIndexType IndexType = MSC->getIndexType();
  bool Truncating = MSC->isTruncatingStore();
 
  bool IsScaled = MSC->isIndexScaled();
  bool IsSigned = MSC->isIndexSigned();
 
  // SVE supports an index scaled by sizeof(MemVT.elt) only, everything else
  // must be calculated before hand.
  uint64_t ScaleVal = Scale->getAsZExtVal();
  if (IsScaled && ScaleVal != MemVT.getScalarStoreSize()) {
    assert(isPowerOf2_64(ScaleVal) && "Expecting power-of-two types");
    EVT IndexVT = Index.getValueType();
    Index = DAG.getNode(ISD::SHL, DL, IndexVT, Index,
                        DAG.getConstant(Log2_32(ScaleVal), DL, IndexVT));
    Scale = DAG.getTargetConstant(1, DL, Scale.getValueType());
 
    SDValue Ops[] = {Chain, StoreVal, Mask, BasePtr, Index, Scale};
    return DAG.getMaskedScatter(MSC->getVTList(), MemVT, DL, Ops,
                                MSC->getMemOperand(), IndexType, Truncating);
  }
 
  // Lower fixed length scatter to a scalable equivalent.
  if (VT.isFixedLengthVector()) {
    assert(Subtarget->useSVEForFixedLengthVectors() &&
           "Cannot lower when not using SVE for fixed vectors!");
 
    // Once bitcast we treat floating-point scatters as if integer.
    if (VT.isFloatingPoint()) {
      VT = VT.changeVectorElementTypeToInteger();
      MemVT = MemVT.changeVectorElementTypeToInteger();
      StoreVal = DAG.getNode(ISD::BITCAST, DL, VT, StoreVal);
    }
 
    // Find the smallest integer fixed length vector we can use for the scatter.
    EVT PromotedVT = VT.changeVectorElementType(*DAG.getContext(), MVT::i32);
    if (VT.getVectorElementType() == MVT::i64 ||
        Index.getValueType().getVectorElementType() == MVT::i64 ||
        Mask.getValueType().getVectorElementType() == MVT::i64)
      PromotedVT = VT.changeVectorElementType(*DAG.getContext(), MVT::i64);
 
    // Promote vector operands.
    unsigned ExtOpcode = IsSigned ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
    Index = DAG.getNode(ExtOpcode, DL, PromotedVT, Index);
    Mask = DAG.getNode(ISD::SIGN_EXTEND, DL, PromotedVT, Mask);
    StoreVal = DAG.getNode(ISD::ANY_EXTEND, DL, PromotedVT, StoreVal);
 
    // A promoted value type forces the need for a truncating store.
    if (PromotedVT != VT)
      Truncating = true;
 
    EVT ContainerVT = getContainerForFixedLengthVector(DAG, PromotedVT);
 
    // Convert fixed length vector operands to scalable.
    MemVT = ContainerVT.changeVectorElementType(*DAG.getContext(),
                                                MemVT.getVectorElementType());
    Index = convertToScalableVector(DAG, ContainerVT, Index);
    Mask = convertFixedMaskToScalableVector(Mask, DAG);
    StoreVal = convertToScalableVector(DAG, ContainerVT, StoreVal);
 
    // Emit equivalent scalable vector scatter.
    SDValue Ops[] = {Chain, StoreVal, Mask, BasePtr, Index, Scale};
    return DAG.getMaskedScatter(MSC->getVTList(), MemVT, DL, Ops,
                                MSC->getMemOperand(), IndexType, Truncating);
  }
 
  // Everything else is legal.
  return Op;
}
 
SDValue AArch64TargetLowering::LowerMLOAD(SDValue Op, SelectionDAG &DAG) const {
  SDLoc DL(Op);
  MaskedLoadSDNode *LoadNode = cast<MaskedLoadSDNode>(Op);
  assert(LoadNode && "Expected custom lowering of a masked load node");
  EVT VT = Op->getValueType(0);
 
  if (useSVEForFixedLengthVectorVT(VT, /*OverrideNEON=*/true))
    return LowerFixedLengthVectorMLoadToSVE(Op, DAG);
 
  SDValue PassThru = LoadNode->getPassThru();
  SDValue Mask = LoadNode->getMask();
 
  if (!LoadNode->isExpandingLoad()) {
    if (PassThru->isUndef() || isZerosVector(PassThru.getNode()))
      return Op;
 
    SDValue Load = DAG.getMaskedLoad(
        VT, DL, LoadNode->getChain(), LoadNode->getBasePtr(),
        LoadNode->getOffset(), Mask, DAG.getUNDEF(VT), LoadNode->getMemoryVT(),
        LoadNode->getMemOperand(), LoadNode->getAddressingMode(),
        LoadNode->getExtensionType());
 
    SDValue Result = DAG.getSelect(DL, VT, Mask, Load, PassThru);
    return DAG.getMergeValues({Result, Load.getValue(1)}, DL);
  }
 
  // Return if EXPAND instruction is not available.
  if ((!Subtarget->isSVEAvailable() || !Subtarget->hasSVE2p2()) &&
      (!Subtarget->isSVEorStreamingSVEAvailable() || !Subtarget->hasSME2p2()))
    return SDValue();
 
  // Create mask using the number of active lanes in the predicate.
  SDValue CntActive = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, MVT::i64,
      DAG.getTargetConstant(Intrinsic::aarch64_sve_cntp, DL, MVT::i64), Mask,
      Mask);
 
  SDValue ActiveMask =
      DAG.getNode(ISD::GET_ACTIVE_LANE_MASK, DL, Mask->getValueType(0),
                  DAG.getConstant(0, DL, MVT::i64), CntActive);
 
  // Contiguous load of elements using the active lane mask above.
  SDValue Load = DAG.getMaskedLoad(
      VT, DL, LoadNode->getChain(), LoadNode->getBasePtr(),
      LoadNode->getOffset(), ActiveMask, DAG.getUNDEF(VT),
      LoadNode->getMemoryVT(), LoadNode->getMemOperand(),
      LoadNode->getAddressingMode(), LoadNode->getExtensionType());
 
  // Expand instruction copies the low-numbered elements to active elements
  // in the original predicate and zeros all other lanes.
  SDValue Result = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, VT,
      DAG.getTargetConstant(Intrinsic::aarch64_sve_expand, DL, MVT::i64), Mask,
      Load);
 
  // Copy the passthrough value unless zero/undef.
  if (!PassThru->isUndef() && !isZerosVector(PassThru.getNode()))
    Result = DAG.getSelect(DL, VT, Mask, Result, PassThru);
 
  return DAG.getMergeValues({Result, Load.getValue(1)}, DL);
}
 
// Custom lower trunc store for v4i8 vectors, since it is promoted to v4i16.
static SDValue LowerTruncateVectorStore(SDLoc DL, StoreSDNode *ST,
                                        EVT VT, EVT MemVT,
                                        SelectionDAG &DAG) {
  assert(VT.isVector() && "VT should be a vector type");
  assert(MemVT == MVT::v4i8 && VT == MVT::v4i16);
 
  SDValue Value = ST->getValue();
 
  // It first extend the promoted v4i16 to v8i16, truncate to v8i8, and extract
  // the word lane which represent the v4i8 subvector.  It optimizes the store
  // to:
  //
  //   xtn  v0.8b, v0.8h
  //   str  s0, [x0]
 
  SDValue Poison = DAG.getPOISON(MVT::i16);
  SDValue PoisonVec =
      DAG.getBuildVector(MVT::v4i16, DL, {Poison, Poison, Poison, Poison});
 
  SDValue TruncExt =
      DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v8i16, Value, PoisonVec);
  SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, MVT::v8i8, TruncExt);
 
  Trunc = DAG.getNode(ISD::BITCAST, DL, MVT::v2i32, Trunc);
  SDValue ExtractTrunc = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::i32,
                                     Trunc, DAG.getConstant(0, DL, MVT::i64));
 
  return DAG.getStore(ST->getChain(), DL, ExtractTrunc,
                      ST->getBasePtr(), ST->getMemOperand());
}
 
static SDValue LowerADDRSPACECAST(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  SDValue Src = Op.getOperand(0);
  MVT DestVT = Op.getSimpleValueType();
  const TargetLowering &TLI = DAG.getTargetLoweringInfo();
  AddrSpaceCastSDNode *N = cast<AddrSpaceCastSDNode>(Op.getNode());
 
  unsigned SrcAS = N->getSrcAddressSpace();
  unsigned DestAS = N->getDestAddressSpace();
  assert(SrcAS != DestAS &&
         "addrspacecast must be between different address spaces");
  assert(TLI.getTargetMachine().getPointerSize(SrcAS) !=
             TLI.getTargetMachine().getPointerSize(DestAS) &&
         "addrspacecast must be between different ptr sizes");
  (void)TLI;
 
  if (SrcAS == ARM64AS::PTR32_SPTR) {
    return DAG.getNode(ISD::SIGN_EXTEND, DL, DestVT, Src,
                       DAG.getTargetConstant(0, DL, DestVT));
  } else if (SrcAS == ARM64AS::PTR32_UPTR) {
    return DAG.getNode(ISD::ZERO_EXTEND, DL, DestVT, Src,
                       DAG.getTargetConstant(0, DL, DestVT));
  } else if ((DestAS == ARM64AS::PTR32_SPTR) ||
             (DestAS == ARM64AS::PTR32_UPTR)) {
    SDValue Ext = DAG.getAnyExtOrTrunc(Src, DL, DestVT);
    SDValue Trunc = DAG.getZeroExtendInReg(Ext, DL, DestVT);
    return Trunc;
  } else {
    return Src;
  }
}
 
// Coordinated with STNP handling in
// `llvm/lib/Target/AArch64/AArch64InstrInfo.td` and
// `LowerNTStore`
static bool isLegalNTStore(Type *DataType, Align Alignment,
                           const DataLayout &DL) {
  // Currently we only support NT stores lowering for little-endian targets.
  if (!DL.isLittleEndian())
    return false;
 
  // The backend can lower to STNPWi in this case
  if (DataType->isIntegerTy(64))
    return true;
 
  auto *DataTypeTy = dyn_cast<FixedVectorType>(DataType);
  if (!DataTypeTy)
    return false;
 
  // Check fixed vector legality
  unsigned NumElements = DataTypeTy->getNumElements();
  unsigned EltSizeBits = DataTypeTy->getElementType()->getScalarSizeInBits();
 
  // Currently only power-of-2 vectors are supported
  if (!isPowerOf2_64(NumElements) || !isPowerOf2_64(EltSizeBits))
    return false;
 
  unsigned TotalSizeBits = DataTypeTy->getPrimitiveSizeInBits().getFixedValue();
 
  // The backend can lower to STNPSi or STNPDi in this case
  // via `llvm/lib/Target/AArch64/AArch64InstrInfo.td`
  if (TotalSizeBits == 64u || TotalSizeBits == 128u)
    return true;
 
  // The backend can lower to STNPQi in this case via `LowerNTStore`
  if (TotalSizeBits == 256u && (EltSizeBits == 8u || EltSizeBits == 16u ||
                                EltSizeBits == 32u || EltSizeBits == 64u))
    return true;
 
  return false;
}
 
// Lower non-temporal stores that would otherwise be broken by legalization.
//
// Coordinated with STNP constraints in
// `llvm/lib/Target/AArch64/AArch64InstrInfo.td` and
// `isLegalNTStore`
static SDValue LowerNTStore(StoreSDNode *StoreNode, EVT VT, EVT MemVT,
                            const SDLoc &DL, SelectionDAG &DAG) {
  assert(StoreNode && "Expected a store operation");
  assert(StoreNode->isNonTemporal() && "Expected a non-temporal store");
 
  // Currently, STNP lowering can only either keep or increase code size, thus
  // we predicate it to not apply when optimizing for code size.
  if (DAG.shouldOptForSize())
    return SDValue();
 
  // Currently we only support NT stores lowering for little-endian targets.
  if (!DAG.getDataLayout().isLittleEndian())
    return SDValue();
 
  if (VT.isVector()) {
    // 256 bit non-temporal stores can be lowered to STNP. Do this as part of
    // the custom lowering, as there are no un-paired non-temporal stores and
    // legalization will break up 256 bit inputs.
    ElementCount EC = MemVT.getVectorElementCount();
    if (VT.isVector() && MemVT.getSizeInBits() == 256u && EC.isKnownEven() &&
        (MemVT.getScalarSizeInBits() == 8u ||
         MemVT.getScalarSizeInBits() == 16u ||
         MemVT.getScalarSizeInBits() == 32u ||
         MemVT.getScalarSizeInBits() == 64u)) {
      SDValue Lo =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL,
                      MemVT.getHalfNumVectorElementsVT(*DAG.getContext()),
                      StoreNode->getValue(), DAG.getConstant(0, DL, MVT::i64));
      SDValue Hi =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL,
                      MemVT.getHalfNumVectorElementsVT(*DAG.getContext()),
                      StoreNode->getValue(),
                      DAG.getConstant(EC.getKnownMinValue() / 2, DL, MVT::i64));
      SDValue Result = DAG.getMemIntrinsicNode(
          AArch64ISD::STNP, DL, DAG.getVTList(MVT::Other),
          {StoreNode->getChain(), DAG.getBitcast(MVT::v2i64, Lo),
           DAG.getBitcast(MVT::v2i64, Hi), StoreNode->getBasePtr()},
          StoreNode->getMemoryVT(), StoreNode->getMemOperand());
      assert(isLegalNTStore(MemVT.getTypeForEVT(*DAG.getContext()),
                            StoreNode->getAlign(), DAG.getDataLayout()) &&
             "Lowering should be consistent with legality");
      return Result;
    }
  }
  return SDValue();
}
 
// Custom lowering for any store, vector or scalar and/or default or with
// a truncate operations.  Currently only custom lower truncate operation
// from vector v4i16 to v4i8 or volatile stores of i128.
SDValue AArch64TargetLowering::LowerSTORE(SDValue Op,
                                          SelectionDAG &DAG) const {
  SDLoc Dl(Op);
  StoreSDNode *StoreNode = cast<StoreSDNode>(Op);
  assert (StoreNode && "Can only custom lower store nodes");
 
  SDValue Value = StoreNode->getValue();
 
  EVT VT = Value.getValueType();
  EVT MemVT = StoreNode->getMemoryVT();
 
  if (StoreNode->isNonTemporal()) {
    if (auto MaybeSTNP = LowerNTStore(StoreNode, VT, MemVT, Dl, DAG))
      return MaybeSTNP;
  }
 
  if (VT.isVector()) {
    if (useSVEForFixedLengthVectorVT(
            VT,
            /*OverrideNEON=*/Subtarget->useSVEForFixedLengthVectors()))
      return LowerFixedLengthVectorStoreToSVE(Op, DAG);
 
    unsigned AS = StoreNode->getAddressSpace();
    Align Alignment = StoreNode->getAlign();
    if (Alignment < MemVT.getStoreSize() &&
        !allowsMisalignedMemoryAccesses(MemVT, AS, Alignment,
                                        StoreNode->getMemOperand()->getFlags(),
                                        nullptr)) {
      return scalarizeVectorStore(StoreNode, DAG);
    }
 
    if (StoreNode->isTruncatingStore() && VT == MVT::v4i16 &&
        MemVT == MVT::v4i8) {
      return LowerTruncateVectorStore(Dl, StoreNode, VT, MemVT, DAG);
    }
  } else if (MemVT == MVT::i128 && StoreNode->isVolatile()) {
    return LowerStore128(Op, DAG);
  } else if (MemVT == MVT::i64x8) {
    SDValue Value = StoreNode->getValue();
    assert(Value->getValueType(0) == MVT::i64x8);
    SDValue Chain = StoreNode->getChain();
    SDValue Base = StoreNode->getBasePtr();
    EVT PtrVT = Base.getValueType();
    for (unsigned i = 0; i < 8; i++) {
      SDValue Part = DAG.getNode(AArch64ISD::LS64_EXTRACT, Dl, MVT::i64, Value,
                                 DAG.getConstant(i, Dl, MVT::i32));
      SDValue Ptr = DAG.getNode(ISD::ADD, Dl, PtrVT, Base,
                                DAG.getConstant(i * 8, Dl, PtrVT));
      Chain = DAG.getStore(Chain, Dl, Part, Ptr, StoreNode->getPointerInfo(),
                           StoreNode->getBaseAlign());
    }
    return Chain;
  }
 
  return SDValue();
}
 
/// Lower atomic or volatile 128-bit stores to a single STP instruction.
SDValue AArch64TargetLowering::LowerStore128(SDValue Op,
                                             SelectionDAG &DAG) const {
  MemSDNode *StoreNode = cast<MemSDNode>(Op);
  assert(StoreNode->getMemoryVT() == MVT::i128);
  assert(StoreNode->isVolatile() || StoreNode->isAtomic());
 
  bool IsStoreRelease =
      StoreNode->getMergedOrdering() == AtomicOrdering::Release;
  if (StoreNode->isAtomic())
    assert((Subtarget->hasFeature(AArch64::FeatureLSE2) &&
            Subtarget->hasFeature(AArch64::FeatureRCPC3) && IsStoreRelease) ||
           StoreNode->getMergedOrdering() == AtomicOrdering::Unordered ||
           StoreNode->getMergedOrdering() == AtomicOrdering::Monotonic);
 
  SDValue Value = (StoreNode->getOpcode() == ISD::STORE ||
                   StoreNode->getOpcode() == ISD::ATOMIC_STORE)
                      ? StoreNode->getOperand(1)
                      : StoreNode->getOperand(2);
  SDLoc DL(Op);
  auto StoreValue = DAG.SplitScalar(Value, DL, MVT::i64, MVT::i64);
  unsigned Opcode = IsStoreRelease ? AArch64ISD::STILP : AArch64ISD::STP;
  if (DAG.getDataLayout().isBigEndian())
    std::swap(StoreValue.first, StoreValue.second);
  SDValue Result = DAG.getMemIntrinsicNode(
      Opcode, DL, DAG.getVTList(MVT::Other),
      {StoreNode->getChain(), StoreValue.first, StoreValue.second,
       StoreNode->getBasePtr()},
      StoreNode->getMemoryVT(), StoreNode->getMemOperand());
  return Result;
}
 
/// Helper function to optimize loads of extended small vectors.
/// These patterns would otherwise get scalarized into inefficient sequences.
static SDValue tryLowerSmallVectorExtLoad(LoadSDNode *Load, SelectionDAG &DAG) {
  const AArch64Subtarget &Subtarget = DAG.getSubtarget<AArch64Subtarget>();
  if (!isEligibleForSmallVectorLoadOpt(Load, Subtarget))
    return SDValue();
 
  EVT MemVT = Load->getMemoryVT();
  EVT ResVT = Load->getValueType(0);
  unsigned NumElts = ResVT.getVectorNumElements();
  unsigned DstEltBits = ResVT.getScalarSizeInBits();
  unsigned SrcEltBits = MemVT.getScalarSizeInBits();
 
  unsigned ExtOpcode;
  switch (Load->getExtensionType()) {
  case ISD::EXTLOAD:
  case ISD::ZEXTLOAD:
    ExtOpcode = ISD::ZERO_EXTEND;
    break;
  case ISD::SEXTLOAD:
    ExtOpcode = ISD::SIGN_EXTEND;
    break;
  case ISD::NON_EXTLOAD:
    return SDValue();
  }
 
  SDLoc DL(Load);
  SDValue Chain = Load->getChain();
  SDValue BasePtr = Load->getBasePtr();
  const MachinePointerInfo &PtrInfo = Load->getPointerInfo();
  Align Alignment = Load->getAlign();
 
  // Load the data as an FP scalar to avoid issues with integer loads.
  unsigned LoadBits = MemVT.getStoreSizeInBits();
  MVT ScalarLoadType = MVT::getFloatingPointVT(LoadBits);
  SDValue ScalarLoad =
      DAG.getLoad(ScalarLoadType, DL, Chain, BasePtr, PtrInfo, Alignment);
 
  MVT ScalarToVecTy = MVT::getVectorVT(ScalarLoadType, 128 / LoadBits);
  SDValue ScalarToVec =
      DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, ScalarToVecTy, ScalarLoad);
  MVT BitcastTy =
      MVT::getVectorVT(MVT::getIntegerVT(SrcEltBits), 128 / SrcEltBits);
  SDValue Bitcast = DAG.getNode(ISD::BITCAST, DL, BitcastTy, ScalarToVec);
 
  SDValue Res = Bitcast;
  unsigned CurrentEltBits = Res.getValueType().getScalarSizeInBits();
  unsigned CurrentNumElts = Res.getValueType().getVectorNumElements();
  while (CurrentEltBits < DstEltBits) {
    if (Res.getValueSizeInBits() >= 128) {
      CurrentNumElts = CurrentNumElts / 2;
      MVT ExtractVT =
          MVT::getVectorVT(MVT::getIntegerVT(CurrentEltBits), CurrentNumElts);
      Res = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, ExtractVT, Res,
                        DAG.getConstant(0, DL, MVT::i64));
    }
    CurrentEltBits = CurrentEltBits * 2;
    MVT ExtVT =
        MVT::getVectorVT(MVT::getIntegerVT(CurrentEltBits), CurrentNumElts);
    Res = DAG.getNode(ExtOpcode, DL, ExtVT, Res);
  }
 
  if (CurrentNumElts != NumElts) {
    MVT FinalVT = MVT::getVectorVT(MVT::getIntegerVT(CurrentEltBits), NumElts);
    Res = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, FinalVT, Res,
                      DAG.getConstant(0, DL, MVT::i64));
  }
 
  return DAG.getMergeValues({Res, ScalarLoad.getValue(1)}, DL);
}
 
SDValue AArch64TargetLowering::LowerLOAD(SDValue Op,
                                         SelectionDAG &DAG) const {
  SDLoc DL(Op);
  LoadSDNode *LoadNode = cast<LoadSDNode>(Op);
  assert(LoadNode && "Expected custom lowering of a load node");
 
  if (SDValue Result = tryLowerSmallVectorExtLoad(LoadNode, DAG))
    return Result;
 
  if (LoadNode->getMemoryVT() == MVT::i64x8) {
    SmallVector<SDValue, 8> Ops;
    SDValue Base = LoadNode->getBasePtr();
    SDValue Chain = LoadNode->getChain();
    EVT PtrVT = Base.getValueType();
    for (unsigned i = 0; i < 8; i++) {
      SDValue Ptr = DAG.getNode(ISD::ADD, DL, PtrVT, Base,
                                DAG.getConstant(i * 8, DL, PtrVT));
      SDValue Part =
          DAG.getLoad(MVT::i64, DL, Chain, Ptr, LoadNode->getPointerInfo(),
                      LoadNode->getBaseAlign());
      Ops.push_back(Part);
      Chain = SDValue(Part.getNode(), 1);
    }
    SDValue Loaded = DAG.getNode(AArch64ISD::LS64_BUILD, DL, MVT::i64x8, Ops);
    return DAG.getMergeValues({Loaded, Chain}, DL);
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerFixedLengthVectorCompressToSVE(
    SDValue Op, SelectionDAG &DAG) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
 
  EVT ContainerVT = getContainerForFixedLengthVector(DAG, VT);
  SDValue Vec = convertToScalableVector(DAG, ContainerVT, Op.getOperand(0));
  SDValue Mask = convertFixedMaskToScalableVector(Op.getOperand(1), DAG);
  SDValue Passthru =
      convertToScalableVector(DAG, ContainerVT, Op.getOperand(2));
 
  SDValue Result =
      DAG.getNode(ISD::VECTOR_COMPRESS, DL, ContainerVT, Vec, Mask, Passthru);
  return convertFromScalableVector(DAG, VT, Result);
}
 
SDValue AArch64TargetLowering::LowerVECTOR_COMPRESS(SDValue Op,
                                                    SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  if (!Subtarget->isSVEAvailable())
    return SDValue();
 
  if (VT.isFixedLengthVector())
    return LowerFixedLengthVectorCompressToSVE(Op, DAG);
 
  SDLoc DL(Op);
  SDValue Vec = Op.getOperand(0);
  SDValue Mask = Op.getOperand(1);
  SDValue Passthru = Op.getOperand(2);
  EVT MaskVT = Mask.getValueType();
 
  SDValue Compressed = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, Vec.getValueType(),
      DAG.getTargetConstant(Intrinsic::aarch64_sve_compact, DL, MVT::i64), Mask,
      Vec);
 
  // compact fills with 0s, so if our passthru is all 0s, do nothing here.
  if (Passthru.isUndef() ||
      ISD::isConstantSplatVectorAllZeros(Passthru.getNode()))
    return Compressed;
 
  SDValue CntActive = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, MVT::i64,
      DAG.getTargetConstant(Intrinsic::aarch64_sve_cntp, DL, MVT::i64), Mask,
      Mask);
 
  SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
  SDValue CompressedMask =
      DAG.getNode(ISD::GET_ACTIVE_LANE_MASK, DL, MaskVT, Zero, CntActive);
 
  return DAG.getNode(ISD::VSELECT, DL, VT, CompressedMask, Compressed,
                     Passthru);
}
 
// Generate SUBS and CSEL for integer abs.
SDValue AArch64TargetLowering::LowerABS(SDValue Op, SelectionDAG &DAG) const {
  MVT VT = Op.getSimpleValueType();
 
  if (VT.isVector())
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::ABS_MERGE_PASSTHRU);
 
  SDLoc DL(Op);
  SDValue Neg = DAG.getNegative(Op.getOperand(0), DL, VT);
 
  // Generate SUBS & CSEL.
  SDValue Cmp = DAG.getNode(AArch64ISD::SUBS, DL, DAG.getVTList(VT, FlagsVT),
                            Op.getOperand(0), DAG.getConstant(0, DL, VT));
  return DAG.getNode(AArch64ISD::CSEL, DL, VT, Op.getOperand(0), Neg,
                     getCondCode(DAG, AArch64CC::PL), Cmp.getValue(1));
}
 
static SDValue LowerBRCOND(SDValue Op, SelectionDAG &DAG) {
  SDValue Chain = Op.getOperand(0);
  SDValue Cond = Op.getOperand(1);
  SDValue Dest = Op.getOperand(2);
 
  AArch64CC::CondCode CC;
  if (SDValue Cmp = emitConjunction(DAG, Cond, CC)) {
    SDLoc DL(Op);
    SDValue CCVal = getCondCode(DAG, CC);
    return DAG.getNode(AArch64ISD::BRCOND, DL, MVT::Other, Chain, Dest, CCVal,
                       Cmp);
  }
 
  return SDValue();
}
 
// Treat FSHR with constant shifts as legal operation, otherwise it is expanded
// FSHL is converted to FSHR before deciding what to do with it
static SDValue LowerFunnelShift(SDValue Op, SelectionDAG &DAG) {
  SDValue Shifts = Op.getOperand(2);
  // Check if the shift amount is a constant and normalise to [0, SrcBitLen)
  // If opcode is FSHL, convert it to FSHR
  if (auto *ShiftNo = dyn_cast<ConstantSDNode>(Shifts)) {
    SDLoc DL(Op);
    MVT VT = Op.getSimpleValueType();
    unsigned int NewShiftNo = ShiftNo->getZExtValue() % VT.getFixedSizeInBits();
 
    if (Op.getOpcode() == ISD::FSHL) {
      if (NewShiftNo == 0)
        return Op.getOperand(0);
 
      NewShiftNo = VT.getFixedSizeInBits() - NewShiftNo;
      return DAG.getNode(
          ISD::FSHR, DL, VT, Op.getOperand(0), Op.getOperand(1),
          DAG.getConstant(NewShiftNo, DL, Shifts.getValueType()));
    }
 
    if (Op.getOpcode() == ISD::FSHR) {
      if (NewShiftNo == 0)
        return Op.getOperand(1);
 
      if (ShiftNo->getZExtValue() == NewShiftNo)
        return Op;
 
      // Rewrite using the normalised shift amount.
      return DAG.getNode(
          ISD::FSHR, DL, VT, Op.getOperand(0), Op.getOperand(1),
          DAG.getConstant(NewShiftNo, DL, Shifts.getValueType()));
    }
  }
 
  return SDValue();
}
 
static SDValue LowerFLDEXP(SDValue Op, SelectionDAG &DAG) {
  SDValue X = Op.getOperand(0);
  EVT XScalarTy = X.getValueType();
  SDValue Exp = Op.getOperand(1);
 
  SDLoc DL(Op);
  EVT XVT, ExpVT;
  switch (Op.getSimpleValueType().SimpleTy) {
  default:
    return SDValue();
  case MVT::bf16:
  case MVT::f16:
    X = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, X);
    [[fallthrough]];
  case MVT::f32:
    XVT = MVT::nxv4f32;
    ExpVT = MVT::nxv4i32;
    break;
  case MVT::f64:
    XVT = MVT::nxv2f64;
    ExpVT = MVT::nxv2i64;
    Exp = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i64, Exp);
    break;
  }
 
  SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
  SDValue VX =
      DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, XVT, DAG.getPOISON(XVT), X, Zero);
  SDValue VExp = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, ExpVT,
                             DAG.getPOISON(ExpVT), Exp, Zero);
  SDValue VPg = DAG.getConstant(
      1, DL, XVT.changeVectorElementType(*DAG.getContext(), MVT::i1));
  SDValue FScale = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, XVT,
      DAG.getTargetConstant(Intrinsic::aarch64_sve_fscale, DL, MVT::i64), VPg,
      VX, VExp);
  SDValue Final =
      DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, X.getValueType(), FScale, Zero);
  if (X.getValueType() != XScalarTy)
    Final = DAG.getNode(ISD::FP_ROUND, DL, XScalarTy, Final,
                        DAG.getIntPtrConstant(1, SDLoc(Op), /*isTarget=*/true));
  return Final;
}
 
SDValue AArch64TargetLowering::LowerADJUST_TRAMPOLINE(SDValue Op,
                                                      SelectionDAG &DAG) const {
  return Op.getOperand(0);
}
 
SDValue AArch64TargetLowering::LowerINIT_TRAMPOLINE(SDValue Op,
                                                    SelectionDAG &DAG) const {
  SDValue Chain = Op.getOperand(0);
  SDValue Trmp = Op.getOperand(1); // trampoline, >=32 bytes
  SDValue FPtr = Op.getOperand(2); // nested function
  SDValue Nest = Op.getOperand(3); // 'nest' parameter value
 
  const Value *TrmpAddr = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
 
  // ldr NestReg, .+16
  // ldr x17, .+20
  // br x17
  // .word 0
  // .nest: .qword nest
  // .fptr: .qword fptr
  SDValue OutChains[5];
 
  const Function *Func =
      cast<Function>(cast<SrcValueSDNode>(Op.getOperand(5))->getValue());
  CallingConv::ID CC = Func->getCallingConv();
  unsigned NestReg;
 
  switch (CC) {
  default:
    NestReg = 0x0f; // X15
    break;
  case CallingConv::ARM64EC_Thunk_X64:
    // Must be kept in sync with AArch64CallingConv.td
    NestReg = 0x04; // X4
    break;
  }
 
  const char FptrReg = 0x11; // X17
 
  SDValue Addr = Trmp;
 
  SDLoc DL(Op);
  OutChains[0] = DAG.getStore(
      Chain, DL, DAG.getConstant(0x58000080u | NestReg, DL, MVT::i32), Addr,
      MachinePointerInfo(TrmpAddr));
 
  Addr = DAG.getNode(ISD::ADD, DL, MVT::i64, Trmp,
                     DAG.getConstant(4, DL, MVT::i64));
  OutChains[1] = DAG.getStore(
      Chain, DL, DAG.getConstant(0x580000b0u | FptrReg, DL, MVT::i32), Addr,
      MachinePointerInfo(TrmpAddr, 4));
 
  Addr = DAG.getNode(ISD::ADD, DL, MVT::i64, Trmp,
                     DAG.getConstant(8, DL, MVT::i64));
  OutChains[2] =
      DAG.getStore(Chain, DL, DAG.getConstant(0xd61f0220u, DL, MVT::i32), Addr,
                   MachinePointerInfo(TrmpAddr, 8));
 
  Addr = DAG.getNode(ISD::ADD, DL, MVT::i64, Trmp,
                     DAG.getConstant(16, DL, MVT::i64));
  OutChains[3] =
      DAG.getStore(Chain, DL, Nest, Addr, MachinePointerInfo(TrmpAddr, 16));
 
  Addr = DAG.getNode(ISD::ADD, DL, MVT::i64, Trmp,
                     DAG.getConstant(24, DL, MVT::i64));
  OutChains[4] =
      DAG.getStore(Chain, DL, FPtr, Addr, MachinePointerInfo(TrmpAddr, 24));
 
  SDValue StoreToken = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, OutChains);
 
  SDValue EndOfTrmp = DAG.getNode(ISD::ADD, DL, MVT::i64, Trmp,
                                  DAG.getConstant(12, DL, MVT::i64));
 
  // Call clear cache on the trampoline instructions.
  return DAG.getNode(ISD::CLEAR_CACHE, DL, MVT::Other, StoreToken, Trmp,
                     EndOfTrmp);
}
 
SDValue AArch64TargetLowering::LowerFMUL(SDValue Op, SelectionDAG &DAG) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  if (VT.getScalarType() != MVT::bf16 ||
      (Subtarget->hasSVEB16B16() &&
       Subtarget->isNonStreamingSVEorSME2Available()))
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMUL_PRED);
 
  assert(Subtarget->hasBF16() && "Expected +bf16 for custom FMUL lowering");
  assert((VT == MVT::nxv4bf16 || VT == MVT::nxv8bf16 || VT == MVT::v8bf16) &&
         "Unexpected FMUL VT");
 
  auto MakeGetIntrinsic = [&](Intrinsic::ID IID) {
    return [&, IID](EVT VT, auto... Ops) {
      return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
                         DAG.getConstant(IID, DL, MVT::i32), Ops...);
    };
  };
 
  auto Reinterpret = [&](SDValue Value, EVT VT) {
    EVT SrcVT = Value.getValueType();
    if (VT == SrcVT)
      return Value;
    if (SrcVT.isFixedLengthVector())
      return convertToScalableVector(DAG, VT, Value);
    if (VT.isFixedLengthVector())
      return convertFromScalableVector(DAG, VT, Value);
    return DAG.getNode(AArch64ISD::REINTERPRET_CAST, DL, VT, Value);
  };
 
  bool UseSVEBFMLAL = VT.isScalableVector();
  auto FCVT = MakeGetIntrinsic(Intrinsic::aarch64_sve_fcvt_bf16f32_v2);
  auto FCVTNT = MakeGetIntrinsic(Intrinsic::aarch64_sve_fcvtnt_bf16f32_v2);
 
  // Note: The NEON BFMLAL[BT] reads even/odd lanes like the SVE variant.
  // This does not match BFCVTN[2], so we use SVE to convert back to bf16.
  auto BFMLALB =
      MakeGetIntrinsic(UseSVEBFMLAL ? Intrinsic::aarch64_sve_bfmlalb
                                    : Intrinsic::aarch64_neon_bfmlalb);
  auto BFMLALT =
      MakeGetIntrinsic(UseSVEBFMLAL ? Intrinsic::aarch64_sve_bfmlalt
                                    : Intrinsic::aarch64_neon_bfmlalt);
 
  EVT AccVT = UseSVEBFMLAL ? MVT::nxv4f32 : MVT::v4f32;
  bool IgnoreZeroSign = DAG.canIgnoreSignBitOfZero(Op);
  SDValue Zero = DAG.getConstantFP(IgnoreZeroSign ? +0.0F : -0.0F, DL, AccVT);
  SDValue Pg = getPredicateForVector(DAG, DL, AccVT);
 
  // Lower bf16 FMUL as a pair (VT == [nx]v8bf16) of BFMLAL top/bottom
  // instructions. These result in two f32 vectors, which can be converted back
  // to bf16 with FCVT and FCVTNT.
  SDValue LHS = Op.getOperand(0);
  SDValue RHS = Op.getOperand(1);
 
  // All SVE intrinsics expect to operate on full bf16 vector types.
  if (UseSVEBFMLAL) {
    LHS = Reinterpret(LHS, MVT::nxv8bf16);
    RHS = Reinterpret(RHS, MVT::nxv8bf16);
  }
 
  SDValue BottomF32 = Reinterpret(BFMLALB(AccVT, Zero, LHS, RHS), MVT::nxv4f32);
  SDValue BottomBF16 =
      FCVT(MVT::nxv8bf16, DAG.getPOISON(MVT::nxv8bf16), Pg, BottomF32);
  // Note: nxv4bf16 only uses even lanes.
  if (VT == MVT::nxv4bf16)
    return Reinterpret(BottomBF16, VT);
 
  SDValue TopF32 = Reinterpret(BFMLALT(AccVT, Zero, LHS, RHS), MVT::nxv4f32);
  SDValue TopBF16 = FCVTNT(MVT::nxv8bf16, BottomBF16, Pg, TopF32);
  return Reinterpret(TopBF16, VT);
}
 
SDValue AArch64TargetLowering::LowerFMA(SDValue Op, SelectionDAG &DAG) const {
  SDValue OpA = Op->getOperand(0);
  SDValue OpB = Op->getOperand(1);
  SDValue OpC = Op->getOperand(2);
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
 
  assert(VT.isVector() && "Scalar fma lowering should be handled by patterns");
 
  // Bail early if we're definitely not looking to merge FNEGs into the FMA.
  if (VT != MVT::v8f16 && VT != MVT::v4f32 && VT != MVT::v2f64)
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMA_PRED);
 
  if (OpC.getOpcode() != ISD::FNEG)
    return useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable())
               ? LowerToPredicatedOp(Op, DAG, AArch64ISD::FMA_PRED)
               : Op; // Fallback to NEON lowering.
 
  // Convert FMA/FNEG nodes to SVE to enable the following patterns:
  // fma(a, b, neg(c)) -> fnmls(a, b, c)
  // fma(neg(a), b, neg(c)) -> fnmla(a, b, c)
  // fma(a, neg(b), neg(c)) -> fnmla(a, b, c)
  SDValue Pg = getPredicateForVector(DAG, DL, VT);
  EVT ContainerVT = getContainerForFixedLengthVector(DAG, VT);
 
  auto ConvertToScalableFnegMt = [&](SDValue Op) {
    if (Op.getOpcode() == ISD::FNEG)
      Op = LowerToPredicatedOp(Op, DAG, AArch64ISD::FNEG_MERGE_PASSTHRU);
    return convertToScalableVector(DAG, ContainerVT, Op);
  };
 
  OpA = ConvertToScalableFnegMt(OpA);
  OpB = ConvertToScalableFnegMt(OpB);
  OpC = ConvertToScalableFnegMt(OpC);
 
  SDValue ScalableRes =
      DAG.getNode(AArch64ISD::FMA_PRED, DL, ContainerVT, Pg, OpA, OpB, OpC);
  return convertFromScalableVector(DAG, VT, ScalableRes);
}
 
static SDValue LowerCLMUL(SDValue Op, SelectionDAG &DAG) {
  EVT VT = Op.getValueType();
  assert(
      (VT == MVT::i64 || VT == MVT::i32 || VT == MVT::i16 || VT == MVT::i8) &&
      "Unexpected Type");
  SDLoc DL(Op);
  EVT VecVT = EVT::getVectorVT(*DAG.getContext(), VT, 64 / VT.getSizeInBits());
  EVT CLMULTy = VT == MVT::i8 ? MVT::v8i8 : MVT::v1i64;
  EVT ExtractTy = VT == MVT::i64 ? MVT::i64 : MVT::i32;
  SDValue VecOp0 =
      DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VecVT, Op.getOperand(0));
  SDValue VecOp1 =
      DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VecVT, Op.getOperand(1));
 
  if (VecVT != CLMULTy) {
    VecOp0 = DAG.getNode(ISD::BITCAST, DL, CLMULTy, VecOp0);
    VecOp1 = DAG.getNode(ISD::BITCAST, DL, CLMULTy, VecOp1);
  }
  SDValue CLMUL = DAG.getNode(ISD::CLMUL, DL, CLMULTy, VecOp0, VecOp1);
  if (ExtractTy == MVT::i32)
    CLMUL = DAG.getNode(ISD::BITCAST, DL, MVT::v2i32, CLMUL);
  SDValue ExtractVecElt =
      DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ExtractTy, CLMUL,
                  DAG.getTargetConstant(0, DL, MVT::i64));
  if (ExtractTy != VT)
    ExtractVecElt = DAG.getNode(ISD::TRUNCATE, DL, VT, ExtractVecElt);
  return ExtractVecElt;
}
 
SDValue AArch64TargetLowering::LowerOperation(SDValue Op,
                                              SelectionDAG &DAG) const {
  LLVM_DEBUG(dbgs() << "Custom lowering: ");
  LLVM_DEBUG(Op.dump());
 
  switch (Op.getOpcode()) {
  default:
    llvm_unreachable("unimplemented operand");
    return SDValue();
  case ISD::LOOP_DEPENDENCE_RAW_MASK:
  case ISD::LOOP_DEPENDENCE_WAR_MASK:
    return LowerLOOP_DEPENDENCE_MASK(Op, DAG);
  case ISD::BITCAST:
    return LowerBITCAST(Op, DAG);
  case ISD::GlobalAddress:
    return LowerGlobalAddress(Op, DAG);
  case ISD::GlobalTLSAddress:
    return LowerGlobalTLSAddress(Op, DAG);
  case ISD::PtrAuthGlobalAddress:
    return LowerPtrAuthGlobalAddress(Op, DAG);
  case ISD::ADJUST_TRAMPOLINE:
    return LowerADJUST_TRAMPOLINE(Op, DAG);
  case ISD::INIT_TRAMPOLINE:
    return LowerINIT_TRAMPOLINE(Op, DAG);
  case ISD::SETCC:
  case ISD::STRICT_FSETCC:
  case ISD::STRICT_FSETCCS:
    return LowerSETCC(Op, DAG);
  case ISD::SETCCCARRY:
    return LowerSETCCCARRY(Op, DAG);
  case ISD::BRCOND:
    return LowerBRCOND(Op, DAG);
  case ISD::BR_CC:
    return LowerBR_CC(Op, DAG);
  case ISD::SELECT:
    return LowerSELECT(Op, DAG);
  case ISD::SELECT_CC:
    return LowerSELECT_CC(Op, DAG);
  case ISD::JumpTable:
    return LowerJumpTable(Op, DAG);
  case ISD::BR_JT:
    return LowerBR_JT(Op, DAG);
  case ISD::BRIND:
    return LowerBRIND(Op, DAG);
  case ISD::ConstantPool:
    return LowerConstantPool(Op, DAG);
  case ISD::BlockAddress:
    return LowerBlockAddress(Op, DAG);
  case ISD::VASTART:
    return LowerVASTART(Op, DAG);
  case ISD::VACOPY:
    return LowerVACOPY(Op, DAG);
  case ISD::VAARG:
    return LowerVAARG(Op, DAG);
  case ISD::UADDO_CARRY:
    return lowerADDSUBO_CARRY(Op, DAG, AArch64ISD::ADCS, false /*unsigned*/);
  case ISD::USUBO_CARRY:
    return lowerADDSUBO_CARRY(Op, DAG, AArch64ISD::SBCS, false /*unsigned*/);
  case ISD::SADDO_CARRY:
    return lowerADDSUBO_CARRY(Op, DAG, AArch64ISD::ADCS, true /*signed*/);
  case ISD::SSUBO_CARRY:
    return lowerADDSUBO_CARRY(Op, DAG, AArch64ISD::SBCS, true /*signed*/);
  case ISD::SADDO:
  case ISD::UADDO:
  case ISD::SSUBO:
  case ISD::USUBO:
  case ISD::SMULO:
  case ISD::UMULO:
    return LowerXALUO(Op, DAG);
  case ISD::FADD:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FADD_PRED);
  case ISD::FSUB:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FSUB_PRED);
  case ISD::FMUL:
    return LowerFMUL(Op, DAG);
  case ISD::FMA:
    return LowerFMA(Op, DAG);
  case ISD::FDIV:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FDIV_PRED);
  case ISD::FNEG:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FNEG_MERGE_PASSTHRU);
  case ISD::FCEIL:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FCEIL_MERGE_PASSTHRU);
  case ISD::FFLOOR:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FFLOOR_MERGE_PASSTHRU);
  case ISD::FNEARBYINT:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FNEARBYINT_MERGE_PASSTHRU);
  case ISD::FRINT:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FRINT_MERGE_PASSTHRU);
  case ISD::FROUND:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FROUND_MERGE_PASSTHRU);
  case ISD::FROUNDEVEN:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FROUNDEVEN_MERGE_PASSTHRU);
  case ISD::FTRUNC:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FTRUNC_MERGE_PASSTHRU);
  case ISD::FSQRT:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FSQRT_MERGE_PASSTHRU);
  case ISD::FABS:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FABS_MERGE_PASSTHRU);
  case ISD::FP_ROUND:
  case ISD::STRICT_FP_ROUND:
    return LowerFP_ROUND(Op, DAG);
  case ISD::FP_EXTEND:
  case ISD::STRICT_FP_EXTEND:
    return LowerFP_EXTEND(Op, DAG);
  case ISD::FRAMEADDR:
    return LowerFRAMEADDR(Op, DAG);
  case ISD::SPONENTRY:
    return LowerSPONENTRY(Op, DAG);
  case ISD::RETURNADDR:
    return LowerRETURNADDR(Op, DAG);
  case ISD::ADDROFRETURNADDR:
    return LowerADDROFRETURNADDR(Op, DAG);
  case ISD::CONCAT_VECTORS:
    return LowerCONCAT_VECTORS(Op, DAG);
  case ISD::INSERT_VECTOR_ELT:
    return LowerINSERT_VECTOR_ELT(Op, DAG);
  case ISD::EXTRACT_VECTOR_ELT:
    return LowerEXTRACT_VECTOR_ELT(Op, DAG);
  case ISD::BUILD_VECTOR:
    return LowerBUILD_VECTOR(Op, DAG);
  case ISD::ANY_EXTEND_VECTOR_INREG:
  case ISD::SIGN_EXTEND_VECTOR_INREG:
    return LowerEXTEND_VECTOR_INREG(Op, DAG);
  case ISD::ZERO_EXTEND_VECTOR_INREG:
    return LowerZERO_EXTEND_VECTOR_INREG(Op, DAG);
  case ISD::VECTOR_SHUFFLE:
    return LowerVECTOR_SHUFFLE(Op, DAG);
  case ISD::SPLAT_VECTOR:
    return LowerSPLAT_VECTOR(Op, DAG);
  case ISD::EXTRACT_SUBVECTOR:
    return LowerEXTRACT_SUBVECTOR(Op, DAG);
  case ISD::INSERT_SUBVECTOR:
    return LowerINSERT_SUBVECTOR(Op, DAG);
  case ISD::MASKED_SDIV:
  case ISD::MASKED_UDIV:
  case ISD::SDIV:
  case ISD::UDIV:
    return LowerDIV(Op, DAG);
  case ISD::SMIN:
  case ISD::UMIN:
  case ISD::SMAX:
  case ISD::UMAX:
    return LowerMinMax(Op, DAG);
  case ISD::SRA:
  case ISD::SRL:
  case ISD::SHL:
    return LowerVectorSRA_SRL_SHL(Op, DAG);
  case ISD::SHL_PARTS:
  case ISD::SRL_PARTS:
  case ISD::SRA_PARTS:
    return LowerShiftParts(Op, DAG);
  case ISD::CTPOP:
  case ISD::PARITY:
    return LowerCTPOP_PARITY(Op, DAG);
  case ISD::FCOPYSIGN:
    return LowerFCOPYSIGN(Op, DAG);
  case ISD::OR:
    return LowerVectorOR(Op, DAG);
  case ISD::XOR:
    return LowerXOR(Op, DAG);
  case ISD::PREFETCH:
    return LowerPREFETCH(Op, DAG);
  case ISD::SINT_TO_FP:
  case ISD::UINT_TO_FP:
  case ISD::STRICT_SINT_TO_FP:
  case ISD::STRICT_UINT_TO_FP:
    return LowerINT_TO_FP(Op, DAG);
  case ISD::FP_TO_SINT:
  case ISD::FP_TO_UINT:
  case ISD::STRICT_FP_TO_SINT:
  case ISD::STRICT_FP_TO_UINT:
    return LowerFP_TO_INT(Op, DAG);
  case ISD::FP_TO_SINT_SAT:
  case ISD::FP_TO_UINT_SAT:
    return LowerFP_TO_INT_SAT(Op, DAG);
  case ISD::GET_ROUNDING:
    return LowerGET_ROUNDING(Op, DAG);
  case ISD::SET_ROUNDING:
    return LowerSET_ROUNDING(Op, DAG);
  case ISD::GET_FPMODE:
    return LowerGET_FPMODE(Op, DAG);
  case ISD::SET_FPMODE:
    return LowerSET_FPMODE(Op, DAG);
  case ISD::RESET_FPMODE:
    return LowerRESET_FPMODE(Op, DAG);
  case ISD::MUL:
    return LowerMUL(Op, DAG);
  case ISD::MULHS:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::MULHS_PRED);
  case ISD::MULHU:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::MULHU_PRED);
  case ISD::INTRINSIC_W_CHAIN:
    return LowerINTRINSIC_W_CHAIN(Op, DAG);
  case ISD::INTRINSIC_WO_CHAIN:
    return LowerINTRINSIC_WO_CHAIN(Op, DAG);
  case ISD::INTRINSIC_VOID:
    return LowerINTRINSIC_VOID(Op, DAG);
  case ISD::ATOMIC_STORE:
    if (cast<MemSDNode>(Op)->getMemoryVT() == MVT::i128) {
      assert(Subtarget->hasLSE2() || Subtarget->hasRCPC3());
      return LowerStore128(Op, DAG);
    }
    return SDValue();
  case ISD::STORE:
    return LowerSTORE(Op, DAG);
  case ISD::MSTORE:
    return LowerMSTORE(Op, DAG);
  case ISD::MGATHER:
    return LowerMGATHER(Op, DAG);
  case ISD::MSCATTER:
    return LowerMSCATTER(Op, DAG);
  case ISD::VECREDUCE_SEQ_FADD:
    return LowerVECREDUCE_SEQ_FADD(Op, DAG);
  case ISD::VECREDUCE_ADD:
  case ISD::VECREDUCE_AND:
  case ISD::VECREDUCE_OR:
  case ISD::VECREDUCE_XOR:
  case ISD::VECREDUCE_SMAX:
  case ISD::VECREDUCE_SMIN:
  case ISD::VECREDUCE_UMAX:
  case ISD::VECREDUCE_UMIN:
  case ISD::VECREDUCE_FADD:
  case ISD::VECREDUCE_FMAX:
  case ISD::VECREDUCE_FMIN:
  case ISD::VECREDUCE_FMAXIMUM:
  case ISD::VECREDUCE_FMINIMUM:
    return LowerVECREDUCE(Op, DAG);
  case ISD::VECREDUCE_MUL:
  case ISD::VECREDUCE_FMUL:
    return LowerVECREDUCE_MUL(Op, DAG);
  case ISD::ATOMIC_LOAD_AND:
    return LowerATOMIC_LOAD_AND(Op, DAG);
  case ISD::DYNAMIC_STACKALLOC:
    return LowerDYNAMIC_STACKALLOC(Op, DAG);
  case ISD::VSCALE:
    return LowerVSCALE(Op, DAG);
  case ISD::VECTOR_COMPRESS:
    return LowerVECTOR_COMPRESS(Op, DAG);
  case ISD::ANY_EXTEND:
  case ISD::SIGN_EXTEND:
  case ISD::ZERO_EXTEND:
    return LowerFixedLengthVectorIntExtendToSVE(Op, DAG);
  case ISD::ADDRSPACECAST:
    return LowerADDRSPACECAST(Op, DAG);
  case ISD::SIGN_EXTEND_INREG: {
    // Only custom lower when ExtraVT has a legal byte based element type.
    EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
    EVT ExtraEltVT = ExtraVT.getVectorElementType();
    if ((ExtraEltVT != MVT::i8) && (ExtraEltVT != MVT::i16) &&
        (ExtraEltVT != MVT::i32) && (ExtraEltVT != MVT::i64))
      return SDValue();
 
    return LowerToPredicatedOp(Op, DAG,
                               AArch64ISD::SIGN_EXTEND_INREG_MERGE_PASSTHRU);
  }
  case ISD::TRUNCATE:
    return LowerTRUNCATE(Op, DAG);
  case ISD::MLOAD:
    return LowerMLOAD(Op, DAG);
  case ISD::LOAD:
    if (useSVEForFixedLengthVectorVT(Op.getValueType(),
                                     !Subtarget->isNeonAvailable()))
      return LowerFixedLengthVectorLoadToSVE(Op, DAG);
    return LowerLOAD(Op, DAG);
  case ISD::ADD:
  case ISD::AND:
  case ISD::SUB:
    return LowerToScalableOp(Op, DAG);
  case ISD::FMAXIMUM:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMAX_PRED);
  case ISD::FMAXNUM:
  case ISD::FMAXNUM_IEEE:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMAXNM_PRED);
  case ISD::FMINIMUM:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMIN_PRED);
  case ISD::FMINNUM:
  case ISD::FMINNUM_IEEE:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::FMINNM_PRED);
  case ISD::VSELECT:
    return LowerFixedLengthVectorSelectToSVE(Op, DAG);
  case ISD::ABS:
    return LowerABS(Op, DAG);
  case ISD::ABDS:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::ABDS_PRED);
  case ISD::ABDU:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::ABDU_PRED);
  case ISD::AVGFLOORS:
    return LowerAVG(Op, DAG, AArch64ISD::HADDS_PRED);
  case ISD::AVGFLOORU:
    return LowerAVG(Op, DAG, AArch64ISD::HADDU_PRED);
  case ISD::AVGCEILS:
    return LowerAVG(Op, DAG, AArch64ISD::RHADDS_PRED);
  case ISD::AVGCEILU:
    return LowerAVG(Op, DAG, AArch64ISD::RHADDU_PRED);
  case ISD::BITREVERSE:
    return LowerBitreverse(Op, DAG);
  case ISD::BSWAP:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::BSWAP_MERGE_PASSTHRU);
  case ISD::CTLZ:
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::CTLZ_MERGE_PASSTHRU);
  case ISD::CTTZ:
    return LowerCTTZ(Op, DAG);
  case ISD::VECTOR_SPLICE_LEFT:
  case ISD::VECTOR_SPLICE_RIGHT:
    return LowerVECTOR_SPLICE(Op, DAG);
  case ISD::VECTOR_DEINTERLEAVE:
    return LowerVECTOR_DEINTERLEAVE(Op, DAG);
  case ISD::VECTOR_INTERLEAVE:
    return LowerVECTOR_INTERLEAVE(Op, DAG);
  case ISD::GET_ACTIVE_LANE_MASK:
    return LowerGET_ACTIVE_LANE_MASK(Op, DAG);
  case ISD::LRINT:
  case ISD::LLRINT:
    if (Op.getValueType().isVector())
      return LowerVectorXRINT(Op, DAG);
    [[fallthrough]];
  case ISD::LROUND:
  case ISD::LLROUND: {
    assert((Op.getOperand(0).getValueType() == MVT::f16 ||
            Op.getOperand(0).getValueType() == MVT::bf16) &&
           "Expected custom lowering of rounding operations only for f16");
    SDLoc DL(Op);
    SDValue Ext = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, Op.getOperand(0));
    return DAG.getNode(Op.getOpcode(), DL, Op.getValueType(), Ext);
  }
  case ISD::STRICT_LROUND:
  case ISD::STRICT_LLROUND:
  case ISD::STRICT_LRINT:
  case ISD::STRICT_LLRINT: {
    assert((Op.getOperand(1).getValueType() == MVT::f16 ||
            Op.getOperand(1).getValueType() == MVT::bf16) &&
           "Expected custom lowering of rounding operations only for f16");
    SDLoc DL(Op);
    SDValue Ext = DAG.getNode(ISD::STRICT_FP_EXTEND, DL, {MVT::f32, MVT::Other},
                              {Op.getOperand(0), Op.getOperand(1)});
    return DAG.getNode(Op.getOpcode(), DL, {Op.getValueType(), MVT::Other},
                       {Ext.getValue(1), Ext.getValue(0)});
  }
  case ISD::WRITE_REGISTER: {
    assert(Op.getOperand(2).getValueType() == MVT::i128 &&
           "WRITE_REGISTER custom lowering is only for 128-bit sysregs");
    SDLoc DL(Op);
 
    SDValue Chain = Op.getOperand(0);
    SDValue SysRegName = Op.getOperand(1);
    std::pair<SDValue, SDValue> Pair =
        DAG.SplitScalar(Op.getOperand(2), DL, MVT::i64, MVT::i64);
 
    // chain = MSRR(chain, sysregname, lo, hi)
    SDValue Result = DAG.getNode(AArch64ISD::MSRR, DL, MVT::Other, Chain,
                                 SysRegName, Pair.first, Pair.second);
 
    return Result;
  }
  case ISD::FSHL:
  case ISD::FSHR:
    return LowerFunnelShift(Op, DAG);
  case ISD::FLDEXP:
    return LowerFLDEXP(Op, DAG);
  case ISD::EXPERIMENTAL_VECTOR_HISTOGRAM:
    return LowerVECTOR_HISTOGRAM(Op, DAG);
  case ISD::PARTIAL_REDUCE_SMLA:
  case ISD::PARTIAL_REDUCE_UMLA:
  case ISD::PARTIAL_REDUCE_SUMLA:
  case ISD::PARTIAL_REDUCE_FMLA:
    return LowerPARTIAL_REDUCE_MLA(Op, DAG);
  case ISD::CLMUL:
    return LowerCLMUL(Op, DAG);
  case ISD::FCANONICALIZE:
    return LowerFCANONICALIZE(Op, DAG);
  case ISD::CTTZ_ELTS:
  case ISD::CTTZ_ELTS_ZERO_POISON: {
    SDLoc DL(Op);
    SDValue CttzOp = Op.getOperand(0);
    EVT VT = CttzOp.getValueType();
    assert(VT.getVectorElementType() == MVT::i1 && "Expected MVT::i1");
 
    if (VT.isFixedLengthVector()) {
      // We can use SVE instructions to lower this intrinsic by first creating
      // an SVE predicate register mask from the fixed-width vector.
      VT = getTypeToTransformTo(*DAG.getContext(), VT);
      SDValue Mask = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, CttzOp);
      CttzOp = convertFixedMaskToScalableVector(Mask, DAG);
    }
 
    SDValue Pg = getPredicateForVector(DAG, DL, VT);
    SDValue NewCttzElts =
        DAG.getNode(AArch64ISD::CTTZ_ELTS, DL, MVT::i64, Pg, CttzOp);
    return DAG.getZExtOrTrunc(NewCttzElts, DL, Op.getValueType());
  }
  }
}
 
bool AArch64TargetLowering::mergeStoresAfterLegalization(EVT VT) const {
  return !Subtarget->useSVEForFixedLengthVectors();
}
 
bool AArch64TargetLowering::useSVEForFixedLengthVectorVT(
    EVT VT, bool OverrideNEON) const {
  if (!VT.isFixedLengthVector() || !VT.isSimple())
    return false;
 
  // Don't use SVE for vectors we cannot scalarize if required.
  switch (VT.getVectorElementType().getSimpleVT().SimpleTy) {
  // Fixed length predicates should be promoted to i8.
  // NOTE: This is consistent with how NEON (and thus 64/128bit vectors) work.
  case MVT::i1:
  default:
    return false;
  case MVT::i8:
  case MVT::i16:
  case MVT::i32:
  case MVT::i64:
  case MVT::f16:
  case MVT::f32:
  case MVT::f64:
    break;
  }
 
  // NEON-sized vectors can be emulated using SVE instructions.
  if (OverrideNEON && (VT.is128BitVector() || VT.is64BitVector()))
    return Subtarget->isSVEorStreamingSVEAvailable();
 
  // Ensure NEON MVTs only belong to a single register class.
  if (VT.getFixedSizeInBits() <= 128)
    return false;
 
  // Ensure wider than NEON code generation is enabled.
  if (!Subtarget->useSVEForFixedLengthVectors())
    return false;
 
  // Don't use SVE for types that don't fit.
  if (VT.getFixedSizeInBits() > Subtarget->getMinSVEVectorSizeInBits())
    return false;
 
  // TODO: Perhaps an artificial restriction, but worth having whilst getting
  // the base fixed length SVE support in place.
  if (!VT.isPow2VectorType())
    return false;
 
  return true;
}
 
//===----------------------------------------------------------------------===//
//                      Calling Convention Implementation
//===----------------------------------------------------------------------===//
 
static unsigned getIntrinsicID(const SDNode *N) {
  unsigned Opcode = N->getOpcode();
  switch (Opcode) {
  default:
    return Intrinsic::not_intrinsic;
  case ISD::INTRINSIC_WO_CHAIN: {
    unsigned IID = N->getConstantOperandVal(0);
    if (IID < Intrinsic::num_intrinsics)
      return IID;
    return Intrinsic::not_intrinsic;
  }
  }
}
 
bool AArch64TargetLowering::isReassocProfitable(SelectionDAG &DAG, SDValue N0,
                                                SDValue N1) const {
  if (!N0.hasOneUse())
    return false;
 
  unsigned IID = getIntrinsicID(N1.getNode());
  // Avoid reassociating expressions that can be lowered to smlal/umlal.
  if (IID == Intrinsic::aarch64_neon_umull ||
      N1.getOpcode() == AArch64ISD::UMULL ||
      IID == Intrinsic::aarch64_neon_smull ||
      N1.getOpcode() == AArch64ISD::SMULL)
    return N0.getOpcode() != ISD::ADD;
 
  return true;
}
 
/// Selects the correct CCAssignFn for a given CallingConvention value.
CCAssignFn *AArch64TargetLowering::CCAssignFnForCall(CallingConv::ID CC,
                                                     bool IsVarArg) const {
  switch (CC) {
  default:
    reportFatalUsageError("unsupported calling convention");
  case CallingConv::GHC:
    return CC_AArch64_GHC;
  case CallingConv::PreserveNone:
    // The VarArg implementation makes assumptions about register
    // argument passing that do not hold for preserve_none, so we
    // instead fall back to C argument passing.
    // The non-vararg case is handled in the CC function itself.
    if (!IsVarArg)
      return CC_AArch64_Preserve_None;
    [[fallthrough]];
  case CallingConv::C:
  case CallingConv::Fast:
  case CallingConv::PreserveMost:
  case CallingConv::PreserveAll:
  case CallingConv::CXX_FAST_TLS:
  case CallingConv::Swift:
  case CallingConv::SwiftTail:
  case CallingConv::Tail:
  case CallingConv::GRAAL:
    if (Subtarget->isTargetWindows()) {
      if (IsVarArg) {
        if (Subtarget->isWindowsArm64EC())
          return CC_AArch64_Arm64EC_VarArg;
        return CC_AArch64_Win64_VarArg;
      }
      return CC_AArch64_Win64PCS;
    }
    if (!Subtarget->isTargetDarwin())
      return CC_AArch64_AAPCS;
    if (!IsVarArg)
      return CC_AArch64_DarwinPCS;
    return Subtarget->isTargetILP32() ? CC_AArch64_DarwinPCS_ILP32_VarArg
                                      : CC_AArch64_DarwinPCS_VarArg;
  case CallingConv::Win64:
    if (IsVarArg) {
      if (Subtarget->isWindowsArm64EC())
        return CC_AArch64_Arm64EC_VarArg;
      return CC_AArch64_Win64_VarArg;
    }
    return CC_AArch64_Win64PCS;
  case CallingConv::CFGuard_Check:
    if (Subtarget->isWindowsArm64EC())
      return CC_AArch64_Arm64EC_CFGuard_Check;
    return CC_AArch64_Win64_CFGuard_Check;
  case CallingConv::AArch64_VectorCall:
  case CallingConv::AArch64_SVE_VectorCall:
  case CallingConv::AArch64_SME_ABI_Support_Routines_PreserveMost_From_X0:
  case CallingConv::AArch64_SME_ABI_Support_Routines_PreserveMost_From_X1:
  case CallingConv::AArch64_SME_ABI_Support_Routines_PreserveMost_From_X2:
    return CC_AArch64_AAPCS;
  case CallingConv::ARM64EC_Thunk_X64:
    return CC_AArch64_Arm64EC_Thunk;
  case CallingConv::ARM64EC_Thunk_Native:
    return CC_AArch64_Arm64EC_Thunk_Native;
  }
}
 
CCAssignFn *
AArch64TargetLowering::CCAssignFnForReturn(CallingConv::ID CC) const {
  switch (CC) {
  default:
    return RetCC_AArch64_AAPCS;
  case CallingConv::ARM64EC_Thunk_X64:
    return RetCC_AArch64_Arm64EC_Thunk;
  case CallingConv::CFGuard_Check:
    if (Subtarget->isWindowsArm64EC())
      return RetCC_AArch64_Arm64EC_CFGuard_Check;
    return RetCC_AArch64_AAPCS;
  }
}
 
static bool isPassedInFPR(EVT VT) {
  return VT.isFixedLengthVector() ||
         (VT.isFloatingPoint() && !VT.isScalableVector());
}
 
SDValue AArch64TargetLowering::lowerEHPadEntry(SDValue Chain, SDLoc const &DL,
                                               SelectionDAG &DAG) const {
  assert(Chain.getOpcode() == ISD::EntryToken && "Unexpected Chain value");
  SDValue Glue = Chain.getValue(1);
 
  MachineFunction &MF = DAG.getMachineFunction();
  auto &FuncInfo = *MF.getInfo<AArch64FunctionInfo>();
 
  SMEAttrs SMEFnAttrs = FuncInfo.getSMEFnAttrs();
 
  // The following conditions are true on entry to an exception handler:
  // - PSTATE.SM is 0.
  // - PSTATE.ZA is 0.
  // - TPIDR2_EL0 is null.
  // See:
  // https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#exceptions
  //
  // Therefore, if the function that contains this exception handler is a
  // streaming[-compatible] function, we must re-enable streaming mode.
  //
  // These mode changes are usually optimized away in catch blocks as they
  // occur before the __cxa_begin_catch (which is a non-streaming function),
  // but are necessary in some cases (such as for cleanups).
  //
  // Additionally, if the function has ZA or ZT0 state, we must restore it.
 
  // [COND_]SMSTART SM
  if (SMEFnAttrs.hasStreamingInterfaceOrBody())
    Chain = changeStreamingMode(DAG, DL, /*Enable=*/true, Chain,
                                /*Glue*/ Glue, AArch64SME::Always);
  else if (SMEFnAttrs.hasStreamingCompatibleInterface())
    Chain = changeStreamingMode(DAG, DL, /*Enable=*/true, Chain, Glue,
                                AArch64SME::IfCallerIsStreaming);
  return Chain;
}
 
SDValue AArch64TargetLowering::LowerFormalArguments(
    SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
    const SmallVectorImpl<ISD::InputArg> &Ins, const SDLoc &DL,
    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals) const {
  MachineFunction &MF = DAG.getMachineFunction();
  const Function &F = MF.getFunction();
  MachineFrameInfo &MFI = MF.getFrameInfo();
  bool IsWin64 =
      Subtarget->isCallingConvWin64(F.getCallingConv(), F.isVarArg());
  bool StackViaX4 = CallConv == CallingConv::ARM64EC_Thunk_X64 ||
                    (isVarArg && Subtarget->isWindowsArm64EC());
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
 
  SmallVector<ISD::OutputArg, 4> Outs;
  GetReturnInfo(CallConv, F.getReturnType(), F.getAttributes(), Outs,
                DAG.getTargetLoweringInfo(), MF.getDataLayout());
  if (any_of(Outs, [](ISD::OutputArg &Out){ return Out.VT.isScalableVector(); }))
    FuncInfo->setIsSVECC(true);
 
  // Assign locations to all of the incoming arguments.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, isVarArg, MF, ArgLocs, *DAG.getContext());
 
  // At this point, Ins[].VT may already be promoted to i32. To correctly
  // handle passing i8 as i8 instead of i32 on stack, we pass in both i32 and
  // i8 to CC_AArch64_AAPCS with i32 being ValVT and i8 being LocVT.
  // Since AnalyzeFormalArguments uses Ins[].VT for both ValVT and LocVT, here
  // we use a special version of AnalyzeFormalArguments to pass in ValVT and
  // LocVT.
  unsigned NumArgs = Ins.size();
  Function::const_arg_iterator CurOrigArg = F.arg_begin();
  unsigned CurArgIdx = 0;
  bool UseVarArgCC = false;
  if (IsWin64)
    UseVarArgCC = isVarArg;
 
  CCAssignFn *AssignFn = CCAssignFnForCall(CallConv, UseVarArgCC);
 
  for (unsigned i = 0; i != NumArgs; ++i) {
    MVT ValVT = Ins[i].VT;
    if (Ins[i].isOrigArg()) {
      std::advance(CurOrigArg, Ins[i].getOrigArgIndex() - CurArgIdx);
      CurArgIdx = Ins[i].getOrigArgIndex();
 
      // Get type of the original argument.
      EVT ActualVT = getValueType(DAG.getDataLayout(), CurOrigArg->getType(),
                                  /*AllowUnknown*/ true);
      MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : MVT::Other;
      // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
      if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
        ValVT = MVT::i8;
      else if (ActualMVT == MVT::i16)
        ValVT = MVT::i16;
    }
    bool Res = AssignFn(i, ValVT, ValVT, CCValAssign::Full, Ins[i].Flags,
                        Ins[i].OrigTy, CCInfo);
    assert(!Res && "Call operand has unhandled type");
    (void)Res;
  }
 
  SMEAttrs Attrs = FuncInfo->getSMEFnAttrs();
  bool IsLocallyStreaming =
      !Attrs.hasStreamingInterface() && Attrs.hasStreamingBody();
  assert(Chain.getOpcode() == ISD::EntryToken && "Unexpected Chain value");
  SDValue Glue = Chain.getValue(1);
 
  unsigned ExtraArgLocs = 0;
  for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i - ExtraArgLocs];
 
    if (Ins[i].Flags.isByVal()) {
      // Byval is used for HFAs in the PCS, but the system should work in a
      // non-compliant manner for larger structs.
      EVT PtrVT = getPointerTy(DAG.getDataLayout());
      int Size = Ins[i].Flags.getByValSize();
      unsigned NumRegs = (Size + 7) / 8;
 
      // FIXME: This works on big-endian for composite byvals, which are the common
      // case. It should also work for fundamental types too.
      unsigned FrameIdx =
        MFI.CreateFixedObject(8 * NumRegs, VA.getLocMemOffset(), false);
      SDValue FrameIdxN = DAG.getFrameIndex(FrameIdx, PtrVT);
      InVals.push_back(FrameIdxN);
 
      continue;
    }
 
    if (Ins[i].Flags.isSwiftAsync())
      MF.getInfo<AArch64FunctionInfo>()->setHasSwiftAsyncContext(true);
 
    SDValue ArgValue;
    if (VA.isRegLoc()) {
      // Arguments stored in registers.
      EVT RegVT = VA.getLocVT();
      const TargetRegisterClass *RC;
 
      if (RegVT == MVT::i32)
        RC = &AArch64::GPR32RegClass;
      else if (RegVT == MVT::i64)
        RC = &AArch64::GPR64RegClass;
      else if (RegVT == MVT::f16 || RegVT == MVT::bf16)
        RC = &AArch64::FPR16RegClass;
      else if (RegVT == MVT::f32)
        RC = &AArch64::FPR32RegClass;
      else if (RegVT == MVT::f64 || RegVT.is64BitVector())
        RC = &AArch64::FPR64RegClass;
      else if (RegVT == MVT::f128 || RegVT.is128BitVector())
        RC = &AArch64::FPR128RegClass;
      else if (RegVT.isScalableVector() &&
               RegVT.getVectorElementType() == MVT::i1) {
        FuncInfo->setIsSVECC(true);
        RC = &AArch64::PPRRegClass;
      } else if (RegVT == MVT::aarch64svcount) {
        FuncInfo->setIsSVECC(true);
        RC = &AArch64::PPRRegClass;
      } else if (RegVT.isScalableVector()) {
        FuncInfo->setIsSVECC(true);
        RC = &AArch64::ZPRRegClass;
      } else
        llvm_unreachable("RegVT not supported by FORMAL_ARGUMENTS Lowering");
 
      // Transform the arguments in physical registers into virtual ones.
      Register Reg = MF.addLiveIn(VA.getLocReg(), RC);
 
      if (IsLocallyStreaming) {
        // LocallyStreamingFunctions must insert the SMSTART in the correct
        // position, so we use Glue to ensure no instructions can be scheduled
        // between the chain of:
        //        t0: ch,glue = EntryNode
        //      t1:  res,ch,glue = CopyFromReg
        //     ...
        //   tn: res,ch,glue = CopyFromReg t(n-1), ..
        // t(n+1): ch, glue = SMSTART t0:0, ...., tn:2
        // ^^^^^^
        // This will be the new Chain/Root node.
        ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT, Glue);
        Glue = ArgValue.getValue(2);
        if (isPassedInFPR(ArgValue.getValueType())) {
          ArgValue =
              DAG.getNode(AArch64ISD::COALESCER_BARRIER, DL,
                          DAG.getVTList(ArgValue.getValueType(), MVT::Glue),
                          {ArgValue, Glue});
          Glue = ArgValue.getValue(1);
        }
      } else
        ArgValue = DAG.getCopyFromReg(Chain, DL, Reg, RegVT);
 
      // If this is an 8, 16 or 32-bit value, it is really passed promoted
      // to 64 bits.  Insert an assert[sz]ext to capture this, then
      // truncate to the right size.
      switch (VA.getLocInfo()) {
      default:
        llvm_unreachable("Unknown loc info!");
      case CCValAssign::Full:
        break;
      case CCValAssign::Indirect:
        assert(
            (VA.getValVT().isScalableVT() || Subtarget->isWindowsArm64EC()) &&
            "Indirect arguments should be scalable on most subtargets");
        break;
      case CCValAssign::BCvt:
        ArgValue = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), ArgValue);
        break;
      case CCValAssign::AExt:
      case CCValAssign::SExt:
      case CCValAssign::ZExt:
        break;
      case CCValAssign::AExtUpper:
        ArgValue = DAG.getNode(ISD::SRL, DL, RegVT, ArgValue,
                               DAG.getConstant(32, DL, RegVT));
        ArgValue = DAG.getZExtOrTrunc(ArgValue, DL, VA.getValVT());
        break;
      }
    } else { // VA.isRegLoc()
      assert(VA.isMemLoc() && "CCValAssign is neither reg nor mem");
      unsigned ArgOffset = VA.getLocMemOffset();
      unsigned ArgSize = (VA.getLocInfo() == CCValAssign::Indirect
                              ? VA.getLocVT().getSizeInBits()
                              : VA.getValVT().getSizeInBits()) / 8;
 
      uint32_t BEAlign = 0;
      if (!Subtarget->isLittleEndian() && ArgSize < 8 &&
          !Ins[i].Flags.isInConsecutiveRegs())
        BEAlign = 8 - ArgSize;
 
      SDValue FIN;
      MachinePointerInfo PtrInfo;
      if (StackViaX4) {
        // In both the ARM64EC varargs convention and the thunk convention,
        // arguments on the stack are accessed relative to x4, not sp. In
        // the thunk convention, there's an additional offset of 32 bytes
        // to account for the shadow store.
        unsigned ObjOffset = ArgOffset + BEAlign;
        if (CallConv == CallingConv::ARM64EC_Thunk_X64)
          ObjOffset += 32;
        Register VReg = MF.addLiveIn(AArch64::X4, &AArch64::GPR64RegClass);
        SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
        FIN = DAG.getNode(ISD::ADD, DL, MVT::i64, Val,
                          DAG.getConstant(ObjOffset, DL, MVT::i64));
        PtrInfo = MachinePointerInfo::getUnknownStack(MF);
      } else {
        int FI = MFI.CreateFixedObject(ArgSize, ArgOffset + BEAlign, true);
 
        // Create load nodes to retrieve arguments from the stack.
        FIN = DAG.getFrameIndex(FI, getPointerTy(DAG.getDataLayout()));
        PtrInfo = MachinePointerInfo::getFixedStack(MF, FI);
      }
 
      // For NON_EXTLOAD, generic code in getLoad assert(ValVT == MemVT)
      ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
      MVT MemVT = VA.getValVT();
 
      switch (VA.getLocInfo()) {
      default:
        break;
      case CCValAssign::Trunc:
      case CCValAssign::BCvt:
        MemVT = VA.getLocVT();
        break;
      case CCValAssign::Indirect:
        assert(
            (VA.getValVT().isScalableVT() || Subtarget->isWindowsArm64EC()) &&
            "Indirect arguments should be scalable on most subtargets");
        MemVT = VA.getLocVT();
        break;
      case CCValAssign::SExt:
        ExtType = ISD::SEXTLOAD;
        break;
      case CCValAssign::ZExt:
        ExtType = ISD::ZEXTLOAD;
        break;
      case CCValAssign::AExt:
        ExtType = ISD::EXTLOAD;
        break;
      }
 
      ArgValue = DAG.getExtLoad(ExtType, DL, VA.getLocVT(), Chain, FIN, PtrInfo,
                                MemVT);
    }
 
    if (VA.getLocInfo() == CCValAssign::Indirect) {
      assert((VA.getValVT().isScalableVT() ||
              Subtarget->isWindowsArm64EC()) &&
             "Indirect arguments should be scalable on most subtargets");
 
      TypeSize PartSize = VA.getValVT().getStoreSize();
      unsigned NumParts = 1;
      if (Ins[i].Flags.isInConsecutiveRegs()) {
        while (!Ins[i + NumParts - 1].Flags.isInConsecutiveRegsLast())
          ++NumParts;
      }
 
      MVT PartLoad = VA.getValVT();
      SDValue Ptr = ArgValue;
 
      // Ensure we generate all loads for each tuple part, whilst updating the
      // pointer after each load correctly using vscale.
      while (NumParts > 0) {
        ArgValue = DAG.getLoad(PartLoad, DL, Chain, Ptr, MachinePointerInfo());
        InVals.push_back(ArgValue);
        NumParts--;
        if (NumParts > 0) {
          SDValue BytesIncrement =
              DAG.getTypeSize(DL, Ptr.getValueType(), PartSize);
          Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
                            BytesIncrement, SDNodeFlags::NoUnsignedWrap);
          ExtraArgLocs++;
          i++;
        }
      }
    } else {
      if (Subtarget->isTargetILP32() && Ins[i].Flags.isPointer())
        ArgValue = DAG.getNode(ISD::AssertZext, DL, ArgValue.getValueType(),
                               ArgValue, DAG.getValueType(MVT::i32));
 
      // i1 arguments are zero-extended to i8 by the caller. Emit a
      // hint to reflect this.
      if (Ins[i].isOrigArg()) {
        Argument *OrigArg = F.getArg(Ins[i].getOrigArgIndex());
        if (OrigArg->getType()->isIntegerTy(1)) {
          if (!Ins[i].Flags.isZExt()) {
            ArgValue = DAG.getNode(AArch64ISD::ASSERT_ZEXT_BOOL, DL,
                                   ArgValue.getValueType(), ArgValue);
          }
        }
      }
 
      InVals.push_back(ArgValue);
    }
  }
  assert((ArgLocs.size() + ExtraArgLocs) == Ins.size());
 
  if (Attrs.hasStreamingCompatibleInterface()) {
    SDValue EntryPStateSM =
        DAG.getNode(AArch64ISD::ENTRY_PSTATE_SM, DL,
                    DAG.getVTList(MVT::i64, MVT::Other), {Chain});
 
    // Copy the value to a virtual register, and save that in FuncInfo.
    Register EntryPStateSMReg =
        MF.getRegInfo().createVirtualRegister(&AArch64::GPR64RegClass);
    Chain = DAG.getCopyToReg(EntryPStateSM.getValue(1), DL, EntryPStateSMReg,
                             EntryPStateSM);
    FuncInfo->setPStateSMReg(EntryPStateSMReg);
  }
 
  // Insert the SMSTART if this is a locally streaming function and
  // make sure it is Glued to the last CopyFromReg value.
  if (IsLocallyStreaming) {
    if (Attrs.hasStreamingCompatibleInterface())
      Chain = changeStreamingMode(DAG, DL, /*Enable*/ true, Chain, Glue,
                                  AArch64SME::IfCallerIsNonStreaming);
    else
      Chain = changeStreamingMode(DAG, DL, /*Enable*/ true, Chain, Glue,
                                  AArch64SME::Always);
 
    // Ensure that the SMSTART happens after the CopyWithChain such that its
    // chain result is used.
    for (unsigned I=0; I<InVals.size(); ++I) {
      Register Reg = MF.getRegInfo().createVirtualRegister(
          getRegClassFor(InVals[I].getValueType().getSimpleVT()));
      Chain = DAG.getCopyToReg(Chain, DL, Reg, InVals[I]);
      InVals[I] = DAG.getCopyFromReg(Chain, DL, Reg,
                                     InVals[I].getValueType());
    }
  }
 
  // varargs
  if (isVarArg) {
    if (DAG.getMachineFunction().getFrameInfo().hasVAStart()) {
      if (!Subtarget->isTargetDarwin() || IsWin64) {
        // The AAPCS variadic function ABI is identical to the non-variadic
        // one. As a result there may be more arguments in registers and we
        // should save them for future reference.
        // Win64 variadic functions also pass arguments in registers, but all
        // float arguments are passed in integer registers.
        saveVarArgRegisters(CCInfo, DAG, DL, Chain);
      }
 
      // This will point to the next argument passed via stack.
      unsigned VarArgsOffset = CCInfo.getStackSize();
      // We currently pass all varargs at 8-byte alignment, or 4 for ILP32
      VarArgsOffset =
          alignTo(VarArgsOffset, Subtarget->isTargetILP32() ? 4 : 8);
      FuncInfo->setVarArgsStackOffset(VarArgsOffset);
      FuncInfo->setVarArgsStackIndex(
          MFI.CreateFixedObject(4, VarArgsOffset, true));
    }
 
    if (MFI.hasMustTailInVarArgFunc()) {
      SmallVector<MVT, 2> RegParmTypes;
      RegParmTypes.push_back(MVT::i64);
      RegParmTypes.push_back(MVT::f128);
      // Compute the set of forwarded registers. The rest are scratch.
      SmallVectorImpl<ForwardedRegister> &Forwards =
                                       FuncInfo->getForwardedMustTailRegParms();
      CCInfo.analyzeMustTailForwardedRegisters(Forwards, RegParmTypes,
                                               CC_AArch64_AAPCS);
 
      // Conservatively forward X8, since it might be used for aggregate return.
      if (!CCInfo.isAllocated(AArch64::X8)) {
        Register X8VReg = MF.addLiveIn(AArch64::X8, &AArch64::GPR64RegClass);
        Forwards.push_back(ForwardedRegister(X8VReg, AArch64::X8, MVT::i64));
      }
    }
  }
 
  // On Windows, InReg pointers must be returned, so record the pointer in a
  // virtual register at the start of the function so it can be returned in the
  // epilogue.
  if (IsWin64 || F.getCallingConv() == CallingConv::ARM64EC_Thunk_X64) {
    for (unsigned I = 0, E = Ins.size(); I != E; ++I) {
      if ((F.getCallingConv() == CallingConv::ARM64EC_Thunk_X64 ||
           Ins[I].Flags.isInReg()) &&
          Ins[I].Flags.isSRet()) {
        assert(!FuncInfo->getSRetReturnReg());
 
        MVT PtrTy = getPointerTy(DAG.getDataLayout());
        Register Reg =
            MF.getRegInfo().createVirtualRegister(getRegClassFor(PtrTy));
        FuncInfo->setSRetReturnReg(Reg);
 
        SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, Reg, InVals[I]);
        Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Copy, Chain);
        break;
      }
    }
  }
 
  unsigned StackArgSize = CCInfo.getStackSize();
  bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
  if (DoesCalleeRestoreStack(CallConv, TailCallOpt)) {
    // This is a non-standard ABI so by fiat I say we're allowed to make full
    // use of the stack area to be popped, which must be aligned to 16 bytes in
    // any case:
    StackArgSize = alignTo(StackArgSize, 16);
 
    // If we're expected to restore the stack (e.g. fastcc) then we'll be adding
    // a multiple of 16.
    FuncInfo->setArgumentStackToRestore(StackArgSize);
 
    // This realignment carries over to the available bytes below. Our own
    // callers will guarantee the space is free by giving an aligned value to
    // CALLSEQ_START.
  }
  // Even if we're not expected to free up the space, it's useful to know how
  // much is there while considering tail calls (because we can reuse it).
  FuncInfo->setBytesInStackArgArea(StackArgSize);
 
  if (Subtarget->hasCustomCallingConv())
    Subtarget->getRegisterInfo()->UpdateCustomCalleeSavedRegs(MF);
 
  if (Subtarget->isTargetWindows() || hasInlineStackProbe(MF)) {
    SDValue Size;
    if (Attrs.hasZAState()) {
      SDValue SVL = DAG.getNode(AArch64ISD::RDSVL, DL, MVT::i64,
                                DAG.getConstant(1, DL, MVT::i32));
      Size = DAG.getNode(ISD::MUL, DL, MVT::i64, SVL, SVL);
    } else if (Attrs.hasAgnosticZAInterface()) {
      RTLIB::Libcall LC = RTLIB::SMEABI_SME_STATE_SIZE;
      RTLIB::LibcallImpl LCImpl = DAG.getLibcalls().getLibcallImpl(LC);
 
      SDValue Callee =
          DAG.getExternalSymbol(LCImpl, getPointerTy(DAG.getDataLayout()));
      auto *RetTy = EVT(MVT::i64).getTypeForEVT(*DAG.getContext());
      TargetLowering::CallLoweringInfo CLI(DAG);
      CLI.setDebugLoc(DL).setChain(Chain).setLibCallee(
          DAG.getLibcalls().getLibcallImplCallingConv(LCImpl), RetTy, Callee,
          {});
      std::tie(Size, Chain) = LowerCallTo(CLI);
    }
    if (Size) {
      SDValue Buffer = DAG.getNode(
          ISD::DYNAMIC_STACKALLOC, DL, DAG.getVTList(MVT::i64, MVT::Other),
          {Chain, Size, DAG.getConstant(1, DL, MVT::i64)});
      Chain = Buffer.getValue(1);
 
      Register BufferPtr =
          MF.getRegInfo().createVirtualRegister(&AArch64::GPR64RegClass);
      Chain = DAG.getCopyToReg(Chain, DL, BufferPtr, Buffer);
      Chain = DAG.getNode(AArch64ISD::SME_STATE_ALLOC, DL,
                          DAG.getVTList(MVT::Other), Chain);
      FuncInfo->setEarlyAllocSMESaveBuffer(BufferPtr);
      MFI.CreateVariableSizedObject(Align(16), nullptr);
    }
  }
 
  if (CallConv == CallingConv::PreserveNone) {
    for (const ISD::InputArg &I : Ins) {
      if (I.Flags.isSwiftSelf() || I.Flags.isSwiftError() ||
          I.Flags.isSwiftAsync()) {
        MachineFunction &MF = DAG.getMachineFunction();
        DAG.getContext()->diagnose(DiagnosticInfoUnsupported(
            MF.getFunction(),
            "Swift attributes can't be used with preserve_none",
            DL.getDebugLoc()));
        break;
      }
    }
  }
 
  return Chain;
}
 
void AArch64TargetLowering::saveVarArgRegisters(CCState &CCInfo,
                                                SelectionDAG &DAG,
                                                const SDLoc &DL,
                                                SDValue &Chain) const {
  MachineFunction &MF = DAG.getMachineFunction();
  MachineFrameInfo &MFI = MF.getFrameInfo();
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
  auto PtrVT = getPointerTy(DAG.getDataLayout());
  Function &F = MF.getFunction();
  bool IsWin64 =
      Subtarget->isCallingConvWin64(F.getCallingConv(), F.isVarArg());
 
  SmallVector<SDValue, 8> MemOps;
 
  auto GPRArgRegs = AArch64::getGPRArgRegs();
  unsigned NumGPRArgRegs = GPRArgRegs.size();
  if (Subtarget->isWindowsArm64EC()) {
    // In the ARM64EC ABI, only x0-x3 are used to pass arguments to varargs
    // functions.
    NumGPRArgRegs = 4;
  }
  unsigned FirstVariadicGPR = CCInfo.getFirstUnallocated(GPRArgRegs);
 
  unsigned GPRSaveSize = 8 * (NumGPRArgRegs - FirstVariadicGPR);
  int GPRIdx = 0;
  if (GPRSaveSize != 0) {
    if (IsWin64) {
      GPRIdx = MFI.CreateFixedObject(GPRSaveSize, -(int)GPRSaveSize, false);
      if (GPRSaveSize & 15)
        // The extra size here, if triggered, will always be 8.
        MFI.CreateFixedObject(16 - (GPRSaveSize & 15), -(int)alignTo(GPRSaveSize, 16), false);
    } else
      GPRIdx = MFI.CreateStackObject(GPRSaveSize, Align(8), false);
 
    SDValue FIN;
    if (Subtarget->isWindowsArm64EC()) {
      // With the Arm64EC ABI, we reserve the save area as usual, but we
      // compute its address relative to x4.  For a normal AArch64->AArch64
      // call, x4 == sp on entry, but calls from an entry thunk can pass in a
      // different address.
      Register VReg = MF.addLiveIn(AArch64::X4, &AArch64::GPR64RegClass);
      SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
      FIN = DAG.getNode(ISD::SUB, DL, MVT::i64, Val,
                        DAG.getConstant(GPRSaveSize, DL, MVT::i64));
    } else {
      FIN = DAG.getFrameIndex(GPRIdx, PtrVT);
    }
 
    for (unsigned i = FirstVariadicGPR; i < NumGPRArgRegs; ++i) {
      Register VReg = MF.addLiveIn(GPRArgRegs[i], &AArch64::GPR64RegClass);
      SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
      SDValue Store =
          DAG.getStore(Val.getValue(1), DL, Val, FIN,
                       IsWin64 ? MachinePointerInfo::getFixedStack(
                                     MF, GPRIdx, (i - FirstVariadicGPR) * 8)
                               : MachinePointerInfo::getStack(MF, i * 8));
      MemOps.push_back(Store);
      FIN =
          DAG.getNode(ISD::ADD, DL, PtrVT, FIN, DAG.getConstant(8, DL, PtrVT));
    }
  }
  FuncInfo->setVarArgsGPRIndex(GPRIdx);
  FuncInfo->setVarArgsGPRSize(GPRSaveSize);
 
  if (Subtarget->hasFPARMv8() && !IsWin64) {
    auto FPRArgRegs = AArch64::getFPRArgRegs();
    const unsigned NumFPRArgRegs = FPRArgRegs.size();
    unsigned FirstVariadicFPR = CCInfo.getFirstUnallocated(FPRArgRegs);
 
    unsigned FPRSaveSize = 16 * (NumFPRArgRegs - FirstVariadicFPR);
    int FPRIdx = 0;
    if (FPRSaveSize != 0) {
      FPRIdx = MFI.CreateStackObject(FPRSaveSize, Align(16), false);
 
      SDValue FIN = DAG.getFrameIndex(FPRIdx, PtrVT);
 
      for (unsigned i = FirstVariadicFPR; i < NumFPRArgRegs; ++i) {
        Register VReg = MF.addLiveIn(FPRArgRegs[i], &AArch64::FPR128RegClass);
        SDValue Val = DAG.getCopyFromReg(Chain, DL, VReg, MVT::f128);
 
        SDValue Store = DAG.getStore(Val.getValue(1), DL, Val, FIN,
                                     MachinePointerInfo::getStack(MF, i * 16));
        MemOps.push_back(Store);
        FIN = DAG.getNode(ISD::ADD, DL, PtrVT, FIN,
                          DAG.getConstant(16, DL, PtrVT));
      }
    }
    FuncInfo->setVarArgsFPRIndex(FPRIdx);
    FuncInfo->setVarArgsFPRSize(FPRSaveSize);
  }
 
  if (!MemOps.empty()) {
    Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
  }
}
 
/// LowerCallResult - Lower the result values of a call into the
/// appropriate copies out of appropriate physical registers.
SDValue AArch64TargetLowering::LowerCallResult(
    SDValue Chain, SDValue InGlue, CallingConv::ID CallConv, bool isVarArg,
    const SmallVectorImpl<CCValAssign> &RVLocs, const SDLoc &DL,
    SelectionDAG &DAG, SmallVectorImpl<SDValue> &InVals, bool isThisReturn,
    SDValue ThisVal, bool RequiresSMChange) const {
  DenseMap<unsigned, SDValue> CopiedRegs;
  // Copy all of the result registers out of their specified physreg.
  for (unsigned i = 0; i != RVLocs.size(); ++i) {
    CCValAssign VA = RVLocs[i];
 
    // Pass 'this' value directly from the argument to return value, to avoid
    // reg unit interference
    if (i == 0 && isThisReturn) {
      assert(!VA.needsCustom() && VA.getLocVT() == MVT::i64 &&
             "unexpected return calling convention register assignment");
      InVals.push_back(ThisVal);
      continue;
    }
 
    // Avoid copying a physreg twice since RegAllocFast is incompetent and only
    // allows one use of a physreg per block.
    SDValue Val = CopiedRegs.lookup(VA.getLocReg());
    if (!Val) {
      Val =
          DAG.getCopyFromReg(Chain, DL, VA.getLocReg(), VA.getLocVT(), InGlue);
      Chain = Val.getValue(1);
      InGlue = Val.getValue(2);
      CopiedRegs[VA.getLocReg()] = Val;
    }
 
    switch (VA.getLocInfo()) {
    default:
      llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full:
      break;
    case CCValAssign::BCvt:
      Val = DAG.getNode(ISD::BITCAST, DL, VA.getValVT(), Val);
      break;
    case CCValAssign::AExtUpper:
      Val = DAG.getNode(ISD::SRL, DL, VA.getLocVT(), Val,
                        DAG.getConstant(32, DL, VA.getLocVT()));
      [[fallthrough]];
    case CCValAssign::AExt:
      [[fallthrough]];
    case CCValAssign::ZExt:
      Val = DAG.getZExtOrTrunc(Val, DL, VA.getValVT());
      break;
    }
 
    if (RequiresSMChange && isPassedInFPR(VA.getValVT()))
      Val = DAG.getNode(AArch64ISD::COALESCER_BARRIER, DL,
                        DAG.getVTList(Val.getValueType(), MVT::Glue), Val);
 
    InVals.push_back(Val);
  }
 
  return Chain;
}
 
/// Return true if the calling convention is one that we can guarantee TCO for.
static bool canGuaranteeTCO(CallingConv::ID CC, bool GuaranteeTailCalls) {
  return (CC == CallingConv::Fast && GuaranteeTailCalls) ||
         CC == CallingConv::Tail || CC == CallingConv::SwiftTail;
}
 
/// Return true if we might ever do TCO for calls with this calling convention.
static bool mayTailCallThisCC(CallingConv::ID CC) {
  switch (CC) {
  case CallingConv::C:
  case CallingConv::AArch64_SVE_VectorCall:
  case CallingConv::PreserveMost:
  case CallingConv::PreserveAll:
  case CallingConv::PreserveNone:
  case CallingConv::Swift:
  case CallingConv::SwiftTail:
  case CallingConv::Tail:
  case CallingConv::Fast:
    return true;
  default:
    return false;
  }
}
 
/// Return true if the call convention supports varargs
/// Currently only those that pass varargs like the C
/// calling convention does are eligible
/// Calling conventions listed in this function must also
/// be properly handled in AArch64Subtarget::isCallingConvWin64
static bool callConvSupportsVarArgs(CallingConv::ID CC) {
  switch (CC) {
  case CallingConv::C:
  case CallingConv::PreserveNone:
  // SVE vector call is only partially supported, but it should
  // support named arguments being passed. Any arguments being passed
  // as varargs, are still unsupported.
  case CallingConv::AArch64_SVE_VectorCall:
    return true;
  default:
    return false;
  }
}
 
static void analyzeCallOperands(const AArch64TargetLowering &TLI,
                                const AArch64Subtarget *Subtarget,
                                const TargetLowering::CallLoweringInfo &CLI,
                                CCState &CCInfo) {
  const SelectionDAG &DAG = CLI.DAG;
  CallingConv::ID CalleeCC = CLI.CallConv;
  bool IsVarArg = CLI.IsVarArg;
  const SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
  bool IsCalleeWin64 = Subtarget->isCallingConvWin64(CalleeCC, IsVarArg);
 
  // For Arm64EC thunks, allocate 32 extra bytes at the bottom of the stack
  // for the shadow store.
  if (CalleeCC == CallingConv::ARM64EC_Thunk_X64)
    CCInfo.AllocateStack(32, Align(16));
 
  unsigned NumArgs = Outs.size();
  for (unsigned i = 0; i != NumArgs; ++i) {
    MVT ArgVT = Outs[i].VT;
    ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
 
    bool UseVarArgCC = false;
    if (IsVarArg) {
      // On Windows, the fixed arguments in a vararg call are passed in GPRs
      // too, so use the vararg CC to force them to integer registers.
      if (IsCalleeWin64) {
        UseVarArgCC = true;
      } else {
        UseVarArgCC = ArgFlags.isVarArg();
      }
    }
 
    if (!UseVarArgCC) {
      // Get type of the original argument.
      EVT ActualVT =
          TLI.getValueType(DAG.getDataLayout(), CLI.Args[Outs[i].OrigArgIndex].Ty,
                       /*AllowUnknown*/ true);
      MVT ActualMVT = ActualVT.isSimple() ? ActualVT.getSimpleVT() : ArgVT;
      // If ActualMVT is i1/i8/i16, we should set LocVT to i8/i8/i16.
      if (ActualMVT == MVT::i1 || ActualMVT == MVT::i8)
        ArgVT = MVT::i8;
      else if (ActualMVT == MVT::i16)
        ArgVT = MVT::i16;
    }
 
    // FIXME: CCAssignFnForCall should be called once, for the call and not per
    // argument. This logic should exactly mirror LowerFormalArguments.
    CCAssignFn *AssignFn = TLI.CCAssignFnForCall(CalleeCC, UseVarArgCC);
    bool Res = AssignFn(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags,
                        Outs[i].OrigTy, CCInfo);
    assert(!Res && "Call operand has unhandled type");
    (void)Res;
  }
}
 
static SMECallAttrs
getSMECallAttrs(const Function &Caller, const RTLIB::RuntimeLibcallsInfo &RTLCI,
                const TargetLowering::CallLoweringInfo &CLI) {
  if (CLI.CB)
    return SMECallAttrs(*CLI.CB, &RTLCI);
  if (auto *ES = dyn_cast<ExternalSymbolSDNode>(CLI.Callee))
    return SMECallAttrs(SMEAttrs(Caller), SMEAttrs(ES->getSymbol(), RTLCI));
  return SMECallAttrs(SMEAttrs(Caller), SMEAttrs(SMEAttrs::Normal));
}
 
bool AArch64TargetLowering::isEligibleForTailCallOptimization(
    const CallLoweringInfo &CLI) const {
  CallingConv::ID CalleeCC = CLI.CallConv;
  if (!mayTailCallThisCC(CalleeCC))
    return false;
 
  SDValue Callee = CLI.Callee;
  bool IsVarArg = CLI.IsVarArg;
  const SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
  const SmallVector<SDValue, 32> &OutVals = CLI.OutVals;
  const SmallVector<ISD::InputArg, 32> &Ins = CLI.Ins;
  const SelectionDAG &DAG = CLI.DAG;
  MachineFunction &MF = DAG.getMachineFunction();
  const Function &CallerF = MF.getFunction();
  CallingConv::ID CallerCC = CallerF.getCallingConv();
 
  // SME Streaming functions are not eligible for TCO as they may require
  // the streaming mode or ZA/ZT0 to be restored after returning from the call.
  SMECallAttrs CallAttrs =
      getSMECallAttrs(CallerF, getRuntimeLibcallsInfo(), CLI);
  if (CallAttrs.requiresSMChange() || CallAttrs.requiresLazySave() ||
      CallAttrs.requiresPreservingAllZAState() ||
      CallAttrs.requiresPreservingZT0() ||
      CallAttrs.caller().hasStreamingBody() || CallAttrs.caller().isNewZA() ||
      CallAttrs.caller().isNewZT0())
    return false;
 
  // Functions using the C or Fast calling convention that have an SVE signature
  // preserve more registers and should assume the SVE_VectorCall CC.
  // The check for matching callee-saved regs will determine whether it is
  // eligible for TCO.
  if ((CallerCC == CallingConv::C || CallerCC == CallingConv::Fast) &&
      MF.getInfo<AArch64FunctionInfo>()->isSVECC())
    CallerCC = CallingConv::AArch64_SVE_VectorCall;
 
  bool CCMatch = CallerCC == CalleeCC;
 
  // When using the Windows calling convention on a non-windows OS, we want
  // to back up and restore X18 in such functions; we can't do a tail call
  // from those functions.
  if (CallerCC == CallingConv::Win64 && !Subtarget->isTargetWindows() &&
      CalleeCC != CallingConv::Win64)
    return false;
 
  // Byval parameters hand the function a pointer directly into the stack area
  // we want to reuse during a tail call. Working around this *is* possible (see
  // X86) but less efficient and uglier in LowerCall.
  for (Function::const_arg_iterator i = CallerF.arg_begin(),
                                    e = CallerF.arg_end();
       i != e; ++i) {
    if (i->hasByValAttr())
      return false;
 
    // On Windows, "inreg" attributes signify non-aggregate indirect returns.
    // In this case, it is necessary to save X0/X1 in the callee and return it
    // in X0. Tail call opt may interfere with this, so we disable tail call
    // opt when the caller has an "inreg" attribute -- except if the callee
    // also has that attribute on the same argument, and the same value is
    // passed.
    if (i->hasInRegAttr()) {
      unsigned ArgIdx = i - CallerF.arg_begin();
      if (!CLI.CB || CLI.CB->arg_size() <= ArgIdx)
        return false;
      AttributeSet Attrs = CLI.CB->getParamAttributes(ArgIdx);
      if (!Attrs.hasAttribute(Attribute::InReg) ||
          !Attrs.hasAttribute(Attribute::StructRet) || !i->hasStructRetAttr() ||
          CLI.CB->getArgOperand(ArgIdx) != i) {
        return false;
      }
    }
  }
 
  if (canGuaranteeTCO(CalleeCC, getTargetMachine().Options.GuaranteedTailCallOpt))
    return CCMatch;
 
  // Externally-defined functions with weak linkage should not be
  // tail-called on AArch64 when the OS does not support dynamic
  // pre-emption of symbols, as the AAELF spec requires normal calls
  // to undefined weak functions to be replaced with a NOP or jump to the
  // next instruction. The behaviour of branch instructions in this
  // situation (as used for tail calls) is implementation-defined, so we
  // cannot rely on the linker replacing the tail call with a return.
  if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
    const GlobalValue *GV = G->getGlobal();
    const Triple &TT = getTargetMachine().getTargetTriple();
    if (GV->hasExternalWeakLinkage() &&
        (!TT.isOSWindows() || TT.isOSBinFormatELF() || TT.isOSBinFormatMachO()))
      return false;
  }
 
  // Now we search for cases where we can use a tail call without changing the
  // ABI. Sibcall is used in some places (particularly gcc) to refer to this
  // concept.
 
  // I want anyone implementing a new calling convention to think long and hard
  // about this assert.
  if (IsVarArg && !callConvSupportsVarArgs(CalleeCC))
    report_fatal_error("Unsupported variadic calling convention");
 
  LLVMContext &C = *DAG.getContext();
  // Check that the call results are passed in the same way.
  if (!CCState::resultsCompatible(CalleeCC, CallerCC, MF, C, Ins,
                                  CCAssignFnForCall(CalleeCC, IsVarArg),
                                  CCAssignFnForCall(CallerCC, IsVarArg)))
    return false;
  // The callee has to preserve all registers the caller needs to preserve.
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
  const uint32_t *CallerPreserved = TRI->getCallPreservedMask(MF, CallerCC);
  if (!CCMatch) {
    const uint32_t *CalleePreserved = TRI->getCallPreservedMask(MF, CalleeCC);
    if (Subtarget->hasCustomCallingConv()) {
      TRI->UpdateCustomCallPreservedMask(MF, &CallerPreserved);
      TRI->UpdateCustomCallPreservedMask(MF, &CalleePreserved);
    }
    if (!TRI->regmaskSubsetEqual(CallerPreserved, CalleePreserved))
      return false;
  }
 
  // Nothing more to check if the callee is taking no arguments
  if (Outs.empty())
    return true;
 
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CalleeCC, IsVarArg, MF, ArgLocs, C);
 
  analyzeCallOperands(*this, Subtarget, CLI, CCInfo);
 
  if (IsVarArg && !(CLI.CB && CLI.CB->isMustTailCall())) {
    // When we are musttail, additional checks have been done and we can safely ignore this check
    // At least two cases here: if caller is fastcc then we can't have any
    // memory arguments (we'd be expected to clean up the stack afterwards). If
    // caller is C then we could potentially use its argument area.
 
    // FIXME: for now we take the most conservative of these in both cases:
    // disallow all variadic memory operands.
    for (const CCValAssign &ArgLoc : ArgLocs)
      if (!ArgLoc.isRegLoc())
        return false;
  }
 
  const AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
 
  // If any of the arguments is passed indirectly, it must be SVE, so the
  // 'getBytesInStackArgArea' is not sufficient to determine whether we need to
  // allocate space on the stack. That is why we determine this explicitly here
  // the call cannot be a tailcall.
  if (llvm::any_of(ArgLocs, [&](CCValAssign &A) {
        assert((A.getLocInfo() != CCValAssign::Indirect ||
                A.getValVT().isScalableVector() ||
                Subtarget->isWindowsArm64EC()) &&
               "Expected value to be scalable");
        return A.getLocInfo() == CCValAssign::Indirect;
      }))
    return false;
 
  // If the stack arguments for this call do not fit into our own save area then
  // the call cannot be made tail.
  if (CCInfo.getStackSize() > FuncInfo->getBytesInStackArgArea())
    return false;
 
  const MachineRegisterInfo &MRI = MF.getRegInfo();
  if (!parametersInCSRMatch(MRI, CallerPreserved, ArgLocs, OutVals))
    return false;
 
  return true;
}
 
SDValue AArch64TargetLowering::addTokenForArgument(SDValue Chain,
                                                   SelectionDAG &DAG,
                                                   MachineFrameInfo &MFI,
                                                   int ClobberedFI) const {
  SmallVector<SDValue, 8> ArgChains;
  int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
  int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
 
  // Include the original chain at the beginning of the list. When this is
  // used by target LowerCall hooks, this helps legalize find the
  // CALLSEQ_BEGIN node.
  ArgChains.push_back(Chain);
 
  // Add a chain value for each stack argument corresponding
  for (SDNode *U : DAG.getEntryNode().getNode()->users())
    if (LoadSDNode *L = dyn_cast<LoadSDNode>(U))
      if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr()))
        if (FI->getIndex() < 0) {
          int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
          int64_t InLastByte = InFirstByte;
          InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
 
          if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
              (FirstByte <= InFirstByte && InFirstByte <= LastByte))
            ArgChains.push_back(SDValue(L, 1));
        }
 
  // Build a tokenfactor for all the chains.
  return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
}
 
bool AArch64TargetLowering::DoesCalleeRestoreStack(CallingConv::ID CallCC,
                                                   bool TailCallOpt) const {
  return (CallCC == CallingConv::Fast && TailCallOpt) ||
         CallCC == CallingConv::Tail || CallCC == CallingConv::SwiftTail;
}
 
// Check if the value is zero-extended from i1 to i8
static bool checkZExtBool(SDValue Arg, const SelectionDAG &DAG) {
  unsigned SizeInBits = Arg.getValueType().getSizeInBits();
  if (SizeInBits < 8)
    return false;
 
  APInt RequiredZero(SizeInBits, 0xFE);
  KnownBits Bits = DAG.computeKnownBits(Arg, 4);
  bool ZExtBool = (Bits.Zero & RequiredZero) == RequiredZero;
  return ZExtBool;
}
 
void AArch64TargetLowering::AdjustInstrPostInstrSelection(MachineInstr &MI,
                                                          SDNode *Node) const {
  // Live-in physreg copies that are glued to SMSTART are applied as
  // implicit-def's in the InstrEmitter. Here we remove them, allowing the
  // register allocator to pass call args in callee saved regs, without extra
  // copies to avoid these fake clobbers of actually-preserved GPRs.
  if (MI.getOpcode() == AArch64::MSRpstatesvcrImm1 ||
      MI.getOpcode() == AArch64::MSRpstatePseudo) {
    for (unsigned I = MI.getNumOperands() - 1; I > 0; --I)
      if (MachineOperand &MO = MI.getOperand(I);
          MO.isReg() && MO.isImplicit() && MO.isDef() &&
          (AArch64::GPR32RegClass.contains(MO.getReg()) ||
           AArch64::GPR64RegClass.contains(MO.getReg())))
        MI.removeOperand(I);
 
    // The SVE vector length can change when entering/leaving streaming mode.
    // FPMR is set to 0 when entering/leaving streaming mode.
    if (MI.getOperand(0).getImm() == AArch64SVCR::SVCRSM ||
        MI.getOperand(0).getImm() == AArch64SVCR::SVCRSMZA) {
      MI.addOperand(MachineOperand::CreateReg(AArch64::VG, /*IsDef=*/false,
                                              /*IsImplicit=*/true));
      MI.addOperand(MachineOperand::CreateReg(AArch64::VG, /*IsDef=*/true,
                                              /*IsImplicit=*/true));
      MI.addOperand(MachineOperand::CreateReg(AArch64::FPMR, /*IsDef=*/true,
                                              /*IsImplicit=*/true));
    }
  }
 
  // Add an implicit use of 'VG' for ADDXri/SUBXri, which are instructions that
  // have nothing to do with VG, were it not that they are used to materialise a
  // frame-address. If they contain a frame-index to a scalable vector, this
  // will likely require an ADDVL instruction to materialise the address, thus
  // reading VG.
  const MachineFunction &MF = *MI.getMF();
  if (MF.getInfo<AArch64FunctionInfo>()->hasStreamingModeChanges() &&
      (MI.getOpcode() == AArch64::ADDXri ||
       MI.getOpcode() == AArch64::SUBXri)) {
    const MachineOperand &MO = MI.getOperand(1);
    if (MO.isFI() && MF.getFrameInfo().hasScalableStackID(MO.getIndex()))
      MI.addOperand(MachineOperand::CreateReg(AArch64::VG, /*IsDef=*/false,
                                              /*IsImplicit=*/true));
  }
}
 
SDValue AArch64TargetLowering::changeStreamingMode(
    SelectionDAG &DAG, SDLoc DL, bool Enable, SDValue Chain, SDValue InGlue,
    unsigned Condition, bool InsertVectorLengthCheck) const {
  MachineFunction &MF = DAG.getMachineFunction();
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
  FuncInfo->setHasStreamingModeChanges(true);
 
  auto GetCheckVL = [&](SDValue Chain, SDValue InGlue = SDValue()) -> SDValue {
    SmallVector<SDValue, 2> Ops = {Chain};
    if (InGlue)
      Ops.push_back(InGlue);
    return DAG.getNode(AArch64ISD::CHECK_MATCHING_VL, DL,
                       DAG.getVTList(MVT::Other, MVT::Glue), Ops);
  };
 
  if (InsertVectorLengthCheck && Enable) {
    // Non-streaming -> Streaming
    // Insert vector length check before smstart
    SDValue CheckVL = GetCheckVL(Chain, InGlue);
    Chain = CheckVL.getValue(0);
    InGlue = CheckVL.getValue(1);
  }
 
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
  SDValue RegMask = DAG.getRegisterMask(TRI->getSMStartStopCallPreservedMask());
  SDValue MSROp =
      DAG.getTargetConstant((int32_t)AArch64SVCR::SVCRSM, DL, MVT::i32);
  SmallVector<SDValue> Ops = {Chain, MSROp};
  unsigned Opcode;
  if (Condition != AArch64SME::Always) {
    Register PStateReg = FuncInfo->getPStateSMReg();
    assert(PStateReg.isValid() && "PStateSM Register is invalid");
    SDValue PStateSM =
        DAG.getCopyFromReg(Chain, DL, PStateReg, MVT::i64, InGlue);
    // Use chain and glue from the CopyFromReg.
    Ops[0] = PStateSM.getValue(1);
    InGlue = PStateSM.getValue(2);
    SDValue ConditionOp = DAG.getTargetConstant(Condition, DL, MVT::i64);
    Opcode = Enable ? AArch64ISD::COND_SMSTART : AArch64ISD::COND_SMSTOP;
    Ops.push_back(ConditionOp);
    Ops.push_back(PStateSM);
  } else {
    Opcode = Enable ? AArch64ISD::SMSTART : AArch64ISD::SMSTOP;
  }
  Ops.push_back(RegMask);
 
  if (InGlue)
    Ops.push_back(InGlue);
 
  SDValue SMChange =
      DAG.getNode(Opcode, DL, DAG.getVTList(MVT::Other, MVT::Glue), Ops);
 
  if (!InsertVectorLengthCheck || Enable)
    return SMChange;
 
  // Streaming -> Non-streaming
  // Insert vector length check after smstop since we cannot read VL
  // in streaming mode
  return GetCheckVL(SMChange.getValue(0), SMChange.getValue(1));
}
 
static AArch64SME::ToggleCondition
getSMToggleCondition(const SMECallAttrs &CallAttrs) {
  if (!CallAttrs.caller().hasStreamingCompatibleInterface() ||
      CallAttrs.caller().hasStreamingBody())
    return AArch64SME::Always;
  if (CallAttrs.callee().hasNonStreamingInterface())
    return AArch64SME::IfCallerIsStreaming;
  if (CallAttrs.callee().hasStreamingInterface())
    return AArch64SME::IfCallerIsNonStreaming;
 
  llvm_unreachable("Unsupported attributes");
}
 
/// Check whether a stack argument requires lowering in a tail call.
static bool shouldLowerTailCallStackArg(const MachineFunction &MF,
                                        const CCValAssign &VA, SDValue Arg,
                                        ISD::ArgFlagsTy Flags, int CallOffset) {
  // FIXME: We should be able to handle this case, but it's not clear how to.
  if (Flags.isZExt() || Flags.isSExt())
    return true;
 
  for (;;) {
    // Look through nodes that don't alter the bits of the incoming value.
    unsigned Op = Arg.getOpcode();
    if (Op == ISD::ZERO_EXTEND || Op == ISD::ANY_EXTEND || Op == ISD::BITCAST ||
        Arg->isAssert() || Op == AArch64ISD::ASSERT_ZEXT_BOOL) {
      Arg = Arg.getOperand(0);
      continue;
    }
    break;
  }
 
  // If the argument is a load from the same immutable stack slot, we can reuse
  // it.
  if (auto *LoadNode = dyn_cast<LoadSDNode>(Arg)) {
    if (auto *FINode = dyn_cast<FrameIndexSDNode>(LoadNode->getBasePtr())) {
      const MachineFrameInfo &MFI = MF.getFrameInfo();
      int FI = FINode->getIndex();
      if (!MFI.isImmutableObjectIndex(FI))
        return true;
      if (CallOffset != MFI.getObjectOffset(FI))
        return true;
      uint64_t SizeInBits = LoadNode->getMemoryVT().getFixedSizeInBits();
      if (SizeInBits != VA.getValVT().getSizeInBits())
        return true;
      return false;
    }
  }
 
  return true;
}
 
/// LowerCall - Lower a call to a callseq_start + CALL + callseq_end chain,
/// and add input and output parameter nodes.
SDValue
AArch64TargetLowering::LowerCall(CallLoweringInfo &CLI,
                                 SmallVectorImpl<SDValue> &InVals) const {
  SelectionDAG &DAG = CLI.DAG;
  SDLoc &DL = CLI.DL;
  SmallVector<ISD::OutputArg, 32> &Outs = CLI.Outs;
  SmallVector<SDValue, 32> &OutVals = CLI.OutVals;
  SmallVector<ISD::InputArg, 32> &Ins = CLI.Ins;
  SDValue Chain = CLI.Chain;
  SDValue Callee = CLI.Callee;
  bool &IsTailCall = CLI.IsTailCall;
  CallingConv::ID &CallConv = CLI.CallConv;
  bool IsVarArg = CLI.IsVarArg;
  const CallBase *CB = CLI.CB;
 
  MachineFunction &MF = DAG.getMachineFunction();
  MachineFunction::CallSiteInfo CSInfo;
  bool IsThisReturn = false;
 
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
  bool TailCallOpt = MF.getTarget().Options.GuaranteedTailCallOpt;
  bool IsCFICall = CLI.CB && CLI.CB->isIndirectCall() && CLI.CFIType;
  bool IsSibCall = false;
  bool GuardWithBTI = false;
 
  if (CLI.CB && CLI.CB->hasFnAttr(Attribute::ReturnsTwice) &&
      !Subtarget->noBTIAtReturnTwice()) {
    GuardWithBTI = FuncInfo->branchTargetEnforcement();
  }
 
  // Analyze operands of the call, assigning locations to each operand.
  SmallVector<CCValAssign, 16> ArgLocs;
  CCState CCInfo(CallConv, IsVarArg, MF, ArgLocs, *DAG.getContext());
 
  if (IsVarArg) {
    unsigned NumArgs = Outs.size();
 
    for (unsigned i = 0; i != NumArgs; ++i) {
      if (Outs[i].Flags.isVarArg() && Outs[i].VT.isScalableVector())
        report_fatal_error("Passing SVE types to variadic functions is "
                           "currently not supported");
    }
  }
 
  analyzeCallOperands(*this, Subtarget, CLI, CCInfo);
 
  CCAssignFn *RetCC = CCAssignFnForReturn(CallConv);
  // Assign locations to each value returned by this call.
  SmallVector<CCValAssign, 16> RVLocs;
  CCState RetCCInfo(CallConv, IsVarArg, DAG.getMachineFunction(), RVLocs,
                    *DAG.getContext());
  RetCCInfo.AnalyzeCallResult(Ins, RetCC);
 
  // Set type id for call site info.
  setTypeIdForCallsiteInfo(CB, MF, CSInfo);
 
  // Check callee args/returns for SVE registers and set calling convention
  // accordingly.
  if (CallConv == CallingConv::C || CallConv == CallingConv::Fast) {
    auto HasSVERegLoc = [](CCValAssign &Loc) {
      if (!Loc.isRegLoc())
        return false;
      return AArch64::ZPRRegClass.contains(Loc.getLocReg()) ||
             AArch64::PPRRegClass.contains(Loc.getLocReg());
    };
    if (any_of(RVLocs, HasSVERegLoc) || any_of(ArgLocs, HasSVERegLoc))
      CallConv = CallingConv::AArch64_SVE_VectorCall;
  }
 
  // Determine whether we need any streaming mode changes.
  SMECallAttrs CallAttrs =
      getSMECallAttrs(MF.getFunction(), getRuntimeLibcallsInfo(), CLI);
 
  std::optional<unsigned> ZAMarkerNode;
  if (CallAttrs.requiresLazySave() || CallAttrs.requiresPreservingAllZAState())
    ZAMarkerNode = AArch64ISD::REQUIRES_ZA_SAVE;
  else if (CallAttrs.requiresPreservingZT0())
    ZAMarkerNode = AArch64ISD::REQUIRES_ZT0_SAVE;
  else if (CallAttrs.caller().hasZAState() || CallAttrs.caller().hasZT0State())
    ZAMarkerNode = AArch64ISD::INOUT_ZA_USE;
 
  if (IsTailCall) {
    // Check if it's really possible to do a tail call.
    IsTailCall = isEligibleForTailCallOptimization(CLI);
 
    // A sibling call is one where we're under the usual C ABI and not planning
    // to change that but can still do a tail call:
    if (!ZAMarkerNode && !TailCallOpt && IsTailCall &&
        CallConv != CallingConv::Tail && CallConv != CallingConv::SwiftTail)
      IsSibCall = true;
 
    if (IsTailCall)
      ++NumTailCalls;
  }
 
  if (!IsTailCall && CLI.CB && CLI.CB->isMustTailCall())
    report_fatal_error("failed to perform tail call elimination on a call "
                       "site marked musttail");
 
  // Get a count of how many bytes are to be pushed on the stack.
  unsigned NumBytes = CCInfo.getStackSize();
 
  if (IsSibCall) {
    // Since we're not changing the ABI to make this a tail call, the memory
    // operands are already available in the caller's incoming argument space.
    NumBytes = 0;
  }
 
  // FPDiff is the byte offset of the call's argument area from the callee's.
  // Stores to callee stack arguments will be placed in FixedStackSlots offset
  // by this amount for a tail call. In a sibling call it must be 0 because the
  // caller will deallocate the entire stack and the callee still expects its
  // arguments to begin at SP+0. Completely unused for non-tail calls.
  int FPDiff = 0;
 
  if (IsTailCall && !IsSibCall) {
    unsigned NumReusableBytes = FuncInfo->getBytesInStackArgArea();
 
    // Since callee will pop argument stack as a tail call, we must keep the
    // popped size 16-byte aligned.
    NumBytes = alignTo(NumBytes, 16);
 
    // FPDiff will be negative if this tail call requires more space than we
    // would automatically have in our incoming argument space. Positive if we
    // can actually shrink the stack.
    FPDiff = NumReusableBytes - NumBytes;
 
    // Update the required reserved area if this is the tail call requiring the
    // most argument stack space.
    if (FPDiff < 0 && FuncInfo->getTailCallReservedStack() < (unsigned)-FPDiff)
      FuncInfo->setTailCallReservedStack(-FPDiff);
 
    // The stack pointer must be 16-byte aligned at all times it's used for a
    // memory operation, which in practice means at *all* times and in
    // particular across call boundaries. Therefore our own arguments started at
    // a 16-byte aligned SP and the delta applied for the tail call should
    // satisfy the same constraint.
    assert(FPDiff % 16 == 0 && "unaligned stack on tail call");
  }
 
  auto DescribeCallsite =
      [&](OptimizationRemarkAnalysis &R) -> OptimizationRemarkAnalysis & {
    R << "call from '" << ore::NV("Caller", MF.getName()) << "' to '";
    if (auto *ES = dyn_cast<ExternalSymbolSDNode>(CLI.Callee))
      R << ore::NV("Callee", ES->getSymbol());
    else if (CLI.CB && CLI.CB->getCalledFunction())
      R << ore::NV("Callee", CLI.CB->getCalledFunction()->getName());
    else
      R << "unknown callee";
    R << "'";
    return R;
  };
 
  bool RequiresSMChange = CallAttrs.requiresSMChange();
  if (RequiresSMChange) {
    OptimizationRemarkEmitter ORE(&MF.getFunction());
    ORE.emit([&]() {
      auto R = CLI.CB ? OptimizationRemarkAnalysis("sme", "SMETransition",
                                                   CLI.CB)
                      : OptimizationRemarkAnalysis("sme", "SMETransition",
                                                   &MF.getFunction());
      DescribeCallsite(R) << " requires a streaming mode transition";
      return R;
    });
  }
 
  // Adjust the stack pointer for the new arguments... and mark ZA uses.
  // These operations are automatically eliminated by the prolog/epilog pass
  assert((!IsSibCall || !ZAMarkerNode) && "ZA markers require CALLSEQ_START");
  if (!IsSibCall) {
    Chain = DAG.getCALLSEQ_START(Chain, IsTailCall ? 0 : NumBytes, 0, DL);
    if (ZAMarkerNode) {
      // Note: We need the CALLSEQ_START to glue the ZAMarkerNode to, simply
      // using a chain can result in incorrect scheduling. The markers refer to
      // the position just before the CALLSEQ_START (though occur after as
      // CALLSEQ_START lacks in-glue).
      Chain =
          DAG.getNode(*ZAMarkerNode, DL, DAG.getVTList(MVT::Other, MVT::Glue),
                      {Chain, Chain.getValue(1)});
    }
  }
 
  SDValue StackPtr = DAG.getCopyFromReg(Chain, DL, AArch64::SP,
                                        getPointerTy(DAG.getDataLayout()));
 
  SmallVector<std::pair<unsigned, SDValue>, 8> RegsToPass;
  SmallSet<unsigned, 8> RegsUsed;
  SmallVector<SDValue, 8> MemOpChains;
  auto PtrVT = getPointerTy(DAG.getDataLayout());
 
  if (IsVarArg && CLI.CB && CLI.CB->isMustTailCall()) {
    const auto &Forwards = FuncInfo->getForwardedMustTailRegParms();
    for (const auto &F : Forwards) {
      SDValue Val = DAG.getCopyFromReg(Chain, DL, F.VReg, F.VT);
       RegsToPass.emplace_back(F.PReg, Val);
    }
  }
 
  // Walk the register/memloc assignments, inserting copies/loads.
  unsigned ExtraArgLocs = 0;
  for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
    CCValAssign &VA = ArgLocs[i - ExtraArgLocs];
    SDValue Arg = OutVals[i];
    ISD::ArgFlagsTy Flags = Outs[i].Flags;
 
    // Promote the value if needed.
    switch (VA.getLocInfo()) {
    default:
      llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full:
      break;
    case CCValAssign::SExt:
      Arg = DAG.getNode(ISD::SIGN_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::ZExt:
      Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
      if (Outs[i].ArgVT == MVT::i1) {
        // AAPCS requires i1 to be zero-extended to 8-bits by the caller.
        //
        // Check if we actually have to do this, because the value may
        // already be zero-extended.
        //
        // We cannot just emit a (zext i8 (trunc (assert-zext i8)))
        // and rely on DAGCombiner to fold this, because the following
        // (anyext i32) is combined with (zext i8) in DAG.getNode:
        //
        //   (ext (zext x)) -> (zext x)
        //
        // This will give us (zext i32), which we cannot remove, so
        // try to check this beforehand.
        if (!checkZExtBool(Arg, DAG)) {
          Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
          Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i8, Arg);
        }
      }
      Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExtUpper:
      assert(VA.getValVT() == MVT::i32 && "only expect 32 -> 64 upper bits");
      Arg = DAG.getNode(ISD::ANY_EXTEND, DL, VA.getLocVT(), Arg);
      Arg = DAG.getNode(ISD::SHL, DL, VA.getLocVT(), Arg,
                        DAG.getConstant(32, DL, VA.getLocVT()));
      break;
    case CCValAssign::BCvt:
      Arg = DAG.getBitcast(VA.getLocVT(), Arg);
      break;
    case CCValAssign::Trunc:
      Arg = DAG.getZExtOrTrunc(Arg, DL, VA.getLocVT());
      break;
    case CCValAssign::FPExt:
      Arg = DAG.getNode(ISD::FP_EXTEND, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::Indirect:
      bool isScalable = VA.getValVT().isScalableVT();
      assert((isScalable || Subtarget->isWindowsArm64EC()) &&
             "Indirect arguments should be scalable on most subtargets");
 
      TypeSize StoreSize = VA.getValVT().getStoreSize();
      TypeSize PartSize = StoreSize;
      unsigned NumParts = 1;
      if (Outs[i].Flags.isInConsecutiveRegs()) {
        while (!Outs[i + NumParts - 1].Flags.isInConsecutiveRegsLast())
          ++NumParts;
        StoreSize *= NumParts;
      }
 
      Type *Ty = EVT(VA.getValVT()).getTypeForEVT(*DAG.getContext());
      Align Alignment = DAG.getDataLayout().getPrefTypeAlign(Ty);
      MachineFrameInfo &MFI = MF.getFrameInfo();
      int FI =
          MFI.CreateStackObject(StoreSize.getKnownMinValue(), Alignment, false);
      if (isScalable) {
        bool IsPred = VA.getValVT() == MVT::aarch64svcount ||
                      VA.getValVT().getVectorElementType() == MVT::i1;
        MFI.setStackID(FI, IsPred ? TargetStackID::ScalablePredicateVector
                                  : TargetStackID::ScalableVector);
      }
 
      MachinePointerInfo MPI = MachinePointerInfo::getFixedStack(MF, FI);
      SDValue Ptr = DAG.getFrameIndex(
          FI, DAG.getTargetLoweringInfo().getFrameIndexTy(DAG.getDataLayout()));
      SDValue SpillSlot = Ptr;
 
      // Ensure we generate all stores for each tuple part, whilst updating the
      // pointer after each store correctly using vscale.
      while (NumParts) {
        SDValue Store = DAG.getStore(Chain, DL, OutVals[i], Ptr, MPI);
        MemOpChains.push_back(Store);
 
        NumParts--;
        if (NumParts > 0) {
          SDValue BytesIncrement =
              DAG.getTypeSize(DL, Ptr.getValueType(), PartSize);
          MPI = MachinePointerInfo(MPI.getAddrSpace());
          Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
                            BytesIncrement, SDNodeFlags::NoUnsignedWrap);
          ExtraArgLocs++;
          i++;
        }
      }
 
      Arg = SpillSlot;
      break;
    }
 
    if (VA.isRegLoc()) {
      if (i == 0 && Flags.isReturned() && !Flags.isSwiftSelf() &&
          Outs[0].VT == MVT::i64) {
        assert(VA.getLocVT() == MVT::i64 &&
               "unexpected calling convention register assignment");
        assert(!Ins.empty() && Ins[0].VT == MVT::i64 &&
               "unexpected use of 'returned'");
        IsThisReturn = true;
      }
      if (RegsUsed.count(VA.getLocReg())) {
        // If this register has already been used then we're trying to pack
        // parts of an [N x i32] into an X-register. The extension type will
        // take care of putting the two halves in the right place but we have to
        // combine them.
        SDValue &Bits =
            llvm::find_if(RegsToPass,
                          [=](const std::pair<unsigned, SDValue> &Elt) {
                            return Elt.first == VA.getLocReg();
                          })
                ->second;
        Bits = DAG.getNode(ISD::OR, DL, Bits.getValueType(), Bits, Arg);
        // Call site info is used for function's parameter entry value
        // tracking. For now we track only simple cases when parameter
        // is transferred through whole register.
        llvm::erase_if(CSInfo.ArgRegPairs,
                       [&VA](MachineFunction::ArgRegPair ArgReg) {
                         return ArgReg.Reg == VA.getLocReg();
                       });
      } else {
        // Add an extra level of indirection for streaming mode changes by
        // using a pseudo copy node that cannot be rematerialised between a
        // smstart/smstop and the call by the simple register coalescer.
        if (RequiresSMChange && isPassedInFPR(Arg.getValueType()))
          Arg = DAG.getNode(AArch64ISD::COALESCER_BARRIER, DL,
                            DAG.getVTList(Arg.getValueType(), MVT::Glue), Arg);
        RegsToPass.emplace_back(VA.getLocReg(), Arg);
        RegsUsed.insert(VA.getLocReg());
        const TargetOptions &Options = DAG.getTarget().Options;
        if (Options.EmitCallSiteInfo)
          CSInfo.ArgRegPairs.emplace_back(VA.getLocReg(), i);
      }
    } else {
      assert(VA.isMemLoc());
 
      SDValue DstAddr;
      MachinePointerInfo DstInfo;
 
      // FIXME: This works on big-endian for composite byvals, which are the
      // common case. It should also work for fundamental types too.
      uint32_t BEAlign = 0;
      unsigned OpSize;
      if (VA.getLocInfo() == CCValAssign::Indirect ||
          VA.getLocInfo() == CCValAssign::Trunc)
        OpSize = VA.getLocVT().getFixedSizeInBits();
      else
        OpSize = Flags.isByVal() ? Flags.getByValSize() * 8
                                 : VA.getValVT().getSizeInBits();
      OpSize = (OpSize + 7) / 8;
      if (!Subtarget->isLittleEndian() && !Flags.isByVal() &&
          !Flags.isInConsecutiveRegs()) {
        if (OpSize < 8)
          BEAlign = 8 - OpSize;
      }
      unsigned LocMemOffset = VA.getLocMemOffset();
      int32_t Offset = LocMemOffset + BEAlign;
 
      if (IsTailCall) {
        // When the frame pointer is perfectly aligned for the tail call and the
        // same stack argument is passed down intact, we can reuse it.
        if (!FPDiff && !shouldLowerTailCallStackArg(MF, VA, Arg, Flags, Offset))
          continue;
 
        Offset = Offset + FPDiff;
        int FI = MF.getFrameInfo().CreateFixedObject(OpSize, Offset, true);
 
        DstAddr = DAG.getFrameIndex(FI, PtrVT);
        DstInfo = MachinePointerInfo::getFixedStack(MF, FI);
 
        // Make sure any stack arguments overlapping with where we're storing
        // are loaded before this eventual operation. Otherwise they'll be
        // clobbered.
        Chain = addTokenForArgument(Chain, DAG, MF.getFrameInfo(), FI);
      } else {
        SDValue PtrOff = DAG.getIntPtrConstant(Offset, DL);
 
        DstAddr = DAG.getNode(ISD::ADD, DL, PtrVT, StackPtr, PtrOff);
        DstInfo = MachinePointerInfo::getStack(MF, LocMemOffset);
      }
 
      if (Outs[i].Flags.isByVal()) {
        SDValue SizeNode =
            DAG.getConstant(Outs[i].Flags.getByValSize(), DL, MVT::i64);
        SDValue Cpy = DAG.getMemcpy(
            Chain, DL, DstAddr, Arg, SizeNode,
            Outs[i].Flags.getNonZeroByValAlign(),
            /*isVol = */ false, /*AlwaysInline = */ false,
            /*CI=*/nullptr, std::nullopt, DstInfo, MachinePointerInfo());
 
        MemOpChains.push_back(Cpy);
      } else {
        // Since we pass i1/i8/i16 as i1/i8/i16 on stack and Arg is already
        // promoted to a legal register type i32, we should truncate Arg back to
        // i1/i8/i16.
        if (VA.getValVT() == MVT::i1 || VA.getValVT() == MVT::i8 ||
            VA.getValVT() == MVT::i16)
          Arg = DAG.getNode(ISD::TRUNCATE, DL, VA.getValVT(), Arg);
 
        SDValue Store = DAG.getStore(Chain, DL, Arg, DstAddr, DstInfo);
        MemOpChains.push_back(Store);
      }
    }
  }
 
  if (IsVarArg && Subtarget->isWindowsArm64EC() &&
      !(CLI.CB && CLI.CB->isMustTailCall())) {
    SDValue ParamPtr = StackPtr;
    if (IsTailCall) {
      // Create a dummy object at the top of the stack that can be used to get
      // the SP after the epilogue
      int FI = MF.getFrameInfo().CreateFixedObject(1, FPDiff, true);
      ParamPtr = DAG.getFrameIndex(FI, PtrVT);
    }
 
    // For vararg calls, the Arm64EC ABI requires values in x4 and x5
    // describing the argument list.  x4 contains the address of the
    // first stack parameter. x5 contains the size in bytes of all parameters
    // passed on the stack.
    RegsToPass.emplace_back(AArch64::X4, ParamPtr);
    RegsToPass.emplace_back(AArch64::X5,
                            DAG.getConstant(NumBytes, DL, MVT::i64));
  }
 
  if (!MemOpChains.empty())
    Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOpChains);
 
  SDValue InGlue;
  if (RequiresSMChange) {
    bool InsertVectorLengthCheck =
        (CallConv == CallingConv::AArch64_SVE_VectorCall);
    Chain = changeStreamingMode(
        DAG, DL, CallAttrs.callee().hasStreamingInterface(), Chain, InGlue,
        getSMToggleCondition(CallAttrs), InsertVectorLengthCheck);
    InGlue = Chain.getValue(1);
  }
 
  // Build a sequence of copy-to-reg nodes chained together with token chain
  // and flag operands which copy the outgoing args into the appropriate regs.
  for (auto &RegToPass : RegsToPass) {
    Chain = DAG.getCopyToReg(Chain, DL, RegToPass.first,
                             RegToPass.second, InGlue);
    InGlue = Chain.getValue(1);
  }
 
  // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
  // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
  // node so that legalize doesn't hack it.
  const GlobalValue *CalledGlobal = nullptr;
  unsigned OpFlags = 0;
  if (auto *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
    CalledGlobal = G->getGlobal();
    OpFlags = Subtarget->classifyGlobalFunctionReference(CalledGlobal,
                                                         getTargetMachine());
    if (OpFlags & AArch64II::MO_GOT) {
      Callee = DAG.getTargetGlobalAddress(CalledGlobal, DL, PtrVT, 0, OpFlags);
      Callee = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, Callee);
    } else if (!CLI.PAI || !IsTailCall) {
      const GlobalValue *GV = G->getGlobal();
      Callee = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, OpFlags);
    }
  } else if (auto *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
    bool UseGot = (getTargetMachine().getCodeModel() == CodeModel::Large &&
                   Subtarget->isTargetMachO()) ||
                  MF.getFunction().getParent()->getRtLibUseGOT();
    const char *Sym = S->getSymbol();
    if (UseGot) {
      Callee = DAG.getTargetExternalSymbol(Sym, PtrVT, AArch64II::MO_GOT);
      Callee = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, Callee);
    } else {
      Callee = DAG.getTargetExternalSymbol(Sym, PtrVT, 0);
    }
  }
 
  // We don't usually want to end the call-sequence here because we would tidy
  // the frame up *after* the call, however in the ABI-changing tail-call case
  // we've carefully laid out the parameters so that when sp is reset they'll be
  // in the correct location.
  if (IsTailCall && !IsSibCall) {
    Chain = DAG.getCALLSEQ_END(Chain, 0, 0, InGlue, DL);
    InGlue = Chain.getValue(1);
  }
 
  unsigned Opc = IsTailCall ? AArch64ISD::TC_RETURN : AArch64ISD::CALL;
 
  std::vector<SDValue> Ops;
  Ops.push_back(Chain);
  Ops.push_back(Callee);
 
  // Calls with operand bundle "clang.arc.attachedcall" are special. They should
  // be expanded to the call, directly followed by a special marker sequence and
  // a call to an ObjC library function.  Use CALL_RVMARKER to do that.
  if (CLI.CB && objcarc::hasAttachedCallOpBundle(CLI.CB)) {
    assert(!IsTailCall &&
           "tail calls cannot be marked with clang.arc.attachedcall");
    Opc = AArch64ISD::CALL_RVMARKER;
 
    // Add a target global address for the retainRV/claimRV runtime function
    // just before the call target.
    Function *ARCFn = *objcarc::getAttachedARCFunction(CLI.CB);
    auto GA = DAG.getTargetGlobalAddress(ARCFn, DL, PtrVT);
    Ops.insert(Ops.begin() + 1, GA);
 
    // We may or may not need to emit both the marker and the retain/claim call.
    // Tell the pseudo expansion using an additional boolean op.
    bool ShouldEmitMarker = objcarc::attachedCallOpBundleNeedsMarker(CLI.CB);
    SDValue DoEmitMarker =
        DAG.getTargetConstant(ShouldEmitMarker, DL, MVT::i32);
    Ops.insert(Ops.begin() + 2, DoEmitMarker);
  } else if (CallConv == CallingConv::ARM64EC_Thunk_X64) {
    Opc = AArch64ISD::CALL_ARM64EC_TO_X64;
  } else if (GuardWithBTI) {
    Opc = AArch64ISD::CALL_BTI;
  }
 
  if (IsTailCall) {
    // Each tail call may have to adjust the stack by a different amount, so
    // this information must travel along with the operation for eventual
    // consumption by emitEpilogue.
    Ops.push_back(DAG.getSignedTargetConstant(FPDiff, DL, MVT::i32));
  }
 
  if (CLI.PAI) {
    const uint64_t Key = CLI.PAI->Key;
    assert((Key == AArch64PACKey::IA || Key == AArch64PACKey::IB) &&
           "Invalid auth call key");
 
    // Split the discriminator into address/integer components.
    SDValue AddrDisc, IntDisc;
    std::tie(IntDisc, AddrDisc) =
        extractPtrauthBlendDiscriminators(CLI.PAI->Discriminator, &DAG);
 
    if (Opc == AArch64ISD::CALL_RVMARKER)
      Opc = AArch64ISD::AUTH_CALL_RVMARKER;
    else
      Opc = IsTailCall ? AArch64ISD::AUTH_TC_RETURN : AArch64ISD::AUTH_CALL;
    Ops.push_back(DAG.getTargetConstant(Key, DL, MVT::i32));
    Ops.push_back(IntDisc);
    Ops.push_back(AddrDisc);
  }
 
  // Add argument registers to the end of the list so that they are known live
  // into the call.
  for (auto &RegToPass : RegsToPass)
    Ops.push_back(DAG.getRegister(RegToPass.first,
                                  RegToPass.second.getValueType()));
 
  // Add a register mask operand representing the call-preserved registers.
  const uint32_t *Mask;
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
  if (IsThisReturn) {
    // For 'this' returns, use the X0-preserving mask if applicable
    Mask = TRI->getThisReturnPreservedMask(MF, CallConv);
    if (!Mask) {
      IsThisReturn = false;
      Mask = TRI->getCallPreservedMask(MF, CallConv);
    }
  } else
    Mask = TRI->getCallPreservedMask(MF, CallConv);
 
  if (Subtarget->hasCustomCallingConv())
    TRI->UpdateCustomCallPreservedMask(MF, &Mask);
 
  if (TRI->isAnyArgRegReserved(MF))
    TRI->emitReservedArgRegCallError(MF);
 
  assert(Mask && "Missing call preserved mask for calling convention");
  Ops.push_back(DAG.getRegisterMask(Mask));
 
  if (InGlue.getNode())
    Ops.push_back(InGlue);
 
  if (CLI.DeactivationSymbol)
    Ops.push_back(DAG.getDeactivationSymbol(CLI.DeactivationSymbol));
 
  // If we're doing a tall call, use a TC_RETURN here rather than an
  // actual call instruction.
  if (IsTailCall) {
    MF.getFrameInfo().setHasTailCall();
    SDValue Ret = DAG.getNode(Opc, DL, MVT::Other, Ops);
    if (IsCFICall)
      Ret.getNode()->setCFIType(CLI.CFIType->getZExtValue());
 
    DAG.addNoMergeSiteInfo(Ret.getNode(), CLI.NoMerge);
    DAG.addCallSiteInfo(Ret.getNode(), std::move(CSInfo));
    if (CalledGlobal &&
        MF.getFunction().getParent()->getModuleFlag("import-call-optimization"))
      DAG.addCalledGlobal(Ret.getNode(), CalledGlobal, OpFlags);
    return Ret;
  }
 
  // Returns a chain and a flag for retval copy to use.
  Chain = DAG.getNode(Opc, DL, {MVT::Other, MVT::Glue}, Ops);
  if (IsCFICall)
    Chain.getNode()->setCFIType(CLI.CFIType->getZExtValue());
 
  DAG.addNoMergeSiteInfo(Chain.getNode(), CLI.NoMerge);
  InGlue = Chain.getValue(1);
  DAG.addCallSiteInfo(Chain.getNode(), std::move(CSInfo));
  if (CalledGlobal &&
      MF.getFunction().getParent()->getModuleFlag("import-call-optimization"))
    DAG.addCalledGlobal(Chain.getNode(), CalledGlobal, OpFlags);
 
  uint64_t CalleePopBytes =
      DoesCalleeRestoreStack(CallConv, TailCallOpt) ? alignTo(NumBytes, 16) : 0;
 
  Chain = DAG.getCALLSEQ_END(Chain, NumBytes, CalleePopBytes, InGlue, DL);
  InGlue = Chain.getValue(1);
 
  // Handle result values, copying them out of physregs into vregs that we
  // return.
  SDValue Result = LowerCallResult(
      Chain, InGlue, CallConv, IsVarArg, RVLocs, DL, DAG, InVals, IsThisReturn,
      IsThisReturn ? OutVals[0] : SDValue(), RequiresSMChange);
 
  if (!Ins.empty())
    InGlue = Result.getValue(Result->getNumValues() - 1);
 
  if (RequiresSMChange) {
    Result = changeStreamingMode(
        DAG, DL, !CallAttrs.callee().hasStreamingInterface(), Result, InGlue,
        getSMToggleCondition(CallAttrs));
  }
 
  if (RequiresSMChange) {
    for (unsigned I = 0; I < InVals.size(); ++I) {
      // The smstart/smstop is chained as part of the call, but when the
      // resulting chain is discarded (which happens when the call is not part
      // of a chain, e.g. a call to @llvm.cos()), we need to ensure the
      // smstart/smstop is chained to the result value. We can do that by doing
      // a vreg -> vreg copy.
      Register Reg = MF.getRegInfo().createVirtualRegister(
          getRegClassFor(InVals[I].getValueType().getSimpleVT()));
      SDValue X = DAG.getCopyToReg(Result, DL, Reg, InVals[I]);
      InVals[I] = DAG.getCopyFromReg(X, DL, Reg,
                                     InVals[I].getValueType());
    }
  }
 
  if (CallConv == CallingConv::PreserveNone) {
    for (const ISD::OutputArg &O : Outs) {
      if (O.Flags.isSwiftSelf() || O.Flags.isSwiftError() ||
          O.Flags.isSwiftAsync()) {
        MachineFunction &MF = DAG.getMachineFunction();
        DAG.getContext()->diagnose(DiagnosticInfoUnsupported(
            MF.getFunction(),
            "Swift attributes can't be used with preserve_none",
            DL.getDebugLoc()));
        break;
      }
    }
  }
 
  return Result;
}
 
bool AArch64TargetLowering::CanLowerReturn(
    CallingConv::ID CallConv, MachineFunction &MF, bool isVarArg,
    const SmallVectorImpl<ISD::OutputArg> &Outs, LLVMContext &Context,
    const Type *RetTy) const {
  CCAssignFn *RetCC = CCAssignFnForReturn(CallConv);
  SmallVector<CCValAssign, 16> RVLocs;
  CCState CCInfo(CallConv, isVarArg, MF, RVLocs, Context);
  return CCInfo.CheckReturn(Outs, RetCC);
}
 
SDValue
AArch64TargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
                                   bool isVarArg,
                                   const SmallVectorImpl<ISD::OutputArg> &Outs,
                                   const SmallVectorImpl<SDValue> &OutVals,
                                   const SDLoc &DL, SelectionDAG &DAG) const {
  auto &MF = DAG.getMachineFunction();
  auto *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
 
  CCAssignFn *RetCC = CCAssignFnForReturn(CallConv);
  SmallVector<CCValAssign, 16> RVLocs;
  CCState CCInfo(CallConv, isVarArg, MF, RVLocs, *DAG.getContext());
  CCInfo.AnalyzeReturn(Outs, RetCC);
 
  // Copy the result values into the output registers.
  SDValue Glue;
  SmallVector<std::pair<unsigned, SDValue>, 4> RetVals;
  SmallSet<unsigned, 4> RegsUsed;
  for (unsigned i = 0, realRVLocIdx = 0; i != RVLocs.size();
       ++i, ++realRVLocIdx) {
    CCValAssign &VA = RVLocs[i];
    assert(VA.isRegLoc() && "Can only return in registers!");
    SDValue Arg = OutVals[realRVLocIdx];
 
    switch (VA.getLocInfo()) {
    default:
      llvm_unreachable("Unknown loc info!");
    case CCValAssign::Full:
      if (Outs[i].ArgVT == MVT::i1) {
        // AAPCS requires i1 to be zero-extended to i8 by the producer of the
        // value. This is strictly redundant on Darwin (which uses "zeroext
        // i1"), but will be optimised out before ISel.
        Arg = DAG.getNode(ISD::TRUNCATE, DL, MVT::i1, Arg);
        Arg = DAG.getNode(ISD::ZERO_EXTEND, DL, VA.getLocVT(), Arg);
      }
      break;
    case CCValAssign::BCvt:
      Arg = DAG.getNode(ISD::BITCAST, DL, VA.getLocVT(), Arg);
      break;
    case CCValAssign::AExt:
    case CCValAssign::ZExt:
      Arg = DAG.getZExtOrTrunc(Arg, DL, VA.getLocVT());
      break;
    case CCValAssign::AExtUpper:
      assert(VA.getValVT() == MVT::i32 && "only expect 32 -> 64 upper bits");
      Arg = DAG.getZExtOrTrunc(Arg, DL, VA.getLocVT());
      Arg = DAG.getNode(ISD::SHL, DL, VA.getLocVT(), Arg,
                        DAG.getConstant(32, DL, VA.getLocVT()));
      break;
    }
 
    if (RegsUsed.count(VA.getLocReg())) {
      SDValue &Bits =
          llvm::find_if(RetVals, [=](const std::pair<unsigned, SDValue> &Elt) {
            return Elt.first == VA.getLocReg();
          })->second;
      Bits = DAG.getNode(ISD::OR, DL, Bits.getValueType(), Bits, Arg);
    } else {
      RetVals.emplace_back(VA.getLocReg(), Arg);
      RegsUsed.insert(VA.getLocReg());
    }
  }
 
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
 
  // Emit SMSTOP before returning from a locally streaming function
  SMEAttrs FuncAttrs = FuncInfo->getSMEFnAttrs();
  if (FuncAttrs.hasStreamingBody() && !FuncAttrs.hasStreamingInterface()) {
    if (FuncAttrs.hasStreamingCompatibleInterface())
      Chain = changeStreamingMode(DAG, DL, /*Enable*/ false, Chain,
                                  /*Glue*/ SDValue(),
                                  AArch64SME::IfCallerIsNonStreaming);
    else
      Chain = changeStreamingMode(DAG, DL, /*Enable*/ false, Chain,
                                  /*Glue*/ SDValue(), AArch64SME::Always);
    Glue = Chain.getValue(1);
  }
 
  SmallVector<SDValue, 4> RetOps(1, Chain);
  for (auto &RetVal : RetVals) {
    if (FuncAttrs.hasStreamingBody() && !FuncAttrs.hasStreamingInterface() &&
        isPassedInFPR(RetVal.second.getValueType()))
      RetVal.second =
          DAG.getNode(AArch64ISD::COALESCER_BARRIER, DL,
                      DAG.getVTList(RetVal.second.getValueType(), MVT::Glue),
                      RetVal.second);
    Chain = DAG.getCopyToReg(Chain, DL, RetVal.first, RetVal.second, Glue);
    Glue = Chain.getValue(1);
    RetOps.push_back(
        DAG.getRegister(RetVal.first, RetVal.second.getValueType()));
  }
 
  // Windows AArch64 ABIs require that for returning structs by value we copy
  // the sret argument into X0 for the return.
  // We saved the argument into a virtual register in the entry block,
  // so now we copy the value out and into X0.
  if (unsigned SRetReg = FuncInfo->getSRetReturnReg()) {
    SDValue Val = DAG.getCopyFromReg(RetOps[0], DL, SRetReg,
                                     getPointerTy(MF.getDataLayout()));
 
    unsigned RetValReg = AArch64::X0;
    if (CallConv == CallingConv::ARM64EC_Thunk_X64)
      RetValReg = AArch64::X8;
    Chain = DAG.getCopyToReg(Chain, DL, RetValReg, Val, Glue);
    Glue = Chain.getValue(1);
 
    RetOps.push_back(
      DAG.getRegister(RetValReg, getPointerTy(DAG.getDataLayout())));
  }
 
  const MCPhysReg *I = TRI->getCalleeSavedRegsViaCopy(&MF);
  if (I) {
    for (; *I; ++I) {
      if (AArch64::GPR64RegClass.contains(*I))
        RetOps.push_back(DAG.getRegister(*I, MVT::i64));
      else if (AArch64::FPR64RegClass.contains(*I))
        RetOps.push_back(DAG.getRegister(*I, MVT::getFloatingPointVT(64)));
      else
        llvm_unreachable("Unexpected register class in CSRsViaCopy!");
    }
  }
 
  RetOps[0] = Chain; // Update chain.
 
  // Add the glue if we have it.
  if (Glue.getNode())
    RetOps.push_back(Glue);
 
  if (CallConv == CallingConv::ARM64EC_Thunk_X64) {
    // ARM64EC entry thunks use a special return sequence: instead of a regular
    // "ret" instruction, they need to explicitly call the emulator.
    EVT PtrVT = getPointerTy(DAG.getDataLayout());
    SDValue Arm64ECRetDest =
        DAG.getExternalSymbol("__os_arm64x_dispatch_ret", PtrVT);
    Arm64ECRetDest =
        getAddr(cast<ExternalSymbolSDNode>(Arm64ECRetDest), DAG, 0);
    Arm64ECRetDest = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), Arm64ECRetDest,
                                 MachinePointerInfo());
    RetOps.insert(RetOps.begin() + 1, Arm64ECRetDest);
    RetOps.insert(RetOps.begin() + 2, DAG.getTargetConstant(0, DL, MVT::i32));
    return DAG.getNode(AArch64ISD::TC_RETURN, DL, MVT::Other, RetOps);
  }
 
  return DAG.getNode(AArch64ISD::RET_GLUE, DL, MVT::Other, RetOps);
}
 
//===----------------------------------------------------------------------===//
//  Other Lowering Code
//===----------------------------------------------------------------------===//
 
SDValue AArch64TargetLowering::getTargetNode(GlobalAddressSDNode *N, EVT Ty,
                                             SelectionDAG &DAG,
                                             unsigned Flag) const {
  return DAG.getTargetGlobalAddress(N->getGlobal(), SDLoc(N), Ty,
                                    N->getOffset(), Flag);
}
 
SDValue AArch64TargetLowering::getTargetNode(JumpTableSDNode *N, EVT Ty,
                                             SelectionDAG &DAG,
                                             unsigned Flag) const {
  return DAG.getTargetJumpTable(N->getIndex(), Ty, Flag);
}
 
SDValue AArch64TargetLowering::getTargetNode(ConstantPoolSDNode *N, EVT Ty,
                                             SelectionDAG &DAG,
                                             unsigned Flag) const {
  return DAG.getTargetConstantPool(N->getConstVal(), Ty, N->getAlign(),
                                   N->getOffset(), Flag);
}
 
SDValue AArch64TargetLowering::getTargetNode(BlockAddressSDNode* N, EVT Ty,
                                             SelectionDAG &DAG,
                                             unsigned Flag) const {
  return DAG.getTargetBlockAddress(N->getBlockAddress(), Ty, 0, Flag);
}
 
SDValue AArch64TargetLowering::getTargetNode(ExternalSymbolSDNode *N, EVT Ty,
                                             SelectionDAG &DAG,
                                             unsigned Flag) const {
  return DAG.getTargetExternalSymbol(N->getSymbol(), Ty, Flag);
}
 
// (loadGOT sym)
template <class NodeTy>
SDValue AArch64TargetLowering::getGOT(NodeTy *N, SelectionDAG &DAG,
                                      unsigned Flags) const {
  LLVM_DEBUG(dbgs() << "AArch64TargetLowering::getGOT\n");
  SDLoc DL(N);
  EVT Ty = getPointerTy(DAG.getDataLayout());
  SDValue GotAddr = getTargetNode(N, Ty, DAG, AArch64II::MO_GOT | Flags);
  // FIXME: Once remat is capable of dealing with instructions with register
  // operands, expand this into two nodes instead of using a wrapper node.
  if (DAG.getMachineFunction()
          .getInfo<AArch64FunctionInfo>()
          ->hasELFSignedGOT())
    return SDValue(DAG.getMachineNode(AArch64::LOADgotAUTH, DL, Ty, GotAddr),
                   0);
  return DAG.getNode(AArch64ISD::LOADgot, DL, Ty, GotAddr);
}
 
// (wrapper %highest(sym), %higher(sym), %hi(sym), %lo(sym))
template <class NodeTy>
SDValue AArch64TargetLowering::getAddrLarge(NodeTy *N, SelectionDAG &DAG,
                                            unsigned Flags) const {
  LLVM_DEBUG(dbgs() << "AArch64TargetLowering::getAddrLarge\n");
  SDLoc DL(N);
  EVT Ty = getPointerTy(DAG.getDataLayout());
  const unsigned char MO_NC = AArch64II::MO_NC;
  return DAG.getNode(
      AArch64ISD::WrapperLarge, DL, Ty,
      getTargetNode(N, Ty, DAG, AArch64II::MO_G3 | Flags),
      getTargetNode(N, Ty, DAG, AArch64II::MO_G2 | MO_NC | Flags),
      getTargetNode(N, Ty, DAG, AArch64II::MO_G1 | MO_NC | Flags),
      getTargetNode(N, Ty, DAG, AArch64II::MO_G0 | MO_NC | Flags));
}
 
// (addlow (adrp %hi(sym)) %lo(sym))
template <class NodeTy>
SDValue AArch64TargetLowering::getAddr(NodeTy *N, SelectionDAG &DAG,
                                       unsigned Flags) const {
  LLVM_DEBUG(dbgs() << "AArch64TargetLowering::getAddr\n");
  SDLoc DL(N);
  EVT Ty = getPointerTy(DAG.getDataLayout());
  SDValue Hi = getTargetNode(N, Ty, DAG, AArch64II::MO_PAGE | Flags);
  SDValue Lo = getTargetNode(N, Ty, DAG,
                             AArch64II::MO_PAGEOFF | AArch64II::MO_NC | Flags);
  SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, Ty, Hi);
  return DAG.getNode(AArch64ISD::ADDlow, DL, Ty, ADRP, Lo);
}
 
// (adr sym)
template <class NodeTy>
SDValue AArch64TargetLowering::getAddrTiny(NodeTy *N, SelectionDAG &DAG,
                                           unsigned Flags) const {
  LLVM_DEBUG(dbgs() << "AArch64TargetLowering::getAddrTiny\n");
  SDLoc DL(N);
  EVT Ty = getPointerTy(DAG.getDataLayout());
  SDValue Sym = getTargetNode(N, Ty, DAG, Flags);
  return DAG.getNode(AArch64ISD::ADR, DL, Ty, Sym);
}
 
SDValue AArch64TargetLowering::LowerGlobalAddress(SDValue Op,
                                                  SelectionDAG &DAG) const {
  GlobalAddressSDNode *GN = cast<GlobalAddressSDNode>(Op);
  const GlobalValue *GV = GN->getGlobal();
  unsigned OpFlags = Subtarget->ClassifyGlobalReference(GV, getTargetMachine());
 
  if (OpFlags != AArch64II::MO_NO_FLAG)
    assert(cast<GlobalAddressSDNode>(Op)->getOffset() == 0 &&
           "unexpected offset in global node");
 
  // This also catches the large code model case for Darwin, and tiny code
  // model with got relocations.
  if ((OpFlags & AArch64II::MO_GOT) != 0) {
    return getGOT(GN, DAG, OpFlags);
  }
 
  SDValue Result;
  if (getTargetMachine().getCodeModel() == CodeModel::Large &&
      !getTargetMachine().isPositionIndependent()) {
    Result = getAddrLarge(GN, DAG, OpFlags);
  } else if (getTargetMachine().getCodeModel() == CodeModel::Tiny) {
    Result = getAddrTiny(GN, DAG, OpFlags);
  } else {
    Result = getAddr(GN, DAG, OpFlags);
  }
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  SDLoc DL(GN);
  if (OpFlags & (AArch64II::MO_DLLIMPORT | AArch64II::MO_COFFSTUB))
    Result = DAG.getLoad(PtrVT, DL, DAG.getEntryNode(), Result,
                         MachinePointerInfo::getGOT(DAG.getMachineFunction()));
  return Result;
}
 
/// Convert a TLS address reference into the correct sequence of loads
/// and calls to compute the variable's address (for Darwin, currently) and
/// return an SDValue containing the final node.
 
/// Darwin only has one TLS scheme which must be capable of dealing with the
/// fully general situation, in the worst case. This means:
///     + "extern __thread" declaration.
///     + Defined in a possibly unknown dynamic library.
///
/// The general system is that each __thread variable has a [3 x i64] descriptor
/// which contains information used by the runtime to calculate the address. The
/// only part of this the compiler needs to know about is the first xword, which
/// contains a function pointer that must be called with the address of the
/// entire descriptor in "x0".
///
/// Since this descriptor may be in a different unit, in general even the
/// descriptor must be accessed via an indirect load. The "ideal" code sequence
/// is:
///     adrp x0, _var@TLVPPAGE
///     ldr x0, [x0, _var@TLVPPAGEOFF]   ; x0 now contains address of descriptor
///     ldr x1, [x0]                     ; x1 contains 1st entry of descriptor,
///                                      ; the function pointer
///     blr x1                           ; Uses descriptor address in x0
///     ; Address of _var is now in x0.
///
/// If the address of _var's descriptor *is* known to the linker, then it can
/// change the first "ldr" instruction to an appropriate "add x0, x0, #imm" for
/// a slight efficiency gain.
SDValue
AArch64TargetLowering::LowerDarwinGlobalTLSAddress(SDValue Op,
                                                   SelectionDAG &DAG) const {
  assert(Subtarget->isTargetDarwin() &&
         "This function expects a Darwin target");
 
  SDLoc DL(Op);
  MVT PtrVT = getPointerTy(DAG.getDataLayout());
  MVT PtrMemVT = getPointerMemTy(DAG.getDataLayout());
  const GlobalValue *GV = cast<GlobalAddressSDNode>(Op)->getGlobal();
 
  SDValue TLVPAddr =
      DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
  SDValue DescAddr = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TLVPAddr);
 
  // The first entry in the descriptor is a function pointer that we must call
  // to obtain the address of the variable.
  SDValue Chain = DAG.getEntryNode();
  SDValue FuncTLVGet = DAG.getLoad(
      PtrMemVT, DL, Chain, DescAddr,
      MachinePointerInfo::getGOT(DAG.getMachineFunction()),
      Align(PtrMemVT.getSizeInBits() / 8),
      MachineMemOperand::MOInvariant | MachineMemOperand::MODereferenceable);
  Chain = FuncTLVGet.getValue(1);
 
  // Extend loaded pointer if necessary (i.e. if ILP32) to DAG pointer.
  FuncTLVGet = DAG.getZExtOrTrunc(FuncTLVGet, DL, PtrVT);
 
  MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
  MFI.setAdjustsStack(true);
 
  // TLS calls preserve all registers except those that absolutely must be
  // trashed: X0 (it takes an argument), LR (it's a call) and NZCV (let's not be
  // silly).
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
  const uint32_t *Mask = TRI->getTLSCallPreservedMask();
  if (Subtarget->hasCustomCallingConv())
    TRI->UpdateCustomCallPreservedMask(DAG.getMachineFunction(), &Mask);
 
  // Finally, we can make the call. This is just a degenerate version of a
  // normal AArch64 call node: x0 takes the address of the descriptor, and
  // returns the address of the variable in this thread.
  Chain = DAG.getCopyToReg(Chain, DL, AArch64::X0, DescAddr, SDValue());
 
  unsigned Opcode = AArch64ISD::CALL;
  SmallVector<SDValue, 8> Ops;
  Ops.push_back(Chain);
  Ops.push_back(FuncTLVGet);
 
  // With ptrauth-calls, the tlv access thunk pointer is authenticated (IA, 0).
  if (DAG.getMachineFunction().getFunction().hasFnAttribute("ptrauth-calls")) {
    Opcode = AArch64ISD::AUTH_CALL;
    Ops.push_back(DAG.getTargetConstant(AArch64PACKey::IA, DL, MVT::i32));
    Ops.push_back(DAG.getTargetConstant(0, DL, MVT::i64)); // Integer Disc.
    Ops.push_back(DAG.getRegister(AArch64::NoRegister, MVT::i64)); // Addr Disc.
  }
 
  Ops.push_back(DAG.getRegister(AArch64::X0, MVT::i64));
  Ops.push_back(DAG.getRegisterMask(Mask));
  Ops.push_back(Chain.getValue(1));
  Chain = DAG.getNode(Opcode, DL, DAG.getVTList(MVT::Other, MVT::Glue), Ops);
  return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Chain.getValue(1));
}
 
/// Convert a thread-local variable reference into a sequence of instructions to
/// compute the variable's address for the local exec TLS model of ELF targets.
/// The sequence depends on the maximum TLS area size.
SDValue AArch64TargetLowering::LowerELFTLSLocalExec(const GlobalValue *GV,
                                                    SDValue ThreadBase,
                                                    const SDLoc &DL,
                                                    SelectionDAG &DAG) const {
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  SDValue TPOff, Addr;
 
  switch (DAG.getTarget().Options.TLSSize) {
  default:
    llvm_unreachable("Unexpected TLS size");
 
  case 12: {
    // mrs   x0, TPIDR_EL0
    // add   x0, x0, :tprel_lo12:a
    SDValue Var = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_PAGEOFF);
    return SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, ThreadBase,
                                      Var,
                                      DAG.getTargetConstant(0, DL, MVT::i32)),
                   0);
  }
 
  case 24: {
    // mrs   x0, TPIDR_EL0
    // add   x0, x0, :tprel_hi12:a
    // add   x0, x0, :tprel_lo12_nc:a
    SDValue HiVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_HI12);
    SDValue LoVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0,
        AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
    Addr = SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, ThreadBase,
                                      HiVar,
                                      DAG.getTargetConstant(0, DL, MVT::i32)),
                   0);
    return SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, Addr,
                                      LoVar,
                                      DAG.getTargetConstant(0, DL, MVT::i32)),
                   0);
  }
 
  case 32: {
    // mrs   x1, TPIDR_EL0
    // movz  x0, #:tprel_g1:a
    // movk  x0, #:tprel_g0_nc:a
    // add   x0, x1, x0
    SDValue HiVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_G1);
    SDValue LoVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0,
        AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
    TPOff = SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
                                       DAG.getTargetConstant(16, DL, MVT::i32)),
                    0);
    TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, LoVar,
                                       DAG.getTargetConstant(0, DL, MVT::i32)),
                    0);
    return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadBase, TPOff);
  }
 
  case 48: {
    // mrs   x1, TPIDR_EL0
    // movz  x0, #:tprel_g2:a
    // movk  x0, #:tprel_g1_nc:a
    // movk  x0, #:tprel_g0_nc:a
    // add   x0, x1, x0
    SDValue HiVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_G2);
    SDValue MiVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0,
        AArch64II::MO_TLS | AArch64II::MO_G1 | AArch64II::MO_NC);
    SDValue LoVar = DAG.getTargetGlobalAddress(
        GV, DL, PtrVT, 0,
        AArch64II::MO_TLS | AArch64II::MO_G0 | AArch64II::MO_NC);
    TPOff = SDValue(DAG.getMachineNode(AArch64::MOVZXi, DL, PtrVT, HiVar,
                                       DAG.getTargetConstant(32, DL, MVT::i32)),
                    0);
    TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, MiVar,
                                       DAG.getTargetConstant(16, DL, MVT::i32)),
                    0);
    TPOff = SDValue(DAG.getMachineNode(AArch64::MOVKXi, DL, PtrVT, TPOff, LoVar,
                                       DAG.getTargetConstant(0, DL, MVT::i32)),
                    0);
    return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadBase, TPOff);
  }
  }
}
 
/// When accessing thread-local variables under either the general-dynamic or
/// local-dynamic system, we make a "TLS-descriptor" call. The variable will
/// have a descriptor, accessible via a PC-relative ADRP, and whose first entry
/// is a function pointer to carry out the resolution.
///
/// The sequence is:
///    adrp  x0, :tlsdesc:var
///    ldr   x1, [x0, #:tlsdesc_lo12:var]
///    add   x0, x0, #:tlsdesc_lo12:var
///    .tlsdesccall var
///    blr   x1
///    (TPIDR_EL0 offset now in x0)
///
///  The above sequence must be produced unscheduled, to enable the linker to
///  optimize/relax this sequence.
///  Therefore, a pseudo-instruction (TLSDESC_CALLSEQ) is used to represent the
///  above sequence, and expanded really late in the compilation flow, to ensure
///  the sequence is produced as per above.
SDValue AArch64TargetLowering::LowerELFTLSDescCallSeq(SDValue SymAddr,
                                                      const SDLoc &DL,
                                                      SelectionDAG &DAG) const {
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  auto &MF = DAG.getMachineFunction();
  auto *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
 
  SDValue Glue;
  SDValue Chain = DAG.getEntryNode();
  SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
 
  SMECallAttrs TLSCallAttrs(FuncInfo->getSMEFnAttrs(), {}, SMEAttrs::Normal);
  bool RequiresSMChange = TLSCallAttrs.requiresSMChange();
 
  auto ChainAndGlue = [](SDValue Chain) -> std::pair<SDValue, SDValue> {
    return {Chain, Chain.getValue(1)};
  };
 
  if (RequiresSMChange)
    std::tie(Chain, Glue) =
        ChainAndGlue(changeStreamingMode(DAG, DL, /*Enable=*/false, Chain, Glue,
                                         getSMToggleCondition(TLSCallAttrs)));
 
  unsigned Opcode =
      DAG.getMachineFunction().getInfo<AArch64FunctionInfo>()->hasELFSignedGOT()
          ? AArch64ISD::TLSDESC_AUTH_CALLSEQ
          : AArch64ISD::TLSDESC_CALLSEQ;
  SDValue Ops[] = {Chain, SymAddr, Glue};
  std::tie(Chain, Glue) = ChainAndGlue(DAG.getNode(
      Opcode, DL, NodeTys, Glue ? ArrayRef(Ops) : ArrayRef(Ops).drop_back()));
 
  if (TLSCallAttrs.requiresLazySave())
    std::tie(Chain, Glue) = ChainAndGlue(DAG.getNode(
        AArch64ISD::REQUIRES_ZA_SAVE, DL, NodeTys, {Chain, Chain.getValue(1)}));
 
  if (RequiresSMChange)
    std::tie(Chain, Glue) =
        ChainAndGlue(changeStreamingMode(DAG, DL, /*Enable=*/true, Chain, Glue,
                                         getSMToggleCondition(TLSCallAttrs)));
 
  return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Glue);
}
 
SDValue
AArch64TargetLowering::LowerELFGlobalTLSAddress(SDValue Op,
                                                SelectionDAG &DAG) const {
  assert(Subtarget->isTargetELF() && "This function expects an ELF target");
 
  const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
  AArch64FunctionInfo *MFI =
      DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
 
  TLSModel::Model Model = MFI->hasELFSignedGOT()
                              ? TLSModel::GeneralDynamic
                              : getTargetMachine().getTLSModel(GA->getGlobal());
 
  if (!EnableAArch64ELFLocalDynamicTLSGeneration) {
    if (Model == TLSModel::LocalDynamic)
      Model = TLSModel::GeneralDynamic;
  }
 
  if (getTargetMachine().getCodeModel() == CodeModel::Large &&
      Model != TLSModel::LocalExec)
    report_fatal_error("ELF TLS only supported in small memory model or "
                       "in local exec TLS model");
  // Different choices can be made for the maximum size of the TLS area for a
  // module. For the small address model, the default TLS size is 16MiB and the
  // maximum TLS size is 4GiB.
  // FIXME: add tiny and large code model support for TLS access models other
  // than local exec. We currently generate the same code as small for tiny,
  // which may be larger than needed.
 
  SDValue TPOff;
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  SDLoc DL(Op);
  const GlobalValue *GV = GA->getGlobal();
 
  SDValue ThreadBase = DAG.getNode(AArch64ISD::THREAD_POINTER, DL, PtrVT);
 
  if (Model == TLSModel::LocalExec) {
    return LowerELFTLSLocalExec(GV, ThreadBase, DL, DAG);
  } else if (Model == TLSModel::InitialExec) {
    TPOff = DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
    TPOff = DAG.getNode(AArch64ISD::LOADgot, DL, PtrVT, TPOff);
  } else if (Model == TLSModel::LocalDynamic) {
    // Local-dynamic accesses proceed in two phases. A general-dynamic TLS
    // descriptor call against the special symbol _TLS_MODULE_BASE_ to calculate
    // the beginning of the module's TLS region, followed by a DTPREL offset
    // calculation.
 
    // These accesses will need deduplicating if there's more than one.
    MFI->incNumLocalDynamicTLSAccesses();
 
    // The call needs a relocation too for linker relaxation. It doesn't make
    // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
    // the address.
    SDValue SymAddr = DAG.getTargetExternalSymbol("_TLS_MODULE_BASE_", PtrVT,
                                                  AArch64II::MO_TLS);
 
    // Now we can calculate the offset from TPIDR_EL0 to this module's
    // thread-local area.
    TPOff = LowerELFTLSDescCallSeq(SymAddr, DL, DAG);
 
    // Now use :dtprel_whatever: operations to calculate this variable's offset
    // in its thread-storage area.
    SDValue HiVar = DAG.getTargetGlobalAddress(
        GV, DL, MVT::i64, 0, AArch64II::MO_TLS | AArch64II::MO_HI12);
    SDValue LoVar = DAG.getTargetGlobalAddress(
        GV, DL, MVT::i64, 0,
        AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
 
    TPOff = SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TPOff, HiVar,
                                       DAG.getTargetConstant(0, DL, MVT::i32)),
                    0);
    TPOff = SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TPOff, LoVar,
                                       DAG.getTargetConstant(0, DL, MVT::i32)),
                    0);
  } else if (Model == TLSModel::GeneralDynamic) {
    // The call needs a relocation too for linker relaxation. It doesn't make
    // sense to call it MO_PAGE or MO_PAGEOFF though so we need another copy of
    // the address.
    SDValue SymAddr =
        DAG.getTargetGlobalAddress(GV, DL, PtrVT, 0, AArch64II::MO_TLS);
 
    // Finally we can make a call to calculate the offset from tpidr_el0.
    TPOff = LowerELFTLSDescCallSeq(SymAddr, DL, DAG);
  } else
    llvm_unreachable("Unsupported ELF TLS access model");
 
  return DAG.getNode(ISD::ADD, DL, PtrVT, ThreadBase, TPOff);
}
 
SDValue
AArch64TargetLowering::LowerWindowsGlobalTLSAddress(SDValue Op,
                                                    SelectionDAG &DAG) const {
  assert(Subtarget->isTargetWindows() && "Windows specific TLS lowering");
 
  SDValue Chain = DAG.getEntryNode();
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  SDLoc DL(Op);
 
  SDValue TEB = DAG.getRegister(AArch64::X18, MVT::i64);
 
  // Load the ThreadLocalStoragePointer from the TEB
  // A pointer to the TLS array is located at offset 0x58 from the TEB.
  SDValue TLSArray =
      DAG.getNode(ISD::ADD, DL, PtrVT, TEB, DAG.getIntPtrConstant(0x58, DL));
  TLSArray = DAG.getLoad(PtrVT, DL, Chain, TLSArray, MachinePointerInfo());
  Chain = TLSArray.getValue(1);
 
  // Load the TLS index from the C runtime;
  // This does the same as getAddr(), but without having a GlobalAddressSDNode.
  // This also does the same as LOADgot, but using a generic i32 load,
  // while LOADgot only loads i64.
  SDValue TLSIndexHi =
      DAG.getTargetExternalSymbol("_tls_index", PtrVT, AArch64II::MO_PAGE);
  SDValue TLSIndexLo = DAG.getTargetExternalSymbol(
      "_tls_index", PtrVT, AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
  SDValue ADRP = DAG.getNode(AArch64ISD::ADRP, DL, PtrVT, TLSIndexHi);
  SDValue TLSIndex =
      DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, ADRP, TLSIndexLo);
  TLSIndex = DAG.getLoad(MVT::i32, DL, Chain, TLSIndex, MachinePointerInfo());
  Chain = TLSIndex.getValue(1);
 
  // The pointer to the thread's TLS data area is at the TLS Index scaled by 8
  // offset into the TLSArray.
  TLSIndex = DAG.getNode(ISD::ZERO_EXTEND, DL, PtrVT, TLSIndex);
  SDValue Slot = DAG.getNode(ISD::SHL, DL, PtrVT, TLSIndex,
                             DAG.getConstant(3, DL, PtrVT));
  SDValue TLS = DAG.getLoad(PtrVT, DL, Chain,
                            DAG.getNode(ISD::ADD, DL, PtrVT, TLSArray, Slot),
                            MachinePointerInfo());
  Chain = TLS.getValue(1);
 
  const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
  const GlobalValue *GV = GA->getGlobal();
  SDValue TGAHi = DAG.getTargetGlobalAddress(
      GV, DL, PtrVT, 0, AArch64II::MO_TLS | AArch64II::MO_HI12);
  SDValue TGALo = DAG.getTargetGlobalAddress(
      GV, DL, PtrVT, 0,
      AArch64II::MO_TLS | AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
 
  // Add the offset from the start of the .tls section (section base).
  SDValue Addr =
      SDValue(DAG.getMachineNode(AArch64::ADDXri, DL, PtrVT, TLS, TGAHi,
                                 DAG.getTargetConstant(0, DL, MVT::i32)),
              0);
  Addr = DAG.getNode(AArch64ISD::ADDlow, DL, PtrVT, Addr, TGALo);
  return Addr;
}
 
SDValue AArch64TargetLowering::LowerGlobalTLSAddress(SDValue Op,
                                                     SelectionDAG &DAG) const {
  const GlobalAddressSDNode *GA = cast<GlobalAddressSDNode>(Op);
  if (DAG.getTarget().useEmulatedTLS())
    return LowerToTLSEmulatedModel(GA, DAG);
 
  if (Subtarget->isTargetDarwin())
    return LowerDarwinGlobalTLSAddress(Op, DAG);
  if (Subtarget->isTargetELF())
    return LowerELFGlobalTLSAddress(Op, DAG);
  if (Subtarget->isTargetWindows())
    return LowerWindowsGlobalTLSAddress(Op, DAG);
 
  llvm_unreachable("Unexpected platform trying to use TLS");
}
 
//===----------------------------------------------------------------------===//
//                      PtrAuthGlobalAddress lowering
//
// We have 3 lowering alternatives to choose from:
// - MOVaddrPAC: similar to MOVaddr, with added PAC.
//   If the GV doesn't need a GOT load (i.e., is locally defined)
//   materialize the pointer using adrp+add+pac. See LowerMOVaddrPAC.
//
// - LOADgotPAC: similar to LOADgot, with added PAC.
//   If the GV needs a GOT load, materialize the pointer using the usual
//   GOT adrp+ldr, +pac. Pointers in GOT are assumed to be not signed, the GOT
//   section is assumed to be read-only (for example, via relro mechanism). See
//   LowerMOVaddrPAC.
//
// - LOADauthptrstatic: similar to LOADgot, but use a
//   special stub slot instead of a GOT slot.
//   Load a signed pointer for symbol 'sym' from a stub slot named
//   'sym$auth_ptr$key$disc' filled by dynamic linker during relocation
//   resolving. This usually lowers to adrp+ldr, but also emits an entry into
//   .data with an @AUTH relocation. See LowerLOADauthptrstatic.
//
// All 3 are pseudos that are expand late to longer sequences: this lets us
// provide integrity guarantees on the to-be-signed intermediate values.
//
// LOADauthptrstatic is undesirable because it requires a large section filled
// with often similarly-signed pointers, making it a good harvesting target.
// Thus, it's only used for ptrauth references to extern_weak to avoid null
// checks.
 
static SDValue LowerPtrAuthGlobalAddressStatically(
    SDValue TGA, SDLoc DL, EVT VT, AArch64PACKey::ID KeyC,
    SDValue Discriminator, SDValue AddrDiscriminator, SelectionDAG &DAG) {
  const auto *TGN = cast<GlobalAddressSDNode>(TGA.getNode());
  assert(TGN->getGlobal()->hasExternalWeakLinkage());
 
  // Offsets and extern_weak don't mix well: ptrauth aside, you'd get the
  // offset alone as a pointer if the symbol wasn't available, which would
  // probably break null checks in users. Ptrauth complicates things further:
  // error out.
  if (TGN->getOffset() != 0)
    report_fatal_error(
        "unsupported non-zero offset in weak ptrauth global reference");
 
  if (!isNullConstant(AddrDiscriminator))
    report_fatal_error("unsupported weak addr-div ptrauth global");
 
  SDValue Key = DAG.getTargetConstant(KeyC, DL, MVT::i32);
  return SDValue(DAG.getMachineNode(AArch64::LOADauthptrstatic, DL, MVT::i64,
                                    {TGA, Key, Discriminator}),
                 0);
}
 
SDValue
AArch64TargetLowering::LowerPtrAuthGlobalAddress(SDValue Op,
                                                 SelectionDAG &DAG) const {
  SDValue Ptr = Op.getOperand(0);
  uint64_t KeyC = Op.getConstantOperandVal(1);
  SDValue AddrDiscriminator = Op.getOperand(2);
  uint64_t DiscriminatorC = Op.getConstantOperandVal(3);
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
 
  if (KeyC > AArch64PACKey::LAST)
    report_fatal_error("key in ptrauth global out of range [0, " +
                       Twine((int)AArch64PACKey::LAST) + "]");
 
  // Blend only works if the integer discriminator is 16-bit wide.
  if (!isUInt<16>(DiscriminatorC))
    report_fatal_error(
        "constant discriminator in ptrauth global out of range [0, 0xffff]");
 
  // Choosing between 3 lowering alternatives is target-specific.
  if (!Subtarget->isTargetELF() && !Subtarget->isTargetMachO())
    report_fatal_error("ptrauth global lowering only supported on MachO/ELF");
 
  int64_t PtrOffsetC = 0;
  if (Ptr.getOpcode() == ISD::ADD) {
    PtrOffsetC = Ptr.getConstantOperandVal(1);
    Ptr = Ptr.getOperand(0);
  }
  const auto *PtrN = cast<GlobalAddressSDNode>(Ptr.getNode());
  const GlobalValue *PtrGV = PtrN->getGlobal();
 
  // Classify the reference to determine whether it needs a GOT load.
  const unsigned OpFlags =
      Subtarget->ClassifyGlobalReference(PtrGV, getTargetMachine());
  const bool NeedsGOTLoad = ((OpFlags & AArch64II::MO_GOT) != 0);
  assert(((OpFlags & (~AArch64II::MO_GOT)) == 0) &&
         "unsupported non-GOT op flags on ptrauth global reference");
 
  // Fold any offset into the GV; our pseudos expect it there.
  PtrOffsetC += PtrN->getOffset();
  SDValue TPtr = DAG.getTargetGlobalAddress(PtrGV, DL, VT, PtrOffsetC,
                                            /*TargetFlags=*/0);
  assert(PtrN->getTargetFlags() == 0 &&
         "unsupported target flags on ptrauth global");
 
  SDValue Key = DAG.getTargetConstant(KeyC, DL, MVT::i32);
  SDValue Discriminator = DAG.getTargetConstant(DiscriminatorC, DL, MVT::i64);
  SDValue TAddrDiscriminator = !isNullConstant(AddrDiscriminator)
                                   ? AddrDiscriminator
                                   : DAG.getRegister(AArch64::XZR, MVT::i64);
 
  // No GOT load needed -> MOVaddrPAC
  if (!NeedsGOTLoad) {
    assert(!PtrGV->hasExternalWeakLinkage() && "extern_weak should use GOT");
    return SDValue(
        DAG.getMachineNode(AArch64::MOVaddrPAC, DL, MVT::i64,
                           {TPtr, Key, TAddrDiscriminator, Discriminator}),
        0);
  }
 
  // GOT load -> LOADgotPAC
  // Note that we disallow extern_weak refs to avoid null checks later.
  if (!PtrGV->hasExternalWeakLinkage())
    return SDValue(
        DAG.getMachineNode(AArch64::LOADgotPAC, DL, MVT::i64,
                           {TPtr, Key, TAddrDiscriminator, Discriminator}),
        0);
 
  // extern_weak ref -> LOADauthptrstatic
  return LowerPtrAuthGlobalAddressStatically(
      TPtr, DL, VT, (AArch64PACKey::ID)KeyC, Discriminator, AddrDiscriminator,
      DAG);
}
 
// Looks through \param Val to determine the bit that can be used to
// check the sign of the value. It returns the unextended value and
// the sign bit position.
std::pair<SDValue, uint64_t> lookThroughSignExtension(SDValue Val) {
  if (Val.getOpcode() == ISD::SIGN_EXTEND_INREG)
    return {Val.getOperand(0),
            cast<VTSDNode>(Val.getOperand(1))->getVT().getFixedSizeInBits() -
                1};
 
  if (Val.getOpcode() == ISD::SIGN_EXTEND)
    return {Val.getOperand(0),
            Val.getOperand(0)->getValueType(0).getFixedSizeInBits() - 1};
 
  return {Val, Val.getValueSizeInBits() - 1};
}
 
// Op is an SDValue that is being compared to 0. If the comparison is a bit
// test, optimize it to a TBZ or TBNZ.
static SDValue optimizeBitTest(SDLoc DL, SDValue Op, SDValue Chain,
                               SDValue Dest, unsigned Opcode,
                               SelectionDAG &DAG) {
  if (Op.getOpcode() != ISD::AND)
    return SDValue();
 
  // See if we can use a TBZ to fold in an AND as well.
  // TBZ has a smaller branch displacement than CBZ.  If the offset is
  // out of bounds, a late MI-layer pass rewrites branches.
  // 403.gcc is an example that hits this case.
  if (isa<ConstantSDNode>(Op.getOperand(1)) &&
      isPowerOf2_64(Op.getConstantOperandVal(1))) {
    SDValue Test = Op.getOperand(0);
    uint64_t Mask = Op.getConstantOperandVal(1);
    return DAG.getNode(Opcode, DL, MVT::Other, Chain, Test,
                       DAG.getConstant(Log2_64(Mask), DL, MVT::i64), Dest);
  }
 
  if (Op.getOperand(0).getOpcode() == ISD::SHL) {
    auto Op00 = Op.getOperand(0).getOperand(0);
    if (isa<ConstantSDNode>(Op00) && Op00->getAsZExtVal() == 1) {
      auto Shr = DAG.getNode(ISD::SRL, DL, Op00.getValueType(),
                             Op.getOperand(1), Op.getOperand(0).getOperand(1));
      return DAG.getNode(Opcode, DL, MVT::Other, Chain, Shr,
                         DAG.getConstant(0, DL, MVT::i64), Dest);
    }
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerBR_CC(SDValue Op, SelectionDAG &DAG) const {
  SDValue Chain = Op.getOperand(0);
  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(1))->get();
  SDValue LHS = Op.getOperand(2);
  SDValue RHS = Op.getOperand(3);
  SDValue Dest = Op.getOperand(4);
  SDLoc DL(Op);
 
  MachineFunction &MF = DAG.getMachineFunction();
  // Speculation tracking/SLH assumes that optimized TB(N)Z/CB(N)Z instructions
  // will not be produced, as they are conditional branch instructions that do
  // not set flags.
  bool ProduceNonFlagSettingCondBr =
      !MF.getFunction().hasFnAttribute(Attribute::SpeculativeLoadHardening);
 
  // Handle f128 first, since lowering it will result in comparing the return
  // value of a libcall against zero, which is just what the rest of LowerBR_CC
  // is expecting to deal with.
  if (LHS.getValueType() == MVT::f128) {
    softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, DL, LHS, RHS);
 
    // If softenSetCCOperands returned a scalar, we need to compare the result
    // against zero to select between true and false values.
    if (!RHS.getNode()) {
      RHS = DAG.getConstant(0, DL, LHS.getValueType());
      CC = ISD::SETNE;
    }
  }
 
  // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a branch
  // instruction.
  if (ISD::isOverflowIntrOpRes(LHS) && isOneConstant(RHS) &&
      (CC == ISD::SETEQ || CC == ISD::SETNE)) {
    // Only lower legal XALUO ops.
    if (!DAG.getTargetLoweringInfo().isTypeLegal(LHS->getValueType(0)))
      return SDValue();
 
    // The actual operation with overflow check.
    AArch64CC::CondCode OFCC;
    SDValue Value, Overflow;
    std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, LHS.getValue(0), DAG);
 
    if (CC == ISD::SETNE)
      OFCC = getInvertedCondCode(OFCC);
    SDValue CCVal = getCondCode(DAG, OFCC);
 
    return DAG.getNode(AArch64ISD::BRCOND, DL, MVT::Other, Chain, Dest, CCVal,
                       Overflow);
  }
 
  if (LHS.getValueType().isInteger()) {
    assert((LHS.getValueType() == RHS.getValueType()) &&
           (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
 
    // Normalize (LHS CC 1) -> (LHS NewCC 0) when LHS is known to be 0 or 1.
    // This enables the CBZ/CBNZ matching below.
    const ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS);
    if (RHSC && RHSC->getZExtValue() == 1 && ProduceNonFlagSettingCondBr &&
        // Don't do this when LHS is an overflow/carry result (resNo == 1)
        // because we can fold cset + cmp #1 + b.cc into a direct
        // flag-consuming branch, which CBZ/CBNZ would prevent.
        LHS.getResNo() == 0 &&
        // This is true only when we somehow know that it's either 0 or 1.
        DAG.computeKnownBits(LHS).getMaxValue().ule(1)) {
      // Output params unused; we only care whether it returns true.
      bool CanNegate, MustBeFirst, PreferFirst;
      // Also skip when LHS is a conjunction tree (AND/OR of SETCCs) --
      // emitConjunction will lower it as a CCMP chain, which is better
      // than materializing the boolean for CBZ.
      if (!canEmitConjunction(DAG, LHS, CanNegate, MustBeFirst, PreferFirst,
                              false)) {
        ISD::CondCode NewCC = ISD::SETCC_INVALID;
        switch (CC) {
        // SETLT/SETGE are canonicalized away before reaching here, but
        // handle them defensively.
        case ISD::SETNE:
        case ISD::SETULT:
        case ISD::SETLT:
          NewCC = ISD::SETEQ;
          break;
        case ISD::SETEQ:
        case ISD::SETUGE:
        case ISD::SETGE:
          NewCC = ISD::SETNE;
          break;
        default:
          break;
        }
        if (NewCC != ISD::SETCC_INVALID) {
          CC = NewCC;
          RHS = DAG.getConstant(0, DL, LHS.getValueType());
          RHSC = cast<ConstantSDNode>(RHS);
        }
      }
    }
 
    // If the RHS of the comparison is zero, we can potentially fold this
    // to a specialized branch.
    if (RHSC && RHSC->getZExtValue() == 0 && ProduceNonFlagSettingCondBr) {
      if (CC == ISD::SETEQ) {
        if (SDValue Result =
                optimizeBitTest(DL, LHS, Chain, Dest, AArch64ISD::TBZ, DAG))
          return Result;
 
        return DAG.getNode(AArch64ISD::CBZ, DL, MVT::Other, Chain, LHS, Dest);
      } else if (CC == ISD::SETNE) {
        if (SDValue Result =
                optimizeBitTest(DL, LHS, Chain, Dest, AArch64ISD::TBNZ, DAG))
          return Result;
 
        return DAG.getNode(AArch64ISD::CBNZ, DL, MVT::Other, Chain, LHS, Dest);
      } else if (CC == ISD::SETLT && LHS.getOpcode() != ISD::AND) {
        // Don't combine AND since emitComparison converts the AND to an ANDS
        // (a.k.a. TST) and the test in the test bit and branch instruction
        // becomes redundant.  This would also increase register pressure.
        uint64_t SignBitPos;
        std::tie(LHS, SignBitPos) = lookThroughSignExtension(LHS);
        return DAG.getNode(AArch64ISD::TBNZ, DL, MVT::Other, Chain, LHS,
                           DAG.getConstant(SignBitPos, DL, MVT::i64), Dest);
      }
    }
    if (RHSC && RHSC->getSExtValue() == -1 && CC == ISD::SETGT &&
        LHS.getOpcode() != ISD::AND && ProduceNonFlagSettingCondBr) {
      // Don't combine AND since emitComparison converts the AND to an ANDS
      // (a.k.a. TST) and the test in the test bit and branch instruction
      // becomes redundant.  This would also increase register pressure.
      uint64_t SignBitPos;
      std::tie(LHS, SignBitPos) = lookThroughSignExtension(LHS);
      return DAG.getNode(AArch64ISD::TBZ, DL, MVT::Other, Chain, LHS,
                         DAG.getConstant(SignBitPos, DL, MVT::i64), Dest);
    }
 
    // Try to emit Armv9.6 CB instructions. We prefer tb{n}z/cb{n}z due to their
    // larger branch displacement but do prefer CB over cmp + br.
    if (Subtarget->hasCMPBR() &&
        AArch64CC::isValidCBCond(changeIntCCToAArch64CC(CC)) &&
        ProduceNonFlagSettingCondBr) {
      SDValue Cond =
          DAG.getTargetConstant(changeIntCCToAArch64CC(CC), DL, CondCodeVT);
      return DAG.getNode(AArch64ISD::CB, DL, MVT::Other, Chain, Cond, LHS, RHS,
                         Dest);
    }
 
    SDValue CCVal;
    SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, DL);
    return DAG.getNode(AArch64ISD::BRCOND, DL, MVT::Other, Chain, Dest, CCVal,
                       Cmp);
  }
 
  assert(LHS.getValueType() == MVT::f16 || LHS.getValueType() == MVT::bf16 ||
         LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
 
  // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
  // clean.  Some of them require two branches to implement.
  SDValue Cmp = emitComparison(LHS, RHS, CC, DL, DAG);
  AArch64CC::CondCode CC1, CC2;
  changeFPCCToAArch64CC(CC, CC1, CC2);
  SDValue CC1Val = getCondCode(DAG, CC1);
  SDValue BR1 =
      DAG.getNode(AArch64ISD::BRCOND, DL, MVT::Other, Chain, Dest, CC1Val, Cmp);
  if (CC2 != AArch64CC::AL) {
    SDValue CC2Val = getCondCode(DAG, CC2);
    return DAG.getNode(AArch64ISD::BRCOND, DL, MVT::Other, BR1, Dest, CC2Val,
                       Cmp);
  }
 
  return BR1;
}
 
SDValue AArch64TargetLowering::LowerFCOPYSIGN(SDValue Op,
                                              SelectionDAG &DAG) const {
  if (!Subtarget->isNeonAvailable() &&
      !Subtarget->useSVEForFixedLengthVectors())
    return SDValue();
 
  EVT VT = Op.getValueType();
  EVT IntVT = VT.changeTypeToInteger();
  SDLoc DL(Op);
 
  SDValue In1 = Op.getOperand(0);
  SDValue In2 = Op.getOperand(1);
  EVT SrcVT = In2.getValueType();
 
  if (!SrcVT.bitsEq(VT))
    In2 = DAG.getFPExtendOrRound(In2, DL, VT);
 
  if (VT.isScalableVector())
    IntVT =
        getPackedSVEVectorVT(VT.getVectorElementType().changeTypeToInteger());
 
  if (VT.isFixedLengthVector() &&
      useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable())) {
    EVT ContainerVT = getContainerForFixedLengthVector(DAG, VT);
 
    In1 = convertToScalableVector(DAG, ContainerVT, In1);
    In2 = convertToScalableVector(DAG, ContainerVT, In2);
 
    SDValue Res = DAG.getNode(ISD::FCOPYSIGN, DL, ContainerVT, In1, In2);
    return convertFromScalableVector(DAG, VT, Res);
  }
 
  // With SVE, but without Neon, extend the scalars to scalable vectors and use
  // a SVE FCOPYSIGN.
  if (!VT.isVector() && !Subtarget->isNeonAvailable() &&
      Subtarget->isSVEorStreamingSVEAvailable()) {
    if (VT != MVT::f16 && VT != MVT::f32 && VT != MVT::f64 && VT != MVT::bf16)
      return SDValue();
    EVT SVT = getPackedSVEVectorVT(VT);
 
    SDValue Poison = DAG.getPOISON(SVT);
    SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
    SDValue Ins1 =
        DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, SVT, Poison, In1, Zero);
    SDValue Ins2 =
        DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, SVT, Poison, In2, Zero);
    SDValue FCS = DAG.getNode(ISD::FCOPYSIGN, DL, SVT, Ins1, Ins2);
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, FCS, Zero);
  }
 
  auto BitCast = [this](EVT VT, SDValue Op, SelectionDAG &DAG) {
    if (VT.isScalableVector())
      return getSVESafeBitCast(VT, Op, DAG);
 
    return DAG.getBitcast(VT, Op);
  };
 
  SDValue VecVal1, VecVal2;
  EVT VecVT;
  auto SetVecVal = [&](int Idx = -1) {
    if (!VT.isVector()) {
      SDValue Poison = DAG.getPOISON(VecVT);
      VecVal1 = DAG.getTargetInsertSubreg(Idx, DL, VecVT, Poison, In1);
      VecVal2 = DAG.getTargetInsertSubreg(Idx, DL, VecVT, Poison, In2);
    } else {
      VecVal1 = BitCast(VecVT, In1, DAG);
      VecVal2 = BitCast(VecVT, In2, DAG);
    }
  };
  if (VT.isVector()) {
    VecVT = IntVT;
    SetVecVal();
  } else if (VT == MVT::f64) {
    VecVT = MVT::v2i64;
    SetVecVal(AArch64::dsub);
  } else if (VT == MVT::f32) {
    VecVT = MVT::v4i32;
    SetVecVal(AArch64::ssub);
  } else if (VT == MVT::f16 || VT == MVT::bf16) {
    VecVT = MVT::v8i16;
    SetVecVal(AArch64::hsub);
  } else {
    llvm_unreachable("Invalid type for copysign!");
  }
 
  unsigned BitWidth = In1.getScalarValueSizeInBits();
  SDValue SignMaskV = DAG.getConstant(~APInt::getSignMask(BitWidth), DL, VecVT);
 
  // We want to materialize a mask with every bit but the high bit set, but the
  // AdvSIMD immediate moves cannot materialize that in a single instruction for
  // 64-bit elements. Instead, materialize all bits set and then negate that.
  if (VT == MVT::f64 || VT == MVT::v2f64) {
    SignMaskV = DAG.getConstant(APInt::getAllOnes(BitWidth), DL, VecVT);
    SignMaskV = DAG.getNode(ISD::BITCAST, DL, MVT::v2f64, SignMaskV);
    SignMaskV = DAG.getNode(ISD::FNEG, DL, MVT::v2f64, SignMaskV);
    SignMaskV = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, SignMaskV);
  }
 
  SDValue BSP =
      DAG.getNode(AArch64ISD::BSP, DL, VecVT, SignMaskV, VecVal1, VecVal2);
  if (VT == MVT::f16 || VT == MVT::bf16)
    return DAG.getTargetExtractSubreg(AArch64::hsub, DL, VT, BSP);
  if (VT == MVT::f32)
    return DAG.getTargetExtractSubreg(AArch64::ssub, DL, VT, BSP);
  if (VT == MVT::f64)
    return DAG.getTargetExtractSubreg(AArch64::dsub, DL, VT, BSP);
 
  return BitCast(VT, BSP, DAG);
}
 
SDValue AArch64TargetLowering::LowerCTPOP_PARITY(SDValue Op,
                                                 SelectionDAG &DAG) const {
  if (DAG.getMachineFunction().getFunction().hasFnAttribute(
          Attribute::NoImplicitFloat))
    return SDValue();
 
  EVT VT = Op.getValueType();
  if (VT.isScalableVector() ||
      useSVEForFixedLengthVectorVT(VT, /*OverrideNEON=*/true))
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::CTPOP_MERGE_PASSTHRU);
 
  bool IsParity = Op.getOpcode() == ISD::PARITY;
  SDValue Val = Op.getOperand(0);
  SDLoc DL(Op);
 
  // for i32, general parity function using EORs is more efficient compared to
  // using floating point
  if (VT == MVT::i32 && IsParity)
    return SDValue();
 
  if (Subtarget->isSVEorStreamingSVEAvailable()) {
    if (VT == MVT::i32 || VT == MVT::i64) {
      EVT ContainerVT = VT == MVT::i32 ? MVT::nxv4i32 : MVT::nxv2i64;
      Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, ContainerVT,
                        DAG.getPOISON(ContainerVT), Val,
                        DAG.getVectorIdxConstant(0, DL));
      Val = DAG.getNode(ISD::CTPOP, DL, ContainerVT, Val);
      Val = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, Val,
                        DAG.getVectorIdxConstant(0, DL));
      if (IsParity)
        Val = DAG.getNode(ISD::AND, DL, VT, Val, DAG.getConstant(1, DL, VT));
      return Val;
    }
 
    if (VT == MVT::i128) {
      Val = DAG.getNode(ISD::BITCAST, DL, MVT::v2i64, Val);
      Val = convertToScalableVector(DAG, MVT::nxv2i64, Val);
      Val = DAG.getNode(ISD::CTPOP, DL, MVT::nxv2i64, Val);
      Val = convertFromScalableVector(DAG, MVT::v2i64, Val);
      Val = DAG.getNode(ISD::VECREDUCE_ADD, DL, MVT::i64, Val);
      Val = DAG.getZExtOrTrunc(Val, DL, VT);
      if (IsParity)
        Val = DAG.getNode(ISD::AND, DL, VT, Val, DAG.getConstant(1, DL, VT));
      return Val;
    }
  }
 
  if (!Subtarget->isNeonAvailable())
    return SDValue();
 
  // If there is no CNT instruction available, GPR popcount can
  // be more efficiently lowered to the following sequence that uses
  // AdvSIMD registers/instructions as long as the copies to/from
  // the AdvSIMD registers are cheap.
  //  FMOV    D0, X0        // copy 64-bit int to vector, high bits zero'd
  //  CNT     V0.8B, V0.8B  // 8xbyte pop-counts
  //  ADDV    B0, V0.8B     // sum 8xbyte pop-counts
  //  FMOV    X0, D0        // copy result back to integer reg
  if (VT == MVT::i32 || VT == MVT::i64) {
    if (VT == MVT::i32)
      Val = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, Val);
    Val = DAG.getNode(ISD::BITCAST, DL, MVT::v8i8, Val);
 
    SDValue CtPop = DAG.getNode(ISD::CTPOP, DL, MVT::v8i8, Val);
    SDValue AddV = DAG.getNode(AArch64ISD::UADDV, DL, MVT::v8i8, CtPop);
    AddV = DAG.getNode(AArch64ISD::NVCAST, DL,
                       VT == MVT::i32 ? MVT::v2i32 : MVT::v1i64, AddV);
    AddV = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, AddV,
                       DAG.getConstant(0, DL, MVT::i64));
    if (IsParity)
      AddV = DAG.getNode(ISD::AND, DL, VT, AddV, DAG.getConstant(1, DL, VT));
    return AddV;
  } else if (VT == MVT::i128) {
    Val = DAG.getNode(ISD::BITCAST, DL, MVT::v16i8, Val);
 
    SDValue CtPop = DAG.getNode(ISD::CTPOP, DL, MVT::v16i8, Val);
    SDValue AddV = DAG.getNode(AArch64ISD::UADDV, DL, MVT::v16i8, CtPop);
    AddV = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, MVT::i64,
                       DAG.getNode(AArch64ISD::NVCAST, DL, MVT::v2i64, AddV),
                       DAG.getConstant(0, DL, MVT::i64));
    AddV = DAG.getZExtOrTrunc(AddV, DL, VT);
    if (IsParity)
      AddV = DAG.getNode(ISD::AND, DL, VT, AddV, DAG.getConstant(1, DL, VT));
    return AddV;
  }
 
  assert(!IsParity && "ISD::PARITY of vector types not supported");
 
  assert((VT == MVT::v1i64 || VT == MVT::v2i64 || VT == MVT::v2i32 ||
          VT == MVT::v4i32 || VT == MVT::v4i16 || VT == MVT::v8i16) &&
         "Unexpected type for custom ctpop lowering");
 
  EVT VT8Bit = VT.is64BitVector() ? MVT::v8i8 : MVT::v16i8;
  Val = DAG.getBitcast(VT8Bit, Val);
  Val = DAG.getNode(ISD::CTPOP, DL, VT8Bit, Val);
 
  if (Subtarget->hasDotProd() && VT.getScalarSizeInBits() != 16 &&
      VT.getVectorNumElements() >= 2) {
    EVT DT = VT == MVT::v2i64 ? MVT::v4i32 : VT;
    SDValue Zeros = DAG.getConstant(0, DL, DT);
    SDValue Ones = DAG.getConstant(1, DL, VT8Bit);
 
    if (VT == MVT::v2i64) {
      Val = DAG.getNode(AArch64ISD::UDOT, DL, DT, Zeros, Ones, Val);
      Val = DAG.getNode(AArch64ISD::UADDLP, DL, VT, Val);
    } else if (VT == MVT::v2i32) {
      Val = DAG.getNode(AArch64ISD::UDOT, DL, DT, Zeros, Ones, Val);
    } else if (VT == MVT::v4i32) {
      Val = DAG.getNode(AArch64ISD::UDOT, DL, DT, Zeros, Ones, Val);
    } else {
      llvm_unreachable("Unexpected type for custom ctpop lowering");
    }
 
    return Val;
  }
 
  // Widen v8i8/v16i8 CTPOP result to VT by repeatedly widening pairwise adds.
  unsigned EltSize = 8;
  unsigned NumElts = VT.is64BitVector() ? 8 : 16;
  while (EltSize != VT.getScalarSizeInBits()) {
    EltSize *= 2;
    NumElts /= 2;
    MVT WidenVT = MVT::getVectorVT(MVT::getIntegerVT(EltSize), NumElts);
    Val = DAG.getNode(AArch64ISD::UADDLP, DL, WidenVT, Val);
  }
 
  return Val;
}
 
SDValue AArch64TargetLowering::LowerCTTZ(SDValue Op, SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  SDValue RBIT = DAG.getNode(ISD::BITREVERSE, DL, VT, Op.getOperand(0));
  return DAG.getNode(ISD::CTLZ, DL, VT, RBIT);
}
 
SDValue AArch64TargetLowering::LowerMinMax(SDValue Op,
                                           SelectionDAG &DAG) const {
 
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  unsigned Opcode = Op.getOpcode();
  ISD::CondCode CC;
  switch (Opcode) {
  default:
    llvm_unreachable("Wrong instruction");
  case ISD::SMAX:
    CC = ISD::SETGT;
    break;
  case ISD::SMIN:
    CC = ISD::SETLT;
    break;
  case ISD::UMAX:
    CC = ISD::SETUGT;
    break;
  case ISD::UMIN:
    CC = ISD::SETULT;
    break;
  }
 
  // Note: This lowering only overrides NEON for v1i64 and v2i64, where we
  // prefer using SVE if available.
  if (VT.isScalableVector() ||
      useSVEForFixedLengthVectorVT(VT, /*OverrideNEON=*/true)) {
    switch (Opcode) {
    default:
      llvm_unreachable("Wrong instruction");
    case ISD::SMAX:
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::SMAX_PRED);
    case ISD::SMIN:
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::SMIN_PRED);
    case ISD::UMAX:
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::UMAX_PRED);
    case ISD::UMIN:
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::UMIN_PRED);
    }
  }
 
  SDValue Op0 = Op.getOperand(0);
  SDValue Op1 = Op.getOperand(1);
  SDValue Cond = DAG.getSetCC(DL, VT, Op0, Op1, CC);
  return DAG.getSelect(DL, VT, Cond, Op0, Op1);
}
 
SDValue AArch64TargetLowering::LowerBitreverse(SDValue Op,
                                               SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
 
  if (VT.isScalableVector() ||
      useSVEForFixedLengthVectorVT(
          VT, /*OverrideNEON=*/Subtarget->useSVEForFixedLengthVectors()))
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::BITREVERSE_MERGE_PASSTHRU);
 
  SDLoc DL(Op);
  SDValue REVB;
  MVT VST;
 
  switch (VT.getSimpleVT().SimpleTy) {
  default:
    llvm_unreachable("Invalid type for bitreverse!");
 
  case MVT::v2i32: {
    VST = MVT::v8i8;
    REVB = DAG.getNode(AArch64ISD::REV32, DL, VST, Op.getOperand(0));
 
    break;
  }
 
  case MVT::v4i32: {
    VST = MVT::v16i8;
    REVB = DAG.getNode(AArch64ISD::REV32, DL, VST, Op.getOperand(0));
 
    break;
  }
 
  case MVT::v1i64: {
    VST = MVT::v8i8;
    REVB = DAG.getNode(AArch64ISD::REV64, DL, VST, Op.getOperand(0));
 
    break;
  }
 
  case MVT::v2i64: {
    VST = MVT::v16i8;
    REVB = DAG.getNode(AArch64ISD::REV64, DL, VST, Op.getOperand(0));
 
    break;
  }
  }
 
  return DAG.getNode(AArch64ISD::NVCAST, DL, VT,
                     DAG.getNode(ISD::BITREVERSE, DL, VST, REVB));
}
 
// Check whether the continuous comparison sequence.
static bool
isOrXorChain(SDValue N, unsigned &Num,
             SmallVector<std::pair<SDValue, SDValue>, 16> &WorkList) {
  if (Num == MaxXors)
    return false;
 
  // Skip the one-use zext
  if (N->getOpcode() == ISD::ZERO_EXTEND && N->hasOneUse())
    N = N->getOperand(0);
 
  // The leaf node must be XOR
  if (N->getOpcode() == ISD::XOR) {
    WorkList.push_back(std::make_pair(N->getOperand(0), N->getOperand(1)));
    Num++;
    return true;
  }
 
  // All the non-leaf nodes must be OR.
  if (N->getOpcode() != ISD::OR || !N->hasOneUse())
    return false;
 
  if (isOrXorChain(N->getOperand(0), Num, WorkList) &&
      isOrXorChain(N->getOperand(1), Num, WorkList))
    return true;
  return false;
}
 
// Transform chains of ORs and XORs, which usually outlined by memcmp/bmp.
static SDValue performOrXorChainCombine(SDNode *N, SelectionDAG &DAG) {
  SDValue LHS = N->getOperand(0);
  SDValue RHS = N->getOperand(1);
  SDLoc DL(N);
  EVT VT = N->getValueType(0);
  SmallVector<std::pair<SDValue, SDValue>, 16> WorkList;
 
  // Only handle integer compares.
  if (N->getOpcode() != ISD::SETCC)
    return SDValue();
 
  ISD::CondCode Cond = cast<CondCodeSDNode>(N->getOperand(2))->get();
  // Try to express conjunction "cmp 0 (or (xor A0 A1) (xor B0 B1))" as:
  // sub A0, A1; ccmp B0, B1, 0, eq; cmp inv(Cond) flag
  unsigned NumXors = 0;
  if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && isNullConstant(RHS) &&
      LHS->getOpcode() == ISD::OR && LHS->hasOneUse() &&
      isOrXorChain(LHS, NumXors, WorkList)) {
    SDValue XOR0, XOR1;
    std::tie(XOR0, XOR1) = WorkList[0];
    unsigned LogicOp = (Cond == ISD::SETEQ) ? ISD::AND : ISD::OR;
    SDValue Cmp = DAG.getSetCC(DL, VT, XOR0, XOR1, Cond);
    for (unsigned I = 1; I < WorkList.size(); I++) {
      std::tie(XOR0, XOR1) = WorkList[I];
      SDValue CmpChain = DAG.getSetCC(DL, VT, XOR0, XOR1, Cond);
      Cmp = DAG.getNode(LogicOp, DL, VT, Cmp, CmpChain);
    }
 
    // Exit early by inverting the condition, which help reduce indentations.
    return Cmp;
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerSETCC(SDValue Op, SelectionDAG &DAG) const {
 
  if (Op.getValueType().isVector())
    return LowerVSETCC(Op, DAG);
 
  bool IsStrict = Op->isStrictFPOpcode();
  bool IsSignaling = Op.getOpcode() == ISD::STRICT_FSETCCS;
  unsigned OpNo = IsStrict ? 1 : 0;
  SDValue Chain;
  if (IsStrict)
    Chain = Op.getOperand(0);
  SDValue LHS = Op.getOperand(OpNo + 0);
  SDValue RHS = Op.getOperand(OpNo + 1);
  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(OpNo + 2))->get();
  SDLoc DL(Op);
 
  // We chose ZeroOrOneBooleanContents, so use zero and one.
  EVT VT = Op.getValueType();
  SDValue TVal = DAG.getConstant(1, DL, VT);
  SDValue FVal = DAG.getConstant(0, DL, VT);
 
  // Handle f128 first, since one possible outcome is a normal integer
  // comparison which gets picked up by the next if statement.
  if (LHS.getValueType() == MVT::f128) {
    softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, DL, LHS, RHS, Chain,
                        IsSignaling);
 
    // If softenSetCCOperands returned a scalar, use it.
    if (!RHS.getNode()) {
      assert(LHS.getValueType() == Op.getValueType() &&
             "Unexpected setcc expansion!");
      return IsStrict ? DAG.getMergeValues({LHS, Chain}, DL) : LHS;
    }
  }
 
  if (LHS.getValueType().isInteger()) {
    if (Subtarget->hasCSSC() && CC == ISD::SETNE && isNullConstant(RHS)) {
      SDValue One = DAG.getConstant(1, DL, LHS.getValueType());
      SDValue UMin = DAG.getNode(ISD::UMIN, DL, LHS.getValueType(), LHS, One);
      SDValue Res = DAG.getZExtOrTrunc(UMin, DL, VT);
      return IsStrict ? DAG.getMergeValues({Res, Chain}, DL) : Res;
    }
    simplifySetCCIntoEq(CC, LHS, RHS, DAG, DL);
 
    SDValue CCVal;
    SDValue Cmp = getAArch64Cmp(
        LHS, RHS, ISD::getSetCCInverse(CC, LHS.getValueType()), CCVal, DAG, DL);
 
    // Note that we inverted the condition above, so we reverse the order of
    // the true and false operands here.  This will allow the setcc to be
    // matched to a single CSINC instruction.
    SDValue Res = DAG.getNode(AArch64ISD::CSEL, DL, VT, FVal, TVal, CCVal, Cmp);
    return IsStrict ? DAG.getMergeValues({Res, Chain}, DL) : Res;
  }
 
  // Now we know we're dealing with FP values.
  assert(LHS.getValueType() == MVT::bf16 || LHS.getValueType() == MVT::f16 ||
         LHS.getValueType() == MVT::f32 || LHS.getValueType() == MVT::f64);
 
  // If that fails, we'll need to perform an FCMP + CSEL sequence.  Go ahead
  // and do the comparison.
  SDValue Cmp;
  if (IsStrict)
    Cmp = emitStrictFPComparison(LHS, RHS, DL, DAG, Chain, IsSignaling);
  else
    Cmp = emitComparison(LHS, RHS, CC, DL, DAG);
 
  AArch64CC::CondCode CC1, CC2;
  changeFPCCToAArch64CC(CC, CC1, CC2);
  SDValue Res;
  if (CC2 == AArch64CC::AL) {
    changeFPCCToAArch64CC(ISD::getSetCCInverse(CC, LHS.getValueType()), CC1,
                          CC2);
    SDValue CC1Val = getCondCode(DAG, CC1);
 
    // Note that we inverted the condition above, so we reverse the order of
    // the true and false operands here.  This will allow the setcc to be
    // matched to a single CSINC instruction.
    Res = DAG.getNode(AArch64ISD::CSEL, DL, VT, FVal, TVal, CC1Val, Cmp);
  } else {
    // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't
    // totally clean.  Some of them require two CSELs to implement.  As is in
    // this case, we emit the first CSEL and then emit a second using the output
    // of the first as the RHS.  We're effectively OR'ing the two CC's together.
 
    // FIXME: It would be nice if we could match the two CSELs to two CSINCs.
    SDValue CC1Val = getCondCode(DAG, CC1);
    SDValue CS1 =
        DAG.getNode(AArch64ISD::CSEL, DL, VT, TVal, FVal, CC1Val, Cmp);
 
    SDValue CC2Val = getCondCode(DAG, CC2);
    Res = DAG.getNode(AArch64ISD::CSEL, DL, VT, TVal, CS1, CC2Val, Cmp);
  }
  return IsStrict ? DAG.getMergeValues({Res, Cmp.getValue(1)}, DL) : Res;
}
 
SDValue AArch64TargetLowering::LowerSETCCCARRY(SDValue Op,
                                               SelectionDAG &DAG) const {
 
  SDValue LHS = Op.getOperand(0);
  SDValue RHS = Op.getOperand(1);
  EVT VT = LHS.getValueType();
  if (VT != MVT::i32 && VT != MVT::i64)
    return SDValue();
 
  SDLoc DL(Op);
  SDValue Carry = Op.getOperand(2);
  // SBCS uses a carry not a borrow so the carry flag should be inverted first.
  SDValue InvCarry = valueToCarryFlag(Carry, DAG, true);
  SDValue Cmp = DAG.getNode(AArch64ISD::SBCS, DL, DAG.getVTList(VT, FlagsVT),
                            LHS, RHS, InvCarry);
 
  EVT OpVT = Op.getValueType();
  SDValue TVal = DAG.getConstant(1, DL, OpVT);
  SDValue FVal = DAG.getConstant(0, DL, OpVT);
 
  ISD::CondCode Cond = cast<CondCodeSDNode>(Op.getOperand(3))->get();
  ISD::CondCode CondInv = ISD::getSetCCInverse(Cond, VT);
  SDValue CCVal = getCondCode(DAG, changeIntCCToAArch64CC(CondInv));
  // Inputs are swapped because the condition is inverted. This will allow
  // matching with a single CSINC instruction.
  return DAG.getNode(AArch64ISD::CSEL, DL, OpVT, FVal, TVal, CCVal,
                     Cmp.getValue(1));
}
 
/// Emit vector comparison for floating-point values, producing a mask.
static SDValue emitVectorComparison(SDValue LHS, SDValue RHS,
                                    AArch64CC::CondCode CC, bool NoNans, EVT VT,
                                    const SDLoc &DL, SelectionDAG &DAG) {
  assert(VT.getSizeInBits() == LHS.getValueType().getSizeInBits() &&
         "function only supposed to emit natural comparisons");
 
  switch (CC) {
  default:
    return SDValue();
  case AArch64CC::NE: {
    SDValue Fcmeq = DAG.getNode(AArch64ISD::FCMEQ, DL, VT, LHS, RHS);
    // Use vector semantics for the inversion to potentially save a copy between
    // SIMD and regular registers.
    if (!LHS.getValueType().isVector()) {
      EVT VecVT =
          EVT::getVectorVT(*DAG.getContext(), VT, 128 / VT.getSizeInBits());
      SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
      SDValue MaskVec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VecVT,
                                    DAG.getPOISON(VecVT), Fcmeq, Zero);
      SDValue InvertedMask = DAG.getNOT(DL, MaskVec, VecVT);
      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, InvertedMask, Zero);
    }
    return DAG.getNOT(DL, Fcmeq, VT);
  }
  case AArch64CC::EQ:
    return DAG.getNode(AArch64ISD::FCMEQ, DL, VT, LHS, RHS);
  case AArch64CC::GE:
    return DAG.getNode(AArch64ISD::FCMGE, DL, VT, LHS, RHS);
  case AArch64CC::GT:
    return DAG.getNode(AArch64ISD::FCMGT, DL, VT, LHS, RHS);
  case AArch64CC::LE:
    if (!NoNans)
      return SDValue();
    // If we ignore NaNs then we can use to the LS implementation.
    [[fallthrough]];
  case AArch64CC::LS:
    return DAG.getNode(AArch64ISD::FCMGE, DL, VT, RHS, LHS);
  case AArch64CC::LT:
    if (!NoNans)
      return SDValue();
    // If we ignore NaNs then we can use to the MI implementation.
    [[fallthrough]];
  case AArch64CC::MI:
    return DAG.getNode(AArch64ISD::FCMGT, DL, VT, RHS, LHS);
  }
}
 
/// For SELECT_CC, when the true/false values are (-1, 0) and the compared
/// values are scalars, try to emit a mask generating vector instruction.
static SDValue emitFloatCompareMask(SDValue LHS, SDValue RHS, SDValue TVal,
                                    SDValue FVal, ISD::CondCode CC, bool NoNaNs,
                                    const SDLoc &DL, SelectionDAG &DAG) {
  assert(!LHS.getValueType().isVector());
  assert(!RHS.getValueType().isVector());
 
  auto *CTVal = dyn_cast<ConstantSDNode>(TVal);
  auto *CFVal = dyn_cast<ConstantSDNode>(FVal);
  if (!CTVal || !CFVal)
    return {};
  if (!(CTVal->isAllOnes() && CFVal->isZero()) &&
      !(CTVal->isZero() && CFVal->isAllOnes()))
    return {};
 
  if (CTVal->isZero())
    CC = ISD::getSetCCInverse(CC, LHS.getValueType());
 
  EVT VT = TVal.getValueType();
  if (VT.getSizeInBits() != LHS.getValueType().getSizeInBits())
    return {};
 
  if (!NoNaNs && (CC == ISD::SETUO || CC == ISD::SETO)) {
    bool OneNaN = false;
    if (LHS == RHS) {
      OneNaN = true;
    } else if (DAG.isKnownNeverNaN(RHS)) {
      OneNaN = true;
      RHS = LHS;
    } else if (DAG.isKnownNeverNaN(LHS)) {
      OneNaN = true;
      LHS = RHS;
    }
    if (OneNaN)
      CC = (CC == ISD::SETUO) ? ISD::SETUNE : ISD::SETOEQ;
  }
 
  AArch64CC::CondCode CC1;
  AArch64CC::CondCode CC2;
  bool ShouldInvert = false;
  changeVectorFPCCToAArch64CC(CC, CC1, CC2, ShouldInvert);
  SDValue Cmp = emitVectorComparison(LHS, RHS, CC1, NoNaNs, VT, DL, DAG);
  SDValue Cmp2;
  if (CC2 != AArch64CC::AL) {
    Cmp2 = emitVectorComparison(LHS, RHS, CC2, NoNaNs, VT, DL, DAG);
    if (!Cmp2)
      return {};
  }
  if (!Cmp2 && !ShouldInvert)
    return Cmp;
 
  EVT VecVT = EVT::getVectorVT(*DAG.getContext(), VT, 128 / VT.getSizeInBits());
  SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
  SDValue Poison = DAG.getPOISON(VecVT);
  Cmp = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VecVT, Poison, Cmp, Zero);
  if (Cmp2) {
    Cmp2 = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VecVT, Poison, Cmp2, Zero);
    Cmp = DAG.getNode(ISD::OR, DL, VecVT, Cmp, Cmp2);
  }
  if (ShouldInvert)
    Cmp = DAG.getNOT(DL, Cmp, VecVT);
  Cmp = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, VT, Cmp, Zero);
  return Cmp;
}
 
SDValue AArch64TargetLowering::LowerSELECT_CC(
    ISD::CondCode CC, SDValue LHS, SDValue RHS, SDValue TVal, SDValue FVal,
    iterator_range<SDNode::user_iterator> Users, SDNodeFlags Flags,
    const SDLoc &DL, SelectionDAG &DAG) const {
  // Handle f128 first, because it will result in a comparison of some RTLIB
  // call result against zero.
  if (LHS.getValueType() == MVT::f128) {
    softenSetCCOperands(DAG, MVT::f128, LHS, RHS, CC, DL, LHS, RHS);
 
    // If softenSetCCOperands returned a scalar, we need to compare the result
    // against zero to select between true and false values.
    if (!RHS.getNode()) {
      RHS = DAG.getConstant(0, DL, LHS.getValueType());
      CC = ISD::SETNE;
    }
  }
 
  // Also handle f16, for which we need to do a f32 comparison.
  if ((LHS.getValueType() == MVT::f16 && !Subtarget->hasFullFP16()) ||
      LHS.getValueType() == MVT::bf16) {
    LHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, LHS);
    RHS = DAG.getNode(ISD::FP_EXTEND, DL, MVT::f32, RHS);
  }
 
  // Next, handle integers.
  if (LHS.getValueType().isInteger()) {
    assert((LHS.getValueType() == RHS.getValueType()) &&
           (LHS.getValueType() == MVT::i32 || LHS.getValueType() == MVT::i64));
 
    ConstantSDNode *CFVal = dyn_cast<ConstantSDNode>(FVal);
    ConstantSDNode *CTVal = dyn_cast<ConstantSDNode>(TVal);
    ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS);
 
    // Check for SMAX(lhs, 0) and SMIN(lhs, 0) patterns.
    // (SELECT_CC setgt, lhs, 0, lhs, 0) -> (BIC lhs, (SRA lhs, typesize-1))
    // (SELECT_CC setlt, lhs, 0, lhs, 0) -> (AND lhs, (SRA lhs, typesize-1))
    // Both require less instructions than compare and conditional select.
    if ((CC == ISD::SETGT || CC == ISD::SETLT) && LHS == TVal &&
        RHSC && RHSC->isZero() && CFVal && CFVal->isZero() &&
        LHS.getValueType() == RHS.getValueType()) {
      EVT VT = LHS.getValueType();
      SDValue Shift =
          DAG.getNode(ISD::SRA, DL, VT, LHS,
                      DAG.getConstant(VT.getSizeInBits() - 1, DL, VT));
 
      if (CC == ISD::SETGT)
        Shift = DAG.getNOT(DL, Shift, VT);
 
      return DAG.getNode(ISD::AND, DL, VT, LHS, Shift);
    }
 
    // Check for sign bit test patterns that can use TST optimization.
    // (SELECT_CC setlt, sign_extend_inreg, 0, tval, fval)
    //                          -> TST %operand, sign_bit; CSEL
    // (SELECT_CC setlt, sign_extend, 0, tval, fval)
    //                          -> TST %operand, sign_bit; CSEL
    if (CC == ISD::SETLT && RHSC && RHSC->isZero() && LHS.hasOneUse() &&
        (LHS.getOpcode() == ISD::SIGN_EXTEND_INREG ||
         LHS.getOpcode() == ISD::SIGN_EXTEND)) {
 
      uint64_t SignBitPos;
      std::tie(LHS, SignBitPos) = lookThroughSignExtension(LHS);
      EVT TestVT = LHS.getValueType();
      SDValue SignBitConst = DAG.getConstant(1ULL << SignBitPos, DL, TestVT);
      SDValue TST =
          DAG.getNode(AArch64ISD::ANDS, DL, DAG.getVTList(TestVT, MVT::i32),
                      LHS, SignBitConst);
 
      SDValue Flags = TST.getValue(1);
      return DAG.getNode(AArch64ISD::CSEL, DL, TVal.getValueType(), TVal, FVal,
                         DAG.getConstant(AArch64CC::NE, DL, MVT::i32), Flags);
    }
 
    // Canonicalise absolute difference patterns:
    //   select_cc lhs, rhs, sub(lhs, rhs), sub(rhs, lhs), cc ->
    //   select_cc lhs, rhs, sub(lhs, rhs), neg(sub(lhs, rhs)), cc
    //
    //   select_cc lhs, rhs, sub(rhs, lhs), sub(lhs, rhs), cc ->
    //   select_cc lhs, rhs, neg(sub(lhs, rhs)), sub(lhs, rhs), cc
    // The second forms can be matched into subs+cneg.
    // NOTE: Drop poison generating flags from the negated operand to avoid
    // inadvertently propagating poison after the canonicalisation.
    if (TVal.getOpcode() == ISD::SUB && FVal.getOpcode() == ISD::SUB) {
      if (TVal.getOperand(0) == LHS && TVal.getOperand(1) == RHS &&
          FVal.getOperand(0) == RHS && FVal.getOperand(1) == LHS) {
        TVal->dropFlags(SDNodeFlags::PoisonGeneratingFlags);
        FVal = DAG.getNegative(TVal, DL, TVal.getValueType());
      } else if (TVal.getOperand(0) == RHS && TVal.getOperand(1) == LHS &&
                 FVal.getOperand(0) == LHS && FVal.getOperand(1) == RHS) {
        FVal->dropFlags(SDNodeFlags::PoisonGeneratingFlags);
        TVal = DAG.getNegative(FVal, DL, FVal.getValueType());
      }
    }
 
    unsigned Opcode = AArch64ISD::CSEL;
 
    // If both the TVal and the FVal are constants, see if we can swap them in
    // order to for a CSINV or CSINC out of them.
    if (CTVal && CFVal && CTVal->isAllOnes() && CFVal->isZero()) {
      std::swap(TVal, FVal);
      std::swap(CTVal, CFVal);
      CC = ISD::getSetCCInverse(CC, LHS.getValueType());
    } else if (CTVal && CFVal && CTVal->isOne() && CFVal->isZero()) {
      std::swap(TVal, FVal);
      std::swap(CTVal, CFVal);
      CC = ISD::getSetCCInverse(CC, LHS.getValueType());
    } else if (TVal.getOpcode() == ISD::XOR) {
      // If TVal is a NOT we want to swap TVal and FVal so that we can match
      // with a CSINV rather than a CSEL.
      if (isAllOnesConstant(TVal.getOperand(1))) {
        std::swap(TVal, FVal);
        std::swap(CTVal, CFVal);
        CC = ISD::getSetCCInverse(CC, LHS.getValueType());
      }
    } else if (TVal.getOpcode() == ISD::SUB) {
      // If TVal is a negation (SUB from 0) we want to swap TVal and FVal so
      // that we can match with a CSNEG rather than a CSEL.
      if (isNullConstant(TVal.getOperand(0))) {
        std::swap(TVal, FVal);
        std::swap(CTVal, CFVal);
        CC = ISD::getSetCCInverse(CC, LHS.getValueType());
      }
    } else if (CTVal && CFVal) {
      const int64_t TrueVal = CTVal->getSExtValue();
      const int64_t FalseVal = CFVal->getSExtValue();
      bool Swap = false;
 
      // If both TVal and FVal are constants, see if FVal is the
      // inverse/negation/increment of TVal and generate a CSINV/CSNEG/CSINC
      // instead of a CSEL in that case.
      if (TrueVal == ~FalseVal) {
        Opcode = AArch64ISD::CSINV;
      } else if (FalseVal > std::numeric_limits<int64_t>::min() &&
                 TrueVal == -FalseVal) {
        Opcode = AArch64ISD::CSNEG;
      } else if (TVal.getValueType() == MVT::i32) {
        // If our operands are only 32-bit wide, make sure we use 32-bit
        // arithmetic for the check whether we can use CSINC. This ensures that
        // the addition in the check will wrap around properly in case there is
        // an overflow (which would not be the case if we do the check with
        // 64-bit arithmetic).
        const uint32_t TrueVal32 = CTVal->getZExtValue();
        const uint32_t FalseVal32 = CFVal->getZExtValue();
 
        if ((TrueVal32 == FalseVal32 + 1) || (TrueVal32 + 1 == FalseVal32)) {
          Opcode = AArch64ISD::CSINC;
 
          if (TrueVal32 > FalseVal32) {
            Swap = true;
          }
        }
      } else {
        // 64-bit check whether we can use CSINC.
        const uint64_t TrueVal64 = TrueVal;
        const uint64_t FalseVal64 = FalseVal;
 
        if ((TrueVal64 == FalseVal64 + 1) || (TrueVal64 + 1 == FalseVal64)) {
          Opcode = AArch64ISD::CSINC;
 
          if (TrueVal > FalseVal) {
            Swap = true;
          }
        }
      }
 
      // Swap TVal and FVal if necessary.
      if (Swap) {
        std::swap(TVal, FVal);
        std::swap(CTVal, CFVal);
        CC = ISD::getSetCCInverse(CC, LHS.getValueType());
      }
 
      if (Opcode != AArch64ISD::CSEL) {
        // Drop FVal since we can get its value by simply inverting/negating
        // TVal.
        FVal = TVal;
      }
    }
 
    // Avoid materializing a constant when possible by reusing a known value in
    // a register.  However, don't perform this optimization if the known value
    // is one, zero or negative one in the case of a CSEL.  We can always
    // materialize these values using CSINC, CSEL and CSINV with wzr/xzr as the
    // FVal, respectively.
    ConstantSDNode *RHSVal = dyn_cast<ConstantSDNode>(RHS);
    if (Opcode == AArch64ISD::CSEL && RHSVal && !RHSVal->isOne() &&
        !RHSVal->isZero() && !RHSVal->isAllOnes()) {
      AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
      // Transform "a == C ? C : x" to "a == C ? a : x" and "a != C ? x : C" to
      // "a != C ? x : a" to avoid materializing C.
      if (CTVal && CTVal == RHSVal && AArch64CC == AArch64CC::EQ)
        TVal = LHS;
      else if (CFVal && CFVal == RHSVal && AArch64CC == AArch64CC::NE)
        FVal = LHS;
    } else if (Opcode == AArch64ISD::CSNEG && RHSVal && RHSVal->isOne()) {
      assert (CTVal && CFVal && "Expected constant operands for CSNEG.");
      // Use a CSINV to transform "a == C ? 1 : -1" to "a == C ? a : -1" to
      // avoid materializing C.
      AArch64CC::CondCode AArch64CC = changeIntCCToAArch64CC(CC);
      if (CTVal == RHSVal && AArch64CC == AArch64CC::EQ) {
        Opcode = AArch64ISD::CSINV;
        TVal = LHS;
        FVal = DAG.getConstant(0, DL, FVal.getValueType());
      }
    }
 
    SDValue CCVal;
    SDValue Cmp = getAArch64Cmp(LHS, RHS, CC, CCVal, DAG, DL);
    EVT VT = TVal.getValueType();
    return DAG.getNode(Opcode, DL, VT, TVal, FVal, CCVal, Cmp);
  }
 
  // Now we know we're dealing with FP values.
  assert(LHS.getValueType() == MVT::f16 || LHS.getValueType() == MVT::f32 ||
         LHS.getValueType() == MVT::f64);
  assert(LHS.getValueType() == RHS.getValueType());
  EVT VT = TVal.getValueType();
 
  // If the purpose of the comparison is to select between all ones
  // or all zeros, try to use a vector comparison because the operands are
  // already stored in SIMD registers.
  if (Subtarget->isNeonAvailable() && all_of(Users, [](const SDNode *U) {
        switch (U->getOpcode()) {
        default:
          return false;
        case ISD::INSERT_VECTOR_ELT:
        case ISD::SCALAR_TO_VECTOR:
        case AArch64ISD::DUP:
          return true;
        }
      })) {
    bool NoNaNs = Flags.hasNoNaNs();
    SDValue VectorCmp =
        emitFloatCompareMask(LHS, RHS, TVal, FVal, CC, NoNaNs, DL, DAG);
    if (VectorCmp)
      return VectorCmp;
  }
 
  SDValue Cmp = emitComparison(LHS, RHS, CC, DL, DAG);
 
  // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
  // clean.  Some of them require two CSELs to implement.
  AArch64CC::CondCode CC1, CC2;
  changeFPCCToAArch64CC(CC, CC1, CC2);
 
  if (Flags.hasNoSignedZeros()) {
    // Transform "a == 0.0 ? 0.0 : x" to "a == 0.0 ? a : x" and
    // "a != 0.0 ? x : 0.0" to "a != 0.0 ? x : a" to avoid materializing 0.0.
    ConstantFPSDNode *RHSVal = dyn_cast<ConstantFPSDNode>(RHS);
    if (RHSVal && RHSVal->isZero()) {
      ConstantFPSDNode *CFVal = dyn_cast<ConstantFPSDNode>(FVal);
      ConstantFPSDNode *CTVal = dyn_cast<ConstantFPSDNode>(TVal);
 
      if ((CC == ISD::SETEQ || CC == ISD::SETOEQ || CC == ISD::SETUEQ) &&
          CTVal && CTVal->isZero() && TVal.getValueType() == LHS.getValueType())
        TVal = LHS;
      else if ((CC == ISD::SETNE || CC == ISD::SETONE || CC == ISD::SETUNE) &&
               CFVal && CFVal->isZero() &&
               FVal.getValueType() == LHS.getValueType())
        FVal = LHS;
    }
  }
 
  // Emit first, and possibly only, CSEL.
  SDValue CC1Val = getCondCode(DAG, CC1);
  SDValue CS1 = DAG.getNode(AArch64ISD::CSEL, DL, VT, TVal, FVal, CC1Val, Cmp);
 
  // If we need a second CSEL, emit it, using the output of the first as the
  // RHS.  We're effectively OR'ing the two CC's together.
  if (CC2 != AArch64CC::AL) {
    SDValue CC2Val = getCondCode(DAG, CC2);
    return DAG.getNode(AArch64ISD::CSEL, DL, VT, TVal, CS1, CC2Val, Cmp);
  }
 
  // Otherwise, return the output of the first CSEL.
  return CS1;
}
 
SDValue AArch64TargetLowering::LowerVECTOR_SPLICE(SDValue Op,
                                                  SelectionDAG &DAG) const {
  EVT Ty = Op.getValueType();
  if (!isa<ConstantSDNode>(Op.getOperand(2)))
    return SDValue();
  auto Idx = Op.getConstantOperandAPInt(2);
  int64_t IdxVal = Idx.getSExtValue();
  assert(Ty.isScalableVector() &&
         "Only expect scalable vectors for custom lowering of VECTOR_SPLICE");
 
  // We can use the splice instruction for certain index values where we are
  // able to efficiently generate the correct predicate. The index will be
  // inverted and used directly as the input to the ptrue instruction, i.e.
  // -1 -> vl1, -2 -> vl2, etc. The predicate will then be reversed to get the
  // splice predicate. However, we can only do this if we can guarantee that
  // there are enough elements in the vector, hence we check the index <= min
  // number of elements.
  std::optional<unsigned> PredPattern;
  if (Ty.isScalableVector() && Op.getOpcode() == ISD::VECTOR_SPLICE_RIGHT &&
      (PredPattern = getSVEPredPatternFromNumElements(IdxVal)) !=
          std::nullopt) {
    SDLoc DL(Op);
 
    // Create a predicate where all but the last -IdxVal elements are false.
    EVT PredVT = Ty.changeVectorElementType(*DAG.getContext(), MVT::i1);
    SDValue Pred = getPTrue(DAG, DL, PredVT, *PredPattern);
    Pred = DAG.getNode(ISD::VECTOR_REVERSE, DL, PredVT, Pred);
 
    // Now splice the two inputs together using the predicate.
    return DAG.getNode(AArch64ISD::SPLICE, DL, Ty, Pred, Op.getOperand(0),
                       Op.getOperand(1));
  }
 
  // We can select to an EXT instruction when indexing the first 256 bytes.
  unsigned BlockSize = AArch64::SVEBitsPerBlock / Ty.getVectorMinNumElements();
  if (Op.getOpcode() == ISD::VECTOR_SPLICE_LEFT &&
      (IdxVal * BlockSize / 8) < 256)
    return Op;
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerSELECT_CC(SDValue Op,
                                              SelectionDAG &DAG) const {
  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(4))->get();
  SDValue LHS = Op.getOperand(0);
  SDValue RHS = Op.getOperand(1);
  SDValue TVal = Op.getOperand(2);
  SDValue FVal = Op.getOperand(3);
  SDNodeFlags Flags = Op->getFlags();
  SDLoc DL(Op);
  return LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(), Flags, DL, DAG);
}
 
SDValue AArch64TargetLowering::LowerSELECT(SDValue Op,
                                           SelectionDAG &DAG) const {
  SDValue CCVal = Op->getOperand(0);
  SDValue TVal = Op->getOperand(1);
  SDValue FVal = Op->getOperand(2);
  SDLoc DL(Op);
 
  EVT Ty = Op.getValueType();
  if (Ty == MVT::aarch64svcount) {
    TVal = DAG.getNode(ISD::BITCAST, DL, MVT::nxv16i1, TVal);
    FVal = DAG.getNode(ISD::BITCAST, DL, MVT::nxv16i1, FVal);
    SDValue Sel =
        DAG.getNode(ISD::SELECT, DL, MVT::nxv16i1, CCVal, TVal, FVal);
    return DAG.getNode(ISD::BITCAST, DL, Ty, Sel);
  }
 
  if (Ty.isScalableVector()) {
    MVT PredVT = MVT::getVectorVT(MVT::i1, Ty.getVectorElementCount());
    SDValue SplatPred = DAG.getNode(ISD::SPLAT_VECTOR, DL, PredVT, CCVal);
    return DAG.getNode(ISD::VSELECT, DL, Ty, SplatPred, TVal, FVal);
  }
 
  if (useSVEForFixedLengthVectorVT(Ty, !Subtarget->isNeonAvailable())) {
    // FIXME: Ideally this would be the same as above using i1 types, however
    // for the moment we can't deal with fixed i1 vector types properly, so
    // instead extend the predicate to a result type sized integer vector.
    MVT SplatValVT = MVT::getIntegerVT(Ty.getScalarSizeInBits());
    MVT PredVT = MVT::getVectorVT(SplatValVT, Ty.getVectorElementCount());
    SDValue SplatVal = DAG.getSExtOrTrunc(CCVal, DL, SplatValVT);
    SDValue SplatPred = DAG.getNode(ISD::SPLAT_VECTOR, DL, PredVT, SplatVal);
    return DAG.getNode(ISD::VSELECT, DL, Ty, SplatPred, TVal, FVal);
  }
 
  // Optimize {s|u}{add|sub|mul}.with.overflow feeding into a select
  // instruction.
  if (ISD::isOverflowIntrOpRes(CCVal)) {
    // Only lower legal XALUO ops.
    if (!DAG.getTargetLoweringInfo().isTypeLegal(CCVal->getValueType(0)))
      return SDValue();
 
    AArch64CC::CondCode OFCC;
    SDValue Value, Overflow;
    std::tie(Value, Overflow) = getAArch64XALUOOp(OFCC, CCVal.getValue(0), DAG);
    SDValue CCVal = getCondCode(DAG, OFCC);
 
    return DAG.getNode(AArch64ISD::CSEL, DL, Op.getValueType(), TVal, FVal,
                       CCVal, Overflow);
  }
 
  // Lower it the same way as we would lower a SELECT_CC node.
  ISD::CondCode CC;
  SDValue LHS, RHS;
  if (CCVal.getOpcode() == ISD::SETCC) {
    LHS = CCVal.getOperand(0);
    RHS = CCVal.getOperand(1);
    CC = cast<CondCodeSDNode>(CCVal.getOperand(2))->get();
  } else {
    LHS = CCVal;
    RHS = DAG.getConstant(0, DL, CCVal.getValueType());
    CC = ISD::SETNE;
  }
 
  // If we are lowering a f16 and we do not have fullf16, convert to a f32 in
  // order to use FCSELSrrr
  if ((Ty == MVT::f16 || Ty == MVT::bf16) && !Subtarget->hasFullFP16()) {
    SDValue Poison = DAG.getPOISON(MVT::f32);
    TVal = DAG.getTargetInsertSubreg(AArch64::hsub, DL, MVT::f32, Poison, TVal);
    FVal = DAG.getTargetInsertSubreg(AArch64::hsub, DL, MVT::f32, Poison, FVal);
  }
 
  SDValue Res = LowerSELECT_CC(CC, LHS, RHS, TVal, FVal, Op->users(),
                               Op->getFlags(), DL, DAG);
 
  if ((Ty == MVT::f16 || Ty == MVT::bf16) && !Subtarget->hasFullFP16()) {
    return DAG.getTargetExtractSubreg(AArch64::hsub, DL, Ty, Res);
  }
 
  return Res;
}
 
SDValue AArch64TargetLowering::LowerJumpTable(SDValue Op,
                                              SelectionDAG &DAG) const {
  // Jump table entries as PC relative offsets. No additional tweaking
  // is necessary here. Just get the address of the jump table.
  JumpTableSDNode *JT = cast<JumpTableSDNode>(Op);
 
  CodeModel::Model CM = getTargetMachine().getCodeModel();
  if (CM == CodeModel::Large && !getTargetMachine().isPositionIndependent() &&
      !Subtarget->isTargetMachO())
    return getAddrLarge(JT, DAG);
  if (CM == CodeModel::Tiny)
    return getAddrTiny(JT, DAG);
  return getAddr(JT, DAG);
}
 
SDValue AArch64TargetLowering::LowerBR_JT(SDValue Op,
                                          SelectionDAG &DAG) const {
  // Jump table entries as PC relative offsets. No additional tweaking
  // is necessary here. Just get the address of the jump table.
  SDLoc DL(Op);
  SDValue JT = Op.getOperand(1);
  SDValue Entry = Op.getOperand(2);
  int JTI = cast<JumpTableSDNode>(JT.getNode())->getIndex();
 
  auto *AFI = DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
  AFI->setJumpTableEntryInfo(JTI, 4, nullptr);
 
  // With aarch64-jump-table-hardening, we only expand the jump table dispatch
  // sequence later, to guarantee the integrity of the intermediate values.
  if (DAG.getMachineFunction().getFunction().hasFnAttribute(
          "aarch64-jump-table-hardening")) {
    CodeModel::Model CM = getTargetMachine().getCodeModel();
    if (Subtarget->isTargetMachO()) {
      if (CM != CodeModel::Small && CM != CodeModel::Large)
        report_fatal_error("Unsupported code-model for hardened jump-table");
    } else {
      // Note that COFF support would likely also need JUMP_TABLE_DEBUG_INFO.
      assert(Subtarget->isTargetELF() &&
             "jump table hardening only supported on MachO/ELF");
      if (CM != CodeModel::Small)
        report_fatal_error("Unsupported code-model for hardened jump-table");
    }
 
    SDValue X16Copy = DAG.getCopyToReg(DAG.getEntryNode(), DL, AArch64::X16,
                                       Entry, SDValue());
    SDNode *B = DAG.getMachineNode(AArch64::BR_JumpTable, DL, MVT::Other,
                                   DAG.getTargetJumpTable(JTI, MVT::i32),
                                   X16Copy.getValue(0), X16Copy.getValue(1));
    return SDValue(B, 0);
  }
 
  SDNode *Dest =
      DAG.getMachineNode(AArch64::JumpTableDest32, DL, MVT::i64, MVT::i64, JT,
                         Entry, DAG.getTargetJumpTable(JTI, MVT::i32));
  SDValue JTInfo = DAG.getJumpTableDebugInfo(JTI, Op.getOperand(0), DL);
  return DAG.getNode(ISD::BRIND, DL, MVT::Other, JTInfo, SDValue(Dest, 0));
}
 
SDValue AArch64TargetLowering::LowerBRIND(SDValue Op, SelectionDAG &DAG) const {
  SDValue Chain = Op.getOperand(0);
  SDValue Dest = Op.getOperand(1);
 
  // BR_JT is lowered to BRIND, but the later lowering is specific to indirectbr
  // Skip over the jump-table BRINDs, where the destination is JumpTableDest32.
  if (Dest->isMachineOpcode() &&
      Dest->getMachineOpcode() == AArch64::JumpTableDest32)
    return SDValue();
 
  const MachineFunction &MF = DAG.getMachineFunction();
  std::optional<uint16_t> BADisc =
      Subtarget->getPtrAuthBlockAddressDiscriminatorIfEnabled(MF.getFunction());
  if (!BADisc)
    return SDValue();
 
  SDLoc DL(Op);
 
  SDValue Disc = DAG.getTargetConstant(*BADisc, DL, MVT::i64);
  SDValue Key = DAG.getTargetConstant(AArch64PACKey::IA, DL, MVT::i32);
  SDValue AddrDisc = DAG.getRegister(AArch64::XZR, MVT::i64);
 
  SDNode *BrA = DAG.getMachineNode(AArch64::BRA, DL, MVT::Other,
                                   {Dest, Key, Disc, AddrDisc, Chain});
  return SDValue(BrA, 0);
}
 
SDValue AArch64TargetLowering::LowerConstantPool(SDValue Op,
                                                 SelectionDAG &DAG) const {
  ConstantPoolSDNode *CP = cast<ConstantPoolSDNode>(Op);
  CodeModel::Model CM = getTargetMachine().getCodeModel();
  if (CM == CodeModel::Large) {
    // Use the GOT for the large code model on iOS.
    if (Subtarget->isTargetMachO()) {
      return getGOT(CP, DAG);
    }
    if (!getTargetMachine().isPositionIndependent())
      return getAddrLarge(CP, DAG);
  } else if (CM == CodeModel::Tiny) {
    return getAddrTiny(CP, DAG);
  }
  return getAddr(CP, DAG);
}
 
SDValue AArch64TargetLowering::LowerBlockAddress(SDValue Op,
                                               SelectionDAG &DAG) const {
  BlockAddressSDNode *BAN = cast<BlockAddressSDNode>(Op);
  const BlockAddress *BA = BAN->getBlockAddress();
 
  if (std::optional<uint16_t> BADisc =
          Subtarget->getPtrAuthBlockAddressDiscriminatorIfEnabled(
              *BA->getFunction())) {
    SDLoc DL(Op);
 
    // This isn't cheap, but BRIND is rare.
    SDValue TargetBA = DAG.getTargetBlockAddress(BA, BAN->getValueType(0));
 
    SDValue Disc = DAG.getTargetConstant(*BADisc, DL, MVT::i64);
 
    SDValue Key = DAG.getTargetConstant(AArch64PACKey::IA, DL, MVT::i32);
    SDValue AddrDisc = DAG.getRegister(AArch64::XZR, MVT::i64);
 
    SDNode *MOV =
        DAG.getMachineNode(AArch64::MOVaddrPAC, DL, {MVT::Other, MVT::Glue},
                           {TargetBA, Key, AddrDisc, Disc});
    return DAG.getCopyFromReg(SDValue(MOV, 0), DL, AArch64::X16, MVT::i64,
                              SDValue(MOV, 1));
  }
 
  CodeModel::Model CM = getTargetMachine().getCodeModel();
  if (CM == CodeModel::Large && !Subtarget->isTargetMachO()) {
    if (!getTargetMachine().isPositionIndependent())
      return getAddrLarge(BAN, DAG);
  } else if (CM == CodeModel::Tiny) {
    return getAddrTiny(BAN, DAG);
  }
  return getAddr(BAN, DAG);
}
 
SDValue AArch64TargetLowering::LowerDarwin_VASTART(SDValue Op,
                                                 SelectionDAG &DAG) const {
  AArch64FunctionInfo *FuncInfo =
      DAG.getMachineFunction().getInfo<AArch64FunctionInfo>();
 
  SDLoc DL(Op);
  SDValue FR = DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(),
                                 getPointerTy(DAG.getDataLayout()));
  FR = DAG.getZExtOrTrunc(FR, DL, getPointerMemTy(DAG.getDataLayout()));
  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  return DAG.getStore(Op.getOperand(0), DL, FR, Op.getOperand(1),
                      MachinePointerInfo(SV));
}
 
SDValue AArch64TargetLowering::LowerWin64_VASTART(SDValue Op,
                                                  SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
 
  SDLoc DL(Op);
  SDValue FR;
  if (Subtarget->isWindowsArm64EC()) {
    // With the Arm64EC ABI, we compute the address of the varargs save area
    // relative to x4. For a normal AArch64->AArch64 call, x4 == sp on entry,
    // but calls from an entry thunk can pass in a different address.
    Register VReg = MF.addLiveIn(AArch64::X4, &AArch64::GPR64RegClass);
    SDValue Val = DAG.getCopyFromReg(DAG.getEntryNode(), DL, VReg, MVT::i64);
    uint64_t StackOffset;
    if (FuncInfo->getVarArgsGPRSize() > 0)
      StackOffset = -(uint64_t)FuncInfo->getVarArgsGPRSize();
    else
      StackOffset = FuncInfo->getVarArgsStackOffset();
    FR = DAG.getNode(ISD::ADD, DL, MVT::i64, Val,
                     DAG.getConstant(StackOffset, DL, MVT::i64));
  } else {
    FR = DAG.getFrameIndex(FuncInfo->getVarArgsGPRSize() > 0
                               ? FuncInfo->getVarArgsGPRIndex()
                               : FuncInfo->getVarArgsStackIndex(),
                           getPointerTy(DAG.getDataLayout()));
  }
  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  return DAG.getStore(Op.getOperand(0), DL, FR, Op.getOperand(1),
                      MachinePointerInfo(SV));
}
 
SDValue AArch64TargetLowering::LowerAAPCS_VASTART(SDValue Op,
                                                  SelectionDAG &DAG) const {
  // The layout of the va_list struct is specified in the AArch64 Procedure Call
  // Standard, section B.3.
  MachineFunction &MF = DAG.getMachineFunction();
  AArch64FunctionInfo *FuncInfo = MF.getInfo<AArch64FunctionInfo>();
  unsigned PtrSize = Subtarget->isTargetILP32() ? 4 : 8;
  auto PtrMemVT = getPointerMemTy(DAG.getDataLayout());
  auto PtrVT = getPointerTy(DAG.getDataLayout());
  SDLoc DL(Op);
 
  SDValue Chain = Op.getOperand(0);
  SDValue VAList = Op.getOperand(1);
  const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  SmallVector<SDValue, 4> MemOps;
 
  // void *__stack at offset 0
  unsigned Offset = 0;
  SDValue Stack = DAG.getFrameIndex(FuncInfo->getVarArgsStackIndex(), PtrVT);
  Stack = DAG.getZExtOrTrunc(Stack, DL, PtrMemVT);
  MemOps.push_back(DAG.getStore(Chain, DL, Stack, VAList,
                                MachinePointerInfo(SV), Align(PtrSize)));
 
  // void *__gr_top at offset 8 (4 on ILP32)
  Offset += PtrSize;
  int GPRSize = FuncInfo->getVarArgsGPRSize();
  if (GPRSize > 0) {
    SDValue GRTop, GRTopAddr;
 
    GRTopAddr = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                            DAG.getConstant(Offset, DL, PtrVT));
 
    GRTop = DAG.getFrameIndex(FuncInfo->getVarArgsGPRIndex(), PtrVT);
    GRTop = DAG.getNode(ISD::ADD, DL, PtrVT, GRTop,
                        DAG.getSignedConstant(GPRSize, DL, PtrVT));
    GRTop = DAG.getZExtOrTrunc(GRTop, DL, PtrMemVT);
 
    MemOps.push_back(DAG.getStore(Chain, DL, GRTop, GRTopAddr,
                                  MachinePointerInfo(SV, Offset),
                                  Align(PtrSize)));
  }
 
  // void *__vr_top at offset 16 (8 on ILP32)
  Offset += PtrSize;
  int FPRSize = FuncInfo->getVarArgsFPRSize();
  if (FPRSize > 0) {
    SDValue VRTop, VRTopAddr;
    VRTopAddr = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                            DAG.getConstant(Offset, DL, PtrVT));
 
    VRTop = DAG.getFrameIndex(FuncInfo->getVarArgsFPRIndex(), PtrVT);
    VRTop = DAG.getNode(ISD::ADD, DL, PtrVT, VRTop,
                        DAG.getSignedConstant(FPRSize, DL, PtrVT));
    VRTop = DAG.getZExtOrTrunc(VRTop, DL, PtrMemVT);
 
    MemOps.push_back(DAG.getStore(Chain, DL, VRTop, VRTopAddr,
                                  MachinePointerInfo(SV, Offset),
                                  Align(PtrSize)));
  }
 
  // int __gr_offs at offset 24 (12 on ILP32)
  Offset += PtrSize;
  SDValue GROffsAddr = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                                   DAG.getConstant(Offset, DL, PtrVT));
  MemOps.push_back(
      DAG.getStore(Chain, DL, DAG.getSignedConstant(-GPRSize, DL, MVT::i32),
                   GROffsAddr, MachinePointerInfo(SV, Offset), Align(4)));
 
  // int __vr_offs at offset 28 (16 on ILP32)
  Offset += 4;
  SDValue VROffsAddr = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                                   DAG.getConstant(Offset, DL, PtrVT));
  MemOps.push_back(
      DAG.getStore(Chain, DL, DAG.getSignedConstant(-FPRSize, DL, MVT::i32),
                   VROffsAddr, MachinePointerInfo(SV, Offset), Align(4)));
 
  return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, MemOps);
}
 
SDValue AArch64TargetLowering::LowerVASTART(SDValue Op,
                                            SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  Function &F = MF.getFunction();
 
  if (Subtarget->isCallingConvWin64(F.getCallingConv(), F.isVarArg()))
    return LowerWin64_VASTART(Op, DAG);
  else if (Subtarget->isTargetDarwin())
    return LowerDarwin_VASTART(Op, DAG);
  else
    return LowerAAPCS_VASTART(Op, DAG);
}
 
SDValue AArch64TargetLowering::LowerVACOPY(SDValue Op,
                                           SelectionDAG &DAG) const {
  // AAPCS has three pointers and two ints (= 32 bytes), Darwin has single
  // pointer.
  SDLoc DL(Op);
  unsigned PtrSize = Subtarget->isTargetILP32() ? 4 : 8;
  unsigned VaListSize =
      (Subtarget->isTargetDarwin() || Subtarget->isTargetWindows())
          ? PtrSize
          : Subtarget->isTargetILP32() ? 20 : 32;
  const Value *DestSV = cast<SrcValueSDNode>(Op.getOperand(3))->getValue();
  const Value *SrcSV = cast<SrcValueSDNode>(Op.getOperand(4))->getValue();
 
  return DAG.getMemcpy(Op.getOperand(0), DL, Op.getOperand(1), Op.getOperand(2),
                       DAG.getConstant(VaListSize, DL, MVT::i32),
                       Align(PtrSize), false, false, /*CI=*/nullptr,
                       std::nullopt, MachinePointerInfo(DestSV),
                       MachinePointerInfo(SrcSV));
}
 
SDValue AArch64TargetLowering::LowerVAARG(SDValue Op, SelectionDAG &DAG) const {
  assert(Subtarget->isTargetDarwin() &&
         "automatic va_arg instruction only works on Darwin");
 
  const Value *V = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  SDValue Chain = Op.getOperand(0);
  SDValue Addr = Op.getOperand(1);
  MaybeAlign Align(Op.getConstantOperandVal(3));
  unsigned MinSlotSize = Subtarget->isTargetILP32() ? 4 : 8;
  auto PtrVT = getPointerTy(DAG.getDataLayout());
  auto PtrMemVT = getPointerMemTy(DAG.getDataLayout());
  SDValue VAList =
      DAG.getLoad(PtrMemVT, DL, Chain, Addr, MachinePointerInfo(V));
  Chain = VAList.getValue(1);
  VAList = DAG.getZExtOrTrunc(VAList, DL, PtrVT);
 
  if (VT.isScalableVector())
    report_fatal_error("Passing SVE types to variadic functions is "
                       "currently not supported");
 
  if (Align && *Align > MinSlotSize) {
    VAList = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                         DAG.getConstant(Align->value() - 1, DL, PtrVT));
    VAList =
        DAG.getNode(ISD::AND, DL, PtrVT, VAList,
                    DAG.getSignedConstant(-(int64_t)Align->value(), DL, PtrVT));
  }
 
  Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
  unsigned ArgSize = DAG.getDataLayout().getTypeAllocSize(ArgTy);
 
  // Scalar integer and FP values smaller than 64 bits are implicitly extended
  // up to 64 bits.  At the very least, we have to increase the striding of the
  // vaargs list to match this, and for FP values we need to introduce
  // FP_ROUND nodes as well.
  if (VT.isInteger() && !VT.isVector())
    ArgSize = std::max(ArgSize, MinSlotSize);
  bool NeedFPTrunc = false;
  if (VT.isFloatingPoint() && !VT.isVector() && VT != MVT::f64) {
    ArgSize = 8;
    NeedFPTrunc = true;
  }
 
  // Increment the pointer, VAList, to the next vaarg
  SDValue VANext = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
                               DAG.getConstant(ArgSize, DL, PtrVT));
  VANext = DAG.getZExtOrTrunc(VANext, DL, PtrMemVT);
 
  // Store the incremented VAList to the legalized pointer
  SDValue APStore =
      DAG.getStore(Chain, DL, VANext, Addr, MachinePointerInfo(V));
 
  // Load the actual argument out of the pointer VAList
  if (NeedFPTrunc) {
    // Load the value as an f64.
    SDValue WideFP =
        DAG.getLoad(MVT::f64, DL, APStore, VAList, MachinePointerInfo());
    // Round the value down to an f32.
    SDValue NarrowFP =
        DAG.getNode(ISD::FP_ROUND, DL, VT, WideFP.getValue(0),
                    DAG.getIntPtrConstant(1, DL, /*isTarget=*/true));
    SDValue Ops[] = { NarrowFP, WideFP.getValue(1) };
    // Merge the rounded value with the chain output of the load.
    return DAG.getMergeValues(Ops, DL);
  }
 
  return DAG.getLoad(VT, DL, APStore, VAList, MachinePointerInfo());
}
 
SDValue AArch64TargetLowering::LowerFRAMEADDR(SDValue Op,
                                              SelectionDAG &DAG) const {
  MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
  MFI.setFrameAddressIsTaken(true);
 
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  unsigned Depth = Op.getConstantOperandVal(0);
  SDValue FrameAddr =
      DAG.getCopyFromReg(DAG.getEntryNode(), DL, AArch64::FP, MVT::i64);
  while (Depth--)
    FrameAddr = DAG.getLoad(VT, DL, DAG.getEntryNode(), FrameAddr,
                            MachinePointerInfo());
 
  if (Subtarget->isTargetILP32())
    FrameAddr = DAG.getNode(ISD::AssertZext, DL, MVT::i64, FrameAddr,
                            DAG.getValueType(VT));
 
  return FrameAddr;
}
 
SDValue AArch64TargetLowering::LowerSPONENTRY(SDValue Op,
                                              SelectionDAG &DAG) const {
  MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
 
  EVT VT = getPointerTy(DAG.getDataLayout());
  int FI = MFI.CreateFixedObject(4, 0, false);
  return DAG.getFrameIndex(FI, VT);
}
 
#define GET_REGISTER_MATCHER
#include "AArch64GenAsmMatcher.inc"
 
// FIXME? Maybe this could be a TableGen attribute on some registers and
// this table could be generated automatically from RegInfo.
Register AArch64TargetLowering::
getRegisterByName(const char* RegName, LLT VT, const MachineFunction &MF) const {
  Register Reg = MatchRegisterName(RegName);
  if (AArch64::X1 <= Reg && Reg <= AArch64::X28) {
    const AArch64RegisterInfo *MRI = Subtarget->getRegisterInfo();
    unsigned DwarfRegNum = MRI->getDwarfRegNum(Reg, false);
    if (!Subtarget->isXRegisterReserved(DwarfRegNum) &&
        !MRI->isReservedReg(MF, Reg))
      Reg = Register();
  }
  return Reg;
}
 
SDValue AArch64TargetLowering::LowerADDROFRETURNADDR(SDValue Op,
                                                     SelectionDAG &DAG) const {
  DAG.getMachineFunction().getFrameInfo().setFrameAddressIsTaken(true);
 
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
 
  SDValue FrameAddr =
      DAG.getCopyFromReg(DAG.getEntryNode(), DL, AArch64::FP, VT);
  SDValue Offset = DAG.getConstant(8, DL, getPointerTy(DAG.getDataLayout()));
 
  return DAG.getNode(ISD::ADD, DL, VT, FrameAddr, Offset);
}
 
SDValue AArch64TargetLowering::LowerRETURNADDR(SDValue Op,
                                               SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
  MachineFrameInfo &MFI = MF.getFrameInfo();
  MFI.setReturnAddressIsTaken(true);
 
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  unsigned Depth = Op.getConstantOperandVal(0);
  SDValue ReturnAddress;
  if (Depth) {
    SDValue FrameAddr = LowerFRAMEADDR(Op, DAG);
    SDValue Offset = DAG.getConstant(8, DL, getPointerTy(DAG.getDataLayout()));
    ReturnAddress = DAG.getLoad(
        VT, DL, DAG.getEntryNode(),
        DAG.getNode(ISD::ADD, DL, VT, FrameAddr, Offset), MachinePointerInfo());
  } else {
    // Return LR, which contains the return address. Mark it an implicit
    // live-in.
    Register Reg = MF.addLiveIn(AArch64::LR, &AArch64::GPR64RegClass);
    ReturnAddress = DAG.getCopyFromReg(DAG.getEntryNode(), DL, Reg, VT);
  }
 
  // The XPACLRI instruction assembles to a hint-space instruction before
  // Armv8.3-A therefore this instruction can be safely used for any pre
  // Armv8.3-A architectures. On Armv8.3-A and onwards XPACI is available so use
  // that instead.
  SDNode *St;
  if (Subtarget->hasPAuth()) {
    St = DAG.getMachineNode(AArch64::XPACI, DL, VT, ReturnAddress);
  } else {
    // XPACLRI operates on LR therefore we must move the operand accordingly.
    SDValue Chain =
        DAG.getCopyToReg(DAG.getEntryNode(), DL, AArch64::LR, ReturnAddress);
    St = DAG.getMachineNode(AArch64::XPACLRI, DL, VT, Chain);
  }
  return SDValue(St, 0);
}
 
/// LowerShiftParts - Lower SHL_PARTS/SRA_PARTS/SRL_PARTS, which returns two
/// i32 values and take a 2 x i32 value to shift plus a shift amount.
SDValue AArch64TargetLowering::LowerShiftParts(SDValue Op,
                                               SelectionDAG &DAG) const {
  SDValue Lo, Hi;
  expandShiftParts(Op.getNode(), Lo, Hi, DAG);
  return DAG.getMergeValues({Lo, Hi}, SDLoc(Op));
}
 
bool AArch64TargetLowering::isOffsetFoldingLegal(
    const GlobalAddressSDNode *GA) const {
  // Offsets are folded in the DAG combine rather than here so that we can
  // intelligently choose an offset based on the uses.
  return false;
}
 
bool AArch64TargetLowering::isFPImmLegalAsFMov(const APFloat &Imm,
                                               EVT VT) const {
  // We can materialize #0.0 as fmov $Rd, XZR for 64-bit, 32-bit cases, and
  // 16-bit case when target has full fp16 support.
  // We encode bf16 bit patterns as if they were fp16. This results in very
  // strange looking assembly but should populate the register with appropriate
  // values. Let's say we wanted to encode 0xR3FC0 which is 1.5 in BF16. We will
  // end up encoding this as the imm8 0x7f. This imm8 will be expanded to the
  // FP16 1.9375 which shares the same bit pattern as BF16 1.5.
  // FIXME: We should be able to handle f128 as well with a clever lowering.
  const APInt ImmInt = Imm.bitcastToAPInt();
 
  if (VT == MVT::f64)
    return AArch64_AM::getFP64Imm(ImmInt) != -1 || Imm.isPosZero();
 
  if (VT == MVT::f32)
    return AArch64_AM::getFP32Imm(ImmInt) != -1 || Imm.isPosZero();
 
  if (VT == MVT::f16 || VT == MVT::bf16)
    return (Subtarget->hasFullFP16() && AArch64_AM::getFP16Imm(ImmInt) != -1) ||
           Imm.isPosZero();
 
  return false;
}
 
bool AArch64TargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
                                         bool OptForSize) const {
  bool IsLegal = isFPImmLegalAsFMov(Imm, VT);
  const APInt ImmInt = Imm.bitcastToAPInt();
 
  // If we can not materialize in immediate field for fmov, check if the
  // value can be encoded as the immediate operand of a logical instruction.
  // The immediate value will be created with either MOVZ, MOVN, or ORR.
  // TODO: fmov h0, w0 is also legal, however we don't have an isel pattern to
  //       generate that fmov.
  if (!IsLegal && (VT == MVT::f64 || VT == MVT::f32)) {
    // The cost is actually exactly the same for mov+fmov vs. adrp+ldr;
    // however the mov+fmov sequence is always better because of the reduced
    // cache pressure. The timings are still the same if you consider
    // movw+movk+fmov vs. adrp+ldr (it's one instruction longer, but the
    // movw+movk is fused). So by default we limit up to 2 instructions
    // or 4 with hasFuseLiterals.
    SmallVector<AArch64_IMM::ImmInsnModel, 4> Insn;
    AArch64_IMM::expandMOVImm(ImmInt.getZExtValue(), VT.getSizeInBits(), Insn);
    assert(Insn.size() <= 4 &&
           "Should be able to build any value with at most 4 moves");
    unsigned Limit = (OptForSize ? 1 : (Subtarget->hasFuseLiterals() ? 4 : 2));
    IsLegal = Insn.size() <= Limit;
  }
 
  LLVM_DEBUG(dbgs() << (IsLegal ? "Legal " : "Illegal ") << VT
                    << " imm value: "; Imm.dump(););
  return IsLegal;
}
 
//===----------------------------------------------------------------------===//
//                          AArch64 Optimization Hooks
//===----------------------------------------------------------------------===//
 
static SDValue getEstimate(const AArch64Subtarget *ST, unsigned Opcode,
                           SDValue Operand, SelectionDAG &DAG,
                           int &ExtraSteps) {
  EVT VT = Operand.getValueType();
  if ((ST->hasNEON() &&
       (VT == MVT::f64 || VT == MVT::v1f64 || VT == MVT::v2f64 ||
        VT == MVT::f32 || VT == MVT::v1f32 || VT == MVT::v2f32 ||
        VT == MVT::v4f32)) ||
      (ST->hasSVE() &&
       (VT == MVT::nxv8f16 || VT == MVT::nxv4f32 || VT == MVT::nxv2f64))) {
    if (ExtraSteps == TargetLoweringBase::ReciprocalEstimate::Unspecified) {
      // For the reciprocal estimates, convergence is quadratic, so the number
      // of digits is doubled after each iteration.  In ARMv8, the accuracy of
      // the initial estimate is 2^-8.  Thus the number of extra steps to refine
      // the result for float (23 mantissa bits) is 2 and for double (52
      // mantissa bits) is 3.
      constexpr unsigned AccurateBits = 8;
      unsigned DesiredBits = APFloat::semanticsPrecision(VT.getFltSemantics());
      ExtraSteps = DesiredBits <= AccurateBits
                       ? 0
                       : Log2_64_Ceil(DesiredBits) - Log2_64_Ceil(AccurateBits);
    }
 
    return DAG.getNode(Opcode, SDLoc(Operand), VT, Operand);
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::getSqrtInputTest(SDValue Op, SelectionDAG &DAG,
                                                const DenormalMode &Mode,
                                                SDNodeFlags Flags) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  EVT CCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
  SDValue FPZero = DAG.getConstantFP(0.0, DL, VT);
  return DAG.getSetCC(DL, CCVT, Op, FPZero, ISD::SETEQ, /*Chain=*/{},
                      /*Signaling=*/false, Flags);
}
 
SDValue
AArch64TargetLowering::getSqrtResultForDenormInput(SDValue Op,
                                                   SelectionDAG &DAG) const {
  return Op;
}
 
SDValue AArch64TargetLowering::getSqrtEstimate(SDValue Operand,
                                               SelectionDAG &DAG, int Enabled,
                                               int &ExtraSteps,
                                               bool &UseOneConst,
                                               bool Reciprocal) const {
  if (Enabled == ReciprocalEstimate::Enabled ||
      (Enabled == ReciprocalEstimate::Unspecified && Subtarget->useRSqrt()))
    if (SDValue Estimate = getEstimate(Subtarget, AArch64ISD::FRSQRTE, Operand,
                                       DAG, ExtraSteps)) {
      SDLoc DL(Operand);
      EVT VT = Operand.getValueType();
 
      // Ensure nodes can be recognized by isAssociativeAndCommutative.
      SDNodeFlags Flags =
          SDNodeFlags::AllowReassociation | SDNodeFlags::NoSignedZeros;
 
      // Newton reciprocal square root iteration: E * 0.5 * (3 - X * E^2)
      // AArch64 reciprocal square root iteration instruction: 0.5 * (3 - M * N)
      for (int i = ExtraSteps; i > 0; --i) {
        SDValue Step = DAG.getNode(ISD::FMUL, DL, VT, Estimate, Estimate,
                                   Flags);
        Step = DAG.getNode(AArch64ISD::FRSQRTS, DL, VT, Operand, Step, Flags);
        Estimate = DAG.getNode(ISD::FMUL, DL, VT, Estimate, Step, Flags);
      }
      if (!Reciprocal)
        Estimate = DAG.getNode(ISD::FMUL, DL, VT, Operand, Estimate, Flags);
 
      ExtraSteps = 0;
      return Estimate;
    }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::getRecipEstimate(SDValue Operand,
                                                SelectionDAG &DAG, int Enabled,
                                                int &ExtraSteps) const {
  if (Enabled == ReciprocalEstimate::Enabled)
    if (SDValue Estimate = getEstimate(Subtarget, AArch64ISD::FRECPE, Operand,
                                       DAG, ExtraSteps)) {
      SDLoc DL(Operand);
      EVT VT = Operand.getValueType();
 
      SDNodeFlags Flags = SDNodeFlags::AllowReassociation;
 
      // Newton reciprocal iteration: E * (2 - X * E)
      // AArch64 reciprocal iteration instruction: (2 - M * N)
      for (int i = ExtraSteps; i > 0; --i) {
        SDValue Step = DAG.getNode(AArch64ISD::FRECPS, DL, VT, Operand,
                                   Estimate, Flags);
        Estimate = DAG.getNode(ISD::FMUL, DL, VT, Estimate, Step, Flags);
      }
 
      ExtraSteps = 0;
      return Estimate;
    }
 
  return SDValue();
}
 
//===----------------------------------------------------------------------===//
//                          AArch64 Inline Assembly Support
//===----------------------------------------------------------------------===//
 
// Table of Constraints
// TODO: This is the current set of constraints supported by ARM for the
// compiler, not all of them may make sense.
//
// r - A general register
// w - An FP/SIMD register of some size in the range v0-v31
// x - An FP/SIMD register of some size in the range v0-v15
// I - Constant that can be used with an ADD instruction
// J - Constant that can be used with a SUB instruction
// K - Constant that can be used with a 32-bit logical instruction
// L - Constant that can be used with a 64-bit logical instruction
// M - Constant that can be used as a 32-bit MOV immediate
// N - Constant that can be used as a 64-bit MOV immediate
// Q - A memory reference with base register and no offset
// S - A symbolic address
// Y - Floating point constant zero
// Z - Integer constant zero
//
//   Note that general register operands will be output using their 64-bit x
// register name, whatever the size of the variable, unless the asm operand
// is prefixed by the %w modifier. Floating-point and SIMD register operands
// will be output with the v prefix unless prefixed by the %b, %h, %s, %d or
// %q modifier.
const char *AArch64TargetLowering::LowerXConstraint(EVT ConstraintVT) const {
  // At this point, we have to lower this constraint to something else, so we
  // lower it to an "r" or "w". However, by doing this we will force the result
  // to be in register, while the X constraint is much more permissive.
  //
  // Although we are correct (we are free to emit anything, without
  // constraints), we might break use cases that would expect us to be more
  // efficient and emit something else.
  if (!Subtarget->hasFPARMv8())
    return "r";
 
  if (ConstraintVT.isFloatingPoint())
    return "w";
 
  if (ConstraintVT.isVector() &&
     (ConstraintVT.getSizeInBits() == 64 ||
      ConstraintVT.getSizeInBits() == 128))
    return "w";
 
  return "r";
}
 
enum class PredicateConstraint { Uph, Upl, Upa };
 
// Returns a {Reg, RegisterClass} tuple if the constraint is
// a specific predicate register.
//
// For some constraint like "{pn3}" the default path in
// TargetLowering::getRegForInlineAsmConstraint() leads it to determine that a
// suitable register class for this register is "PPRorPNR", after which it
// determines that nxv16i1 is an appropriate type for the constraint, which is
// not what we want. The code here pre-empts this by matching the register
// explicitly.
static std::optional<std::pair<unsigned, const TargetRegisterClass *>>
parseSVERegAsConstraint(StringRef Constraint) {
  if (!Constraint.starts_with('{') || !Constraint.ends_with('}') ||
      (Constraint[1] != 'p' && Constraint[1] != 'z'))
    return std::nullopt;
 
  bool IsPredicate = Constraint[1] == 'p';
  Constraint = Constraint.substr(2, Constraint.size() - 3);
  bool IsPredicateAsCount = IsPredicate && Constraint.starts_with("n");
  if (IsPredicateAsCount)
    Constraint = Constraint.drop_front(1);
 
  unsigned V;
  if (Constraint.getAsInteger(10, V) || V > 31)
    return std::nullopt;
 
  if (IsPredicateAsCount)
    return std::make_pair(AArch64::PN0 + V, &AArch64::PNRRegClass);
  if (IsPredicate)
    return std::make_pair(AArch64::P0 + V, &AArch64::PPRRegClass);
  return std::make_pair(AArch64::Z0 + V, &AArch64::ZPRRegClass);
}
 
static std::optional<PredicateConstraint>
parsePredicateConstraint(StringRef Constraint) {
  return StringSwitch<std::optional<PredicateConstraint>>(Constraint)
      .Case("Uph", PredicateConstraint::Uph)
      .Case("Upl", PredicateConstraint::Upl)
      .Case("Upa", PredicateConstraint::Upa)
      .Default(std::nullopt);
}
 
static const TargetRegisterClass *
getPredicateRegisterClass(PredicateConstraint Constraint, EVT VT) {
  if (VT != MVT::aarch64svcount &&
      (!VT.isScalableVector() || VT.getVectorElementType() != MVT::i1))
    return nullptr;
 
  switch (Constraint) {
  case PredicateConstraint::Uph:
    return VT == MVT::aarch64svcount ? &AArch64::PNR_p8to15RegClass
                                     : &AArch64::PPR_p8to15RegClass;
  case PredicateConstraint::Upl:
    return VT == MVT::aarch64svcount ? &AArch64::PNR_3bRegClass
                                     : &AArch64::PPR_3bRegClass;
  case PredicateConstraint::Upa:
    return VT == MVT::aarch64svcount ? &AArch64::PNRRegClass
                                     : &AArch64::PPRRegClass;
  }
 
  llvm_unreachable("Missing PredicateConstraint!");
}
 
enum class ReducedGprConstraint { Uci, Ucj };
 
static std::optional<ReducedGprConstraint>
parseReducedGprConstraint(StringRef Constraint) {
  return StringSwitch<std::optional<ReducedGprConstraint>>(Constraint)
      .Case("Uci", ReducedGprConstraint::Uci)
      .Case("Ucj", ReducedGprConstraint::Ucj)
      .Default(std::nullopt);
}
 
static const TargetRegisterClass *
getReducedGprRegisterClass(ReducedGprConstraint Constraint, EVT VT) {
  if (!VT.isScalarInteger() || VT.getFixedSizeInBits() > 64)
    return nullptr;
 
  switch (Constraint) {
  case ReducedGprConstraint::Uci:
    return &AArch64::MatrixIndexGPR32_8_11RegClass;
  case ReducedGprConstraint::Ucj:
    return &AArch64::MatrixIndexGPR32_12_15RegClass;
  }
 
  llvm_unreachable("Missing ReducedGprConstraint!");
}
 
// The set of cc code supported is from
// https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Flag-Output-Operands
static AArch64CC::CondCode parseConstraintCode(llvm::StringRef Constraint) {
  AArch64CC::CondCode Cond = StringSwitch<AArch64CC::CondCode>(Constraint)
                                 .Case("{@cchi}", AArch64CC::HI)
                                 .Case("{@cccs}", AArch64CC::HS)
                                 .Case("{@cclo}", AArch64CC::LO)
                                 .Case("{@ccls}", AArch64CC::LS)
                                 .Case("{@cccc}", AArch64CC::LO)
                                 .Case("{@cceq}", AArch64CC::EQ)
                                 .Case("{@ccgt}", AArch64CC::GT)
                                 .Case("{@ccge}", AArch64CC::GE)
                                 .Case("{@cclt}", AArch64CC::LT)
                                 .Case("{@ccle}", AArch64CC::LE)
                                 .Case("{@cchs}", AArch64CC::HS)
                                 .Case("{@ccne}", AArch64CC::NE)
                                 .Case("{@ccvc}", AArch64CC::VC)
                                 .Case("{@ccpl}", AArch64CC::PL)
                                 .Case("{@ccvs}", AArch64CC::VS)
                                 .Case("{@ccmi}", AArch64CC::MI)
                                 .Default(AArch64CC::Invalid);
  return Cond;
}
 
/// Helper function to create 'CSET', which is equivalent to 'CSINC <Wd>, WZR,
/// WZR, invert(<cond>)'.
static SDValue getSETCC(AArch64CC::CondCode CC, SDValue NZCV, const SDLoc &DL,
                        SelectionDAG &DAG) {
  return DAG.getNode(AArch64ISD::CSINC, DL, MVT::i32,
                     DAG.getConstant(0, DL, MVT::i32),
                     DAG.getConstant(0, DL, MVT::i32),
                     getCondCode(DAG, getInvertedCondCode(CC)), NZCV);
}
 
// Lower @cc flag output via getSETCC.
SDValue AArch64TargetLowering::LowerAsmOutputForConstraint(
    SDValue &Chain, SDValue &Glue, const SDLoc &DL,
    const AsmOperandInfo &OpInfo, SelectionDAG &DAG) const {
  AArch64CC::CondCode Cond = parseConstraintCode(OpInfo.ConstraintCode);
  if (Cond == AArch64CC::Invalid)
    return SDValue();
  // The output variable should be a scalar integer.
  if (OpInfo.ConstraintVT.isVector() || !OpInfo.ConstraintVT.isInteger() ||
      OpInfo.ConstraintVT.getSizeInBits() < 8)
    report_fatal_error("Flag output operand is of invalid type");
 
  // Get NZCV register. Only update chain when copyfrom is glued.
  if (Glue.getNode()) {
    Glue = DAG.getCopyFromReg(Chain, DL, AArch64::NZCV, FlagsVT, Glue);
    Chain = Glue.getValue(1);
  } else
    Glue = DAG.getCopyFromReg(Chain, DL, AArch64::NZCV, FlagsVT);
  // Extract CC code.
  SDValue CC = getSETCC(Cond, Glue, DL, DAG);
 
  SDValue Result;
 
  // Truncate or ZERO_EXTEND based on value types.
  if (OpInfo.ConstraintVT.getSizeInBits() <= 32)
    Result = DAG.getNode(ISD::TRUNCATE, DL, OpInfo.ConstraintVT, CC);
  else
    Result = DAG.getNode(ISD::ZERO_EXTEND, DL, OpInfo.ConstraintVT, CC);
 
  return Result;
}
 
/// getConstraintType - Given a constraint letter, return the type of
/// constraint it is for this target.
AArch64TargetLowering::ConstraintType
AArch64TargetLowering::getConstraintType(StringRef Constraint) const {
  if (Constraint.size() == 1) {
    switch (Constraint[0]) {
    default:
      break;
    case 'x':
    case 'w':
    case 'y':
      return C_RegisterClass;
    // An address with a single base register. Due to the way we
    // currently handle addresses it is the same as 'r'.
    case 'Q':
      return C_Memory;
    case 'I':
    case 'J':
    case 'K':
    case 'L':
    case 'M':
    case 'N':
    case 'Y':
    case 'Z':
      return C_Immediate;
    case 'z':
    case 'S': // A symbol or label reference with a constant offset
      return C_Other;
    }
  } else if (parsePredicateConstraint(Constraint))
    return C_RegisterClass;
  else if (parseReducedGprConstraint(Constraint))
    return C_RegisterClass;
  else if (parseConstraintCode(Constraint) != AArch64CC::Invalid)
    return C_Other;
  return TargetLowering::getConstraintType(Constraint);
}
 
/// Examine constraint type and operand type and determine a weight value.
/// This object must already have been set up with the operand type
/// and the current alternative constraint selected.
TargetLowering::ConstraintWeight
AArch64TargetLowering::getSingleConstraintMatchWeight(
    AsmOperandInfo &info, const char *constraint) const {
  ConstraintWeight weight = CW_Invalid;
  Value *CallOperandVal = info.CallOperandVal;
  // If we don't have a value, we can't do a match,
  // but allow it at the lowest weight.
  if (!CallOperandVal)
    return CW_Default;
  Type *type = CallOperandVal->getType();
  // Look at the constraint type.
  switch (*constraint) {
  default:
    weight = TargetLowering::getSingleConstraintMatchWeight(info, constraint);
    break;
  case 'x':
  case 'w':
  case 'y':
    if (type->isFloatingPointTy() || type->isVectorTy())
      weight = CW_Register;
    break;
  case 'z':
    weight = CW_Constant;
    break;
  case 'U':
    if (parsePredicateConstraint(constraint) ||
        parseReducedGprConstraint(constraint))
      weight = CW_Register;
    break;
  }
  return weight;
}
 
std::pair<unsigned, const TargetRegisterClass *>
AArch64TargetLowering::getRegForInlineAsmConstraint(
    const TargetRegisterInfo *TRI, StringRef Constraint, MVT VT) const {
  if (Constraint.size() == 1) {
    switch (Constraint[0]) {
    case 'r':
      if (VT.isScalableVector())
        return std::make_pair(0U, nullptr);
      if (Subtarget->hasLS64() && VT.getSizeInBits() == 512)
        return std::make_pair(0U, &AArch64::GPR64x8ClassRegClass);
      if (VT.getFixedSizeInBits() == 64)
        return std::make_pair(0U, &AArch64::GPR64commonRegClass);
      return std::make_pair(0U, &AArch64::GPR32commonRegClass);
    case 'w': {
      if (!Subtarget->hasFPARMv8())
        break;
      if (VT.isScalableVector()) {
        if (VT.getVectorElementType() != MVT::i1)
          return std::make_pair(0U, &AArch64::ZPRRegClass);
        return std::make_pair(0U, nullptr);
      }
      if (VT == MVT::Other)
        break;
      uint64_t VTSize = VT.getFixedSizeInBits();
      if (VTSize == 16)
        return std::make_pair(0U, &AArch64::FPR16RegClass);
      if (VTSize == 32)
        return std::make_pair(0U, &AArch64::FPR32RegClass);
      if (VTSize == 64)
        return std::make_pair(0U, &AArch64::FPR64RegClass);
      if (VTSize == 128)
        return std::make_pair(0U, &AArch64::FPR128RegClass);
      break;
    }
    // The instructions that this constraint is designed for can
    // only take 128-bit registers so just use that regclass.
    case 'x':
      if (!Subtarget->hasFPARMv8())
        break;
      if (VT.isScalableVector())
        return std::make_pair(0U, &AArch64::ZPR_4bRegClass);
      if (VT.getSizeInBits() == 128)
        return std::make_pair(0U, &AArch64::FPR128_loRegClass);
      break;
    case 'y':
      if (!Subtarget->hasFPARMv8())
        break;
      if (VT.isScalableVector())
        return std::make_pair(0U, &AArch64::ZPR_3bRegClass);
      break;
    }
  } else {
    if (const auto P = parseSVERegAsConstraint(Constraint)) {
      // SME functions that are not in streaming mode, should
      // still observe clobbers of Z-registers by clobbering
      // the lower 128bits of those registers.
      if (AArch64::ZPRRegClass.hasSubClassEq(P->second) &&
          !Subtarget->isSVEorStreamingSVEAvailable())
        return std::make_pair(TRI->getSubReg(P->first, AArch64::zsub),
                              &AArch64::FPR128RegClass);
      return *P;
    }
    if (const auto PC = parsePredicateConstraint(Constraint))
      if (const auto *RegClass = getPredicateRegisterClass(*PC, VT))
        return std::make_pair(0U, RegClass);
 
    if (const auto RGC = parseReducedGprConstraint(Constraint))
      if (const auto *RegClass = getReducedGprRegisterClass(*RGC, VT))
        return std::make_pair(0U, RegClass);
  }
  if (StringRef("{cc}").equals_insensitive(Constraint) ||
      parseConstraintCode(Constraint) != AArch64CC::Invalid)
    return std::make_pair(unsigned(AArch64::NZCV), &AArch64::CCRRegClass);
 
  if (Constraint == "{za}") {
    return std::make_pair(unsigned(AArch64::ZA), &AArch64::MPRRegClass);
  }
 
  if (Constraint == "{zt0}") {
    return std::make_pair(unsigned(AArch64::ZT0), &AArch64::ZTRRegClass);
  }
 
  // Use the default implementation in TargetLowering to convert the register
  // constraint into a member of a register class.
  std::pair<unsigned, const TargetRegisterClass *> Res;
  Res = TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
 
  // Not found as a standard register?
  if (!Res.second) {
    unsigned Size = Constraint.size();
    if ((Size == 4 || Size == 5) && Constraint[0] == '{' &&
        tolower(Constraint[1]) == 'v' && Constraint[Size - 1] == '}') {
      int RegNo;
      bool Failed = Constraint.slice(2, Size - 1).getAsInteger(10, RegNo);
      if (!Failed && RegNo >= 0 && RegNo <= 31) {
        // v0 - v31 are aliases of q0/d0/s0/h0 - ...31 depending on size.
        // By default we'll emit v0-v31 for this unless there's a modifier where
        // we'll emit the correct register as well.
        if (VT != MVT::Other) {
          switch (VT.getSizeInBits()) {
          case 16:
            Res.first = AArch64::FPR16RegClass.getRegister(RegNo);
            Res.second = &AArch64::FPR16RegClass;
            break;
          case 32:
            Res.first = AArch64::FPR32RegClass.getRegister(RegNo);
            Res.second = &AArch64::FPR32RegClass;
            break;
          case 64:
            Res.first = AArch64::FPR64RegClass.getRegister(RegNo);
            Res.second = &AArch64::FPR64RegClass;
            break;
          case 128:
            Res.first = AArch64::FPR128RegClass.getRegister(RegNo);
            Res.second = &AArch64::FPR128RegClass;
            break;
          default:
            return std::make_pair(0U, nullptr);
          }
        } else {
          Res.first = AArch64::FPR128RegClass.getRegister(RegNo);
          Res.second = &AArch64::FPR128RegClass;
        }
      }
    }
  }
 
  if (Res.second && !Subtarget->hasFPARMv8() &&
      !AArch64::GPR32allRegClass.hasSubClassEq(Res.second) &&
      !AArch64::GPR64allRegClass.hasSubClassEq(Res.second))
    return std::make_pair(0U, nullptr);
 
  return Res;
}
 
EVT AArch64TargetLowering::getAsmOperandValueType(const DataLayout &DL,
                                                  llvm::Type *Ty,
                                                  bool AllowUnknown) const {
  if (Subtarget->hasLS64() && Ty->isIntegerTy(512))
    return EVT(MVT::i64x8);
 
  return TargetLowering::getAsmOperandValueType(DL, Ty, AllowUnknown);
}
 
/// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
/// vector.  If it is invalid, don't add anything to Ops.
void AArch64TargetLowering::LowerAsmOperandForConstraint(
    SDValue Op, StringRef Constraint, std::vector<SDValue> &Ops,
    SelectionDAG &DAG) const {
  SDValue Result;
 
  // Currently only support length 1 constraints.
  if (Constraint.size() != 1)
    return;
 
  char ConstraintLetter = Constraint[0];
  switch (ConstraintLetter) {
  default:
    break;
 
  // This set of constraints deal with valid constants for various instructions.
  // Validate and return a target constant for them if we can.
  case 'z': {
    // 'z' maps to xzr or wzr so it needs an input of 0.
    if (!isNullConstant(Op))
      return;
 
    if (Op.getValueType() == MVT::i64)
      Result = DAG.getRegister(AArch64::XZR, MVT::i64);
    else
      Result = DAG.getRegister(AArch64::WZR, MVT::i32);
    break;
  }
  case 'S':
    // Use the generic code path for "s". In GCC's aarch64 port, "S" is
    // supported for PIC while "s" isn't, making "s" less useful. We implement
    // "S" but not "s".
    TargetLowering::LowerAsmOperandForConstraint(Op, "s", Ops, DAG);
    break;
 
  case 'I':
  case 'J':
  case 'K':
  case 'L':
  case 'M':
  case 'N':
    ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op);
    if (!C)
      return;
 
    // Grab the value and do some validation.
    uint64_t CVal = C->getZExtValue();
    switch (ConstraintLetter) {
    // The I constraint applies only to simple ADD or SUB immediate operands:
    // i.e. 0 to 4095 with optional shift by 12
    // The J constraint applies only to ADD or SUB immediates that would be
    // valid when negated, i.e. if [an add pattern] were to be output as a SUB
    // instruction [or vice versa], in other words -1 to -4095 with optional
    // left shift by 12.
    case 'I':
      if (isUInt<12>(CVal) || isShiftedUInt<12, 12>(CVal))
        break;
      return;
    case 'J': {
      uint64_t NVal = -C->getSExtValue();
      if (isUInt<12>(NVal) || isShiftedUInt<12, 12>(NVal)) {
        CVal = C->getSExtValue();
        break;
      }
      return;
    }
    // The K and L constraints apply *only* to logical immediates, including
    // what used to be the MOVI alias for ORR (though the MOVI alias has now
    // been removed and MOV should be used). So these constraints have to
    // distinguish between bit patterns that are valid 32-bit or 64-bit
    // "bitmask immediates": for example 0xaaaaaaaa is a valid bimm32 (K), but
    // not a valid bimm64 (L) where 0xaaaaaaaaaaaaaaaa would be valid, and vice
    // versa.
    case 'K':
      if (AArch64_AM::isLogicalImmediate(CVal, 32))
        break;
      return;
    case 'L':
      if (AArch64_AM::isLogicalImmediate(CVal, 64))
        break;
      return;
    // The M and N constraints are a superset of K and L respectively, for use
    // with the MOV (immediate) alias. As well as the logical immediates they
    // also match 32 or 64-bit immediates that can be loaded either using a
    // *single* MOVZ or MOVN , such as 32-bit 0x12340000, 0x00001234, 0xffffedca
    // (M) or 64-bit 0x1234000000000000 (N) etc.
    // As a note some of this code is liberally stolen from the asm parser.
    case 'M': {
      if (!isUInt<32>(CVal))
        return;
      if (AArch64_AM::isLogicalImmediate(CVal, 32))
        break;
      if ((CVal & 0xFFFF) == CVal)
        break;
      if ((CVal & 0xFFFF0000ULL) == CVal)
        break;
      uint64_t NCVal = ~(uint32_t)CVal;
      if ((NCVal & 0xFFFFULL) == NCVal)
        break;
      if ((NCVal & 0xFFFF0000ULL) == NCVal)
        break;
      return;
    }
    case 'N': {
      if (AArch64_AM::isLogicalImmediate(CVal, 64))
        break;
      if ((CVal & 0xFFFFULL) == CVal)
        break;
      if ((CVal & 0xFFFF0000ULL) == CVal)
        break;
      if ((CVal & 0xFFFF00000000ULL) == CVal)
        break;
      if ((CVal & 0xFFFF000000000000ULL) == CVal)
        break;
      uint64_t NCVal = ~CVal;
      if ((NCVal & 0xFFFFULL) == NCVal)
        break;
      if ((NCVal & 0xFFFF0000ULL) == NCVal)
        break;
      if ((NCVal & 0xFFFF00000000ULL) == NCVal)
        break;
      if ((NCVal & 0xFFFF000000000000ULL) == NCVal)
        break;
      return;
    }
    default:
      return;
    }
 
    // All assembler immediates are 64-bit integers.
    Result = DAG.getTargetConstant(CVal, SDLoc(Op), MVT::i64);
    break;
  }
 
  if (Result.getNode()) {
    Ops.push_back(Result);
    return;
  }
 
  return TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
}
 
//===----------------------------------------------------------------------===//
//                     AArch64 Advanced SIMD Support
//===----------------------------------------------------------------------===//
 
/// WidenVector - Given a value in the V64 register class, produce the
/// equivalent value in the V128 register class.
static SDValue WidenVector(SDValue V64Reg, SelectionDAG &DAG) {
  EVT VT = V64Reg.getValueType();
  unsigned NarrowSize = VT.getVectorNumElements();
  MVT EltTy = VT.getVectorElementType().getSimpleVT();
  MVT WideTy = MVT::getVectorVT(EltTy, 2 * NarrowSize);
  SDLoc DL(V64Reg);
 
  return DAG.getNode(ISD::INSERT_SUBVECTOR, DL, WideTy, DAG.getPOISON(WideTy),
                     V64Reg, DAG.getConstant(0, DL, MVT::i64));
}
 
/// getExtFactor - Determine the adjustment factor for the position when
/// generating an "extract from vector registers" instruction.
static unsigned getExtFactor(SDValue &V) {
  EVT EltType = V.getValueType().getVectorElementType();
  return EltType.getSizeInBits() / 8;
}
 
// Check if a vector is built from one vector via extracted elements of
// another together with an AND mask, ensuring that all elements fit
// within range. This can be reconstructed using AND and NEON's TBL1.
SDValue ReconstructShuffleWithRuntimeMask(SDValue Op, SelectionDAG &DAG) {
  assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  assert(!VT.isScalableVector() &&
         "Scalable vectors cannot be used with ISD::BUILD_VECTOR");
 
  // Can only recreate a shuffle with 16xi8 or 8xi8 elements, as they map
  // directly to TBL1.
  if (VT != MVT::v16i8 && VT != MVT::v8i8)
    return SDValue();
 
  unsigned NumElts = VT.getVectorNumElements();
  assert((NumElts == 8 || NumElts == 16) &&
         "Need to have exactly 8 or 16 elements in vector.");
 
  SDValue SourceVec;
  SDValue MaskSourceVec;
  SmallVector<SDValue, 16> AndMaskConstants;
 
  for (unsigned i = 0; i < NumElts; ++i) {
    SDValue V = Op.getOperand(i);
    if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
      return SDValue();
 
    SDValue OperandSourceVec = V.getOperand(0);
    if (!SourceVec)
      SourceVec = OperandSourceVec;
    else if (SourceVec != OperandSourceVec)
      return SDValue();
 
    // This only looks at shuffles with elements that are
    // a) truncated by a constant AND mask extracted from a mask vector, or
    // b) extracted directly from a mask vector.
    SDValue MaskSource = V.getOperand(1);
    if (MaskSource.getOpcode() == ISD::AND) {
      if (!isa<ConstantSDNode>(MaskSource.getOperand(1)))
        return SDValue();
 
      AndMaskConstants.push_back(MaskSource.getOperand(1));
      MaskSource = MaskSource->getOperand(0);
    } else if (!AndMaskConstants.empty()) {
      // Either all or no operands should have an AND mask.
      return SDValue();
    }
 
    // An ANY_EXTEND may be inserted between the AND and the source vector
    // extraction. We don't care about that, so we can just skip it.
    if (MaskSource.getOpcode() == ISD::ANY_EXTEND)
      MaskSource = MaskSource.getOperand(0);
 
    if (MaskSource.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
      return SDValue();
 
    SDValue MaskIdx = MaskSource.getOperand(1);
    if (!isa<ConstantSDNode>(MaskIdx) ||
        !cast<ConstantSDNode>(MaskIdx)->getConstantIntValue()->equalsInt(i))
      return SDValue();
 
    // We only apply this if all elements come from the same vector with the
    // same vector type.
    if (!MaskSourceVec) {
      MaskSourceVec = MaskSource->getOperand(0);
      if (MaskSourceVec.getValueType() != VT)
        return SDValue();
    } else if (MaskSourceVec != MaskSource->getOperand(0)) {
      return SDValue();
    }
  }
 
  // We need a v16i8 for TBL, so we extend the source with a placeholder vector
  // for v8i8 to get a v16i8. As the pattern we are replacing is extract +
  // insert, we know that the index in the mask must be smaller than the number
  // of elements in the source, or we would have an out-of-bounds access.
  if (NumElts == 8)
    SourceVec = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, SourceVec,
                            DAG.getPOISON(VT));
 
  // Preconditions met, so we can use a vector (AND +) TBL to build this vector.
  if (!AndMaskConstants.empty())
    MaskSourceVec = DAG.getNode(ISD::AND, DL, VT, MaskSourceVec,
                                DAG.getBuildVector(VT, DL, AndMaskConstants));
 
  return DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, VT,
      DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl1, DL, MVT::i32),
      SourceVec, MaskSourceVec);
}
 
// Gather data to see if the operation can be modelled as a
// shuffle in combination with VEXTs.
SDValue AArch64TargetLowering::ReconstructShuffle(SDValue Op,
                                                  SelectionDAG &DAG) const {
  assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
  LLVM_DEBUG(dbgs() << "AArch64TargetLowering::ReconstructShuffle\n");
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  assert(!VT.isScalableVector() &&
         "Scalable vectors cannot be used with ISD::BUILD_VECTOR");
  unsigned NumElts = VT.getVectorNumElements();
 
  struct ShuffleSourceInfo {
    SDValue Vec;
    unsigned MinElt;
    unsigned MaxElt;
 
    // We may insert some combination of BITCASTs and VEXT nodes to force Vec to
    // be compatible with the shuffle we intend to construct. As a result
    // ShuffleVec will be some sliding window into the original Vec.
    SDValue ShuffleVec;
 
    // Code should guarantee that element i in Vec starts at element "WindowBase
    // + i * WindowScale in ShuffleVec".
    int WindowBase;
    int WindowScale;
 
    ShuffleSourceInfo(SDValue Vec)
      : Vec(Vec), MinElt(std::numeric_limits<unsigned>::max()), MaxElt(0),
          ShuffleVec(Vec), WindowBase(0), WindowScale(1) {}
 
    bool operator ==(SDValue OtherVec) { return Vec == OtherVec; }
  };
 
  // First gather all vectors used as an immediate source for this BUILD_VECTOR
  // node.
  SmallVector<ShuffleSourceInfo, 2> Sources;
  for (unsigned i = 0; i < NumElts; ++i) {
    SDValue V = Op.getOperand(i);
    if (V.isUndef())
      continue;
    else if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
             !isa<ConstantSDNode>(V.getOperand(1)) ||
             V.getOperand(0).getValueType().isScalableVector()) {
      LLVM_DEBUG(
          dbgs() << "Reshuffle failed: "
                    "a shuffle can only come from building a vector from "
                    "various elements of other fixed-width vectors, provided "
                    "their indices are constant\n");
      return SDValue();
    }
 
    // Add this element source to the list if it's not already there.
    SDValue SourceVec = V.getOperand(0);
    auto Source = find(Sources, SourceVec);
    if (Source == Sources.end())
      Source = Sources.insert(Sources.end(), ShuffleSourceInfo(SourceVec));
 
    // Update the minimum and maximum lane number seen.
    unsigned EltNo = V.getConstantOperandVal(1);
    Source->MinElt = std::min(Source->MinElt, EltNo);
    Source->MaxElt = std::max(Source->MaxElt, EltNo);
  }
 
  // If we have 3 or 4 sources, try to generate a TBL, which will at least be
  // better than moving to/from gpr registers for larger vectors.
  if ((Sources.size() == 3 || Sources.size() == 4) && NumElts > 4) {
    // Construct a mask for the tbl. We may need to adjust the index for types
    // larger than i8.
    SmallVector<unsigned, 16> Mask;
    unsigned OutputFactor = VT.getScalarSizeInBits() / 8;
    for (unsigned I = 0; I < NumElts; ++I) {
      SDValue V = Op.getOperand(I);
      if (V.isUndef()) {
        for (unsigned OF = 0; OF < OutputFactor; OF++)
          Mask.push_back(-1);
        continue;
      }
      // Set the Mask lanes adjusted for the size of the input and output
      // lanes. The Mask is always i8, so it will set OutputFactor lanes per
      // output element, adjusted in their positions per input and output types.
      unsigned Lane = V.getConstantOperandVal(1);
      for (unsigned S = 0; S < Sources.size(); S++) {
        if (V.getOperand(0) == Sources[S].Vec) {
          unsigned InputSize = Sources[S].Vec.getScalarValueSizeInBits();
          unsigned InputBase = 16 * S + Lane * InputSize / 8;
          for (unsigned OF = 0; OF < OutputFactor; OF++)
            Mask.push_back(InputBase + OF);
          break;
        }
      }
    }
 
    // Construct the tbl3/tbl4 out of an intrinsic, the sources converted to
    // v16i8, and the TBLMask
    SmallVector<SDValue, 16> TBLOperands;
    TBLOperands.push_back(DAG.getConstant(Sources.size() == 3
                                              ? Intrinsic::aarch64_neon_tbl3
                                              : Intrinsic::aarch64_neon_tbl4,
                                          DL, MVT::i32));
    for (unsigned i = 0; i < Sources.size(); i++) {
      SDValue Src = Sources[i].Vec;
      EVT SrcVT = Src.getValueType();
      Src = DAG.getBitcast(SrcVT.is64BitVector() ? MVT::v8i8 : MVT::v16i8, Src);
      assert((SrcVT.is64BitVector() || SrcVT.is128BitVector()) &&
             "Expected a legally typed vector");
      if (SrcVT.is64BitVector())
        Src = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, Src,
                          DAG.getPOISON(MVT::v8i8));
      TBLOperands.push_back(Src);
    }
 
    SmallVector<SDValue, 16> TBLMask;
    for (unsigned i = 0; i < Mask.size(); i++)
      TBLMask.push_back(DAG.getConstant(Mask[i], DL, MVT::i32));
    assert((Mask.size() == 8 || Mask.size() == 16) &&
           "Expected a v8i8 or v16i8 Mask");
    TBLOperands.push_back(DAG.getBuildVector(
        Mask.size() == 8 ? MVT::v8i8 : MVT::v16i8, DL, TBLMask));
 
    SDValue Shuffle =
        DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL,
                    Mask.size() == 8 ? MVT::v8i8 : MVT::v16i8, TBLOperands);
    return DAG.getBitcast(VT, Shuffle);
  }
 
  if (Sources.size() > 2) {
    LLVM_DEBUG(dbgs() << "Reshuffle failed: currently only do something "
                      << "sensible when at most two source vectors are "
                      << "involved\n");
    return SDValue();
  }
 
  // Find out the smallest element size among result and two sources, and use
  // it as element size to build the shuffle_vector.
  EVT SmallestEltTy = VT.getVectorElementType();
  for (auto &Source : Sources) {
    EVT SrcEltTy = Source.Vec.getValueType().getVectorElementType();
    if (SrcEltTy.bitsLT(SmallestEltTy)) {
      SmallestEltTy = SrcEltTy;
    }
  }
  unsigned ResMultiplier =
      VT.getScalarSizeInBits() / SmallestEltTy.getFixedSizeInBits();
  uint64_t VTSize = VT.getFixedSizeInBits();
  NumElts = VTSize / SmallestEltTy.getFixedSizeInBits();
  EVT ShuffleVT = EVT::getVectorVT(*DAG.getContext(), SmallestEltTy, NumElts);
 
  // If the source vector is too wide or too narrow, we may nevertheless be able
  // to construct a compatible shuffle either by concatenating it with UNDEF or
  // extracting a suitable range of elements.
  for (auto &Src : Sources) {
    EVT SrcVT = Src.ShuffleVec.getValueType();
 
    TypeSize SrcVTSize = SrcVT.getSizeInBits();
    if (SrcVTSize == TypeSize::getFixed(VTSize))
      continue;
 
    // This stage of the search produces a source with the same element type as
    // the original, but with a total width matching the BUILD_VECTOR output.
    EVT EltVT = SrcVT.getVectorElementType();
    unsigned NumSrcElts = VTSize / EltVT.getFixedSizeInBits();
    EVT DestVT = EVT::getVectorVT(*DAG.getContext(), EltVT, NumSrcElts);
 
    if (SrcVTSize.getFixedValue() < VTSize) {
      assert(2 * SrcVTSize == VTSize);
      // We can pad out the smaller vector for free, so if it's part of a
      // shuffle...
      Src.ShuffleVec =
          DAG.getNode(ISD::CONCAT_VECTORS, DL, DestVT, Src.ShuffleVec,
                      DAG.getPOISON(Src.ShuffleVec.getValueType()));
      continue;
    }
 
    if (SrcVTSize.getFixedValue() != 2 * VTSize) {
      LLVM_DEBUG(
          dbgs() << "Reshuffle failed: result vector too small to extract\n");
      return SDValue();
    }
 
    if (Src.MaxElt - Src.MinElt >= NumSrcElts) {
      LLVM_DEBUG(
          dbgs() << "Reshuffle failed: span too large for a VEXT to cope\n");
      return SDValue();
    }
 
    if (Src.MinElt >= NumSrcElts) {
      // The extraction can just take the second half
      Src.ShuffleVec =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, DestVT, Src.ShuffleVec,
                      DAG.getConstant(NumSrcElts, DL, MVT::i64));
      Src.WindowBase = -NumSrcElts;
    } else if (Src.MaxElt < NumSrcElts) {
      // The extraction can just take the first half
      Src.ShuffleVec =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, DestVT, Src.ShuffleVec,
                      DAG.getConstant(0, DL, MVT::i64));
    } else {
      // An actual VEXT is needed
      SDValue VEXTSrc1 =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, DestVT, Src.ShuffleVec,
                      DAG.getConstant(0, DL, MVT::i64));
      SDValue VEXTSrc2 =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, DestVT, Src.ShuffleVec,
                      DAG.getConstant(NumSrcElts, DL, MVT::i64));
      unsigned Imm = Src.MinElt * getExtFactor(VEXTSrc1);
 
      if (!SrcVT.is64BitVector()) {
        LLVM_DEBUG(
          dbgs() << "Reshuffle failed: don't know how to lower AArch64ISD::EXT "
                    "for SVE vectors.");
        return SDValue();
      }
 
      Src.ShuffleVec =
          DAG.getNode(AArch64ISD::EXT, DL, DestVT, VEXTSrc1, VEXTSrc2,
                      DAG.getConstant(Imm, DL, MVT::i32));
      Src.WindowBase = -Src.MinElt;
    }
  }
 
  // Another possible incompatibility occurs from the vector element types. We
  // can fix this by bitcasting the source vectors to the same type we intend
  // for the shuffle.
  for (auto &Src : Sources) {
    EVT SrcEltTy = Src.ShuffleVec.getValueType().getVectorElementType();
    if (SrcEltTy == SmallestEltTy)
      continue;
    assert(ShuffleVT.getVectorElementType() == SmallestEltTy);
    if (DAG.getDataLayout().isBigEndian()) {
      Src.ShuffleVec =
          DAG.getNode(AArch64ISD::NVCAST, DL, ShuffleVT, Src.ShuffleVec);
    } else {
      Src.ShuffleVec = DAG.getNode(ISD::BITCAST, DL, ShuffleVT, Src.ShuffleVec);
    }
    Src.WindowScale =
        SrcEltTy.getFixedSizeInBits() / SmallestEltTy.getFixedSizeInBits();
    Src.WindowBase *= Src.WindowScale;
  }
 
  // Final check before we try to actually produce a shuffle.
  LLVM_DEBUG({
    for (auto Src : Sources)
      assert(Src.ShuffleVec.getValueType() == ShuffleVT);
  });
 
  // The stars all align, our next step is to produce the mask for the shuffle.
  SmallVector<int, 8> Mask(ShuffleVT.getVectorNumElements(), -1);
  int BitsPerShuffleLane = ShuffleVT.getScalarSizeInBits();
  for (unsigned i = 0; i < VT.getVectorNumElements(); ++i) {
    SDValue Entry = Op.getOperand(i);
    if (Entry.isUndef())
      continue;
 
    auto Src = find(Sources, Entry.getOperand(0));
    int EltNo = cast<ConstantSDNode>(Entry.getOperand(1))->getSExtValue();
 
    // EXTRACT_VECTOR_ELT performs an implicit any_ext; BUILD_VECTOR an implicit
    // trunc. So only std::min(SrcBits, DestBits) actually get defined in this
    // segment.
    EVT OrigEltTy = Entry.getOperand(0).getValueType().getVectorElementType();
    int BitsDefined = std::min(OrigEltTy.getScalarSizeInBits(),
                               VT.getScalarSizeInBits());
    int LanesDefined = BitsDefined / BitsPerShuffleLane;
 
    // This source is expected to fill ResMultiplier lanes of the final shuffle,
    // starting at the appropriate offset.
    int *LaneMask = &Mask[i * ResMultiplier];
 
    int ExtractBase = EltNo * Src->WindowScale + Src->WindowBase;
    ExtractBase += NumElts * (Src - Sources.begin());
    for (int j = 0; j < LanesDefined; ++j)
      LaneMask[j] = ExtractBase + j;
  }
 
  // Final check before we try to produce nonsense...
  if (!isShuffleMaskLegal(Mask, ShuffleVT)) {
    LLVM_DEBUG(dbgs() << "Reshuffle failed: illegal shuffle mask\n");
    return SDValue();
  }
 
  SDValue Poison = DAG.getPOISON(ShuffleVT);
  SDValue ShuffleOps[] = {Poison, Poison};
  for (unsigned i = 0; i < Sources.size(); ++i)
    ShuffleOps[i] = Sources[i].ShuffleVec;
 
  SDValue Shuffle =
      DAG.getVectorShuffle(ShuffleVT, DL, ShuffleOps[0], ShuffleOps[1], Mask);
  SDValue V;
  if (DAG.getDataLayout().isBigEndian()) {
    V = DAG.getNode(AArch64ISD::NVCAST, DL, VT, Shuffle);
  } else {
    V = DAG.getNode(ISD::BITCAST, DL, VT, Shuffle);
  }
 
  LLVM_DEBUG(dbgs() << "Reshuffle, creating node: "; Shuffle.dump();
             dbgs() << "Reshuffle, creating node: "; V.dump(););
 
  return V;
}
 
// check if an EXT instruction can handle the shuffle mask when the
// vector sources of the shuffle are the same.
static bool isSingletonEXTMask(ArrayRef<int> M, EVT VT, unsigned &Imm) {
  unsigned NumElts = VT.getVectorNumElements();
 
  // Assume that the first shuffle index is not UNDEF.  Fail if it is.
  if (M[0] < 0)
    return false;
 
  Imm = M[0];
 
  // If this is a VEXT shuffle, the immediate value is the index of the first
  // element.  The other shuffle indices must be the successive elements after
  // the first one.
  unsigned ExpectedElt = Imm;
  for (unsigned i = 1; i < NumElts; ++i) {
    // Increment the expected index.  If it wraps around, just follow it
    // back to index zero and keep going.
    ++ExpectedElt;
    if (ExpectedElt == NumElts)
      ExpectedElt = 0;
 
    if (M[i] < 0)
      continue; // ignore UNDEF indices
    if (ExpectedElt != static_cast<unsigned>(M[i]))
      return false;
  }
 
  return true;
}
 
// Detect patterns of a0,a1,a2,a3,b0,b1,b2,b3,c0,c1,c2,c3,d0,d1,d2,d3 from
// v4i32s. This is really a truncate, which we can construct out of (legal)
// concats and truncate nodes.
static SDValue ReconstructTruncateFromBuildVector(SDValue V, SelectionDAG &DAG) {
  if (V.getValueType() != MVT::v16i8)
    return SDValue();
  assert(V.getNumOperands() == 16 && "Expected 16 operands on the BUILDVECTOR");
 
  for (unsigned X = 0; X < 4; X++) {
    // Check the first item in each group is an extract from lane 0 of a v4i32
    // or v4i16.
    SDValue BaseExt = V.getOperand(X * 4);
    if (BaseExt.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
        (BaseExt.getOperand(0).getValueType() != MVT::v4i16 &&
         BaseExt.getOperand(0).getValueType() != MVT::v4i32) ||
        !isa<ConstantSDNode>(BaseExt.getOperand(1)) ||
        BaseExt.getConstantOperandVal(1) != 0)
      return SDValue();
    SDValue Base = BaseExt.getOperand(0);
    // And check the other items are extracts from the same vector.
    for (unsigned Y = 1; Y < 4; Y++) {
      SDValue Ext = V.getOperand(X * 4 + Y);
      if (Ext.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
          Ext.getOperand(0) != Base ||
          !isa<ConstantSDNode>(Ext.getOperand(1)) ||
          Ext.getConstantOperandVal(1) != Y)
        return SDValue();
    }
  }
 
  // Turn the buildvector into a series of truncates and concates, which will
  // become uzip1's. Any v4i32s we found get truncated to v4i16, which are
  // concat together to produce 2 v8i16. These are both truncated and concat
  // together.
  SDLoc DL(V);
  SDValue Trunc[4] = {
      V.getOperand(0).getOperand(0), V.getOperand(4).getOperand(0),
      V.getOperand(8).getOperand(0), V.getOperand(12).getOperand(0)};
  for (SDValue &V : Trunc)
    if (V.getValueType() == MVT::v4i32)
      V = DAG.getNode(ISD::TRUNCATE, DL, MVT::v4i16, V);
  SDValue Concat0 =
      DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v8i16, Trunc[0], Trunc[1]);
  SDValue Concat1 =
      DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v8i16, Trunc[2], Trunc[3]);
  SDValue Trunc0 = DAG.getNode(ISD::TRUNCATE, DL, MVT::v8i8, Concat0);
  SDValue Trunc1 = DAG.getNode(ISD::TRUNCATE, DL, MVT::v8i8, Concat1);
  return DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, Trunc0, Trunc1);
}
 
/// Check if a vector shuffle corresponds to a DUP instructions with a larger
/// element width than the vector lane type. If that is the case the function
/// returns true and writes the value of the DUP instruction lane operand into
/// DupLaneOp
static bool isWideDUPMask(ArrayRef<int> M, EVT VT, unsigned BlockSize,
                          unsigned &DupLaneOp) {
  assert((BlockSize == 16 || BlockSize == 32 || BlockSize == 64) &&
         "Only possible block sizes for wide DUP are: 16, 32, 64");
 
  if (BlockSize <= VT.getScalarSizeInBits())
    return false;
  if (BlockSize % VT.getScalarSizeInBits() != 0)
    return false;
  if (VT.getSizeInBits() % BlockSize != 0)
    return false;
 
  size_t SingleVecNumElements = VT.getVectorNumElements();
  size_t NumEltsPerBlock = BlockSize / VT.getScalarSizeInBits();
  size_t NumBlocks = VT.getSizeInBits() / BlockSize;
 
  // We are looking for masks like
  // [0, 1, 0, 1] or [2, 3, 2, 3] or [4, 5, 6, 7, 4, 5, 6, 7] where any element
  // might be replaced by 'undefined'. BlockIndices will eventually contain
  // lane indices of the duplicated block (i.e. [0, 1], [2, 3] and [4, 5, 6, 7]
  // for the above examples)
  SmallVector<int, 8> BlockElts(NumEltsPerBlock, -1);
  for (size_t BlockIndex = 0; BlockIndex < NumBlocks; BlockIndex++)
    for (size_t I = 0; I < NumEltsPerBlock; I++) {
      int Elt = M[BlockIndex * NumEltsPerBlock + I];
      if (Elt < 0)
        continue;
      // For now we don't support shuffles that use the second operand
      if ((unsigned)Elt >= SingleVecNumElements)
        return false;
      if (BlockElts[I] < 0)
        BlockElts[I] = Elt;
      else if (BlockElts[I] != Elt)
        return false;
    }
 
  // We found a candidate block (possibly with some undefs). It must be a
  // sequence of consecutive integers starting with a value divisible by
  // NumEltsPerBlock with some values possibly replaced by undef-s.
 
  // Find first non-undef element
  auto FirstRealEltIter = find_if(BlockElts, [](int Elt) { return Elt >= 0; });
  assert(FirstRealEltIter != BlockElts.end() &&
         "Shuffle with all-undefs must have been caught by previous cases, "
         "e.g. isSplat()");
  if (FirstRealEltIter == BlockElts.end()) {
    DupLaneOp = 0;
    return true;
  }
 
  // Index of FirstRealElt in BlockElts
  size_t FirstRealIndex = FirstRealEltIter - BlockElts.begin();
 
  if ((unsigned)*FirstRealEltIter < FirstRealIndex)
    return false;
  // BlockElts[0] must have the following value if it isn't undef:
  size_t Elt0 = *FirstRealEltIter - FirstRealIndex;
 
  // Check the first element
  if (Elt0 % NumEltsPerBlock != 0)
    return false;
  // Check that the sequence indeed consists of consecutive integers (modulo
  // undefs)
  for (size_t I = 0; I < NumEltsPerBlock; I++)
    if (BlockElts[I] >= 0 && (unsigned)BlockElts[I] != Elt0 + I)
      return false;
 
  DupLaneOp = Elt0 / NumEltsPerBlock;
  return true;
}
 
// check if an EXT instruction can handle the shuffle mask when the
// vector sources of the shuffle are different.
static bool isEXTMask(ArrayRef<int> M, EVT VT, bool &ReverseEXT,
                      unsigned &Imm) {
  // Look for the first non-undef element.
  const int *FirstRealElt = find_if(M, [](int Elt) { return Elt >= 0; });
 
  // Benefit from APInt to handle overflow when calculating expected element.
  unsigned NumElts = VT.getVectorNumElements();
  unsigned MaskBits = APInt(32, NumElts * 2).logBase2();
  APInt ExpectedElt = APInt(MaskBits, *FirstRealElt + 1, /*isSigned=*/false,
                            /*implicitTrunc=*/true);
  // The following shuffle indices must be the successive elements after the
  // first real element.
  bool FoundWrongElt = std::any_of(FirstRealElt + 1, M.end(), [&](int Elt) {
    return Elt != ExpectedElt++ && Elt >= 0;
  });
  if (FoundWrongElt)
    return false;
 
  // The index of an EXT is the first element if it is not UNDEF.
  // Watch out for the beginning UNDEFs. The EXT index should be the expected
  // value of the first element.  E.g.
  // <-1, -1, 3, ...> is treated as <1, 2, 3, ...>.
  // <-1, -1, 0, 1, ...> is treated as <2*NumElts-2, 2*NumElts-1, 0, 1, ...>.
  // ExpectedElt is the last mask index plus 1.
  Imm = ExpectedElt.getZExtValue();
 
  // There are two difference cases requiring to reverse input vectors.
  // For example, for vector <4 x i32> we have the following cases,
  // Case 1: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, -1, 0>)
  // Case 2: shufflevector(<4 x i32>,<4 x i32>,<-1, -1, 7, 0>)
  // For both cases, we finally use mask <5, 6, 7, 0>, which requires
  // to reverse two input vectors.
  if (Imm < NumElts)
    ReverseEXT = true;
  else
    Imm -= NumElts;
 
  return true;
}
 
// Check if an EXT instruction can handle the shuffle mask when one source is a
// splat. This matches shuffles where the splat occupies either a prefix or a
// suffix and the remaining lanes are a contiguous slice from the non-splat
// source.
static bool isEXTMaskWithSplat(ArrayRef<int> M, EVT VT, unsigned SplatOperand,
                               bool &ReverseEXT, unsigned &Imm) {
  unsigned NumElts = VT.getVectorNumElements();
  unsigned OtherBase = SplatOperand == 0 ? NumElts : 0;
  auto IsSplatElt = [=](int Elt) {
    return Elt < 0 ||
           (SplatOperand == 0 ? Elt < (int)NumElts : Elt >= (int)NumElts);
  };
 
  unsigned PrefixSplatElts = 0;
  while (PrefixSplatElts != NumElts && IsSplatElt(M[PrefixSplatElts]))
    ++PrefixSplatElts;
 
  if (PrefixSplatElts > 0 && PrefixSplatElts < NumElts) {
    bool Match = true;
    for (unsigned I = PrefixSplatElts; I != NumElts; ++I) {
      int Expected = OtherBase + I - PrefixSplatElts;
      if (M[I] >= 0 && M[I] != Expected) {
        Match = false;
        break;
      }
    }
 
    if (Match) {
      ReverseEXT = SplatOperand == 1;
      Imm = NumElts - PrefixSplatElts;
      return true;
    }
  }
 
  unsigned SuffixSplatElts = 0;
  while (SuffixSplatElts != NumElts &&
         IsSplatElt(M[NumElts - 1 - SuffixSplatElts]))
    ++SuffixSplatElts;
 
  if (0 < SuffixSplatElts && SuffixSplatElts < NumElts) {
    bool Match = true;
    for (unsigned I = 0; I != NumElts - SuffixSplatElts; ++I) {
      int Expected = OtherBase + I + SuffixSplatElts;
      if (M[I] >= 0 && M[I] != Expected) {
        Match = false;
        break;
      }
    }
 
    if (Match) {
      ReverseEXT = SplatOperand == 0;
      Imm = SuffixSplatElts;
      return true;
    }
  }
 
  return false;
}
 
/// isZIP_v_undef_Mask - Special case of isZIPMask for canonical form of
/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
/// Mask is e.g., <0, 0, 1, 1> instead of <0, 4, 1, 5>.
static bool isZIP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
  unsigned NumElts = VT.getVectorNumElements();
  if (NumElts % 2 != 0)
    return false;
  WhichResult = (M[0] == 0 ? 0 : 1);
  unsigned Idx = WhichResult * NumElts / 2;
  for (unsigned i = 0; i != NumElts; i += 2) {
    if ((M[i] >= 0 && (unsigned)M[i] != Idx) ||
        (M[i + 1] >= 0 && (unsigned)M[i + 1] != Idx))
      return false;
    Idx += 1;
  }
 
  return true;
}
 
/// isUZP_v_undef_Mask - Special case of isUZPMask for canonical form of
/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
/// Mask is e.g., <0, 2, 0, 2> instead of <0, 2, 4, 6>,
static bool isUZP_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
  unsigned Half = VT.getVectorNumElements() / 2;
  WhichResult = (M[0] == 0 ? 0 : 1);
  for (unsigned j = 0; j != 2; ++j) {
    unsigned Idx = WhichResult;
    for (unsigned i = 0; i != Half; ++i) {
      int MIdx = M[i + j * Half];
      if (MIdx >= 0 && (unsigned)MIdx != Idx)
        return false;
      Idx += 2;
    }
  }
 
  return true;
}
 
/// isTRN_v_undef_Mask - Special case of isTRNMask for canonical form of
/// "vector_shuffle v, v", i.e., "vector_shuffle v, undef".
/// Mask is e.g., <0, 0, 2, 2> instead of <0, 4, 2, 6>.
static bool isTRN_v_undef_Mask(ArrayRef<int> M, EVT VT, unsigned &WhichResult) {
  unsigned NumElts = VT.getVectorNumElements();
  if (NumElts % 2 != 0)
    return false;
  WhichResult = (M[0] == 0 ? 0 : 1);
  for (unsigned i = 0; i < NumElts; i += 2) {
    if ((M[i] >= 0 && (unsigned)M[i] != i + WhichResult) ||
        (M[i + 1] >= 0 && (unsigned)M[i + 1] != i + WhichResult))
      return false;
  }
  return true;
}
 
static bool isINSMask(ArrayRef<int> M, int NumInputElements,
                      bool &DstIsLeft, int &Anomaly) {
  if (M.size() != static_cast<size_t>(NumInputElements))
    return false;
 
  int NumLHSMatch = 0, NumRHSMatch = 0;
  int LastLHSMismatch = -1, LastRHSMismatch = -1;
 
  for (int i = 0; i < NumInputElements; ++i) {
    if (M[i] == -1) {
      ++NumLHSMatch;
      ++NumRHSMatch;
      continue;
    }
 
    if (M[i] == i)
      ++NumLHSMatch;
    else
      LastLHSMismatch = i;
 
    if (M[i] == i + NumInputElements)
      ++NumRHSMatch;
    else
      LastRHSMismatch = i;
  }
 
  if (NumLHSMatch == NumInputElements - 1) {
    DstIsLeft = true;
    Anomaly = LastLHSMismatch;
    return true;
  } else if (NumRHSMatch == NumInputElements - 1) {
    DstIsLeft = false;
    Anomaly = LastRHSMismatch;
    return true;
  }
 
  return false;
}
 
static bool isConcatMask(ArrayRef<int> Mask, EVT VT, bool SplitLHS) {
  if (VT.getSizeInBits() != 128)
    return false;
 
  unsigned NumElts = VT.getVectorNumElements();
 
  for (int I = 0, E = NumElts / 2; I != E; I++) {
    if (Mask[I] != I)
      return false;
  }
 
  int Offset = NumElts / 2;
  for (int I = NumElts / 2, E = NumElts; I != E; I++) {
    if (Mask[I] != I + SplitLHS * Offset)
      return false;
  }
 
  return true;
}
 
static SDValue tryFormConcatFromShuffle(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  SDValue V0 = Op.getOperand(0);
  SDValue V1 = Op.getOperand(1);
  ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Op)->getMask();
 
  if (VT.getVectorElementType() != V0.getValueType().getVectorElementType() ||
      VT.getVectorElementType() != V1.getValueType().getVectorElementType())
    return SDValue();
 
  bool SplitV0 = V0.getValueSizeInBits() == 128;
 
  if (!isConcatMask(Mask, VT, SplitV0))
    return SDValue();
 
  EVT CastVT = VT.getHalfNumVectorElementsVT(*DAG.getContext());
  if (SplitV0) {
    V0 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V0,
                     DAG.getConstant(0, DL, MVT::i64));
  }
  if (V1.getValueSizeInBits() == 128) {
    V1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, CastVT, V1,
                     DAG.getConstant(0, DL, MVT::i64));
  }
  return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, V0, V1);
}
 
/// GeneratePerfectShuffle - Given an entry in the perfect-shuffle table, emit
/// the specified operations to build the shuffle. ID is the perfect-shuffle
//ID, V1 and V2 are the original shuffle inputs. PFEntry is the Perfect shuffle
//table entry and LHS/RHS are the immediate inputs for this stage of the
//shuffle.
static SDValue GeneratePerfectShuffle(unsigned ID, SDValue V1, SDValue V2,
                                      unsigned PFEntry, SDValue LHS,
                                      SDValue RHS, SelectionDAG &DAG,
                                      const SDLoc &DL) {
  unsigned OpNum = (PFEntry >> 26) & 0x0F;
  unsigned LHSID = (PFEntry >> 13) & ((1 << 13) - 1);
  unsigned RHSID = (PFEntry >> 0) & ((1 << 13) - 1);
 
  enum {
    OP_COPY = 0, // Copy, used for things like <u,u,u,3> to say it is <0,1,2,3>
    OP_VREV,
    OP_VDUP0,
    OP_VDUP1,
    OP_VDUP2,
    OP_VDUP3,
    OP_VEXT1,
    OP_VEXT2,
    OP_VEXT3,
    OP_VUZPL,  // VUZP, left result
    OP_VUZPR,  // VUZP, right result
    OP_VZIPL,  // VZIP, left result
    OP_VZIPR,  // VZIP, right result
    OP_VTRNL,  // VTRN, left result
    OP_VTRNR,  // VTRN, right result
    OP_MOVLANE // Move lane. RHSID is the lane to move into
  };
 
  if (OpNum == OP_COPY) {
    if (LHSID == (1 * 9 + 2) * 9 + 3)
      return LHS;
    assert(LHSID == ((4 * 9 + 5) * 9 + 6) * 9 + 7 && "Illegal OP_COPY!");
    return RHS;
  }
 
  if (OpNum == OP_MOVLANE) {
    // Decompose a PerfectShuffle ID to get the Mask for lane Elt
    auto getPFIDLane = [](unsigned ID, int Elt) -> int {
      assert(Elt < 4 && "Expected Perfect Lanes to be less than 4");
      Elt = 3 - Elt;
      while (Elt > 0) {
        ID /= 9;
        Elt--;
      }
      return (ID % 9 == 8) ? -1 : ID % 9;
    };
 
    // For OP_MOVLANE shuffles, the RHSID represents the lane to move into. We
    // get the lane to move from the PFID, which is always from the
    // original vectors (V1 or V2).
    SDValue OpLHS = GeneratePerfectShuffle(
        LHSID, V1, V2, PerfectShuffleTable[LHSID], LHS, RHS, DAG, DL);
    EVT VT = OpLHS.getValueType();
    assert(RHSID < 8 && "Expected a lane index for RHSID!");
    unsigned ExtLane = 0;
    SDValue Input;
 
    // OP_MOVLANE are either D movs (if bit 0x4 is set) or S movs. D movs
    // convert into a higher type.
    if (RHSID & 0x4) {
      int MaskElt = getPFIDLane(ID, (RHSID & 0x01) << 1) >> 1;
      if (MaskElt == -1)
        MaskElt = (getPFIDLane(ID, ((RHSID & 0x01) << 1) + 1) - 1) >> 1;
      assert(MaskElt >= 0 && "Didn't expect an undef movlane index!");
      ExtLane = MaskElt < 2 ? MaskElt : (MaskElt - 2);
      Input = MaskElt < 2 ? V1 : V2;
      if (VT.getScalarSizeInBits() == 16) {
        Input = DAG.getBitcast(MVT::v2f32, Input);
        OpLHS = DAG.getBitcast(MVT::v2f32, OpLHS);
      } else {
        assert(VT.getScalarSizeInBits() == 32 &&
               "Expected 16 or 32 bit shuffle elements");
        Input = DAG.getBitcast(MVT::v2f64, Input);
        OpLHS = DAG.getBitcast(MVT::v2f64, OpLHS);
      }
    } else {
      int MaskElt = getPFIDLane(ID, RHSID);
      assert(MaskElt >= 0 && "Didn't expect an undef movlane index!");
      ExtLane = MaskElt < 4 ? MaskElt : (MaskElt - 4);
      Input = MaskElt < 4 ? V1 : V2;
      // Be careful about creating illegal types. Use f16 instead of i16.
      if (VT == MVT::v4i16) {
        Input = DAG.getBitcast(MVT::v4f16, Input);
        OpLHS = DAG.getBitcast(MVT::v4f16, OpLHS);
      }
    }
    SDValue Ext = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
                              Input.getValueType().getVectorElementType(),
                              Input, DAG.getVectorIdxConstant(ExtLane, DL));
    SDValue Ins =
        DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, Input.getValueType(), OpLHS,
                    Ext, DAG.getVectorIdxConstant(RHSID & 0x3, DL));
    return DAG.getBitcast(VT, Ins);
  }
 
  SDValue OpLHS, OpRHS;
  OpLHS = GeneratePerfectShuffle(LHSID, V1, V2, PerfectShuffleTable[LHSID], LHS,
                                 RHS, DAG, DL);
  OpRHS = GeneratePerfectShuffle(RHSID, V1, V2, PerfectShuffleTable[RHSID], LHS,
                                 RHS, DAG, DL);
  EVT VT = OpLHS.getValueType();
 
  switch (OpNum) {
  default:
    llvm_unreachable("Unknown shuffle opcode!");
  case OP_VREV: {
    // VREV divides the vector in half and swaps within the half.
    if (VT.getVectorElementType() == MVT::i32 ||
        VT.getVectorElementType() == MVT::f32)
      return DAG.getNode(AArch64ISD::REV64, DL, VT, OpLHS);
    // vrev <4 x i16> -> REV32
    if (VT.getVectorElementType() == MVT::i16 ||
        VT.getVectorElementType() == MVT::f16 ||
        VT.getVectorElementType() == MVT::bf16)
      return DAG.getNode(AArch64ISD::REV32, DL, VT, OpLHS);
    // vrev <4 x i8> -> BSWAP which is REV16
    assert(VT == MVT::v8i8 || VT == MVT::v16i8);
    EVT BSVT = VT == MVT::v8i8 ? MVT::v4i16 : MVT::v8i16;
    return DAG.getNode(
        AArch64ISD::NVCAST, DL, VT,
        DAG.getNode(ISD::BSWAP, DL, BSVT,
                    DAG.getNode(AArch64ISD::NVCAST, DL, BSVT, OpLHS)));
  }
  case OP_VDUP0:
  case OP_VDUP1:
  case OP_VDUP2:
  case OP_VDUP3: {
    EVT EltTy = VT.getVectorElementType();
    unsigned Opcode;
    if (EltTy == MVT::i8)
      Opcode = AArch64ISD::DUPLANE8;
    else if (EltTy == MVT::i16 || EltTy == MVT::f16 || EltTy == MVT::bf16)
      Opcode = AArch64ISD::DUPLANE16;
    else if (EltTy == MVT::i32 || EltTy == MVT::f32)
      Opcode = AArch64ISD::DUPLANE32;
    else if (EltTy == MVT::i64 || EltTy == MVT::f64)
      Opcode = AArch64ISD::DUPLANE64;
    else
      llvm_unreachable("Invalid vector element type?");
 
    if (VT.getSizeInBits() == 64)
      OpLHS = WidenVector(OpLHS, DAG);
    SDValue Lane = DAG.getConstant(OpNum - OP_VDUP0, DL, MVT::i64);
    return DAG.getNode(Opcode, DL, VT, OpLHS, Lane);
  }
  case OP_VEXT1:
  case OP_VEXT2:
  case OP_VEXT3: {
    unsigned Imm = (OpNum - OP_VEXT1 + 1) * getExtFactor(OpLHS);
    return DAG.getNode(AArch64ISD::EXT, DL, VT, OpLHS, OpRHS,
                       DAG.getConstant(Imm, DL, MVT::i32));
  }
  case OP_VUZPL:
    return DAG.getNode(AArch64ISD::UZP1, DL, VT, OpLHS, OpRHS);
  case OP_VUZPR:
    return DAG.getNode(AArch64ISD::UZP2, DL, VT, OpLHS, OpRHS);
  case OP_VZIPL:
    return DAG.getNode(AArch64ISD::ZIP1, DL, VT, OpLHS, OpRHS);
  case OP_VZIPR:
    return DAG.getNode(AArch64ISD::ZIP2, DL, VT, OpLHS, OpRHS);
  case OP_VTRNL:
    return DAG.getNode(AArch64ISD::TRN1, DL, VT, OpLHS, OpRHS);
  case OP_VTRNR:
    return DAG.getNode(AArch64ISD::TRN2, DL, VT, OpLHS, OpRHS);
  }
}
 
static SDValue GenerateTBL(SDValue Op, ArrayRef<int> ShuffleMask,
                           SelectionDAG &DAG) {
  // Check to see if we can use the TBL instruction.
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
  SDLoc DL(Op);
 
  EVT EltVT = Op.getValueType().getVectorElementType();
  unsigned BytesPerElt = EltVT.getSizeInBits() / 8;
 
  bool Swap = false;
  if (V1.isUndef() || isZerosVector(V1.getNode())) {
    std::swap(V1, V2);
    Swap = true;
  }
 
  // If the V2 source is undef or zero then we can use a tbl1, as tbl1 will fill
  // out of range values with 0s. We do need to make sure that any out-of-range
  // values are really out-of-range for a v16i8 vector.
  bool IsUndefOrZero = V2.isUndef() || isZerosVector(V2.getNode());
  MVT IndexVT = MVT::v8i8;
  unsigned IndexLen = 8;
  if (Op.getValueSizeInBits() == 128) {
    IndexVT = MVT::v16i8;
    IndexLen = 16;
  }
 
  SmallVector<SDValue, 8> TBLMask;
  for (int Val : ShuffleMask) {
    for (unsigned Byte = 0; Byte < BytesPerElt; ++Byte) {
      unsigned Offset = Byte + Val * BytesPerElt;
      if (Swap)
        Offset = Offset < IndexLen ? Offset + IndexLen : Offset - IndexLen;
      if (IsUndefOrZero && Offset >= IndexLen)
        Offset = 255;
      TBLMask.push_back(DAG.getConstant(Offset, DL, MVT::i32));
    }
  }
 
  SDValue V1Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V1);
  SDValue V2Cst = DAG.getNode(ISD::BITCAST, DL, IndexVT, V2);
 
  SDValue Shuffle;
  if (IsUndefOrZero) {
    if (IndexLen == 8)
      V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V1Cst);
    Shuffle = DAG.getNode(
        ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
        DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl1, DL, MVT::i32),
        V1Cst,
        DAG.getBuildVector(IndexVT, DL, ArrayRef(TBLMask.data(), IndexLen)));
  } else {
    if (IndexLen == 8) {
      V1Cst = DAG.getNode(ISD::CONCAT_VECTORS, DL, MVT::v16i8, V1Cst, V2Cst);
      Shuffle = DAG.getNode(
          ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
          DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl1, DL, MVT::i32),
          V1Cst,
          DAG.getBuildVector(IndexVT, DL, ArrayRef(TBLMask.data(), IndexLen)));
    } else {
      // FIXME: We cannot, for the moment, emit a TBL2 instruction because we
      // cannot currently represent the register constraints on the input
      // table registers.
      //  Shuffle = DAG.getNode(AArch64ISD::TBL2, DL, IndexVT, V1Cst, V2Cst,
      //                   DAG.getBuildVector(IndexVT, DL, &TBLMask[0],
      //                   IndexLen));
      Shuffle = DAG.getNode(
          ISD::INTRINSIC_WO_CHAIN, DL, IndexVT,
          DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl2, DL, MVT::i32),
          V1Cst, V2Cst,
          DAG.getBuildVector(IndexVT, DL, ArrayRef(TBLMask.data(), IndexLen)));
    }
  }
  return DAG.getNode(ISD::BITCAST, DL, Op.getValueType(), Shuffle);
}
 
static unsigned getDUPLANEOp(EVT EltType) {
  if (EltType == MVT::i8)
    return AArch64ISD::DUPLANE8;
  if (EltType == MVT::i16 || EltType == MVT::f16 || EltType == MVT::bf16)
    return AArch64ISD::DUPLANE16;
  if (EltType == MVT::i32 || EltType == MVT::f32)
    return AArch64ISD::DUPLANE32;
  if (EltType == MVT::i64 || EltType == MVT::f64)
    return AArch64ISD::DUPLANE64;
 
  llvm_unreachable("Invalid vector element type?");
}
 
static SDValue constructDup(SDValue V, int Lane, SDLoc DL, EVT VT,
                            unsigned Opcode, SelectionDAG &DAG) {
  // Try to eliminate a bitcasted extract subvector before a DUPLANE.
  auto getScaledOffsetDup = [](SDValue BitCast, int &LaneC, MVT &CastVT) {
    // Match: dup (bitcast (extract_subv X, C)), LaneC
    if (BitCast.getOpcode() != ISD::BITCAST ||
        BitCast.getOperand(0).getOpcode() != ISD::EXTRACT_SUBVECTOR)
      return false;
 
    // The extract index must align in the destination type. That may not
    // happen if the bitcast is from narrow to wide type.
    SDValue Extract = BitCast.getOperand(0);
    unsigned ExtIdx = Extract.getConstantOperandVal(1);
    unsigned SrcEltBitWidth = Extract.getScalarValueSizeInBits();
    unsigned ExtIdxInBits = ExtIdx * SrcEltBitWidth;
    unsigned CastedEltBitWidth = BitCast.getScalarValueSizeInBits();
    if (ExtIdxInBits % CastedEltBitWidth != 0)
      return false;
 
    // Can't handle cases where vector size is not 128-bit
    if (!Extract.getOperand(0).getValueType().is128BitVector())
      return false;
 
    // Update the lane value by offsetting with the scaled extract index.
    LaneC += ExtIdxInBits / CastedEltBitWidth;
 
    // Determine the casted vector type of the wide vector input.
    // dup (bitcast (extract_subv X, C)), LaneC --> dup (bitcast X), LaneC'
    // Examples:
    // dup (bitcast (extract_subv v2f64 X, 1) to v2f32), 1 --> dup v4f32 X, 3
    // dup (bitcast (extract_subv v16i8 X, 8) to v4i16), 1 --> dup v8i16 X, 5
    unsigned SrcVecNumElts =
        Extract.getOperand(0).getValueSizeInBits() / CastedEltBitWidth;
    CastVT = MVT::getVectorVT(BitCast.getSimpleValueType().getScalarType(),
                              SrcVecNumElts);
    return true;
  };
  MVT CastVT;
  if (getScaledOffsetDup(V, Lane, CastVT)) {
    V = DAG.getBitcast(CastVT, V.getOperand(0).getOperand(0));
  } else if (V.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
             V.getOperand(0).getValueType().is128BitVector()) {
    // The lane is incremented by the index of the extract.
    // Example: dup v2f32 (extract v4f32 X, 2), 1 --> dup v4f32 X, 3
    Lane += V.getConstantOperandVal(1);
    V = V.getOperand(0);
  } else if (V.getOpcode() == ISD::CONCAT_VECTORS) {
    // The lane is decremented if we are splatting from the 2nd operand.
    // Example: dup v4i32 (concat v2i32 X, v2i32 Y), 3 --> dup v4i32 Y, 1
    unsigned Idx = Lane >= (int)VT.getVectorNumElements() / 2;
    Lane -= Idx * VT.getVectorNumElements() / 2;
    V = WidenVector(V.getOperand(Idx), DAG);
  } else if (VT.getSizeInBits() == 64) {
    // Widen the operand to 128-bit register with undef.
    V = WidenVector(V, DAG);
  }
  return DAG.getNode(Opcode, DL, VT, V, DAG.getConstant(Lane, DL, MVT::i64));
}
 
// Try to widen element type to get a new mask value for a better permutation
// sequence, so that we can use NEON shuffle instructions, such as zip1/2,
// UZP1/2, TRN1/2, REV, INS, etc.
// For example:
//  shufflevector <4 x i32> %a, <4 x i32> %b,
//                <4 x i32> <i32 6, i32 7, i32 2, i32 3>
// is equivalent to:
//  shufflevector <2 x i64> %a, <2 x i64> %b, <2 x i32> <i32 3, i32 1>
// Finally, we can get:
//  mov     v0.d[0], v1.d[1]
static SDValue tryWidenMaskForShuffle(SDValue Op, SelectionDAG &DAG) {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  EVT ScalarVT = VT.getVectorElementType();
  unsigned ElementSize = ScalarVT.getFixedSizeInBits();
  SDValue V0 = Op.getOperand(0);
  SDValue V1 = Op.getOperand(1);
  ArrayRef<int> Mask = cast<ShuffleVectorSDNode>(Op)->getMask();
 
  // If combining adjacent elements, like two i16's -> i32, two i32's -> i64 ...
  // We need to make sure the wider element type is legal. Thus, ElementSize
  // should be not larger than 32 bits, and i1 type should also be excluded.
  if (ElementSize > 32 || ElementSize == 1)
    return SDValue();
 
  SmallVector<int, 8> NewMask;
  if (widenShuffleMaskElts(Mask, NewMask)) {
    MVT NewEltVT = VT.isFloatingPoint()
                       ? MVT::getFloatingPointVT(ElementSize * 2)
                       : MVT::getIntegerVT(ElementSize * 2);
    MVT NewVT = MVT::getVectorVT(NewEltVT, VT.getVectorNumElements() / 2);
    if (DAG.getTargetLoweringInfo().isTypeLegal(NewVT)) {
      V0 = DAG.getBitcast(NewVT, V0);
      V1 = DAG.getBitcast(NewVT, V1);
      return DAG.getBitcast(VT,
                            DAG.getVectorShuffle(NewVT, DL, V0, V1, NewMask));
    }
  }
 
  return SDValue();
}
 
// Try to fold shuffle (tbl2, tbl2) into a single tbl4.
static SDValue tryToConvertShuffleOfTbl2ToTbl4(SDValue Op,
                                               ArrayRef<int> ShuffleMask,
                                               SelectionDAG &DAG) {
  SDValue Tbl1 = Op->getOperand(0);
  SDValue Tbl2 = Op->getOperand(1);
  SDLoc DL(Op);
  SDValue Tbl2ID =
      DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl2, DL, MVT::i64);
 
  EVT VT = Op.getValueType();
  if (Tbl1.getOpcode() != ISD::INTRINSIC_WO_CHAIN ||
      Tbl1.getOperand(0) != Tbl2ID ||
      Tbl2.getOpcode() != ISD::INTRINSIC_WO_CHAIN ||
      Tbl2.getOperand(0) != Tbl2ID)
    return SDValue();
 
  if (Tbl1.getValueType() != MVT::v16i8 || Tbl2.getValueType() != MVT::v16i8)
    return SDValue();
 
  SDValue Mask1 = Tbl1.getOperand(3);
  SDValue Mask2 = Tbl2.getOperand(3);
  if (Mask1.getOpcode() != ISD::BUILD_VECTOR ||
      Mask2.getOpcode() != ISD::BUILD_VECTOR)
    return SDValue();
 
  SmallVector<SDValue, 16> TBLMaskParts(16, SDValue());
  for (unsigned I = 0; I < 16; I++) {
    if (ShuffleMask[I] < 16)
      TBLMaskParts[I] = Mask1.getOperand(ShuffleMask[I]);
    else {
      auto *C = dyn_cast<ConstantSDNode>(Mask2.getOperand(ShuffleMask[I] - 16));
      if (!C)
        return SDValue();
      TBLMaskParts[I] = DAG.getConstant(C->getSExtValue() + 32, DL, MVT::i32);
    }
  }
 
  SDValue TBLMask = DAG.getBuildVector(VT, DL, TBLMaskParts);
  SDValue ID =
      DAG.getTargetConstant(Intrinsic::aarch64_neon_tbl4, DL, MVT::i64);
 
  return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, MVT::v16i8,
                     {ID, Tbl1->getOperand(1), Tbl1->getOperand(2),
                      Tbl2->getOperand(1), Tbl2->getOperand(2), TBLMask});
}
 
SDValue
AArch64TargetLowering::LowerEXTEND_VECTOR_INREG(SDValue Op,
                                                SelectionDAG &DAG) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  assert(VT.isScalableVector() && "Unexpected result type!");
 
  bool Signed = Op.getOpcode() == ISD::SIGN_EXTEND_VECTOR_INREG;
  unsigned UnpackOpcode = Signed ? AArch64ISD::SUNPKLO : AArch64ISD::UUNPKLO;
 
  // Repeatedly unpack Val until the result is of the desired type.
  SDValue Val = Op.getOperand(0);
  switch (Val.getSimpleValueType().SimpleTy) {
  default:
    return SDValue();
  case MVT::nxv16i8:
    Val = DAG.getNode(UnpackOpcode, DL, MVT::nxv8i16, Val);
    if (VT == MVT::nxv8i16)
      break;
    [[fallthrough]];
  case MVT::nxv8i16:
    Val = DAG.getNode(UnpackOpcode, DL, MVT::nxv4i32, Val);
    if (VT == MVT::nxv4i32)
      break;
    [[fallthrough]];
  case MVT::nxv4i32:
    Val = DAG.getNode(UnpackOpcode, DL, MVT::nxv2i64, Val);
    assert(VT == MVT::nxv2i64 && "Unexpected result type!");
    break;
  }
 
  return Val;
}
 
// Baseline legalization for ZERO_EXTEND_VECTOR_INREG will blend-in zeros,
// but we don't have an appropriate instruction,
// so custom-lower it as ZIP1-with-zeros.
SDValue
AArch64TargetLowering::LowerZERO_EXTEND_VECTOR_INREG(SDValue Op,
                                                     SelectionDAG &DAG) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
 
  if (VT.isScalableVector())
    return LowerEXTEND_VECTOR_INREG(Op, DAG);
 
  SDValue SrcOp = Op.getOperand(0);
  EVT SrcVT = SrcOp.getValueType();
  assert(VT.getScalarSizeInBits() % SrcVT.getScalarSizeInBits() == 0 &&
         "Unexpected extension factor.");
  unsigned Scale = VT.getScalarSizeInBits() / SrcVT.getScalarSizeInBits();
  // FIXME: support multi-step zipping?
  if (Scale != 2)
    return SDValue();
  SDValue Zeros = DAG.getConstant(0, DL, SrcVT);
  return DAG.getBitcast(VT,
                        DAG.getNode(AArch64ISD::ZIP1, DL, SrcVT, SrcOp, Zeros));
}
 
SDValue AArch64TargetLowering::LowerVECTOR_SHUFFLE(SDValue Op,
                                                   SelectionDAG &DAG) const {
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
 
  ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(Op.getNode());
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthVECTOR_SHUFFLEToSVE(Op, DAG);
 
  // Convert shuffles that are directly supported on NEON to target-specific
  // DAG nodes, instead of keeping them as shuffles and matching them again
  // during code selection.  This is more efficient and avoids the possibility
  // of inconsistencies between legalization and selection.
  ArrayRef<int> ShuffleMask = SVN->getMask();
 
  SDValue V1 = Op.getOperand(0);
  SDValue V2 = Op.getOperand(1);
 
  assert(V1.getValueType() == VT && "Unexpected VECTOR_SHUFFLE type!");
  assert(ShuffleMask.size() == VT.getVectorNumElements() &&
         "Unexpected VECTOR_SHUFFLE mask size!");
 
  if (SDValue Res = tryToConvertShuffleOfTbl2ToTbl4(Op, ShuffleMask, DAG))
    return Res;
 
  if (SVN->isSplat()) {
    int Lane = SVN->getSplatIndex();
    // If this is undef splat, generate it via "just" vdup, if possible.
    if (Lane == -1)
      Lane = 0;
 
    if (Lane == 0 && V1.getOpcode() == ISD::SCALAR_TO_VECTOR)
      return DAG.getNode(AArch64ISD::DUP, DL, V1.getValueType(),
                         V1.getOperand(0));
    // Test if V1 is a BUILD_VECTOR and the lane being referenced is a non-
    // constant. If so, we can just reference the lane's definition directly.
    if (V1.getOpcode() == ISD::BUILD_VECTOR &&
        !isa<ConstantSDNode>(V1.getOperand(Lane)))
      return DAG.getNode(AArch64ISD::DUP, DL, VT, V1.getOperand(Lane));
 
    // Otherwise, duplicate from the lane of the input vector.
    unsigned Opcode = getDUPLANEOp(V1.getValueType().getVectorElementType());
    return constructDup(V1, Lane, DL, VT, Opcode, DAG);
  }
 
  // Check if the mask matches a DUP for a wider element
  for (unsigned LaneSize : {64U, 32U, 16U}) {
    unsigned Lane = 0;
    if (isWideDUPMask(ShuffleMask, VT, LaneSize, Lane)) {
      unsigned Opcode = LaneSize == 64 ? AArch64ISD::DUPLANE64
                                       : LaneSize == 32 ? AArch64ISD::DUPLANE32
                                                        : AArch64ISD::DUPLANE16;
      // Cast V1 to an integer vector with required lane size
      MVT NewEltTy = MVT::getIntegerVT(LaneSize);
      unsigned NewEltCount = VT.getSizeInBits() / LaneSize;
      MVT NewVecTy = MVT::getVectorVT(NewEltTy, NewEltCount);
      V1 = DAG.getBitcast(NewVecTy, V1);
      // Construct the DUP instruction
      V1 = constructDup(V1, Lane, DL, NewVecTy, Opcode, DAG);
      // Cast back to the original type
      return DAG.getBitcast(VT, V1);
    }
  }
 
  unsigned NumElts = VT.getVectorNumElements();
  unsigned EltSize = VT.getScalarSizeInBits();
  if (isREVMask(ShuffleMask, EltSize, NumElts, 64))
    return DAG.getNode(AArch64ISD::REV64, DL, V1.getValueType(), V1);
  if (isREVMask(ShuffleMask, EltSize, NumElts, 32))
    return DAG.getNode(AArch64ISD::REV32, DL, V1.getValueType(), V1);
  if (isREVMask(ShuffleMask, EltSize, NumElts, 16)) {
    EVT VT = V1.getValueType();
    assert(VT == MVT::v8i8 || VT == MVT::v16i8);
    EVT BSVT = VT == MVT::v8i8 ? MVT::v4i16 : MVT::v8i16;
    return DAG.getNode(
        AArch64ISD::NVCAST, DL, VT,
        DAG.getNode(ISD::BSWAP, DL, BSVT,
                    DAG.getNode(AArch64ISD::NVCAST, DL, BSVT, V1)));
  }
 
  if (((NumElts == 8 && EltSize == 16) || (NumElts == 16 && EltSize == 8)) &&
      ShuffleVectorInst::isReverseMask(ShuffleMask, ShuffleMask.size())) {
    SDValue Rev = DAG.getNode(AArch64ISD::REV64, DL, VT, V1);
    return DAG.getNode(AArch64ISD::EXT, DL, VT, Rev, Rev,
                       DAG.getConstant(8, DL, MVT::i32));
  }
 
  bool IsSplat1 =
      V1.getValueType() == VT && DAG.isSplatValue(V1, /*AllowUndefs=*/false);
  bool IsSplat2 =
      V2.getValueType() == VT && DAG.isSplatValue(V2, /*AllowUndefs=*/false);
  for (unsigned SplatOperand : {0U, 1U}) {
    if ((SplatOperand == 0 && !IsSplat1) || (SplatOperand == 1 && !IsSplat2))
      continue;
 
    bool ReverseSplatEXT = false;
    unsigned SplatImm;
    if (isEXTMaskWithSplat(ShuffleMask, VT, SplatOperand, ReverseSplatEXT,
                           SplatImm)) {
      SDValue ExtOp1 = V1;
      SDValue ExtOp2 = V2;
      if (ReverseSplatEXT)
        std::swap(ExtOp1, ExtOp2);
      SplatImm *= getExtFactor(ExtOp1);
      return DAG.getNode(AArch64ISD::EXT, DL, VT, ExtOp1, ExtOp2,
                         DAG.getConstant(SplatImm, DL, MVT::i32));
    }
  }
 
  bool ReverseEXT = false;
  unsigned Imm;
  if (isEXTMask(ShuffleMask, VT, ReverseEXT, Imm)) {
    if (ReverseEXT)
      std::swap(V1, V2);
    Imm *= getExtFactor(V1);
    return DAG.getNode(AArch64ISD::EXT, DL, V1.getValueType(), V1, V2,
                       DAG.getConstant(Imm, DL, MVT::i32));
  } else if (V2->isUndef() && isSingletonEXTMask(ShuffleMask, VT, Imm)) {
    Imm *= getExtFactor(V1);
    return DAG.getNode(AArch64ISD::EXT, DL, V1.getValueType(), V1, V1,
                       DAG.getConstant(Imm, DL, MVT::i32));
  }
 
  unsigned WhichResult;
  unsigned OperandOrder;
  if (isZIPMask(ShuffleMask, NumElts, WhichResult, OperandOrder)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
    return DAG.getNode(Opc, DL, V1.getValueType(), OperandOrder == 0 ? V1 : V2,
                       OperandOrder == 0 ? V2 : V1);
  }
  if (isUZPMask(ShuffleMask, NumElts, WhichResult)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
    return DAG.getNode(Opc, DL, V1.getValueType(), V1, V2);
  }
  if (isTRNMask(ShuffleMask, NumElts, WhichResult, OperandOrder)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
    return DAG.getNode(Opc, DL, V1.getValueType(), OperandOrder == 0 ? V1 : V2,
                       OperandOrder == 0 ? V2 : V1);
  }
 
  if (isZIP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::ZIP1 : AArch64ISD::ZIP2;
    return DAG.getNode(Opc, DL, V1.getValueType(), V1, V1);
  }
  if (isUZP_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::UZP1 : AArch64ISD::UZP2;
    return DAG.getNode(Opc, DL, V1.getValueType(), V1, V1);
  }
  if (isTRN_v_undef_Mask(ShuffleMask, VT, WhichResult)) {
    unsigned Opc = (WhichResult == 0) ? AArch64ISD::TRN1 : AArch64ISD::TRN2;
    return DAG.getNode(Opc, DL, V1.getValueType(), V1, V1);
  }
 
  if (SDValue Concat = tryFormConcatFromShuffle(Op, DAG))
    return Concat;
 
  bool DstIsLeft;
  int Anomaly;
  int NumInputElements = V1.getValueType().getVectorNumElements();
  if (isINSMask(ShuffleMask, NumInputElements, DstIsLeft, Anomaly)) {
    SDValue DstVec = DstIsLeft ? V1 : V2;
    SDValue DstLaneV = DAG.getConstant(Anomaly, DL, MVT::i64);
 
    SDValue SrcVec = V1;
    int SrcLane = ShuffleMask[Anomaly];
    if (SrcLane >= NumInputElements) {
      SrcVec = V2;
      SrcLane -= NumElts;
    }
    SDValue SrcLaneV = DAG.getConstant(SrcLane, DL, MVT::i64);
 
    EVT ScalarVT = VT.getVectorElementType();
 
    if (ScalarVT.getFixedSizeInBits() < 32 && ScalarVT.isInteger())
      ScalarVT = MVT::i32;
 
    return DAG.getNode(
        ISD::INSERT_VECTOR_ELT, DL, VT, DstVec,
        DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ScalarVT, SrcVec, SrcLaneV),
        DstLaneV);
  }
 
  if (SDValue NewSD = tryWidenMaskForShuffle(Op, DAG))
    return NewSD;
 
  // If the shuffle is not directly supported and it has 4 elements, use
  // the PerfectShuffle-generated table to synthesize it from other shuffles.
  if (NumElts == 4) {
    unsigned PFIndexes[4];
    for (unsigned i = 0; i != 4; ++i) {
      if (ShuffleMask[i] < 0)
        PFIndexes[i] = 8;
      else
        PFIndexes[i] = ShuffleMask[i];
    }
 
    // Compute the index in the perfect shuffle table.
    unsigned PFTableIndex = PFIndexes[0] * 9 * 9 * 9 + PFIndexes[1] * 9 * 9 +
                            PFIndexes[2] * 9 + PFIndexes[3];
    unsigned PFEntry = PerfectShuffleTable[PFTableIndex];
    return GeneratePerfectShuffle(PFTableIndex, V1, V2, PFEntry, V1, V2, DAG,
                                  DL);
  }
 
  // Check for a "select shuffle", generating a BSL to pick between lanes in
  // V1/V2.
  if (ShuffleVectorInst::isSelectMask(ShuffleMask, NumElts)) {
    assert(VT.getScalarSizeInBits() <= 32 &&
           "Expected larger vector element sizes to be handled already");
    SmallVector<SDValue> MaskElts;
    for (int M : ShuffleMask)
      MaskElts.push_back(DAG.getConstant(
          M >= static_cast<int>(NumElts) ? 0 : 0xffffffff, DL, MVT::i32));
    EVT IVT = VT.changeVectorElementTypeToInteger();
    SDValue MaskConst = DAG.getBuildVector(IVT, DL, MaskElts);
    return DAG.getBitcast(VT, DAG.getNode(AArch64ISD::BSP, DL, IVT, MaskConst,
                                          DAG.getBitcast(IVT, V1),
                                          DAG.getBitcast(IVT, V2)));
  }
 
  // Fall back to generating a TBL
  return GenerateTBL(Op, ShuffleMask, DAG);
}
 
SDValue AArch64TargetLowering::LowerSPLAT_VECTOR(SDValue Op,
                                                 SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
    return LowerToScalableOp(Op, DAG);
 
  assert(VT.isScalableVector() && VT.getVectorElementType() == MVT::i1 &&
         "Unexpected vector type!");
 
  // We can handle the constant cases during isel.
  if (isa<ConstantSDNode>(Op.getOperand(0)))
    return Op;
 
  // There isn't a natural way to handle the general i1 case, so we use some
  // trickery with whilelo.
  SDLoc DL(Op);
  SDValue SplatVal = DAG.getAnyExtOrTrunc(Op.getOperand(0), DL, MVT::i64);
  SplatVal = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i64, SplatVal,
                         DAG.getValueType(MVT::i1));
  SDValue ID =
      DAG.getTargetConstant(Intrinsic::aarch64_sve_whilelo, DL, MVT::i64);
  SDValue Zero = DAG.getConstant(0, DL, MVT::i64);
  if (VT == MVT::nxv1i1)
    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::nxv1i1,
                       DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, MVT::nxv2i1, ID,
                                   Zero, SplatVal),
                       Zero);
  return DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT, ID, Zero, SplatVal);
}
 
SDValue AArch64TargetLowering::LowerDUPQLane(SDValue Op,
                                             SelectionDAG &DAG) const {
  SDLoc DL(Op);
 
  EVT VT = Op.getValueType();
  if (!isTypeLegal(VT) || !VT.isScalableVector())
    return SDValue();
 
  // Current lowering only supports the SVE-ACLE types.
  if (VT.getSizeInBits().getKnownMinValue() != AArch64::SVEBitsPerBlock)
    return SDValue();
 
  // The DUPQ operation is independent of element type so normalise to i64s.
  SDValue Idx128 = Op.getOperand(2);
 
  // DUPQ can be used when idx is in range.
  auto *CIdx = dyn_cast<ConstantSDNode>(Idx128);
  if (CIdx && (CIdx->getZExtValue() <= 3)) {
    SDValue CI = DAG.getTargetConstant(CIdx->getZExtValue(), DL, MVT::i64);
    return DAG.getNode(AArch64ISD::DUPLANE128, DL, VT, Op.getOperand(1), CI);
  }
 
  SDValue V = DAG.getNode(ISD::BITCAST, DL, MVT::nxv2i64, Op.getOperand(1));
 
  // The ACLE says this must produce the same result as:
  //   svtbl(data, svadd_x(svptrue_b64(),
  //                       svand_x(svptrue_b64(), svindex_u64(0, 1), 1),
  //                       index * 2))
  SDValue One = DAG.getConstant(1, DL, MVT::i64);
  SDValue SplatOne = DAG.getNode(ISD::SPLAT_VECTOR, DL, MVT::nxv2i64, One);
 
  // create the vector 0,1,0,1,...
  SDValue SV = DAG.getStepVector(DL, MVT::nxv2i64);
  SV = DAG.getNode(ISD::AND, DL, MVT::nxv2i64, SV, SplatOne);
 
  // create the vector idx64,idx64+1,idx64,idx64+1,...
  SDValue Idx64 = DAG.getNode(ISD::ADD, DL, MVT::i64, Idx128, Idx128);
  SDValue SplatIdx64 = DAG.getNode(ISD::SPLAT_VECTOR, DL, MVT::nxv2i64, Idx64);
  SDValue ShuffleMask = DAG.getNode(ISD::ADD, DL, MVT::nxv2i64, SV, SplatIdx64);
 
  // create the vector Val[idx64],Val[idx64+1],Val[idx64],Val[idx64+1],...
  SDValue TBL = DAG.getNode(AArch64ISD::TBL, DL, MVT::nxv2i64, V, ShuffleMask);
  return DAG.getNode(ISD::BITCAST, DL, VT, TBL);
}
 
 
static bool resolveBuildVector(BuildVectorSDNode *BVN, APInt &CnstBits,
                               APInt &UndefBits) {
  EVT VT = BVN->getValueType(0);
  APInt SplatBits, SplatUndef;
  unsigned SplatBitSize;
  bool HasAnyUndefs;
  if (BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize, HasAnyUndefs)) {
    unsigned NumSplats = VT.getSizeInBits() / SplatBitSize;
 
    for (unsigned i = 0; i < NumSplats; ++i) {
      CnstBits <<= SplatBitSize;
      UndefBits <<= SplatBitSize;
      CnstBits |= SplatBits.zextOrTrunc(VT.getSizeInBits());
      UndefBits |= (SplatBits ^ SplatUndef).zextOrTrunc(VT.getSizeInBits());
    }
 
    return true;
  }
 
  return false;
}
 
// Try 64-bit splatted SIMD immediate.
static SDValue tryAdvSIMDModImm64(unsigned NewOp, SDValue Op, SelectionDAG &DAG,
                                 const APInt &Bits) {
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    EVT VT = Op.getValueType();
    MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v2i64 : MVT::f64;
 
    if (AArch64_AM::isAdvSIMDModImmType10(Value)) {
      Value = AArch64_AM::encodeAdvSIMDModImmType10(Value);
 
      SDLoc DL(Op);
      SDValue Mov =
          DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32));
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Try 32-bit splatted SIMD immediate.
static SDValue tryAdvSIMDModImm32(unsigned NewOp, SDValue Op, SelectionDAG &DAG,
                                  const APInt &Bits,
                                  const SDValue *LHS = nullptr) {
  EVT VT = Op.getValueType();
  if (VT.isFixedLengthVector() &&
      !DAG.getSubtarget<AArch64Subtarget>().isNeonAvailable())
    return SDValue();
 
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
    bool isAdvSIMDModImm = false;
    uint64_t Shift;
 
    if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType1(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType1(Value);
      Shift = 0;
    }
    else if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType2(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType2(Value);
      Shift = 8;
    }
    else if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType3(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType3(Value);
      Shift = 16;
    }
    else if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType4(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType4(Value);
      Shift = 24;
    }
 
    if (isAdvSIMDModImm) {
      SDLoc DL(Op);
      SDValue Mov;
 
      if (LHS)
        Mov = DAG.getNode(NewOp, DL, MovTy,
                          DAG.getNode(AArch64ISD::NVCAST, DL, MovTy, *LHS),
                          DAG.getConstant(Value, DL, MVT::i32),
                          DAG.getConstant(Shift, DL, MVT::i32));
      else
        Mov =
            DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32),
                        DAG.getConstant(Shift, DL, MVT::i32));
 
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Try 16-bit splatted SIMD immediate.
static SDValue tryAdvSIMDModImm16(unsigned NewOp, SDValue Op, SelectionDAG &DAG,
                                  const APInt &Bits,
                                  const SDValue *LHS = nullptr) {
  EVT VT = Op.getValueType();
  if (VT.isFixedLengthVector() &&
      !DAG.getSubtarget<AArch64Subtarget>().isNeonAvailable())
    return SDValue();
 
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v8i16 : MVT::v4i16;
    bool isAdvSIMDModImm = false;
    uint64_t Shift;
 
    if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType5(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType5(Value);
      Shift = 0;
    }
    else if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType6(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType6(Value);
      Shift = 8;
    }
 
    if (isAdvSIMDModImm) {
      SDLoc DL(Op);
      SDValue Mov;
 
      if (LHS)
        Mov = DAG.getNode(NewOp, DL, MovTy,
                          DAG.getNode(AArch64ISD::NVCAST, DL, MovTy, *LHS),
                          DAG.getConstant(Value, DL, MVT::i32),
                          DAG.getConstant(Shift, DL, MVT::i32));
      else
        Mov =
            DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32),
                        DAG.getConstant(Shift, DL, MVT::i32));
 
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Try 32-bit splatted SIMD immediate with shifted ones.
static SDValue tryAdvSIMDModImm321s(unsigned NewOp, SDValue Op,
                                    SelectionDAG &DAG, const APInt &Bits) {
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    EVT VT = Op.getValueType();
    MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v4i32 : MVT::v2i32;
    bool isAdvSIMDModImm = false;
    uint64_t Shift;
 
    if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType7(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType7(Value);
      Shift = 264;
    }
    else if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType8(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType8(Value);
      Shift = 272;
    }
 
    if (isAdvSIMDModImm) {
      SDLoc DL(Op);
      SDValue Mov =
          DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32),
                      DAG.getConstant(Shift, DL, MVT::i32));
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Try 8-bit splatted SIMD immediate.
static SDValue tryAdvSIMDModImm8(unsigned NewOp, SDValue Op, SelectionDAG &DAG,
                                 const APInt &Bits) {
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    EVT VT = Op.getValueType();
    MVT MovTy = (VT.getSizeInBits() == 128) ? MVT::v16i8 : MVT::v8i8;
 
    if (AArch64_AM::isAdvSIMDModImmType9(Value)) {
      Value = AArch64_AM::encodeAdvSIMDModImmType9(Value);
 
      SDLoc DL(Op);
      SDValue Mov =
          DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32));
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Try FP splatted SIMD immediate.
static SDValue tryAdvSIMDModImmFP(unsigned NewOp, SDValue Op, SelectionDAG &DAG,
                                  const APInt &Bits) {
  if (Bits.getHiBits(64) == Bits.getLoBits(64)) {
    uint64_t Value = Bits.zextOrTrunc(64).getZExtValue();
    EVT VT = Op.getValueType();
    bool isWide = (VT.getSizeInBits() == 128);
    MVT MovTy;
    bool isAdvSIMDModImm = false;
 
    if ((isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType11(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType11(Value);
      MovTy = isWide ? MVT::v4f32 : MVT::v2f32;
    }
    else if (isWide &&
             (isAdvSIMDModImm = AArch64_AM::isAdvSIMDModImmType12(Value))) {
      Value = AArch64_AM::encodeAdvSIMDModImmType12(Value);
      MovTy = MVT::v2f64;
    }
 
    if (isAdvSIMDModImm) {
      SDLoc DL(Op);
      SDValue Mov =
          DAG.getNode(NewOp, DL, MovTy, DAG.getConstant(Value, DL, MVT::i32));
      return DAG.getNode(AArch64ISD::NVCAST, DL, VT, Mov);
    }
  }
 
  return SDValue();
}
 
// Specialized code to quickly find if PotentialBVec is a BuildVector that
// consists of only the same constant int value, returned in reference arg
// ConstVal
static bool isAllConstantBuildVector(const SDValue &PotentialBVec,
                                     uint64_t &ConstVal) {
  BuildVectorSDNode *Bvec = dyn_cast<BuildVectorSDNode>(PotentialBVec);
  if (!Bvec)
    return false;
  ConstantSDNode *FirstElt = dyn_cast<ConstantSDNode>(Bvec->getOperand(0));
  if (!FirstElt)
    return false;
  EVT VT = Bvec->getValueType(0);
  unsigned NumElts = VT.getVectorNumElements();
  for (unsigned i = 1; i < NumElts; ++i)
    if (dyn_cast<ConstantSDNode>(Bvec->getOperand(i)) != FirstElt)
      return false;
  ConstVal = FirstElt->getZExtValue();
  return true;
}
 
static bool isAllInactivePredicate(SDValue N) {
  // Look through cast.
  while (N.getOpcode() == AArch64ISD::REINTERPRET_CAST)
    N = N.getOperand(0);
 
  return ISD::isConstantSplatVectorAllZeros(N.getNode());
}
 
static bool isAllActivePredicate(SelectionDAG &DAG, SDValue N) {
  unsigned NumElts = N.getValueType().getVectorMinNumElements();
 
  // Look through cast.
  while (N.getOpcode() == AArch64ISD::REINTERPRET_CAST) {
    N = N.getOperand(0);
    // When reinterpreting from a type with fewer elements the "new" elements
    // are not active, so bail if they're likely to be used.
    if (N.getValueType().getVectorMinNumElements() < NumElts)
      return false;
  }
 
  if (ISD::isConstantSplatVectorAllOnes(N.getNode()))
    return true;
 
  // "ptrue p.<ty>, all" can be considered all active when <ty> is the same size
  // or smaller than the implicit element type represented by N.
  // NOTE: A larger element count implies a smaller element type.
  if (N.getOpcode() == AArch64ISD::PTRUE &&
      N.getConstantOperandVal(0) == AArch64SVEPredPattern::all)
    return N.getValueType().getVectorMinNumElements() >= NumElts;
 
  return false;
}
 
// Attempt to form a vector S[LR]I from (or (and X, BvecC1), (lsl Y, C2)),
// to (SLI X, Y, C2), where X and Y have matching vector types, BvecC1 is a
// BUILD_VECTORs with constant element C1, C2 is a constant, and:
//   - for the SLI case: C1 == ~(Ones(ElemSizeInBits) << C2)
//   - for the SRI case: C1 == ~(Ones(ElemSizeInBits) >> C2)
// The (or (lsl Y, C2), (and X, BvecC1)) case is also handled.
static SDValue tryLowerToSLI(SDNode *N, SelectionDAG &DAG) {
  EVT VT = N->getValueType(0);
 
  if (!VT.isVector())
    return SDValue();
 
  SDLoc DL(N);
 
  SDValue And;
  SDValue Shift;
 
  SDValue FirstOp = N->getOperand(0);
  unsigned FirstOpc = FirstOp.getOpcode();
  SDValue SecondOp = N->getOperand(1);
  unsigned SecondOpc = SecondOp.getOpcode();
 
  // Is one of the operands an AND or a BICi? The AND may have been optimised to
  // a BICi in order to use an immediate instead of a register.
  // Is the other operand an shl or lshr? This will have been turned into:
  // AArch64ISD::VSHL vector, #shift or AArch64ISD::VLSHR vector, #shift
  // or (AArch64ISD::SHL_PRED || AArch64ISD::SRL_PRED) mask, vector, #shiftVec.
  if ((FirstOpc == ISD::AND || FirstOpc == AArch64ISD::BICi) &&
      (SecondOpc == AArch64ISD::VSHL || SecondOpc == AArch64ISD::VLSHR ||
       SecondOpc == AArch64ISD::SHL_PRED ||
       SecondOpc == AArch64ISD::SRL_PRED)) {
    And = FirstOp;
    Shift = SecondOp;
 
  } else if ((SecondOpc == ISD::AND || SecondOpc == AArch64ISD::BICi) &&
             (FirstOpc == AArch64ISD::VSHL || FirstOpc == AArch64ISD::VLSHR ||
              FirstOpc == AArch64ISD::SHL_PRED ||
              FirstOpc == AArch64ISD::SRL_PRED)) {
    And = SecondOp;
    Shift = FirstOp;
  } else
    return SDValue();
 
  bool IsAnd = And.getOpcode() == ISD::AND;
  bool IsShiftRight = Shift.getOpcode() == AArch64ISD::VLSHR ||
                      Shift.getOpcode() == AArch64ISD::SRL_PRED;
  bool ShiftHasPredOp = Shift.getOpcode() == AArch64ISD::SHL_PRED ||
                        Shift.getOpcode() == AArch64ISD::SRL_PRED;
 
  // Is the shift amount constant and are all lanes active?
  uint64_t C2;
  if (ShiftHasPredOp) {
    if (!isAllActivePredicate(DAG, Shift.getOperand(0)))
      return SDValue();
    APInt C;
    if (!ISD::isConstantSplatVector(Shift.getOperand(2).getNode(), C))
      return SDValue();
    C2 = C.getZExtValue();
  } else if (ConstantSDNode *C2node =
                 dyn_cast<ConstantSDNode>(Shift.getOperand(1)))
    C2 = C2node->getZExtValue();
  else
    return SDValue();
 
  APInt C1AsAPInt;
  unsigned ElemSizeInBits = VT.getScalarSizeInBits();
  if (IsAnd) {
    // Is the and mask vector all constant?
    if (!ISD::isConstantSplatVector(And.getOperand(1).getNode(), C1AsAPInt))
      return SDValue();
  } else {
    // Reconstruct the corresponding AND immediate from the two BICi immediates.
    ConstantSDNode *C1nodeImm = dyn_cast<ConstantSDNode>(And.getOperand(1));
    ConstantSDNode *C1nodeShift = dyn_cast<ConstantSDNode>(And.getOperand(2));
    assert(C1nodeImm && C1nodeShift);
    C1AsAPInt = ~(C1nodeImm->getAPIntValue() << C1nodeShift->getAPIntValue());
    C1AsAPInt = C1AsAPInt.zextOrTrunc(ElemSizeInBits);
  }
 
  // Is C1 == ~(Ones(ElemSizeInBits) << C2) or
  // C1 == ~(Ones(ElemSizeInBits) >> C2), taking into account
  // how much one can shift elements of a particular size?
  if (C2 > ElemSizeInBits)
    return SDValue();
 
  APInt RequiredC1 = IsShiftRight ? APInt::getHighBitsSet(ElemSizeInBits, C2)
                                  : APInt::getLowBitsSet(ElemSizeInBits, C2);
  if (C1AsAPInt != RequiredC1)
    return SDValue();
 
  SDValue X = And.getOperand(0);
  SDValue Y = ShiftHasPredOp ? Shift.getOperand(1) : Shift.getOperand(0);
  SDValue Imm = ShiftHasPredOp ? DAG.getTargetConstant(C2, DL, MVT::i32)
                               : Shift.getOperand(1);
 
  unsigned Inst = IsShiftRight ? AArch64ISD::VSRI : AArch64ISD::VSLI;
  return DAG.getNode(Inst, DL, VT, X, Y, Imm);
}
 
static SDValue tryLowerToBSL(SDValue N, SelectionDAG &DAG) {
  EVT VT = N->getValueType(0);
  assert(VT.isVector() && "Expected vector type in tryLowerToBSL\n");
  SDLoc DL(N);
  const auto &Subtarget = DAG.getSubtarget<AArch64Subtarget>();
 
  if (VT.isScalableVector() && !Subtarget.hasSVE2())
    return SDValue();
 
  SDValue N0 = N->getOperand(0);
  if (N0.getOpcode() != ISD::AND)
    return SDValue();
 
  SDValue N1 = N->getOperand(1);
  if (N1.getOpcode() != ISD::AND)
    return SDValue();
 
  // InstCombine does (not (neg a)) => (add a -1).
  // Try: (or (and (neg a) b) (and (add a -1) c)) => (bsl (neg a) b c)
  // Loop over all combinations of AND operands.
  for (int i = 1; i >= 0; --i) {
    for (int j = 1; j >= 0; --j) {
      SDValue O0 = N0->getOperand(i);
      SDValue O1 = N1->getOperand(j);
      SDValue Sub, Add, SubSibling, AddSibling;
 
      // Find a SUB and an ADD operand, one from each AND.
      if (O0.getOpcode() == ISD::SUB && O1.getOpcode() == ISD::ADD) {
        Sub = O0;
        Add = O1;
        SubSibling = N0->getOperand(1 - i);
        AddSibling = N1->getOperand(1 - j);
      } else if (O0.getOpcode() == ISD::ADD && O1.getOpcode() == ISD::SUB) {
        Add = O0;
        Sub = O1;
        AddSibling = N0->getOperand(1 - i);
        SubSibling = N1->getOperand(1 - j);
      } else
        continue;
 
      if (!ISD::isConstantSplatVectorAllZeros(Sub.getOperand(0).getNode()))
        continue;
 
      // Constant ones is always righthand operand of the Add.
      if (!ISD::isConstantSplatVectorAllOnes(Add.getOperand(1).getNode()))
        continue;
 
      if (Sub.getOperand(1) != Add.getOperand(0))
        continue;
 
      return DAG.getNode(AArch64ISD::BSP, DL, VT, Sub, SubSibling, AddSibling);
    }
  }
 
  // (or (and a b) (and (not a) c)) => (bsl a b c)
  // We only have to look for constant vectors here since the general, variable
  // case can be handled in TableGen.
  unsigned Bits = VT.getScalarSizeInBits();
  for (int i = 1; i >= 0; --i)
    for (int j = 1; j >= 0; --j) {
      APInt Val1, Val2;
 
      if (ISD::isConstantSplatVector(N0->getOperand(i).getNode(), Val1) &&
          ISD::isConstantSplatVector(N1->getOperand(j).getNode(), Val2) &&
          ~Val1.trunc(Bits) == Val2.trunc(Bits)) {
        return DAG.getNode(AArch64ISD::BSP, DL, VT, N0->getOperand(i),
                           N0->getOperand(1 - i), N1->getOperand(1 - j));
      }
      BuildVectorSDNode *BVN0 = dyn_cast<BuildVectorSDNode>(N0->getOperand(i));
      BuildVectorSDNode *BVN1 = dyn_cast<BuildVectorSDNode>(N1->getOperand(j));
      if (!BVN0 || !BVN1)
        continue;
 
      bool FoundMatch = true;
      for (unsigned k = 0; k < VT.getVectorNumElements(); ++k) {
        ConstantSDNode *CN0 = dyn_cast<ConstantSDNode>(BVN0->getOperand(k));
        ConstantSDNode *CN1 = dyn_cast<ConstantSDNode>(BVN1->getOperand(k));
        if (!CN0 || !CN1 ||
            CN0->getAPIntValue().trunc(Bits) !=
                ~CN1->getAsAPIntVal().trunc(Bits)) {
          FoundMatch = false;
          break;
        }
      }
      if (FoundMatch)
        return DAG.getNode(AArch64ISD::BSP, DL, VT, N0->getOperand(i),
                           N0->getOperand(1 - i), N1->getOperand(1 - j));
    }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerVectorOR(SDValue Op,
                                             SelectionDAG &DAG) const {
  if (useSVEForFixedLengthVectorVT(Op.getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerToScalableOp(Op, DAG);
 
  if (SDValue Res = tryLowerToBSL(Op, DAG))
    return Res;
 
  // Attempt to form a vector S[LR]I from (or (and X, C1), (lsl Y, C2))
  if (SDValue Res = tryLowerToSLI(Op.getNode(), DAG))
    return Res;
 
  EVT VT = Op.getValueType();
  if (VT.isScalableVector())
    return Op;
 
  SDValue LHS = Op.getOperand(0);
  BuildVectorSDNode *BVN =
      dyn_cast<BuildVectorSDNode>(Op.getOperand(1).getNode());
  if (!BVN) {
    // OR commutes, so try swapping the operands.
    LHS = Op.getOperand(1);
    BVN = dyn_cast<BuildVectorSDNode>(Op.getOperand(0).getNode());
  }
  if (!BVN)
    return Op;
 
  APInt DefBits(VT.getSizeInBits(), 0);
  APInt UndefBits(VT.getSizeInBits(), 0);
  if (resolveBuildVector(BVN, DefBits, UndefBits)) {
    SDValue NewOp;
 
    if ((NewOp = tryAdvSIMDModImm32(AArch64ISD::ORRi, Op, DAG,
                                    DefBits, &LHS)) ||
        (NewOp = tryAdvSIMDModImm16(AArch64ISD::ORRi, Op, DAG,
                                    DefBits, &LHS)))
      return NewOp;
 
    if ((NewOp = tryAdvSIMDModImm32(AArch64ISD::ORRi, Op, DAG,
                                    UndefBits, &LHS)) ||
        (NewOp = tryAdvSIMDModImm16(AArch64ISD::ORRi, Op, DAG,
                                    UndefBits, &LHS)))
      return NewOp;
  }
 
  // We can always fall back to a non-immediate OR.
  return Op;
}
 
// Normalize the operands of BUILD_VECTOR. The value of constant operands will
// be truncated to fit element width.
static SDValue NormalizeBuildVector(SDValue Op,
                                    SelectionDAG &DAG) {
  assert(Op.getOpcode() == ISD::BUILD_VECTOR && "Unknown opcode!");
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
  EVT EltTy= VT.getVectorElementType();
 
  if (EltTy.isFloatingPoint() || EltTy.getSizeInBits() > 16)
    return Op;
 
  SmallVector<SDValue, 16> Ops;
  for (SDValue Lane : Op->ops()) {
    // For integer vectors, type legalization would have promoted the
    // operands already. Otherwise, if Op is a floating-point splat
    // (with operands cast to integers), then the only possibilities
    // are constants and UNDEFs.
    if (auto *CstLane = dyn_cast<ConstantSDNode>(Lane)) {
      Lane = DAG.getConstant(
          CstLane->getAPIntValue().trunc(EltTy.getSizeInBits()).getZExtValue(),
          DL, MVT::i32);
    } else if (Lane.getOpcode() == ISD::POISON) {
      Lane = DAG.getPOISON(MVT::i32);
    } else if (Lane.getOpcode() == ISD::UNDEF) {
      Lane = DAG.getUNDEF(MVT::i32);
    } else {
      assert(Lane.getValueType() == MVT::i32 &&
             "Unexpected BUILD_VECTOR operand type");
    }
    Ops.push_back(Lane);
  }
  return DAG.getBuildVector(VT, DL, Ops);
}
 
static SDValue trySVESplat64(SDValue Op, SelectionDAG &DAG,
                             const AArch64Subtarget *ST, APInt &DefBits) {
  EVT VT = Op.getValueType();
  // TODO: We should be able to support 64-bit destinations too
  if (!ST->hasSVE() || !VT.is128BitVector() ||
      DefBits.getHiBits(64) != DefBits.getLoBits(64))
    return SDValue();
 
  // See if we can make use of the SVE dup instruction.
  APInt Val64 = DefBits.trunc(64);
  int32_t ImmVal, ShiftVal;
  uint64_t Encoding;
  if (!AArch64_AM::isSVECpyDupImm(64, Val64.getSExtValue(), ImmVal, ShiftVal) &&
      !AArch64_AM::isSVELogicalImm(64, Val64.getZExtValue(), Encoding))
    return SDValue();
 
  SDLoc DL(Op);
  SDValue SplatVal = DAG.getNode(AArch64ISD::DUP, DL, MVT::v2i64,
                                 DAG.getConstant(Val64, DL, MVT::i64));
  return DAG.getNode(AArch64ISD::NVCAST, DL, VT, SplatVal);
}
 
static SDValue ConstantBuildVector(SDValue Op, SelectionDAG &DAG,
                                   const AArch64Subtarget *ST) {
  EVT VT = Op.getValueType();
  assert((VT.getSizeInBits() == 64 || VT.getSizeInBits() == 128) &&
         "Expected a legal NEON vector");
 
  APInt DefBits(VT.getSizeInBits(), 0);
  APInt UndefBits(VT.getSizeInBits(), 0);
  BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
  if (resolveBuildVector(BVN, DefBits, UndefBits)) {
    auto TryMOVIWithBits = [&](APInt DefBits) {
      SDValue NewOp;
      if ((NewOp =
               tryAdvSIMDModImm64(AArch64ISD::MOVIedit, Op, DAG, DefBits)) ||
          (NewOp =
               tryAdvSIMDModImm32(AArch64ISD::MOVIshift, Op, DAG, DefBits)) ||
          (NewOp =
               tryAdvSIMDModImm321s(AArch64ISD::MOVImsl, Op, DAG, DefBits)) ||
          (NewOp =
               tryAdvSIMDModImm16(AArch64ISD::MOVIshift, Op, DAG, DefBits)) ||
          (NewOp = tryAdvSIMDModImm8(AArch64ISD::MOVI, Op, DAG, DefBits)) ||
          (NewOp = tryAdvSIMDModImmFP(AArch64ISD::FMOV, Op, DAG, DefBits)))
        return NewOp;
 
      APInt NotDefBits = ~DefBits;
      if ((NewOp = tryAdvSIMDModImm32(AArch64ISD::MVNIshift, Op, DAG,
                                      NotDefBits)) ||
          (NewOp = tryAdvSIMDModImm321s(AArch64ISD::MVNImsl, Op, DAG,
                                        NotDefBits)) ||
          (NewOp =
               tryAdvSIMDModImm16(AArch64ISD::MVNIshift, Op, DAG, NotDefBits)))
        return NewOp;
      return SDValue();
    };
    if (SDValue R = TryMOVIWithBits(DefBits))
      return R;
    if (SDValue R = TryMOVIWithBits(UndefBits))
      return R;
 
    // Try to materialise the constant using SVE when available.
    if (SDValue R = trySVESplat64(Op, DAG, ST, DefBits))
      return R;
 
    // See if a fneg of the constant can be materialized with a MOVI, etc
    auto TryWithFNeg = [&](APInt DefBits, MVT FVT) {
      // FNegate each sub-element of the constant
      assert(VT.getSizeInBits() % FVT.getScalarSizeInBits() == 0);
      APInt Neg = APInt::getHighBitsSet(FVT.getSizeInBits(), 1)
                      .zext(VT.getSizeInBits());
      APInt NegBits(VT.getSizeInBits(), 0);
      unsigned NumElts = VT.getSizeInBits() / FVT.getScalarSizeInBits();
      for (unsigned i = 0; i < NumElts; i++)
        NegBits |= Neg << (FVT.getScalarSizeInBits() * i);
      NegBits = DefBits ^ NegBits;
 
      // Try to create the new constants with MOVI, and if so generate a fneg
      // for it.
      if (SDValue NewOp = TryMOVIWithBits(NegBits)) {
        SDLoc DL(Op);
        MVT VFVT = NumElts == 1 ? FVT : MVT::getVectorVT(FVT, NumElts);
        return DAG.getNode(
            AArch64ISD::NVCAST, DL, VT,
            DAG.getNode(ISD::FNEG, DL, VFVT,
                        DAG.getNode(AArch64ISD::NVCAST, DL, VFVT, NewOp)));
      }
      return SDValue();
    };
    SDValue R;
    if ((R = TryWithFNeg(DefBits, MVT::f32)) ||
        (R = TryWithFNeg(DefBits, MVT::f64)) ||
        (ST->hasFullFP16() && (R = TryWithFNeg(DefBits, MVT::f16))))
      return R;
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerFixedLengthBuildVectorToSVE(
    SDValue Op, SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  EVT ContainerVT = getContainerForFixedLengthVector(DAG, VT);
  auto *BVN = cast<BuildVectorSDNode>(Op);
 
  if (auto SeqInfo = BVN->isArithmeticSequence()) {
    SDValue Start = DAG.getConstant(SeqInfo->first, DL, ContainerVT);
    SDValue Steps = DAG.getStepVector(DL, ContainerVT, SeqInfo->second);
    SDValue Seq = DAG.getNode(ISD::ADD, DL, ContainerVT, Start, Steps);
    return convertFromScalableVector(DAG, VT, Seq);
  }
 
  unsigned NumElems = VT.getVectorNumElements();
  if (!VT.isPow2VectorType() || VT.getFixedSizeInBits() > 128 ||
      NumElems <= 1 || BVN->isConstant())
    return SDValue();
 
  auto IsExtractElt = [](SDValue Op) {
    return Op.getOpcode() == ISD::EXTRACT_VECTOR_ELT;
  };
 
  // For integer types that are not already in vectors limit to at most four
  // elements. This is an arbitrary restriction to avoid many fmovs from GPRs.
  if (VT.getScalarType().isInteger() &&
      NumElems - count_if(Op->op_values(), IsExtractElt) > 4)
    return SDValue();
 
  // Lower (pow2) BUILD_VECTORS that are <= 128-bit to a sequence of ZIP1s.
  SDValue ZeroI64 = DAG.getConstant(0, DL, MVT::i64);
  SmallVector<SDValue, 16> Intermediates = map_to_vector<16>(
      Op->op_values(), [&, Poison = DAG.getPOISON(ContainerVT)](SDValue Op) {
        return Op.isUndef() ? Poison
                            : DAG.getNode(ISD::INSERT_VECTOR_ELT, DL,
                                          ContainerVT, Poison, Op, ZeroI64);
      });
 
  ElementCount ZipEC = ContainerVT.getVectorElementCount();
  while (Intermediates.size() > 1) {
    EVT ZipVT = getPackedSVEVectorVT(ZipEC);
 
    for (unsigned I = 0; I < Intermediates.size(); I += 2) {
      SDValue Op0 = DAG.getBitcast(ZipVT, Intermediates[I + 0]);
      SDValue Op1 = DAG.getBitcast(ZipVT, Intermediates[I + 1]);
      Intermediates[I / 2] =
          Op1.isUndef() ? Op0
                        : DAG.getNode(AArch64ISD::ZIP1, DL, ZipVT, Op0, Op1);
    }
 
    Intermediates.resize(Intermediates.size() / 2);
    ZipEC = ZipEC.divideCoefficientBy(2);
  }
 
  assert(Intermediates.size() == 1);
  SDValue Vec = DAG.getBitcast(ContainerVT, Intermediates[0]);
  return convertFromScalableVector(DAG, VT, Vec);
}
 
SDValue AArch64TargetLowering::LowerBUILD_VECTOR(SDValue Op,
                                                 SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
 
  bool OverrideNEON = !Subtarget->isNeonAvailable() ||
                      cast<BuildVectorSDNode>(Op)->isArithmeticSequence();
  if (useSVEForFixedLengthVectorVT(VT, OverrideNEON))
    return LowerFixedLengthBuildVectorToSVE(Op, DAG);
 
  // Try to build a simple constant vector.
  Op = NormalizeBuildVector(Op, DAG);
  // Thought this might return a non-BUILD_VECTOR (e.g. CONCAT_VECTORS), if so,
  // abort.
  if (Op.getOpcode() != ISD::BUILD_VECTOR)
    return SDValue();
 
  // Certain vector constants, used to express things like logical NOT and
  // arithmetic NEG, are passed through unmodified.  This allows special
  // patterns for these operations to match, which will lower these constants
  // to whatever is proven necessary.
  BuildVectorSDNode *BVN = cast<BuildVectorSDNode>(Op.getNode());
  if (BVN->isConstant()) {
    if (ConstantSDNode *Const = BVN->getConstantSplatNode()) {
      unsigned BitSize = VT.getVectorElementType().getSizeInBits();
      APInt Val(BitSize,
                Const->getAPIntValue().zextOrTrunc(BitSize).getZExtValue());
      if (Val.isZero() || (VT.isInteger() && Val.isAllOnes()))
        return Op;
    }
    if (ConstantFPSDNode *Const = BVN->getConstantFPSplatNode())
      if (Const->isZero() && !Const->isNegative())
        return Op;
  }
 
  if (SDValue V = ConstantBuildVector(Op, DAG, Subtarget))
    return V;
 
  // Scan through the operands to find some interesting properties we can
  // exploit:
  //   1) If only one value is used, we can use a DUP, or
  //   2) if only the low element is not undef, we can just insert that, or
  //   3) if only one constant value is used (w/ some non-constant lanes),
  //      we can splat the constant value into the whole vector then fill
  //      in the non-constant lanes.
  //   4) FIXME: If different constant values are used, but we can intelligently
  //             select the values we'll be overwriting for the non-constant
  //             lanes such that we can directly materialize the vector
  //             some other way (MOVI, e.g.), we can be sneaky.
  //   5) if all operands are EXTRACT_VECTOR_ELT, check for VUZP.
  SDLoc DL(Op);
  unsigned NumElts = VT.getVectorNumElements();
  bool isOnlyLowElement = true;
  bool usesOnlyOneValue = true;
  bool usesOnlyOneConstantValue = true;
  bool isConstant = true;
  bool AllLanesExtractElt = true;
  unsigned NumConstantLanes = 0;
  unsigned NumDifferentLanes = 0;
  unsigned NumUndefLanes = 0;
  SDValue Value;
  SDValue ConstantValue;
  SmallMapVector<SDValue, unsigned, 16> DifferentValueMap;
  unsigned ConsecutiveValCount = 0;
  SDValue PrevVal;
  auto IsZero = [&](SDValue V) {
    return isNullConstant(V) || isNullFPConstant(V);
  };
  bool MaybeLowHalfZeroHigh =
      VT.isFixedLengthVector() && VT.getSizeInBits() == 128;
  unsigned HalfElts = MaybeLowHalfZeroHigh ? (NumElts >> 1) : 0;
  SDValue LowHalfFirstVal = MaybeLowHalfZeroHigh ? Op.getOperand(0) : SDValue();
  for (unsigned i = 0; i < NumElts; ++i) {
    SDValue V = Op.getOperand(i);
    if (V.getOpcode() != ISD::EXTRACT_VECTOR_ELT)
      AllLanesExtractElt = false;
    if (V.isUndef()) {
      ++NumUndefLanes;
      MaybeLowHalfZeroHigh = false;
      continue;
    }
    if (i > 0)
      isOnlyLowElement = false;
    if (!isIntOrFPConstant(V))
      isConstant = false;
 
    if (isIntOrFPConstant(V)) {
      ++NumConstantLanes;
      if (!ConstantValue.getNode())
        ConstantValue = V;
      else if (ConstantValue != V)
        usesOnlyOneConstantValue = false;
    }
 
    if (!Value.getNode())
      Value = V;
    else if (V != Value) {
      usesOnlyOneValue = false;
      ++NumDifferentLanes;
    }
 
    if (PrevVal != V) {
      ConsecutiveValCount = 0;
      PrevVal = V;
    }
    if (MaybeLowHalfZeroHigh) {
      if (i < HalfElts) {
        if (V != LowHalfFirstVal)
          MaybeLowHalfZeroHigh = false;
      } else if (!IsZero(V)) {
        MaybeLowHalfZeroHigh = false;
      }
    }
 
    // Keep different values and its last consecutive count. For example,
    //
    //  t22: v16i8 = build_vector t23, t23, t23, t23, t23, t23, t23, t23,
    //                            t24, t24, t24, t24, t24, t24, t24, t24
    //  t23 = consecutive count 8
    //  t24 = consecutive count 8
    // ------------------------------------------------------------------
    //  t22: v16i8 = build_vector t24, t24, t23, t23, t23, t23, t23, t24,
    //                            t24, t24, t24, t24, t24, t24, t24, t24
    //  t23 = consecutive count 5
    //  t24 = consecutive count 9
    DifferentValueMap[V] = ++ConsecutiveValCount;
  }
 
  if (!Value.getNode()) {
    LLVM_DEBUG(
        dbgs() << "LowerBUILD_VECTOR: value undefined, creating undef node\n");
    return DAG.getUNDEF(VT);
  }
 
  // Convert BUILD_VECTOR where all elements but the lowest are undef into
  // SCALAR_TO_VECTOR, except for when we have a single-element constant vector
  // as SimplifyDemandedBits will just turn that back into BUILD_VECTOR.
  if (isOnlyLowElement && !(NumElts == 1 && isIntOrFPConstant(Value))) {
    LLVM_DEBUG(dbgs() << "LowerBUILD_VECTOR: only low element used, creating 1 "
                         "SCALAR_TO_VECTOR node\n");
    return DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VT, Value);
  }
 
  if (MaybeLowHalfZeroHigh && LowHalfFirstVal.getNode() &&
      !LowHalfFirstVal.isUndef() && !isIntOrFPConstant(LowHalfFirstVal)) {
    EVT LaneVT = VT.getVectorElementType();
    EVT HalfVT = VT.getHalfNumVectorElementsVT(*DAG.getContext());
 
    SDValue HiZero = LaneVT.isInteger() ? DAG.getConstant(0, DL, HalfVT)
                                        : DAG.getConstantFP(0.0, DL, HalfVT);
 
    SDValue LoHalf =
        LaneVT.getSizeInBits() == 64
            ? DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, HalfVT, LowHalfFirstVal)
            : DAG.getNode(AArch64ISD::DUP, DL, HalfVT, LowHalfFirstVal);
 
    return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, LoHalf, HiZero);
  }
 
  if (AllLanesExtractElt) {
    SDNode *Vector = nullptr;
    bool Even = false;
    bool Odd = false;
    // Check whether the extract elements match the Even pattern <0,2,4,...> or
    // the Odd pattern <1,3,5,...>.
    for (unsigned i = 0; i < NumElts; ++i) {
      SDValue V = Op.getOperand(i);
      const SDNode *N = V.getNode();
      if (!isa<ConstantSDNode>(N->getOperand(1))) {
        Even = false;
        Odd = false;
        break;
      }
      SDValue N0 = N->getOperand(0);
 
      // All elements are extracted from the same vector.
      if (!Vector) {
        Vector = N0.getNode();
        // Check that the type of EXTRACT_VECTOR_ELT matches the type of
        // BUILD_VECTOR.
        if (VT.getVectorElementType() !=
            N0.getValueType().getVectorElementType())
          break;
      } else if (Vector != N0.getNode()) {
        Odd = false;
        Even = false;
        break;
      }
 
      // Extracted values are either at Even indices <0,2,4,...> or at Odd
      // indices <1,3,5,...>.
      uint64_t Val = N->getConstantOperandVal(1);
      if (Val == 2 * i) {
        Even = true;
        continue;
      }
      if (Val - 1 == 2 * i) {
        Odd = true;
        continue;
      }
 
      // Something does not match: abort.
      Odd = false;
      Even = false;
      break;
    }
    if (Even || Odd) {
      SDValue LHS =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, SDValue(Vector, 0),
                      DAG.getConstant(0, DL, MVT::i64));
      SDValue RHS =
          DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, SDValue(Vector, 0),
                      DAG.getConstant(NumElts, DL, MVT::i64));
 
      if (Even && !Odd)
        return DAG.getNode(AArch64ISD::UZP1, DL, VT, LHS, RHS);
      if (Odd && !Even)
        return DAG.getNode(AArch64ISD::UZP2, DL, VT, LHS, RHS);
    }
  }
 
  // Use DUP for non-constant splats. For f32 constant splats, reduce to
  // i32 and try again.
  if (usesOnlyOneValue) {
    if (!isConstant) {
      if (Value.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
          Value.getValueType() != VT) {
        LLVM_DEBUG(
            dbgs() << "LowerBUILD_VECTOR: use DUP for non-constant splats\n");
        return DAG.getNode(AArch64ISD::DUP, DL, VT, Value);
      }
 
      // This is actually a DUPLANExx operation, which keeps everything vectory.
 
      SDValue Lane = Value.getOperand(1);
      Value = Value.getOperand(0);
      if (Value.getValueSizeInBits() == 64) {
        LLVM_DEBUG(
            dbgs() << "LowerBUILD_VECTOR: DUPLANE works on 128-bit vectors, "
                      "widening it\n");
        Value = WidenVector(Value, DAG);
      }
 
      unsigned Opcode = getDUPLANEOp(VT.getVectorElementType());
      return DAG.getNode(Opcode, DL, VT, Value, Lane);
    }
 
    if (VT.getVectorElementType().isFloatingPoint()) {
      SmallVector<SDValue, 8> Ops;
      EVT EltTy = VT.getVectorElementType();
      assert ((EltTy == MVT::f16 || EltTy == MVT::bf16 || EltTy == MVT::f32 ||
               EltTy == MVT::f64) && "Unsupported floating-point vector type");
      LLVM_DEBUG(
          dbgs() << "LowerBUILD_VECTOR: float constant splats, creating int "
                    "BITCASTS, and try again\n");
      MVT NewType = MVT::getIntegerVT(EltTy.getSizeInBits());
      for (unsigned i = 0; i < NumElts; ++i)
        Ops.push_back(DAG.getNode(ISD::BITCAST, DL, NewType, Op.getOperand(i)));
      EVT VecVT = EVT::getVectorVT(*DAG.getContext(), NewType, NumElts);
      SDValue Val = DAG.getBuildVector(VecVT, DL, Ops);
      LLVM_DEBUG(dbgs() << "LowerBUILD_VECTOR: trying to lower new vector: ";
                 Val.dump(););
      Val = LowerBUILD_VECTOR(Val, DAG);
      if (Val.getNode())
        return DAG.getNode(ISD::BITCAST, DL, VT, Val);
    }
  }
 
  // If we need to insert a small number of different non-constant elements and
  // the vector width is sufficiently large, prefer using DUP with the common
  // value and INSERT_VECTOR_ELT for the different lanes. If DUP is preferred,
  // skip the constant lane handling below.
  bool PreferDUPAndInsert =
      !isConstant && NumDifferentLanes >= 1 &&
      NumDifferentLanes < ((NumElts - NumUndefLanes) / 2) &&
      NumDifferentLanes >= NumConstantLanes;
 
  // If there was only one constant value used and for more than one lane,
  // start by splatting that value, then replace the non-constant lanes. This
  // is better than the default, which will perform a separate initialization
  // for each lane.
  if (!PreferDUPAndInsert && NumConstantLanes > 0 && usesOnlyOneConstantValue) {
    // Firstly, try to materialize the splat constant.
    SDValue Val = DAG.getSplatBuildVector(VT, DL, ConstantValue);
    unsigned BitSize = VT.getScalarSizeInBits();
    APInt ConstantValueAPInt(1, 0);
    if (auto *C = dyn_cast<ConstantSDNode>(ConstantValue))
      ConstantValueAPInt = C->getAPIntValue().zextOrTrunc(BitSize);
    if (!isNullConstant(ConstantValue) && !isNullFPConstant(ConstantValue) &&
        !ConstantValueAPInt.isAllOnes()) {
      Val = ConstantBuildVector(Val, DAG, Subtarget);
      if (!Val)
        // Otherwise, materialize the constant and splat it.
        Val = DAG.getNode(AArch64ISD::DUP, DL, VT, ConstantValue);
    }
 
    // Now insert the non-constant lanes.
    for (unsigned i = 0; i < NumElts; ++i) {
      SDValue V = Op.getOperand(i);
      SDValue LaneIdx = DAG.getConstant(i, DL, MVT::i64);
      if (!isIntOrFPConstant(V) && !V.isUndef())
        // Note that type legalization likely mucked about with the VT of the
        // source operand, so we may have to convert it here before inserting.
        Val = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, Val, V, LaneIdx);
    }
    return Val;
  }
 
  // Handle 64-bit constant BUILD_VECTORs by packing them into an i64 immediate.
  // This is cheaper than a load if the immediate can be materialized in a few
  // mov instructions. This optimization is disabled for big-endian targets for
  // now.
  if (BVN->isConstant() && VT.isFixedLengthVector() &&
      VT.getSizeInBits() == 64 && !DAG.getDataLayout().isBigEndian()) {
    const SDLoc DL(Op);
    APInt PackedVal(64, 0);
    unsigned BitPos = 0;
 
    unsigned EltSizeInBits = VT.getScalarSizeInBits();
    for (unsigned i = 0, e = BVN->getNumOperands(); i != e; ++i) {
      const SDValue &LaneOp = BVN->getOperand(i);
      APInt LaneBits;
      if (LaneOp.getOpcode() == ISD::UNDEF)
        LaneBits = APInt(EltSizeInBits, 0);
      else if (auto *C = dyn_cast<ConstantSDNode>(LaneOp))
        LaneBits = C->getAPIntValue();
      else if (auto *CFP = dyn_cast<ConstantFPSDNode>(LaneOp))
        LaneBits = CFP->getValueAPF().bitcastToAPInt();
      else
        return SDValue();
 
      PackedVal |= LaneBits.trunc(VT.getScalarSizeInBits()).zext(64) << BitPos;
      BitPos += EltSizeInBits;
    }
 
    // This optimization kicks in if the number of mov instructions
    // is under 2
    SmallVector<AArch64_IMM::ImmInsnModel, 4> Insns;
    AArch64_IMM::expandMOVImm(PackedVal.getZExtValue(), 64, Insns);
    if (Insns.size() > 2)
      return SDValue();
 
    SDValue ScalarConst = DAG.getConstant(PackedVal, DL, MVT::i64);
    // Use BITCAST to reinterpret the scalar constant's bits as a vector.
    return DAG.getNode(ISD::BITCAST, DL, VT, ScalarConst);
  }
 
  // This will generate a load from the constant pool.
  if (isConstant) {
    LLVM_DEBUG(
        dbgs() << "LowerBUILD_VECTOR: all elements are constant, use default "
                  "expansion\n");
    return SDValue();
  }
 
  // Detect patterns of a0,a1,a2,a3,b0,b1,b2,b3,c0,c1,c2,c3,d0,d1,d2,d3 from
  // v4i32s. This is really a truncate, which we can construct out of (legal)
  // concats and truncate nodes.
  if (SDValue M = ReconstructTruncateFromBuildVector(Op, DAG))
    return M;
 
  // Empirical tests suggest this is rarely worth it for vectors of length <= 2.
  if (NumElts >= 4) {
    if (SDValue Shuffle = ReconstructShuffle(Op, DAG))
      return Shuffle;
 
    if (SDValue Shuffle = ReconstructShuffleWithRuntimeMask(Op, DAG))
      return Shuffle;
  }
 
  if (PreferDUPAndInsert) {
    // First, build a constant vector with the common element.
    SmallVector<SDValue, 8> Ops(NumElts, Value);
    SDValue NewVector = LowerBUILD_VECTOR(DAG.getBuildVector(VT, DL, Ops), DAG);
    // Next, insert the elements that do not match the common value.
    for (unsigned I = 0; I < NumElts; ++I)
      if (Op.getOperand(I) != Value)
        NewVector =
            DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, NewVector,
                        Op.getOperand(I), DAG.getConstant(I, DL, MVT::i64));
 
    return NewVector;
  }
 
  // If vector consists of two different values, try to generate two DUPs and
  // (CONCAT_VECTORS or VECTOR_SHUFFLE).
  if (DifferentValueMap.size() == 2 && NumUndefLanes == 0) {
    SmallVector<SDValue, 2> Vals;
    // Check the consecutive count of the value is the half number of vector
    // elements. In this case, we can use CONCAT_VECTORS. For example,
    //
    // canUseVECTOR_CONCAT = true;
    //  t22: v16i8 = build_vector t23, t23, t23, t23, t23, t23, t23, t23,
    //                            t24, t24, t24, t24, t24, t24, t24, t24
    //
    // canUseVECTOR_CONCAT = false;
    //  t22: v16i8 = build_vector t23, t23, t23, t23, t23, t24, t24, t24,
    //                            t24, t24, t24, t24, t24, t24, t24, t24
    bool canUseVECTOR_CONCAT = true;
    for (auto Pair : DifferentValueMap) {
      // Check different values have same length which is NumElts / 2.
      if (Pair.second != NumElts / 2)
        canUseVECTOR_CONCAT = false;
      Vals.push_back(Pair.first);
    }
 
    // If canUseVECTOR_CONCAT is true, we can generate two DUPs and
    // CONCAT_VECTORs. For example,
    //
    //  t22: v16i8 = BUILD_VECTOR t23, t23, t23, t23, t23, t23, t23, t23,
    //                            t24, t24, t24, t24, t24, t24, t24, t24
    // ==>
    //    t26: v8i8 = AArch64ISD::DUP t23
    //    t28: v8i8 = AArch64ISD::DUP t24
    //  t29: v16i8 = concat_vectors t26, t28
    if (canUseVECTOR_CONCAT) {
      EVT SubVT = VT.getHalfNumVectorElementsVT(*DAG.getContext());
      if (isTypeLegal(SubVT) && SubVT.isVector() &&
          SubVT.getVectorNumElements() >= 2) {
        SmallVector<SDValue, 8> Ops1(NumElts / 2, Vals[0]);
        SmallVector<SDValue, 8> Ops2(NumElts / 2, Vals[1]);
        SDValue DUP1 =
            LowerBUILD_VECTOR(DAG.getBuildVector(SubVT, DL, Ops1), DAG);
        SDValue DUP2 =
            LowerBUILD_VECTOR(DAG.getBuildVector(SubVT, DL, Ops2), DAG);
        SDValue CONCAT_VECTORS =
            DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, DUP1, DUP2);
        return CONCAT_VECTORS;
      }
    }
 
    // Let's try to generate VECTOR_SHUFFLE. For example,
    //
    //  t24: v8i8 = BUILD_VECTOR t25, t25, t25, t25, t26, t26, t26, t26
    //  ==>
    //    t27: v8i8 = BUILD_VECTOR t26, t26, t26, t26, t26, t26, t26, t26
    //    t28: v8i8 = BUILD_VECTOR t25, t25, t25, t25, t25, t25, t25, t25
    //  t29: v8i8 = vector_shuffle<0,1,2,3,12,13,14,15> t27, t28
    if (NumElts >= 8) {
      SmallVector<int, 16> MaskVec;
      // Build mask for VECTOR_SHUFLLE.
      SDValue FirstLaneVal = Op.getOperand(0);
      for (unsigned i = 0; i < NumElts; ++i) {
        SDValue Val = Op.getOperand(i);
        if (FirstLaneVal == Val)
          MaskVec.push_back(i);
        else
          MaskVec.push_back(i + NumElts);
      }
 
      SmallVector<SDValue, 8> Ops1(NumElts, Vals[0]);
      SmallVector<SDValue, 8> Ops2(NumElts, Vals[1]);
      SDValue VEC1 = DAG.getBuildVector(VT, DL, Ops1);
      SDValue VEC2 = DAG.getBuildVector(VT, DL, Ops2);
      SDValue VECTOR_SHUFFLE =
          DAG.getVectorShuffle(VT, DL, VEC1, VEC2, MaskVec);
      return VECTOR_SHUFFLE;
    }
  }
 
  // If all else fails, just use a sequence of INSERT_VECTOR_ELT when we
  // know the default expansion would otherwise fall back on something even
  // worse. For a vector with one or two non-undef values, that's
  // scalar_to_vector for the elements followed by a shuffle (provided the
  // shuffle is valid for the target) and materialization element by element
  // on the stack followed by a load for everything else.
  if (!isConstant && !usesOnlyOneValue) {
    LLVM_DEBUG(
        dbgs() << "LowerBUILD_VECTOR: alternatives failed, creating sequence "
                  "of INSERT_VECTOR_ELT\n");
 
    SDValue Vec = DAG.getPOISON(VT);
    SDValue Op0 = Op.getOperand(0);
    unsigned i = 0;
 
    // Use SCALAR_TO_VECTOR for lane zero to
    // a) Avoid a RMW dependency on the full vector register, and
    // b) Allow the register coalescer to fold away the copy if the
    //    value is already in an S or D register, and we're forced to emit an
    //    INSERT_SUBREG that we can't fold anywhere.
    //
    // We also allow types like i8 and i16 which are illegal scalar but legal
    // vector element types. After type-legalization the inserted value is
    // extended (i32) and it is safe to cast them to the vector type by ignoring
    // the upper bits of the lowest lane (e.g. v8i8, v4i16).
    if (!Op0.isUndef()) {
      LLVM_DEBUG(dbgs() << "Creating node for op0, it is not undefined:\n");
      Vec = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, VT, Op0);
      ++i;
    }
    LLVM_DEBUG({
      if (i < NumElts)
        dbgs() << "Creating nodes for the other vector elements:\n";
    });
    for (; i < NumElts; ++i) {
      SDValue V = Op.getOperand(i);
      if (V.isUndef())
        continue;
      SDValue LaneIdx = DAG.getConstant(i, DL, MVT::i64);
      Vec = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT, Vec, V, LaneIdx);
    }
    return Vec;
  }
 
  LLVM_DEBUG(
      dbgs() << "LowerBUILD_VECTOR: use default expansion, failed to find "
                "better alternative\n");
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerCONCAT_VECTORS(SDValue Op,
                                                   SelectionDAG &DAG) const {
  if (useSVEForFixedLengthVectorVT(Op.getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerFixedLengthConcatVectorsToSVE(Op, DAG);
 
  assert(Op.getValueType().isScalableVector() &&
         isTypeLegal(Op.getValueType()) &&
         "Expected legal scalable vector type!");
 
  if (isTypeLegal(Op.getOperand(0).getValueType())) {
    unsigned NumOperands = Op->getNumOperands();
    assert(NumOperands > 1 && isPowerOf2_32(NumOperands) &&
           "Unexpected number of operands in CONCAT_VECTORS");
 
    if (NumOperands == 2)
      return Op;
 
    // Concat each pair of subvectors and pack into the lower half of the array.
    SmallVector<SDValue> ConcatOps(Op->ops());
    while (ConcatOps.size() > 1) {
      for (unsigned I = 0, E = ConcatOps.size(); I != E; I += 2) {
        SDValue V1 = ConcatOps[I];
        SDValue V2 = ConcatOps[I + 1];
        EVT SubVT = V1.getValueType();
        EVT PairVT = SubVT.getDoubleNumVectorElementsVT(*DAG.getContext());
        ConcatOps[I / 2] =
            DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(Op), PairVT, V1, V2);
      }
      ConcatOps.resize(ConcatOps.size() / 2);
    }
    return ConcatOps[0];
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerINSERT_VECTOR_ELT(SDValue Op,
                                                      SelectionDAG &DAG) const {
  assert(Op.getOpcode() == ISD::INSERT_VECTOR_ELT && "Unknown opcode!");
 
  if (useSVEForFixedLengthVectorVT(Op.getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerFixedLengthInsertVectorElt(Op, DAG);
 
  EVT VT = Op.getValueType();
  SDValue Vec = Op.getOperand(0);
  SDValue Elt = Op.getOperand(1);
  SDValue Idx = Op.getOperand(2);
 
  if (VT.getScalarType() == MVT::i1) {
    SDLoc DL(Op);
 
    // MVT::nxv1i8 is not a legal type so widen->insert->shrink instead.
    if (VT == MVT::nxv1i1) {
      SDValue WidenVec =
          DAG.getInsertSubvector(DL, DAG.getPOISON(MVT::nxv2i1), Vec, 0);
      SDValue Insert = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, MVT::nxv2i1,
                                   WidenVec, Elt, Idx);
      return DAG.getExtractSubvector(DL, MVT::nxv1i1, Insert, 0);
    }
 
    EVT PromoteVT = getPromotedVTForPredicate(VT);
    SDValue PromoteVec = DAG.getNode(ISD::ANY_EXTEND, DL, PromoteVT, Vec);
    if (PromoteVT.getVectorElementType() == MVT::i64)
      Elt = DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, Elt);
    SDValue Insert = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, PromoteVT,
                                 PromoteVec, Elt, Idx);
    return DAG.getNode(ISD::TRUNCATE, DL, VT, Insert);
  }
 
  // Check for non-constant or out of range lane.
  ConstantSDNode *CI = dyn_cast<ConstantSDNode>(Idx);
  if (!CI || CI->getZExtValue() >= VT.getVectorNumElements())
    return SDValue();
 
  return Op;
}
 
SDValue
AArch64TargetLowering::LowerEXTRACT_VECTOR_ELT(SDValue Op,
                                               SelectionDAG &DAG) const {
  assert(Op.getOpcode() == ISD::EXTRACT_VECTOR_ELT && "Unknown opcode!");
  EVT VT = Op.getOperand(0).getValueType();
 
  if (VT.getScalarType() == MVT::i1) {
    SDLoc DL(Op);
    // There are no operations to extend a nxv1i1 predicate to a nxv1i128 vector
    // An easy lowering is widening the input predicate to nxv2i1.
    if (VT == MVT::nxv1i1) {
      SDValue WidenedPred = DAG.getInsertSubvector(
          DL, DAG.getPOISON(MVT::nxv2i1), Op->getOperand(0), 0);
      return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, Op.getValueType(),
                         WidenedPred, Op.getOperand(1));
    }
    // We can't directly extract from an SVE predicate; extend it first.
    // (This isn't the only possible lowering, but it's straightforward.)
    EVT VectorVT = getPromotedVTForPredicate(VT);
    SDValue Extend =
        DAG.getNode(ISD::ANY_EXTEND, DL, VectorVT, Op.getOperand(0));
    MVT ExtractTy = VectorVT == MVT::nxv2i64 ? MVT::i64 : MVT::i32;
    SDValue Extract = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ExtractTy,
                                  Extend, Op.getOperand(1));
    return DAG.getAnyExtOrTrunc(Extract, DL, Op.getValueType());
  }
 
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
    return LowerFixedLengthExtractVectorElt(Op, DAG);
 
  // Check for non-constant or out of range lane.
  ConstantSDNode *CI = dyn_cast<ConstantSDNode>(Op.getOperand(1));
  if (!CI || CI->getZExtValue() >= VT.getVectorNumElements())
    return SDValue();
 
  // Insertion/extraction are legal for V128 types.
  if (VT == MVT::v16i8 || VT == MVT::v8i16 || VT == MVT::v4i32 ||
      VT == MVT::v2i64 || VT == MVT::v4f32 || VT == MVT::v2f64 ||
      VT == MVT::v8f16 || VT == MVT::v8bf16)
    return Op;
 
  if (VT != MVT::v8i8 && VT != MVT::v4i16 && VT != MVT::v2i32 &&
      VT != MVT::v1i64 && VT != MVT::v2f32 && VT != MVT::v4f16 &&
      VT != MVT::v4bf16)
    return SDValue();
 
  // For V64 types, we perform extraction by expanding the value
  // to a V128 type and perform the extraction on that.
  SDLoc DL(Op);
  SDValue WideVec = WidenVector(Op.getOperand(0), DAG);
  EVT WideTy = WideVec.getValueType();
 
  EVT ExtrTy = WideTy.getVectorElementType();
  if (ExtrTy == MVT::i16 || ExtrTy == MVT::i8)
    ExtrTy = MVT::i32;
 
  // For extractions, we just return the result directly.
  return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ExtrTy, WideVec,
                     Op.getOperand(1));
}
 
SDValue AArch64TargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
                                                      SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  assert(VT.isFixedLengthVector() &&
         "Only cases that extract a fixed length vector are supported!");
  EVT InVT = Op.getOperand(0).getValueType();
 
  // If we don't have legal types yet, do nothing
  if (!isTypeLegal(InVT))
    return SDValue();
 
  if (InVT.is128BitVector()) {
    assert(VT.is64BitVector() && "Extracting unexpected vector type!");
    unsigned Idx = Op.getConstantOperandVal(1);
 
    // This will get lowered to an appropriate EXTRACT_SUBREG in ISel.
    if (Idx == 0)
      return Op;
 
    // If this is extracting the upper 64-bits of a 128-bit vector, we match
    // that directly.
    if (Idx * InVT.getScalarSizeInBits() == 64 && Subtarget->isNeonAvailable())
      return Op;
  }
 
  if (InVT.isScalableVector() ||
      useSVEForFixedLengthVectorVT(InVT, !Subtarget->isNeonAvailable())) {
    SDLoc DL(Op);
    SDValue Vec = Op.getOperand(0);
    SDValue Idx = Op.getOperand(1);
 
    EVT PackedVT = getPackedSVEVectorVT(InVT.getVectorElementType());
    if (PackedVT != InVT) {
      // Pack input into the bottom part of an SVE register and try again.
      SDValue Container = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, PackedVT,
                                      DAG.getPOISON(PackedVT), Vec,
                                      DAG.getVectorIdxConstant(0, DL));
      return DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, Container, Idx);
    }
 
    // This will get matched by custom code during ISelDAGToDAG.
    if (isNullConstant(Idx))
      return Op;
 
    assert(InVT.isScalableVector() && "Unexpected vector type!");
    // Move requested subvector to the start of the vector and try again.
    SDValue Splice =
        DAG.getNode(ISD::VECTOR_SPLICE_LEFT, DL, InVT, Vec, Vec, Idx);
    return convertFromScalableVector(DAG, VT, Splice);
  }
 
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerINSERT_SUBVECTOR(SDValue Op,
                                                     SelectionDAG &DAG) const {
  assert(Op.getValueType().isScalableVector() &&
         "Only expect to lower inserts into scalable vectors!");
 
  EVT InVT = Op.getOperand(1).getValueType();
  unsigned Idx = Op.getConstantOperandVal(2);
 
  SDValue Vec0 = Op.getOperand(0);
  SDValue Vec1 = Op.getOperand(1);
  SDLoc DL(Op);
  EVT VT = Op.getValueType();
 
  if (InVT.isScalableVector()) {
    if (!isTypeLegal(VT))
      return SDValue();
 
    // Break down insert_subvector into simpler parts.
    if (VT.getVectorElementType() == MVT::i1) {
      unsigned NumElts = VT.getVectorMinNumElements();
      EVT HalfVT = VT.getHalfNumVectorElementsVT(*DAG.getContext());
 
      SDValue Lo, Hi;
      Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, Vec0,
                       DAG.getVectorIdxConstant(0, DL));
      Hi = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, HalfVT, Vec0,
                       DAG.getVectorIdxConstant(NumElts / 2, DL));
      if (Idx < (NumElts / 2))
        Lo = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, HalfVT, Lo, Vec1,
                         DAG.getVectorIdxConstant(Idx, DL));
      else
        Hi = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, HalfVT, Hi, Vec1,
                         DAG.getVectorIdxConstant(Idx - (NumElts / 2), DL));
 
      return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);
    }
 
    // We can select these directly.
    if (isTypeLegal(InVT) && Vec0.isUndef())
      return Op;
 
    // Ensure the subvector is half the size of the main vector.
    if (VT.getVectorElementCount() != (InVT.getVectorElementCount() * 2))
      return SDValue();
 
    // Here narrow and wide refers to the vector element types. After "casting"
    // both vectors must have the same bit length and so because the subvector
    // has fewer elements, those elements need to be bigger.
    EVT NarrowVT = getPackedSVEVectorVT(VT.getVectorElementCount());
    EVT WideVT = getPackedSVEVectorVT(InVT.getVectorElementCount());
 
    // NOP cast operands to the largest legal vector of the same element count.
    if (VT.isFloatingPoint()) {
      Vec0 = getSVESafeBitCast(NarrowVT, Vec0, DAG);
      Vec1 = getSVESafeBitCast(NarrowVT, Vec1, DAG);
    } else {
      // Legal integer vectors are already their largest so Vec0 is fine as is.
      Vec1 = DAG.getNode(ISD::ANY_EXTEND, DL, WideVT, Vec1);
      Vec1 = DAG.getNode(AArch64ISD::NVCAST, DL, NarrowVT, Vec1);
    }
 
    // To replace the top/bottom half of vector V with vector SubV we widen the
    // preserved half of V, concatenate this to SubV (the order depending on the
    // half being replaced) and then narrow the result.
    SDValue Narrow;
    if (Idx == 0) {
      SDValue HiVec0 = DAG.getNode(AArch64ISD::UUNPKHI, DL, WideVT, Vec0);
      HiVec0 = DAG.getNode(AArch64ISD::NVCAST, DL, NarrowVT, HiVec0);
      Narrow = DAG.getNode(AArch64ISD::UZP1, DL, NarrowVT, Vec1, HiVec0);
    } else {
      assert(Idx == InVT.getVectorMinNumElements() &&
             "Invalid subvector index!");
      SDValue LoVec0 = DAG.getNode(AArch64ISD::UUNPKLO, DL, WideVT, Vec0);
      LoVec0 = DAG.getNode(AArch64ISD::NVCAST, DL, NarrowVT, LoVec0);
      Narrow = DAG.getNode(AArch64ISD::UZP1, DL, NarrowVT, LoVec0, Vec1);
    }
 
    return getSVESafeBitCast(VT, Narrow, DAG);
  }
 
  if (Idx == 0 && isPackedVectorType(VT, DAG)) {
    // This will be matched by custom code during ISelDAGToDAG.
    if (Vec0.isUndef())
      return Op;
 
    std::optional<unsigned> PredPattern =
        getSVEPredPatternFromNumElements(InVT.getVectorNumElements());
    auto PredTy = VT.changeVectorElementType(*DAG.getContext(), MVT::i1);
    SDValue PTrue = getPTrue(DAG, DL, PredTy, *PredPattern);
    SDValue ScalableVec1 = convertToScalableVector(DAG, VT, Vec1);
    return DAG.getNode(ISD::VSELECT, DL, VT, PTrue, ScalableVec1, Vec0);
  }
 
  return SDValue();
}
 
static bool isPow2Splat(SDValue Op, uint64_t &SplatVal, bool &Negated) {
  if (Op.getOpcode() != AArch64ISD::DUP &&
      Op.getOpcode() != ISD::SPLAT_VECTOR &&
      Op.getOpcode() != ISD::BUILD_VECTOR)
    return false;
 
  if (Op.getOpcode() == ISD::BUILD_VECTOR &&
      !isAllConstantBuildVector(Op, SplatVal))
    return false;
 
  if (Op.getOpcode() != ISD::BUILD_VECTOR &&
      !isa<ConstantSDNode>(Op->getOperand(0)))
    return false;
 
  SplatVal = Op->getConstantOperandVal(0);
  if (Op.getValueType().getVectorElementType() != MVT::i64)
    SplatVal = (int32_t)SplatVal;
 
  Negated = false;
  if (isPowerOf2_64(SplatVal))
    return true;
 
  Negated = true;
  if (isPowerOf2_64(-SplatVal)) {
    SplatVal = -SplatVal;
    return true;
  }
 
  return false;
}
 
SDValue AArch64TargetLowering::LowerDIV(SDValue Op, SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
 
  if (useSVEForFixedLengthVectorVT(VT, /*OverrideNEON=*/true))
    return LowerFixedLengthVectorIntDivideToSVE(Op, DAG);
 
  unsigned Opc = Op.getOpcode();
  assert((Opc == ISD::SDIV || Opc == ISD::UDIV) && "Expected a DIV opcode.");
  assert(VT.isScalableVector() && "Expected a scalable vector.");
  bool Signed = Opc == ISD::SDIV;
 
  bool Negated;
  uint64_t SplatVal;
  // NOTE: SRAD cannot be used to represent sdiv-by-one.
  if (Signed && isPow2Splat(Op.getOperand(1), SplatVal, Negated) &&
      SplatVal > 1) {
    SDValue Pg = getPredicateForScalableVector(DAG, DL, VT);
    SDValue Res =
        DAG.getNode(AArch64ISD::ASRD_MERGE_OP1, DL, VT, Pg, Op->getOperand(0),
                    DAG.getTargetConstant(Log2_64(SplatVal), DL, MVT::i32));
    if (Negated)
      Res = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), Res);
 
    return Res;
  }
 
  if (VT == MVT::nxv4i32 || VT == MVT::nxv2i64) {
    unsigned MaskedOpcode = Signed ? ISD::MASKED_SDIV : ISD::MASKED_UDIV;
    return DAG.getNode(MaskedOpcode, DL, VT, Op.getOperand(0), Op.getOperand(1),
                       getPredicateForVector(DAG, DL, VT));
  }
 
  // SVE doesn't have i8 and i16 DIV operations; widen them to 32-bit
  // operations, and truncate the result.
  EVT WidenedVT;
  if (VT == MVT::nxv16i8)
    WidenedVT = MVT::nxv8i16;
  else if (VT == MVT::nxv8i16)
    WidenedVT = MVT::nxv4i32;
  else
    llvm_unreachable("Unexpected Custom DIV operation");
 
  unsigned UnpkLo = Signed ? AArch64ISD::SUNPKLO : AArch64ISD::UUNPKLO;
  unsigned UnpkHi = Signed ? AArch64ISD::SUNPKHI : AArch64ISD::UUNPKHI;
  SDValue Op0Lo = DAG.getNode(UnpkLo, DL, WidenedVT, Op.getOperand(0));
  SDValue Op1Lo = DAG.getNode(UnpkLo, DL, WidenedVT, Op.getOperand(1));
  SDValue Op0Hi = DAG.getNode(UnpkHi, DL, WidenedVT, Op.getOperand(0));
  SDValue Op1Hi = DAG.getNode(UnpkHi, DL, WidenedVT, Op.getOperand(1));
  SDValue ResultLo = DAG.getNode(Opc, DL, WidenedVT, Op0Lo, Op1Lo);
  SDValue ResultHi = DAG.getNode(Opc, DL, WidenedVT, Op0Hi, Op1Hi);
  SDValue ResultLoCast = DAG.getNode(AArch64ISD::NVCAST, DL, VT, ResultLo);
  SDValue ResultHiCast = DAG.getNode(AArch64ISD::NVCAST, DL, VT, ResultHi);
  return DAG.getNode(AArch64ISD::UZP1, DL, VT, ResultLoCast, ResultHiCast);
}
 
bool AArch64TargetLowering::shouldExpandBuildVectorWithShuffles(
    EVT VT, unsigned DefinedValues) const {
  if (!Subtarget->isNeonAvailable())
    return false;
  return TargetLowering::shouldExpandBuildVectorWithShuffles(VT, DefinedValues);
}
 
bool AArch64TargetLowering::isShuffleMaskLegal(ArrayRef<int> M, EVT VT) const {
  // Currently no fixed length shuffles that require SVE are legal.
  if (useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
    return false;
 
  if (VT.getVectorNumElements() == 4 &&
      (VT.is128BitVector() || VT.is64BitVector())) {
    unsigned Cost = getPerfectShuffleCost(M);
    if (Cost <= 1)
      return true;
  }
 
  bool DummyBool;
  int DummyInt;
  unsigned DummyUnsigned;
 
  unsigned EltSize = VT.getScalarSizeInBits();
  unsigned NumElts = VT.getVectorNumElements();
  return (ShuffleVectorSDNode::isSplatMask(M) ||
          isREVMask(M, EltSize, NumElts, 64) ||
          isREVMask(M, EltSize, NumElts, 32) ||
          isREVMask(M, EltSize, NumElts, 16) ||
          isEXTMask(M, VT, DummyBool, DummyUnsigned) ||
          isSingletonEXTMask(M, VT, DummyUnsigned) ||
          isTRNMask(M, NumElts, DummyUnsigned, DummyUnsigned) ||
          isUZPMask(M, NumElts, DummyUnsigned) ||
          isZIPMask(M, NumElts, DummyUnsigned, DummyUnsigned) ||
          isTRN_v_undef_Mask(M, VT, DummyUnsigned) ||
          isUZP_v_undef_Mask(M, VT, DummyUnsigned) ||
          isZIP_v_undef_Mask(M, VT, DummyUnsigned) ||
          isINSMask(M, NumElts, DummyBool, DummyInt) ||
          isConcatMask(M, VT, VT.getSizeInBits() == 128));
}
 
bool AArch64TargetLowering::isVectorClearMaskLegal(ArrayRef<int> M,
                                                   EVT VT) const {
  // Just delegate to the generic legality, clear masks aren't special.
  return isShuffleMaskLegal(M, VT);
}
 
/// getVShiftImm - Check if this is a valid build_vector for the immediate
/// operand of a vector shift operation, where all the elements of the
/// build_vector must have the same constant integer value.
static bool getVShiftImm(SDValue Op, unsigned ElementBits, int64_t &Cnt) {
  // Ignore bit_converts.
  while (Op.getOpcode() == ISD::BITCAST)
    Op = Op.getOperand(0);
  BuildVectorSDNode *BVN = dyn_cast<BuildVectorSDNode>(Op.getNode());
  APInt SplatBits, SplatUndef;
  unsigned SplatBitSize;
  bool HasAnyUndefs;
  if (!BVN || !BVN->isConstantSplat(SplatBits, SplatUndef, SplatBitSize,
                                    HasAnyUndefs, ElementBits) ||
      SplatBitSize > ElementBits)
    return false;
  Cnt = SplatBits.getSExtValue();
  return true;
}
 
/// isVShiftLImm - Check if this is a valid build_vector for the immediate
/// operand of a vector shift left operation.  That value must be in the range:
///   0 <= Value < ElementBits for a left shift; or
///   0 <= Value <= ElementBits for a long left shift.
static bool isVShiftLImm(SDValue Op, EVT VT, bool isLong, int64_t &Cnt) {
  assert(VT.isVector() && "vector shift count is not a vector type");
  int64_t ElementBits = VT.getScalarSizeInBits();
  if (!getVShiftImm(Op, ElementBits, Cnt))
    return false;
  return (Cnt >= 0 && (isLong ? Cnt - 1 : Cnt) < ElementBits);
}
 
/// isVShiftRImm - Check if this is a valid build_vector for the immediate
/// operand of a vector shift right operation. The value must be in the range:
///   1 <= Value <= ElementBits for a right shift; or
static bool isVShiftRImm(SDValue Op, EVT VT, bool isNarrow, int64_t &Cnt) {
  assert(VT.isVector() && "vector shift count is not a vector type");
  int64_t ElementBits = VT.getScalarSizeInBits();
  if (!getVShiftImm(Op, ElementBits, Cnt))
    return false;
  return (Cnt >= 1 && Cnt <= (isNarrow ? ElementBits / 2 : ElementBits));
}
 
SDValue AArch64TargetLowering::LowerTRUNCATE(SDValue Op,
                                             SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
 
  if (VT.getScalarType() == MVT::i1) {
    // Lower i1 truncate to `(x & 1) != 0`.
    SDLoc DL(Op);
    EVT OpVT = Op.getOperand(0).getValueType();
    SDValue Zero = DAG.getConstant(0, DL, OpVT);
    SDValue One = DAG.getConstant(1, DL, OpVT);
    SDValue And = DAG.getNode(ISD::AND, DL, OpVT, Op.getOperand(0), One);
    return DAG.getSetCC(DL, VT, And, Zero, ISD::SETNE);
  }
 
  if (!VT.isVector() || VT.isScalableVector())
    return SDValue();
 
  if (useSVEForFixedLengthVectorVT(Op.getOperand(0).getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerFixedLengthVectorTruncateToSVE(Op, DAG);
 
  // We can select these directly.
  if (VT.is64BitVector() && Op.getOperand(0).getValueType().is128BitVector())
    return Op;
 
  return SDValue();
}
 
// Check if we can we lower this SRL to a rounding shift instruction. ResVT is
// possibly a truncated type, it tells how many bits of the value are to be
// used.
static bool canLowerSRLToRoundingShiftForVT(SDValue Shift, EVT ResVT,
                                            SelectionDAG &DAG,
                                            unsigned &ShiftValue,
                                            SDValue &RShOperand) {
  if (Shift->getOpcode() != ISD::SRL)
    return false;
 
  EVT VT = Shift.getValueType();
  assert(VT.isScalableVT());
 
  auto ShiftOp1 =
      dyn_cast_or_null<ConstantSDNode>(DAG.getSplatValue(Shift->getOperand(1)));
  if (!ShiftOp1)
    return false;
 
  ShiftValue = ShiftOp1->getZExtValue();
  if (ShiftValue < 1 || ShiftValue > ResVT.getScalarSizeInBits())
    return false;
 
  SDValue Add = Shift->getOperand(0);
  if (Add->getOpcode() != ISD::ADD || !Add->hasOneUse())
    return false;
 
  assert(ResVT.getScalarSizeInBits() <= VT.getScalarSizeInBits() &&
         "ResVT must be truncated or same type as the shift.");
  // Check if an overflow can lead to incorrect results.
  uint64_t ExtraBits = VT.getScalarSizeInBits() - ResVT.getScalarSizeInBits();
  if (ShiftValue > ExtraBits && !Add->getFlags().hasNoUnsignedWrap())
    return false;
 
  auto AddOp1 =
      dyn_cast_or_null<ConstantSDNode>(DAG.getSplatValue(Add->getOperand(1)));
  if (!AddOp1)
    return false;
  uint64_t AddValue = AddOp1->getZExtValue();
  if (AddValue != 1ULL << (ShiftValue - 1))
    return false;
 
  RShOperand = Add->getOperand(0);
  return true;
}
 
SDValue AArch64TargetLowering::LowerVectorSRA_SRL_SHL(SDValue Op,
                                                      SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  SDLoc DL(Op);
  int64_t Cnt;
 
  if (!Op.getOperand(1).getValueType().isVector())
    return Op;
  unsigned EltSize = VT.getScalarSizeInBits();
 
  switch (Op.getOpcode()) {
  case ISD::SHL:
    if (VT.isScalableVector() ||
        useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable()))
      return LowerToPredicatedOp(Op, DAG, AArch64ISD::SHL_PRED);
 
    if (isVShiftLImm(Op.getOperand(1), VT, false, Cnt) && Cnt < EltSize)
      return DAG.getNode(AArch64ISD::VSHL, DL, VT, Op.getOperand(0),
                         DAG.getTargetConstant(Cnt, DL, MVT::i32));
    return DAG.getNode(
        ISD::INTRINSIC_WO_CHAIN, DL, VT,
        DAG.getTargetConstant(Intrinsic::aarch64_neon_ushl, DL, MVT::i32),
        Op.getOperand(0), Op.getOperand(1));
  case ISD::SRA:
  case ISD::SRL:
    if (VT.isScalableVector() &&
        (Subtarget->hasSVE2() ||
         (Subtarget->hasSME() && Subtarget->isStreaming()))) {
      SDValue RShOperand;
      unsigned ShiftValue;
      if (canLowerSRLToRoundingShiftForVT(Op, VT, DAG, ShiftValue, RShOperand))
        return DAG.getNode(AArch64ISD::URSHR_I_PRED, DL, VT,
                           getPredicateForVector(DAG, DL, VT), RShOperand,
                           DAG.getTargetConstant(ShiftValue, DL, MVT::i32));
    }
 
    if (VT.isScalableVector() ||
        useSVEForFixedLengthVectorVT(VT, !Subtarget->isNeonAvailable())) {
      unsigned Opc = Op.getOpcode() == ISD::SRA ? AArch64ISD::SRA_PRED
                                                : AArch64ISD::SRL_PRED;
      return LowerToPredicatedOp(Op, DAG, Opc);
    }
 
    // Right shift immediate
    if (isVShiftRImm(Op.getOperand(1), VT, false, Cnt) && Cnt < EltSize) {
      unsigned Opc =
          (Op.getOpcode() == ISD::SRA) ? AArch64ISD::VASHR : AArch64ISD::VLSHR;
      return DAG.getNode(Opc, DL, VT, Op.getOperand(0),
                         DAG.getTargetConstant(Cnt, DL, MVT::i32),
                         Op->getFlags());
    }
 
    // Right shift register.  Note, there is not a shift right register
    // instruction, but the shift left register instruction takes a signed
    // value, where negative numbers specify a right shift.
    unsigned Opc = (Op.getOpcode() == ISD::SRA) ? Intrinsic::aarch64_neon_sshl
                                                : Intrinsic::aarch64_neon_ushl;
    // negate the shift amount
    SDValue NegShift = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT),
                                   Op.getOperand(1));
    SDValue NegShiftLeft =
        DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, VT,
                    DAG.getConstant(Opc, DL, MVT::i32), Op.getOperand(0),
                    NegShift);
    return NegShiftLeft;
  }
 
  llvm_unreachable("unexpected shift opcode");
}
 
SDValue AArch64TargetLowering::LowerVSETCC(SDValue Op,
                                           SelectionDAG &DAG) const {
  if (Op.getValueType().isScalableVector())
    return LowerToPredicatedOp(Op, DAG, AArch64ISD::SETCC_MERGE_ZERO);
 
  if (useSVEForFixedLengthVectorVT(Op.getOperand(0).getValueType(),
                                   !Subtarget->isNeonAvailable()))
    return LowerFixedLengthVectorSetccToSVE(Op, DAG);
 
  ISD::CondCode CC = cast<CondCodeSDNode>(Op.getOperand(2))->get();
  SDValue LHS = Op.getOperand(0);
  SDValue RHS = Op.getOperand(1);
  EVT CmpVT = LHS.getValueType().changeVectorElementTypeToInteger();
  SDLoc DL(Op);
 
  if (LHS.getValueType().getVectorElementType().isInteger())
    return Op;
 
  assert(((!Subtarget->hasFullFP16() &&
           LHS.getValueType().getVectorElementType() != MVT::f16) ||
          LHS.getValueType().getVectorElementType() != MVT::bf16 ||
          LHS.getValueType().getVectorElementType() != MVT::f128) &&
         "Unexpected type!");
 
  // Lower isnan(x) | isnan(never-nan) to x != x.
  // Lower !isnan(x) & !isnan(never-nan) to x == x.
  if (CC == ISD::SETUO || CC == ISD::SETO) {
    bool OneNaN = false;
    if (LHS == RHS) {
      OneNaN = true;
    } else if (DAG.isKnownNeverNaN(RHS)) {
      OneNaN = true;
      RHS = LHS;
    } else if (DAG.isKnownNeverNaN(LHS)) {
      OneNaN = true;
      LHS = RHS;
    }
    if (OneNaN) {
      CC = CC == ISD::SETUO ? ISD::SETUNE : ISD::SETOEQ;
    }
  }
 
  // Unfortunately, the mapping of LLVM FP CC's onto AArch64 CC's isn't totally
  // clean.  Some of them require two branches to implement.
  AArch64CC::CondCode CC1, CC2;
  bool ShouldInvert;
  changeVectorFPCCToAArch64CC(CC, CC1, CC2, ShouldInvert);
 
  bool NoNaNs = Op->getFlags().hasNoNaNs();
  SDValue Cmp = emitVectorComparison(LHS, RHS, CC1, NoNaNs, CmpVT, DL, DAG);
  if (!Cmp.getNode())
    return SDValue();
 
  if (CC2 != AArch64CC::AL) {
    SDValue Cmp2 = emitVectorComparison(LHS, RHS, CC2, NoNaNs, CmpVT, DL, DAG);
    if (!Cmp2.getNode())
      return SDValue();
 
    Cmp = DAG.getNode(ISD::OR, DL, CmpVT, Cmp, Cmp2);
  }
 
  Cmp = DAG.getSExtOrTrunc(Cmp, DL, Op.getValueType());
 
  if (ShouldInvert)
    Cmp = DAG.getNOT(DL, Cmp, Cmp.getValueType());
 
  return Cmp;
}
 
static SDValue getReductionSDNode(unsigned Op, SDLoc DL, SDValue ScalarOp,
                                  SelectionDAG &DAG) {
  SDValue VecOp = ScalarOp.getOperand(0);
  auto Rdx = DAG.getNode(Op, DL, VecOp.getSimpleValueType(), VecOp);
  return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, ScalarOp.getValueType(), Rdx,
                     DAG.getConstant(0, DL, MVT::i64));
}
 
static SDValue getVectorBitwiseReduce(unsigned Opcode, SDValue Vec, EVT VT,
                                      SDLoc DL, SelectionDAG &DAG) {
  unsigned ScalarOpcode;
  switch (Opcode) {
  case ISD::VECREDUCE_AND:
    ScalarOpcode = ISD::AND;
    break;
  case ISD::VECREDUCE_OR:
    ScalarOpcode = ISD::OR;
    break;
  case ISD::VECREDUCE_XOR:
    ScalarOpcode = ISD::XOR;
    break;
  default:
    llvm_unreachable("Expected bitwise vector reduction");
    return SDValue();
  }
 
  EVT VecVT = Vec.getValueType();
  assert(VecVT.isFixedLengthVector() && VecVT.isPow2VectorType() &&
         "Expected power-of-2 length vector");
 
  EVT ElemVT = VecVT.getVectorElementType();
 
  SDValue Result;
  unsigned NumElems = VecVT.getVectorNumElements();
 
  // Special case for boolean reductions
  if (ElemVT == MVT::i1) {
    // Split large vectors into smaller ones
    if (NumElems > 16) {
      SDValue Lo, Hi;
      std::tie(Lo, Hi) = DAG.SplitVector(Vec, DL);
      EVT HalfVT = Lo.getValueType();
      SDValue HalfVec = DAG.getNode(ScalarOpcode, DL, HalfVT, Lo, Hi);
      return getVectorBitwiseReduce(Opcode, HalfVec, VT, DL, DAG);
    }
 
    // Results of setcc operations get widened to 128 bits if their input
    // operands are 128 bits wide, otherwise vectors that are less than 64 bits
    // get widened to neatly fit a 64 bit register, so e.g. <4 x i1> gets
    // lowered to either <4 x i16> or <4 x i32>. Sign extending to this element
    // size leads to the best codegen, since e.g. setcc results might need to be
    // truncated otherwise.
    unsigned ExtendedWidth = 64;
    if (Vec.getOpcode() == ISD::SETCC &&
        Vec.getOperand(0).getValueSizeInBits() >= 128) {
      ExtendedWidth = 128;
    }
    EVT ExtendedVT = MVT::getIntegerVT(std::max(ExtendedWidth / NumElems, 8u));
 
    // any_ext doesn't work with umin/umax, so only use it for uadd.
    unsigned ExtendOp =
        ScalarOpcode == ISD::XOR ? ISD::ANY_EXTEND : ISD::SIGN_EXTEND;
    SDValue Extended = DAG.getNode(
        ExtendOp, DL,
        VecVT.changeVectorElementType(*DAG.getContext(), ExtendedVT), Vec);
    // The uminp/uminv and umaxp/umaxv instructions don't have .2d variants, so
    // in that case we bitcast the sign extended values from v2i64 to v4i32
    // before reduction for optimal code generation.
    if ((ScalarOpcode == ISD::AND || ScalarOpcode == ISD::OR) &&
        NumElems == 2 && ExtendedWidth == 128) {
      Extended = DAG.getBitcast(MVT::v4i32, Extended);
      ExtendedVT = MVT::i32;
    }
    switch (ScalarOpcode) {
    case ISD::AND:
      Result = DAG.getNode(ISD::VECREDUCE_UMIN, DL, ExtendedVT, Extended);
      break;
    case ISD::OR:
      Result = DAG.getNode(ISD::VECREDUCE_UMAX, DL, ExtendedVT, Extended);
      break;
    case ISD::XOR:
      Result = DAG.getNode(ISD::VECREDUCE_ADD, DL, ExtendedVT, Extended);
      break;
    default:
      llvm_unreachable("Unexpected Opcode");
    }
 
    Result = DAG.getAnyExtOrTrunc(Result, DL, MVT::i1);
  } else {
    // Iteratively split the vector in half and combine using the bitwise
    // operation until it fits in a 64 bit register.
    while (VecVT.getSizeInBits() > 64) {
      SDValue Lo, Hi;
      std::tie(Lo, Hi) = DAG.SplitVector(Vec, DL);
      VecVT = Lo.getValueType();
      NumElems = VecVT.getVectorNumElements();
      Vec = DAG.getNode(ScalarOpcode, DL, VecVT, Lo, Hi);
    }
 
    EVT ScalarVT = EVT::getIntegerVT(*DAG.getContext(), VecVT.getSizeInBits());
 
    // Do the remaining work on a scalar since it allows the code generator to
    // combine the shift and bitwise operation into one instruction and since
    // integer instructions can have higher throughput than vector instructions.
    SDValue Scalar = DAG.getBitcast(ScalarVT, Vec);
 
    // Iteratively combine the lower and upper halves of the scalar using the
    // bitwise operation, halving the relevant region of the scalar in each
    // iteration, until the relevant region is just one element of the original
    // vector.
    for (unsigned Shift = NumElems / 2; Shift > 0; Shift /= 2) {
      SDValue ShiftAmount =
          DAG.getConstant(Shift * ElemVT.getSizeInBits(), DL, MVT::i64);
      SDValue Shifted =
          DAG.getNode(ISD::SRL, DL, ScalarVT, Scalar, ShiftAmount);
      Scalar = DAG.getNode(ScalarOpcode, DL, ScalarVT, Scalar, Shifted);
    }
 
    Result = DAG.getAnyExtOrTrunc(Scalar, DL, ElemVT);
  }
 
  return DAG.getAnyExtOrTrunc(Result, DL, VT);
}
 
SDValue AArch64TargetLowering::LowerVECREDUCE(SDValue Op,
                                              SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Src = Op.getOperand(0);
  EVT SrcVT = Src.getValueType();
 
  // Scalarize v2f16 to turn it into a faddp. This will be more efficient than
  // widening by inserting zeroes.
  if (Subtarget->hasFullFP16() && Op.getOpcode() == ISD::VECREDUCE_FADD &&
      SrcVT == MVT::v2f16) {
    return DAG.getNode(ISD::FADD, DL, MVT::f16,
                       DAG.getExtractVectorElt(DL, MVT::f16, Src, 0),
                       DAG.getExtractVectorElt(DL, MVT::f16, Src, 1));
  }
 
  // Try lowering the reduction to SVE. This will fail for NEON reductions where
  // SVE is not preferred.
  if (SDValue Result = LowerReductionToSVE(Op, DAG))
    return Result;
 
  // Lower NEON reductions.
  switch (Op.getOpcode()) {
  case ISD::VECREDUCE_AND:
  case ISD::VECREDUCE_OR:
  case ISD::VECREDUCE_XOR:
    return getVectorBitwiseReduce(Op.getOpcode(), Op.getOperand(0),
                                  Op.getValueType(), DL, DAG);
  case ISD::VECREDUCE_ADD:
    return getReductionSDNode(AArch64ISD::UADDV, DL, Op, DAG);
  case ISD::VECREDUCE_SMAX:
    return getReductionSDNode(AArch64ISD::SMAXV, DL, Op, DAG);
  case ISD::VECREDUCE_SMIN:
    return getReductionSDNode(AArch64ISD::SMINV, DL, Op, DAG);
  case ISD::VECREDUCE_UMAX:
    return getReductionSDNode(AArch64ISD::UMAXV, DL, Op, DAG);
  case ISD::VECREDUCE_UMIN:
    return getReductionSDNode(AArch64ISD::UMINV, DL, Op, DAG);
  default:
    llvm_unreachable("Unhandled reduction");
  }
}
 
SDValue AArch64TargetLowering::LowerVECREDUCE_MUL(SDValue Op,
                                                  SelectionDAG &DAG) const {
  SDLoc DL(Op);
  SDValue Src = Op.getOperand(0);
  EVT SrcVT = Src.getValueType();
  assert(SrcVT.isScalableVector() && "Unexpected operand type!");
 
  SDVTList SrcVTs = DAG.getVTList(SrcVT, SrcVT);
  unsigned BaseOpc = ISD::getVecReduceBaseOpcode(Op.getOpcode());
  SDValue Identity = DAG.getIdentityElement(BaseOpc, DL, SrcVT, Op->getFlags());
 
  // Whilst we don't know the size of the vector we do know the maximum size so
  // can perform a tree reduction with an identity vector, which means once we
  // arrive at the result the remaining stages (when the vector is smaller than
  // the maximum) have no affect.
 
  unsigned Segments = AArch64::SVEMaxBitsPerVector / AArch64::SVEBitsPerBlock;
  unsigned Stages = llvm::Log2_32(Segments * SrcVT.getVectorMinNumElements());
 
  for (unsigned I = 0; I < Stages; ++I) {
    Src = DAG.getNode(ISD::VECTOR_DEINTERLEAVE, DL, SrcVTs, Src, Identity);
    Src = DAG.getNode(BaseOpc, DL, SrcVT, Src.getValue(0), Src.getValue(1));
  }
 
  return DAG.getExtractVectorElt(DL, Op.getValueType(), Src, 0);
}
 
SDValue AArch64TargetLowering::LowerATOMIC_LOAD_AND(SDValue Op,
                                                    SelectionDAG &DAG) const {
  auto &Subtarget = DAG.getSubtarget<AArch64Subtarget>();
  // No point replacing if we don't have the relevant instruction/libcall anyway
  if (!Subtarget.hasLSE() && !Subtarget.outlineAtomics())
    return SDValue();
 
  // LSE has an atomic load-clear instruction, but not a load-and.
  SDLoc DL(Op);
  MVT VT = Op.getSimpleValueType();
  assert(VT != MVT::i128 && "Handled elsewhere, code replicated.");
  SDValue RHS = Op.getOperand(2);
  AtomicSDNode *AN = cast<AtomicSDNode>(Op.getNode());
  RHS = DAG.getNode(ISD::XOR, DL, VT, DAG.getAllOnesConstant(DL, VT), RHS);
  return DAG.getAtomic(ISD::ATOMIC_LOAD_CLR, DL, AN->getMemoryVT(),
                       Op.getOperand(0), Op.getOperand(1), RHS,
                       AN->getMemOperand());
}
 
SDValue
AArch64TargetLowering::LowerWindowsDYNAMIC_STACKALLOC(SDValue Op,
                                                      SelectionDAG &DAG) const {
 
  SDLoc DL(Op);
  // Get the inputs.
  SDNode *Node = Op.getNode();
  SDValue Chain = Op.getOperand(0);
  SDValue Size = Op.getOperand(1);
  MaybeAlign Align =
      cast<ConstantSDNode>(Op.getOperand(2))->getMaybeAlignValue();
  EVT VT = Node->getValueType(0);
 
  if (DAG.getMachineFunction().getFunction().hasFnAttribute(
          "no-stack-arg-probe")) {
    SDValue SP = DAG.getCopyFromReg(Chain, DL, AArch64::SP, MVT::i64);
    Chain = SP.getValue(1);
    SP = DAG.getNode(ISD::SUB, DL, MVT::i64, SP, Size);
    if (Align)
      SP = DAG.getNode(ISD::AND, DL, VT, SP.getValue(0),
                       DAG.getSignedConstant(-Align->value(), DL, VT));
    Chain = DAG.getCopyToReg(Chain, DL, AArch64::SP, SP);
    SDValue Ops[2] = {SP, Chain};
    return DAG.getMergeValues(Ops, DL);
  }
 
  RTLIB::LibcallImpl ChkStkImpl = getLibcallImpl(RTLIB::STACK_PROBE);
  if (ChkStkImpl == RTLIB::Unsupported)
    return SDValue();
 
  Chain = DAG.getCALLSEQ_START(Chain, 0, 0, DL);
 
  EVT PtrVT = getPointerTy(DAG.getDataLayout());
  SDValue Callee = DAG.getTargetExternalSymbol(
      getLibcallImplName(ChkStkImpl).data(), PtrVT, 0);
 
  const AArch64RegisterInfo *TRI = Subtarget->getRegisterInfo();
  const uint32_t *Mask = TRI->getWindowsStackProbePreservedMask();
  if (Subtarget->hasCustomCallingConv())
    TRI->UpdateCustomCallPreservedMask(DAG.getMachineFunction(), &Mask);
 
  Size = DAG.getNode(ISD::SRL, DL, MVT::i64, Size,
                     DAG.getConstant(4, DL, MVT::i64));
  Chain = DAG.getCopyToReg(Chain, DL, AArch64::X15, Size, SDValue());
  Chain =
      DAG.getNode(AArch64ISD::CALL, DL, DAG.getVTList(MVT::Other, MVT::Glue),
                  Chain, Callee, DAG.getRegister(AArch64::X15, MVT::i64),
                  DAG.getRegisterMask(Mask), Chain.getValue(1));
  // To match the actual intent better, we should read the output from X15 here
  // again (instead of potentially spilling it to the stack), but rereading Size
  // from X15 here doesn't work at -O0, since it thinks that X15 is undefined
  // here.
 
  Size = DAG.getNode(ISD::SHL, DL, MVT::i64, Size,
                     DAG.getConstant(4, DL, MVT::i64));
 
  SDValue SP = DAG.getCopyFromReg(Chain, DL, AArch64::SP, MVT::i64);
  Chain = SP.getValue(1);
  SP = DAG.getNode(ISD::SUB, DL, MVT::i64, SP, Size);
  if (Align)
    SP = DAG.getNode(ISD::AND, DL, VT, SP.getValue(0),
                     DAG.getSignedConstant(-Align->value(), DL, VT));
  Chain = DAG.getCopyToReg(Chain, DL, AArch64::SP, SP);
 
  Chain = DAG.getCALLSEQ_END(Chain, 0, 0, SDValue(), DL);
 
  SDValue Ops[2] = {SP, Chain};
  return DAG.getMergeValues(Ops, DL);
}
 
SDValue
AArch64TargetLowering::LowerInlineDYNAMIC_STACKALLOC(SDValue Op,
                                                     SelectionDAG &DAG) const {
  // Get the inputs.
  SDNode *Node = Op.getNode();
  SDValue Chain = Op.getOperand(0);
  SDValue Size = Op.getOperand(1);
 
  MaybeAlign Align =
      cast<ConstantSDNode>(Op.getOperand(2))->getMaybeAlignValue();
  SDLoc DL(Op);
  EVT VT = Node->getValueType(0);
 
  // Construct the new SP value in a GPR.
  SDValue SP = DAG.getCopyFromReg(Chain, DL, AArch64::SP, MVT::i64);
  Chain = SP.getValue(1);
  SP = DAG.getNode(ISD::SUB, DL, MVT::i64, SP, Size);
  if (Align)
    SP = DAG.getNode(ISD::AND, DL, VT, SP.getValue(0),
                     DAG.getSignedConstant(-Align->value(), DL, VT));
 
  // Set the real SP to the new value with a probing loop.
  Chain = DAG.getNode(AArch64ISD::PROBED_ALLOCA, DL, MVT::Other, Chain, SP);
  SDValue Ops[2] = {SP, Chain};
  return DAG.getMergeValues(Ops, DL);
}
 
SDValue
AArch64TargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
                                               SelectionDAG &DAG) const {
  MachineFunction &MF = DAG.getMachineFunction();
 
  if (Subtarget->isTargetWindows())
    return LowerWindowsDYNAMIC_STACKALLOC(Op, DAG);
  else if (hasInlineStackProbe(MF))
    return LowerInlineDYNAMIC_STACKALLOC(Op, DAG);
  else
    return SDValue();
}
 
SDValue AArch64TargetLowering::LowerAVG(SDValue Op, SelectionDAG &DAG,
                                        unsigned NewOp) const {
  if (Subtarget->hasSVE2())
    return LowerToPredicatedOp(Op, DAG, NewOp);
 
  // Default to expand.
  return SDValue();
}
 
SDValue AArch64TargetLowering::LowerVSCALE(SDValue Op,
                                           SelectionDAG &DAG) const {
  EVT VT = Op.getValueType();
  assert(VT != MVT::i64 && "Expected illegal VSCALE node");
 
  SDLoc DL(Op);
  APInt MulImm = Op.getConstantOperandAPInt(0);
  return DAG.getZExtOrTrunc(DAG.getVScale(DL, MVT::i64, MulImm.sext(64)), DL,
                            VT);
}
 
/// Set the IntrinsicInfo for the `aarch64_sve_st<N>` intrinsics.
template <unsigned NumVecs>
static void
setInfoSVEStN(const AArch64TargetLowering &TLI, const DataLayout &DL,
              AArch64TargetLowering::IntrinsicInfo &Info, const CallBase &CI) {
  Info.opc = ISD::INTRINSIC_VOID;
  // Retrieve EC from first vector argument.
  const EVT VT = TLI.getMemValueType(DL, CI.getArgOperand(0)->getType());
  ElementCount EC = VT.getVectorElementCount();
#ifndef NDEBUG
  // Check the assumption that all input vectors are the same type.
  for (unsigned I = 0; I < NumVecs; ++I)
    assert(VT == TLI.getMemValueType(DL, CI.getArgOperand(I)->getType()) &&
           "Invalid type.");
#endif
  // memVT is `NumVecs * VT`.
  Info.memVT = EVT::getVectorVT(CI.getType()->getContext(), VT.getScalarType(),
                                EC * NumVecs);
  Info.ptrVal = CI.getArgOperand(CI.arg_size() - 1);
  Info.offset = 0;
  Info.align.reset();
  Info.flags = MachineMemOperand::MOStore;
}
 
/// getTgtMemIntrinsic - Represent NEON load and store intrinsics as
/// MemIntrinsicNodes.  The associated MachineMemOperands record the alignment
/// specified in the intrinsic calls.
void AArch64TargetLowering::getTgtMemIntrinsic(
    SmallVectorImpl<IntrinsicInfo> &Infos, const CallBase &I,
    MachineFunction &MF, unsigned Intrinsic) const {
  IntrinsicInfo Info;
  auto &DL = I.getDataLayout();
  switch (Intrinsic) {
  case Intrinsic::aarch64_sve_st2:
    setInfoSVEStN<2>(*this, DL, Info, I);
    Infos.push_back(Info);
    return;
  case Intrinsic::aarch64_sve_st3:
    setInfoSVEStN<3>(*this, DL, Info, I);
    Infos.push_back(Info);
    return;
  case Intrinsic::aarch64_sve_st4:
    setInfoSVEStN<4>(*this, DL, Info, I);
    Infos.push_back(Info);
    return;
  case Intrinsic::aarch64_neon_ld2:
  case Intrinsic::aarch64_neon_ld3:
  case Intrinsic::aarch64_neon_ld4:
  case Intrinsic::aarch64_neon_ld1x2:
  case Intrinsic::aarch64_neon_ld1x3:
  case Intrinsic::aarch64_neon_ld1x4: {
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    uint64_t NumElts = DL.getTypeSizeInBits(I.getType()) / 64;
    Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
    Info.ptrVal = I.getArgOperand(I.arg_size() - 1);
    Info.offset = 0;
    Info.align.reset();
    // volatile loads with NEON intrinsics not supported
    Info.flags = MachineMemOperand::MOLoad;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_neon_ld2lane:
  case Intrinsic::aarch64_neon_ld3lane:
  case Intrinsic::aarch64_neon_ld4lane:
  case Intrinsic::aarch64_neon_ld2r:
  case Intrinsic::aarch64_neon_ld3r:
  case Intrinsic::aarch64_neon_ld4r: {
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    // ldx return struct with the same vec type
    Type *RetTy = I.getType();
    auto *StructTy = cast<StructType>(RetTy);
    unsigned NumElts = StructTy->getNumElements();
    Type *VecTy = StructTy->getElementType(0);
    MVT EleVT = MVT::getVT(VecTy).getVectorElementType();
    Info.memVT = EVT::getVectorVT(I.getType()->getContext(), EleVT, NumElts);
    Info.ptrVal = I.getArgOperand(I.arg_size() - 1);
    Info.offset = 0;
    Info.align.reset();
    // volatile loads with NEON intrinsics not supported
    Info.flags = MachineMemOperand::MOLoad;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_neon_st2:
  case Intrinsic::aarch64_neon_st3:
  case Intrinsic::aarch64_neon_st4:
  case Intrinsic::aarch64_neon_st1x2:
  case Intrinsic::aarch64_neon_st1x3:
  case Intrinsic::aarch64_neon_st1x4: {
    Info.opc = ISD::INTRINSIC_VOID;
    unsigned NumElts = 0;
    for (const Value *Arg : I.args()) {
      Type *ArgTy = Arg->getType();
      if (!ArgTy->isVectorTy())
        break;
      NumElts += DL.getTypeSizeInBits(ArgTy) / 64;
    }
    Info.memVT = EVT::getVectorVT(I.getType()->getContext(), MVT::i64, NumElts);
    Info.ptrVal = I.getArgOperand(I.arg_size() - 1);
    Info.offset = 0;
    Info.align.reset();
    // volatile stores with NEON intrinsics not supported
    Info.flags = MachineMemOperand::MOStore;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_neon_st2lane:
  case Intrinsic::aarch64_neon_st3lane:
  case Intrinsic::aarch64_neon_st4lane: {
    Info.opc = ISD::INTRINSIC_VOID;
    unsigned NumElts = 0;
    // all the vector type is same
    Type *VecTy = I.getArgOperand(0)->getType();
    MVT EleVT = MVT::getVT(VecTy).getVectorElementType();
 
    for (const Value *Arg : I.args()) {
      Type *ArgTy = Arg->getType();
      if (!ArgTy->isVectorTy())
        break;
      NumElts += 1;
    }
 
    Info.memVT = EVT::getVectorVT(I.getType()->getContext(), EleVT, NumElts);
    Info.ptrVal = I.getArgOperand(I.arg_size() - 1);
    Info.offset = 0;
    Info.align.reset();
    // volatile stores with NEON intrinsics not supported
    Info.flags = MachineMemOperand::MOStore;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_ldaxr:
  case Intrinsic::aarch64_ldxr: {
    Type *ValTy = I.getParamElementType(0);
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::getVT(ValTy);
    Info.ptrVal = I.getArgOperand(0);
    Info.offset = 0;
    Info.align = DL.getABITypeAlign(ValTy);
    Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MOVolatile;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_stlxr:
  case Intrinsic::aarch64_stxr: {
    Type *ValTy = I.getParamElementType(1);
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::getVT(ValTy);
    Info.ptrVal = I.getArgOperand(1);
    Info.offset = 0;
    Info.align = DL.getABITypeAlign(ValTy);
    Info.flags = MachineMemOperand::MOStore | MachineMemOperand::MOVolatile;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_ldaxp:
  case Intrinsic::aarch64_ldxp:
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::i128;
    Info.ptrVal = I.getArgOperand(0);
    Info.offset = 0;
    Info.align = Align(16);
    Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MOVolatile;
    Infos.push_back(Info);
    return;
  case Intrinsic::aarch64_stlxp:
  case Intrinsic::aarch64_stxp:
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::i128;
    Info.ptrVal = I.getArgOperand(2);
    Info.offset = 0;
    Info.align = Align(16);
    Info.flags = MachineMemOperand::MOStore | MachineMemOperand::MOVolatile;
    Infos.push_back(Info);
    return;
  case Intrinsic::aarch64_sve_ldnt1: {
    Type *ElTy = cast<VectorType>(I.getType())->getElementType();
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::getVT(I.getType());
    Info.ptrVal = I.getArgOperand(1);
    Info.offset = 0;
    Info.align = DL.getABITypeAlign(ElTy);
    Info.flags = MachineMemOperand::MOLoad | MachineMemOperand::MONonTemporal;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_sve_stnt1: {
    Type *ElTy =
        cast<VectorType>(I.getArgOperand(0)->getType())->getElementType();
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::getVT(I.getOperand(0)->getType());
    Info.ptrVal = I.getArgOperand(2);
    Info.offset = 0;
    Info.align = DL.getABITypeAlign(ElTy);
    Info.flags = MachineMemOperand::MOStore | MachineMemOperand::MONonTemporal;
    Infos.push_back(Info);
    return;
  }
  case Intrinsic::aarch64_mops_memset_tag: {
    Value *Dst = I.getArgOperand(0);
    Value *Val = I.getArgOperand(1);
    Info.opc = ISD::INTRINSIC_W_CHAIN;
    Info.memVT = MVT::getVT(Val->getType());
    Info.ptrVal = Dst;
    Info.offset = 0;
    Info.align = I.getParamAlign(0).valueOrOne();
    Info.flags = MachineMemOperand::MOStore;
    // The size of the memory being operated on is unknown at this point
    Info.size = MemoryLocation::UnknownSize;
    Infos.push_back(Info);
    return;
  }
  default:
    break;
  }
}
 
bool AArch64TargetLowering::shouldReduceLoadWidth(
    SDNode *Load, ISD::LoadExtType ExtTy, EVT NewVT,
    std::optional<unsigned> ByteOffset) const {
  // TODO: This may be worth removing. Check regression tests for diffs.
  if (!TargetLoweringBase::shouldReduceLoadWidth(Load, ExtTy, NewVT,
                                                 ByteOffset))
    return false;
 
  // If we're reducing the load width in order to avoid having to use an extra
  // instruction to do extension then it's probably a good idea.
  if (ExtTy != ISD::NON_EXTLOAD)
    return true;
  // Don't reduce load width if it would prevent us from combining a shift into
  // the offset.
  MemSDNode *Mem = dyn_cast<MemSDNode>(Load);
  assert(Mem);
  const SDValue &Base = Mem->getBasePtr();
  if (Base.getOpcode() == ISD::ADD &&
      Base.getOperand(1).getOpcode() == ISD::SHL &&
      Base.getOperand(1).hasOneUse() &&
      Base.getOperand(1).getOperand(1).getOpcode() == ISD::Constant) {
    // It's unknown whether a scalable vector has a power-of-2 bitwidth.
    if (Mem->getMemoryVT().isScalableVector())
      return false;
    // The shift can be combined if it matches the size of the value being
    // loaded (and so reducing the width would make it not match).
    uint64_t ShiftAmount = Base.getOperand(1).getConstantOperandVal(1);
    uint64_t LoadBytes = Mem->getMemoryVT().getSizeInBits()/8;
    if (ShiftAmount == Log2_32(LoadBytes))
      return false;
  }
  // We have no reason to disallow reducing the load width, so allow it.
  return true;
}
 
// Treat a sext_inreg(extract(..)) as free if it has multiple uses.
bool AArch64TargetLowering::shouldRemoveRedundantExtend(SDValue Extend) const {
  EVT VT = Extend.getValueType();
  if ((VT == MVT::i64 || VT == MVT::i32) && Extend->use_size()) {
    SDValue Extract = Extend.getOperand(0);
    if (Extract.getOpcode() == ISD::ANY_EXTEND && Extract.hasOneUse())
      Extract = Extract.getOperand(0);
    if (Extract.getOpcode() == ISD::EXTRACT_VECTOR_ELT && Extract.hasOneUse()) {
      EVT VecVT = Extract.getOperand(0).getValueType();
      if (VecVT.getScalarType() == MVT::i8 || VecVT.getScalarType() == MVT::i16)
        return false;
    }
  }
  return true;
}
 
// Truncations from 64-bit GPR to 32-bit GPR is free.
bool AArch64TargetLowering::isTruncateFree(Type *Ty1, Type *Ty2) const {
  if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
    return false;
  uint64_t NumBits1 = Ty1->getPrimitiveSizeInBits().getFixedValue();
  uint64_t NumBits2 = Ty2->getPrimitiveSizeInBits().getFixedValue();
  return NumBits1 > NumBits2;
}
bool AArch64TargetLowering::isTruncateFree(EVT VT1, EVT VT2) const {
  if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
    return false;
  uint64_t NumBits1 = VT1.getFixedSizeInBits();
  uint64_t NumBits2 = VT2.getFixedSizeInBits();
  return NumBits1 > NumBits2;
}
 
/// Check if it is profitable to hoist instruction in then/else to if.
/// Not profitable if I and it's user can form a FMA instruction
/// because we prefer FMSUB/FMADD.
bool AArch64TargetLowering::isProfitableToHoist(Instruction *I) const {
  if (I->getOpcode() != Instruction::FMul)
    return true;
 
  if (!I->hasOneUse())
    return true;
 
  Instruction *User = I->user_back();
 
  if (!(User->getOpcode() == Instruction::FSub ||
        User->getOpcode() == Instruction::FAdd))
    return true;
 
  const TargetOptions &Options = getTargetMachine().Options;
  const Function *F = I->getFunction();
  const DataLayout &DL = F->getDataLayout();
  Type *Ty = User->getOperand(0)->getType();
 
  return !(isFMAFasterThanFMulAndFAdd(*F, Ty) &&
           isOperationLegalOrCustom(ISD::FMA, getValueType(DL, Ty)) &&
           (Options.AllowFPOpFusion == FPOpFusion::Fast ||
            I->getFastMathFlags().allowContract()));
}
 
// All 32-bit GPR operations implicitly zero the high-half of the corresponding
// 64-bit GPR.
bool AArch64TargetLowering::isZExtFree(Type *Ty1, Type *Ty2) const {
  if (!Ty1->isIntegerTy() || !Ty2->isIntegerTy())
    return false;
  unsigned NumBits1 = Ty1->getPrimitiveSizeInBits();
  unsigned NumBits2 = Ty2->getPrimitiveSizeInBits();
  return NumBits1 == 32 && NumBits2 == 64;
}
bool AArch64TargetLowering::isZExtFree(EVT VT1, EVT VT2) const {
  if (VT1.isVector() || VT2.isVector() || !VT1.isInteger() || !VT2.isInteger())
    return false;
  unsigned NumBits1 = VT1.getSizeInBits();
  unsigned NumBits2 = VT2.getSizeInBits();
  return NumBits1 == 32 && NumBits2 == 64;
}
 
bool AArch64TargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
  EVT VT1 = Val.getValueType();
  if (isZExtFree(VT1, VT2)) {
    return true;
  }
 
  if (Val.getOpcode() != ISD::LOAD)
    return false;
 
  // 8-, 16-, and 32-bit integer loads all implicitly zero-extend.
  return (VT1.isSimple() && !VT1.isVector() && VT1.isInteger() &&
          VT2.isSimple() && !VT2.isVector() && VT2.isInteger() &&
          VT1.getSizeInBits() <= 32);
}
 
bool AArch64TargetLowering::isExtFreeImpl(const Instruction *Ext) const {
  if (isa<FPExtInst>(Ext))
    return false;
 
  // Vector types are not free.
  if (Ext->getType()->isVectorTy())
    return false;
 
  for (const Use &U : Ext->uses()) {
    // The extension is free if we can fold it with a left shift in an
    // addressing mode or an arithmetic operation: add, sub, and cmp.
 
    // Is there a shift?
    const Instruction *Instr = cast<Instruction>(U.getUser());
 
    // Is this a constant shift?
    switch (Instr->getOpcode()) {
    case Instruction::Shl:
      if (!isa<ConstantInt>(Instr->getOperand(1)))
        return false;
      break;
    case Instruction::GetElementPtr: {
      gep_type_iterator GTI = gep_type_begin(Instr);
      auto &DL = Ext->getDataLayout();
      std::advance(GTI, U.getOperandNo()-1);
      Type *IdxTy = GTI.getIndexedType();
      // This extension will end up with a shift because of the scaling factor.
      // 8-bit sized types have a scaling factor of 1, thus a shift amount of 0.
      // Get the shift amount based on the scaling factor:
      // log2(sizeof(IdxTy)) - log2(8).
      if (IdxTy->isScalableTy())
        return false;
      uint64_t ShiftAmt =
          llvm::countr_zero(DL.getTypeStoreSizeInBits(IdxTy).getFixedValue()) -
          3;
      // Is the constant foldable in the shift of the addressing mode?
      // I.e., shift amount is between 1 and 4 inclusive.
      if (ShiftAmt == 0 || ShiftAmt > 4)
        return false;
      break;
    }
    case Instruction::Trunc:
      // Check if this is a noop.
      // trunc(sext ty1 to ty2) to ty1.
      if (Instr->getType() == Ext->getOperand(0)->getType())
        continue;
      [[fallthrough]];
    default:
      return false;
    }
 
    // At this point we can use the bfm family, so this extension is free
    // for that use.
  }
  return true;
}
 
static bool createTblShuffleMask(unsigned SrcWidth, unsigned DstWidth,
                                 unsigned NumElts, bool IsLittleEndian,
                                 SmallVectorImpl<int> &Mask) {
  if (DstWidth % 8 != 0 || DstWidth <= 16 || DstWidth > 64)
    return false;
 
  assert(DstWidth % SrcWidth == 0 &&
         "TBL lowering is not supported for a conversion instruction with this "
         "source and destination element type.");
 
  unsigned Factor = DstWidth / SrcWidth;
  unsigned MaskLen = NumElts * Factor;
 
  Mask.clear();
  Mask.resize(MaskLen, NumElts);
 
  unsigned SrcIndex = 0;
  for (unsigned I = IsLittleEndian ? 0 : Factor - 1; I < MaskLen; I += Factor)
    Mask[I] = SrcIndex++;
 
  return true;
}
 
static Value *createTblShuffleForZExt(IRBuilderBase &Builder, Value *Op,
                                      FixedVectorType *ZExtTy,
                                      FixedVectorType *DstTy,
                                      bool IsLittleEndian) {
  auto *SrcTy = cast<FixedVectorType>(Op->getType());
  unsigned NumElts = SrcTy->getNumElements();
  auto SrcWidth = cast<IntegerType>(SrcTy->getElementType())->getBitWidth();
  auto DstWidth = cast<IntegerType>(DstTy->getElementType())->getBitWidth();
 
  SmallVector<int> Mask;
  if (!createTblShuffleMask(SrcWidth, DstWidth, NumElts, IsLittleEndian, Mask))
    return nullptr;
 
  auto *FirstEltZero = Builder.CreateInsertElement(
      PoisonValue::get(SrcTy), Builder.getIntN(SrcWidth, 0), uint64_t(0));
  Value *Result = Builder.CreateShuffleVector(Op, FirstEltZero, Mask);
  Result = Builder.CreateBitCast(Result, DstTy);
  if (DstTy != ZExtTy)
    Result = Builder.CreateZExt(Result, ZExtTy);
  return Result;
}
 
static Value *createTblShuffleForSExt(IRBuilderBase &Builder, Value *Op,
                                      FixedVectorType *DstTy,
                                      bool IsLittleEndian) {
  auto *SrcTy = cast<FixedVectorType>(Op->getType());
  auto SrcWidth = cast<IntegerType>(SrcTy->getElementType())->getBitWidth();
  auto DstWidth = cast<IntegerType>(DstTy->getElementType())->getBitWidth();
 
  SmallVector<int> Mask;
  if (!createTblShuffleMask(SrcWidth, DstWidth, SrcTy->getNumElements(),
                            !IsLittleEndian, Mask))
    return nullptr;
 
  auto *FirstEltZero = Builder.CreateInsertElement(
      PoisonValue::get(SrcTy), Builder.getIntN(SrcWidth, 0), uint64_t(0));
 
  return Builder.CreateShuffleVector(Op, FirstEltZero, Mask);
}
 
static void createTblForTrunc(TruncInst *TI, bool IsLittleEndian) {
  IRBuilder<> Builder(TI);
  SmallVector<Value *> Parts;
  int NumElements = cast<FixedVectorType>(TI->getType())->getNumElements();
  auto *SrcTy = cast<FixedVectorType>(TI->getOperand(0)->getType());
  auto *DstTy = cast<FixedVectorType>(TI->getType());
  assert(SrcTy->getElementType()->isIntegerTy() &&
         "Non-integer type source vector element is not supported");
  assert(DstTy->getElementType()->isIntegerTy(8) &&
         "Unsupported destination vector element type");
  unsigned SrcElemTySz =
      cast<IntegerType>(SrcTy->getElementType())->getBitWidth();
  unsigned DstElemTySz =
      cast<IntegerType>(DstTy->getElementType())->getBitWidth();
  assert((SrcElemTySz % DstElemTySz == 0) &&
         "Cannot lower truncate to tbl instructions for a source element size "
         "that is not divisible by the destination element size");
  unsigned TruncFactor = SrcElemTySz / DstElemTySz;
  assert((SrcElemTySz == 16 || SrcElemTySz == 32 || SrcElemTySz == 64) &&
         "Unsupported source vector element type size");
  Type *VecTy = FixedVectorType::get(Builder.getInt8Ty(), 16);
 
  // Create a mask to choose every nth byte from the source vector table of
  // bytes to create the truncated destination vector, where 'n' is the truncate
  // ratio. For example, for a truncate from Yxi64 to Yxi8, choose
  // 0,8,16,..Y*8th bytes for the little-endian format
  SmallVector<Constant *, 16> MaskConst;
  for (int Itr = 0; Itr < 16; Itr++) {
    if (Itr < NumElements)
      MaskConst.push_back(Builder.getInt8(
          IsLittleEndian ? Itr * TruncFactor
                         : Itr * TruncFactor + (TruncFactor - 1)));
    else
      MaskConst.push_back(Builder.getInt8(255));
  }
 
  int MaxTblSz = 128 * 4;
  int MaxSrcSz = SrcElemTySz * NumElements;
  int ElemsPerTbl =
      (MaxTblSz > MaxSrcSz) ? NumElements : (MaxTblSz / SrcElemTySz);
  assert(ElemsPerTbl <= 16 &&
         "Maximum elements selected using TBL instruction cannot exceed 16!");
 
  int ShuffleCount = 128 / SrcElemTySz;
  SmallVector<int> ShuffleLanes;
  for (int i = 0; i < ShuffleCount; ++i)
    ShuffleLanes.push_back(i);
 
  // Create TBL's table of bytes in 1,2,3 or 4 FP/SIMD registers using shuffles
  // over the source vector. If TBL's maximum 4 FP/SIMD registers are saturated,
  // call TBL & save the result in a vector of TBL results for combining later.
  SmallVector<Value *> Results;
  while (ShuffleLanes.back() < NumElements) {
    Parts.push_back(Builder.CreateBitCast(
        Builder.CreateShuffleVector(TI->getOperand(0), ShuffleLanes), VecTy));
 
    if (Parts.size() == 4) {
      Parts.push_back(ConstantVector::get(MaskConst));
      Results.push_back(
          Builder.CreateIntrinsic(Intrinsic::aarch64_neon_tbl4, VecTy, Parts));
      Parts.clear();
    }
 
    for (int i = 0; i < ShuffleCount; ++i)
      ShuffleLanes[i] += ShuffleCount;
  }
 
  assert((Parts.empty() || Results.empty()) &&
         "Lowering trunc for vectors requiring different TBL instructions is "
         "not supported!");
  // Call TBL for the residual table bytes present in 1,2, or 3 FP/SIMD
  // registers
  if (!Parts.empty()) {
    Intrinsic::ID TblID;
    switch (Parts.size()) {
    case 1:
      TblID = Intrinsic::aarch64_neon_tbl1;
      break;
    case 2:
      TblID = Intrinsic::aarch64_neon_tbl2;
      break;
    case 3:
      TblID = Intrinsic::aarch64_neon_tbl3;
      break;
    }
 
    Parts.push_back(ConstantVector::get(MaskConst));
    Results.push_back(Builder.CreateIntrinsic(TblID, VecTy, Parts));
  }
 
  // Extract the destination vector from TBL result(s) after combining them
  // where applicable. Currently, at most two TBLs are supported.
  assert(Results.size() <= 2 && "Trunc lowering does not support generation of "
                                "more than 2 tbl instructions!");
  Value *FinalResult = Results[0];
  if (Results.size() == 1) {
    if (ElemsPerTbl < 16) {
      SmallVector<int> FinalMask(ElemsPerTbl);
      std::iota(FinalMask.begin(), FinalMask.end(), 0);
      FinalResult = Builder.CreateShuffleVector(Results[0], FinalMask);
    }
  } else {
    SmallVector<int> FinalMask(ElemsPerTbl * Results.size());
    if (ElemsPerTbl < 16) {
      std::iota(FinalMask.begin(), FinalMask.begin() + ElemsPerTbl, 0);
      std::iota(FinalMask.begin() + ElemsPerTbl, FinalMask.end(), 16);
    } else {
      std::iota(FinalMask.begin(), FinalMask.end(), 0);
    }
    FinalResult =
        Builder.CreateShuffleVector(Results[0], Results[1], FinalMask);
  }
 
  TI->replaceAllUsesWith(FinalResult);
  TI->eraseFromParent();
}
 
bool AArch64TargetLowering::optimizeExtendOrTruncateConversion(
    Instruction *I, Loop *L, const TargetTransformInfo &TTI) const {
  // shuffle_vector instructions are serialized when targeting SVE,
  // see LowerSPLAT_VECTOR. This peephole is not beneficial.
  if (!EnableExtToTBL || Subtarget->useSVEForFixedLengthVectors())
    return false;
 
  // Try to optimize conversions using tbl. This requires materializing constant
  // index vectors, which can increase code size and add loads. Skip the
  // transform unless the conversion is in a loop block guaranteed to execute
  // and we are not optimizing for size.
  Function *F = I->getParent()->getParent();
  if (!L || L->getHeader() != I->getParent() || F->hasOptSize())
    return false;
 
  auto *SrcTy = dyn_cast<FixedVectorType>(I->getOperand(0)->getType());
  auto *DstTy = dyn_cast<FixedVectorType>(I->getType());
  if (!SrcTy || !DstTy)
    return false;
 
  // Convert 'zext <Y x i8> %x to <Y x i8X>' to a shuffle that can be
  // lowered to tbl instructions to insert the original i8 elements
  // into i8x lanes. This is enabled for cases where it is beneficial.
  auto *ZExt = dyn_cast<ZExtInst>(I);
  if (ZExt && SrcTy->getElementType()->isIntegerTy(8)) {
    auto DstWidth = DstTy->getElementType()->getScalarSizeInBits();
    if (DstWidth % 8 != 0)
      return false;
 
    auto *TruncDstType =
        cast<FixedVectorType>(VectorType::getTruncatedElementVectorType(DstTy));
    // If the ZExt can be lowered to a single ZExt to the next power-of-2 and
    // the remaining ZExt folded into the user, don't use tbl lowering.
    auto SrcWidth = SrcTy->getElementType()->getScalarSizeInBits();
    if (TTI.getCastInstrCost(I->getOpcode(), DstTy, TruncDstType,
                             TargetTransformInfo::getCastContextHint(I),
                             TTI::TCK_SizeAndLatency, I) == TTI::TCC_Free) {
      if (SrcWidth * 2 >= TruncDstType->getElementType()->getScalarSizeInBits())
        return false;
 
      DstTy = TruncDstType;
    }
 
    // mul(zext(i8), sext) can be transformed into smull(zext, sext) which
    // performs one extend implicitly. If DstWidth is at most 4 * SrcWidth, at
    // most one extra extend step is needed and using tbl is not profitable.
    // Similarly, bail out if partial_reduce(acc, zext(i8)) can be lowered to a
    // udot instruction.
    if (SrcWidth * 4 <= DstWidth) {
      if (all_of(I->users(), [&](auto *U) {
            using namespace llvm::PatternMatch;
            auto *SingleUser = cast<Instruction>(&*U);
            if (match(SingleUser, m_c_Mul(m_Specific(I), m_SExt(m_Value()))))
              return true;
            if (match(SingleUser,
                      m_Intrinsic<Intrinsic::vector_partial_reduce_add>(
                          m_Value(), m_Specific(I))))
              return true;
            return false;
          }))
        return false;
    }
 
    if (DstTy->getScalarSizeInBits() >= 64)
      return false;
 
    IRBuilder<> Builder(ZExt);
    Value *Result = createTblShuffleForZExt(
        Builder, ZExt->getOperand(0), cast<FixedVectorType>(ZExt->getType()),
        DstTy, Subtarget->isLittleEndian());
    if (!Result)
      return false;
    ZExt->replaceAllUsesWith(Result);
    ZExt->eraseFromParent();
    return true;
  }
 
  auto *UIToFP = dyn_cast<UIToFPInst>(I);
  if (UIToFP && ((SrcTy->getElementType()->isIntegerTy(8) &&
                  DstTy->getElementType()->isFloatTy()) ||
                 (SrcTy->getElementType()->isIntegerTy(16) &&
                  DstTy->getElementType()->isDoubleTy()))) {
    IRBuilder<> Builder(I);
    Value *ZExt = createTblShuffleForZExt(
        Builder, I->getOperand(0), FixedVectorType::getInteger(DstTy),
        FixedVectorType::getInteger(DstTy), Subtarget->isLittleEndian());
    assert(ZExt && "Cannot fail for the i8 to float conversion");
    auto *UI = Builder.CreateUIToFP(ZExt, DstTy);
    I->replaceAllUsesWith(UI);
    I->eraseFromParent();
    return true;
  }
 
  auto *SIToFP = dyn_cast<SIToFPInst>(I);
  if (SIToFP && SrcTy->getElementType()->isIntegerTy(8) &&
      DstTy->getElementType()->isFloatTy()) {
    IRBuilder<> Builder(I);
    auto *Shuffle = createTblShuffleForSExt(Builder, I->getOperand(0),
                                            FixedVectorType::getInteger(DstTy),
                                            Subtarget->isLittleEndian());
    assert(Shuffle && "Cannot fail for the i8 to float conversion");
    auto *Cast = Builder.CreateBitCast(Shuffle, VectorType::getInteger(DstTy));
    auto *AShr = Builder.CreateAShr(Cast, 24, "", true);
    auto *SI = Builder.CreateSIToFP(AShr, DstTy);
    I->replaceAllUsesWith(SI);
    I->eraseFromParent();
    return true;
  }
 
  // Convert 'fptoui <(8|16) x float> to <(8|16) x i8>' to a wide fptoui
  // followed by a truncate lowered to using tbl.4.
  auto *FPToUI = dyn_cast<FPToUIInst>(I);
  if (FPToUI &&
      (SrcTy->getNumElements() == 8 || SrcTy->getNumElements() == 16) &&
      SrcTy->getElementType()->isFloatTy() &&
      DstTy->getElementType()->isIntegerTy(8)) {
    IRBuilder<> Builder(I);
    auto *WideConv = Builder.CreateFPToUI(FPToUI->getOperand(0),
                                          VectorType::getInteger(SrcTy));
    auto *TruncI = Builder.CreateTrunc(WideConv, DstTy);
    I->replaceAllUsesWith(TruncI);
    I->eraseFromParent();
    createTblForTrunc(cast<TruncInst>(TruncI), Subtarget->isLittleEndian());
    return true;
  }
 
  // Convert 'trunc <(8|16) x (i32|i64)> %x to <(8|16) x i8>' to an appropriate
  // tbl instruction selecting the lowest/highest (little/big endian) 8 bits
  // per lane of the input that is represented using 1,2,3 or 4 128-bit table
  // registers
  auto *TI = dyn_cast<TruncInst>(I);
  if (TI && DstTy->getElementType()->isIntegerTy(8) &&
      ((SrcTy->getElementType()->isIntegerTy(32) ||
        SrcTy->getElementType()->isIntegerTy(64)) &&
       (SrcTy->getNumElements() == 16 || SrcTy->getNumElements() == 8))) {
    createTblForTrunc(TI, Subtarget->isLittleEndian());
    return true;
  }
 
  return false;
}
 
bool AArch64TargetLowering::hasPairedLoad(EVT LoadedType,
                                          Align &RequiredAlignment) const {
  if (!LoadedType.isSimple() ||
      (!LoadedType.isInteger() && !LoadedType.isFloatingPoint()))
    return false;
  // Cyclone supports unaligned accesses.
  RequiredAlignment = Align(1);
  unsigned NumBits = LoadedType.getSizeInBits();
  return NumBits == 32 || NumBits == 64;
}
 
/// A helper function for determining the number of interleaved accesses we
/// will generate when lowering accesses of the given type.
unsigned AArch64TargetLowering::getNumInterleavedAccesses(
    VectorType *VecTy, const DataLayout &DL, bool UseScalable) const {
  unsigned VecSize = 128;
  unsigned ElSize = DL.getTypeSizeInBits(VecTy->getElementType());
  unsigned MinElts = VecTy->getElementCount().getKnownMinValue();
  if (UseScalable && isa<FixedVectorType>(VecTy))
    VecSize = std::max(Subtarget->getMinSVEVectorSizeInBits(), 128u);
  return std::max<unsigned>(1, (MinElts * ElSize + 127) / VecSize);
}
 
MachineMemOperand::Flags
AArch64TargetLowering::getTargetMMOFlags(const Instruction &I) const {
  if (Subtarget->getProcFamily() == AArch64Subtarget::Falkor &&
      I.hasMetadata(FALKOR_STRIDED_ACCESS_MD))
    return MOStridedAccess;
  return MachineMemOperand::MONone;
}
 
bool AArch64TargetLowering::isLegalInterleavedAccessType(
    VectorType *VecTy, const DataLayout &DL, bool &UseScalable) const {
  unsigned ElSize = DL.getTypeSizeInBits(VecTy->getElementType());
  auto EC = VecTy->getElementCount();
  unsigned MinElts = EC.getKnownMinValue();
 
  UseScalable = false;
 
  if (isa<FixedVectorType>(VecTy) && !Subtarget->isNeonAvailable() &&
      (!Subtarget->useSVEForFixedLengthVectors() ||
       !getSVEPredPatternFromNumElements(MinElts)))
    return false;
 
  if (isa<ScalableVectorType>(VecTy) &&
      !Subtarget->isSVEorStreamingSVEAvailable())
    return false;
 
  // Ensure the number of vector elements is greater than 1.
  if (MinElts < 2)
    return false;
 
  // Ensure the element type is legal.
  if (ElSize != 8 && ElSize != 16 && ElSize != 32 && ElSize != 64)
    return false;
 
  if (EC.isScalable()) {
    UseScalable = true;
    return isPowerOf2_32(MinElts) && (MinElts * ElSize) % 128 == 0;
  }
 
  unsigned VecSize = DL.getTypeSizeInBits(VecTy);
  if (Subtarget->useSVEForFixedLengthVectors()) {
    unsigned MinSVEVectorSize =
        std::max(Subtarget->getMinSVEVectorSizeInBits(), 128u);
    if (VecSize % MinSVEVectorSize == 0 ||
        (VecSize < MinSVEVectorSize && isPowerOf2_32(MinElts) &&
         (!Subtarget->isNeonAvailable() || VecSize > 128))) {
      UseScalable = true;
      return true;
    }
  }
 
  // Ensure the total vector size is 64 or a multiple of 128. Types larger than
  // 128 will be split into multiple interleaved accesses.
  return Subtarget->isNeonAvailable() && (VecSize == 64 || VecSize % 128 == 0);
}
 
static ScalableVectorType *getSVEContainerIRType(FixedVectorType *VTy) {
  if (VTy->getElementType() == Type::getDoubleTy(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 2);
 
  if (VTy->getElementType() == Type::getFloatTy(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 4);
 
  if (VTy->getElementType() == Type::getBFloatTy(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 8);
 
  if (VTy->getElementType() == Type::getHalfTy(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 8);
 
  if (VTy->getElementType() == Type::getInt64Ty(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 2);
 
  if (VTy->getElementType() == Type::getInt32Ty(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 4);
 
  if (VTy->getElementType() == Type::getInt16Ty(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 8);
 
  if (VTy->getElementType() == Type::getInt8Ty(VTy->getContext()))
    return ScalableVectorType::get(VTy->getElementType(), 16);
 
  llvm_unreachable("Cannot handle input vector type");
}
 
static Function *getStructuredLoadFunction(Module *M, unsigned Factor,
                                           bool Scalable, Type *LDVTy,
                                           Type *PtrTy) {
  assert(Factor >= 2 && Factor <= 4 && "Invalid interleave factor");
  static const Intrinsic::ID SVELoads[3] = {Intrinsic::aarch64_sve_ld2_sret,
                                            Intrinsic::aarch64_sve_ld3_sret,
                                            Intrinsic::aarch64_sve_ld4_sret};
  static const Intrinsic::ID NEONLoads[3] = {Intrinsic::aarch64_neon_ld2,
                                             Intrinsic::aarch64_neon_ld3,
                                             Intrinsic::aarch64_neon_ld4};
  if (Scalable)
    return Intrinsic::getOrInsertDeclaration(M, SVELoads[Factor - 2],
                                             {LDVTy, PtrTy});
 
  return Intrinsic::getOrInsertDeclaration(M, NEONLoads[Factor - 2],
                                           {LDVTy, PtrTy});
}
 
static Function *getStructuredStoreFunction(Module *M, unsigned Factor,
                                            bool Scalable, Type *STVTy,
                                            Type *PtrTy) {
  assert(Factor >= 2 && Factor <= 4 && "Invalid interleave factor");
  static const Intrinsic::ID SVEStores[3] = {Intrinsic::aarch64_sve_st2,
                                             Intrinsic::aarch64_sve_st3,
                                             Intrinsic::aarch64_sve_st4};
  static const Intrinsic::ID NEONStores[3] = {Intrinsic::aarch64_neon_st2,
                                              Intrinsic::aarch64_neon_st3,
                                              Intrinsic::aarch64_neon_st4};
  if (Scalable)
    return Intrinsic::getOrInsertDeclaration(M, SVEStores[Factor - 2],
                                             {STVTy, PtrTy});
 
  return Intrinsic::getOrInsertDeclaration(M, NEONStores[Factor - 2],
                                           {STVTy, PtrTy});
}
 
/// Lower an interleaved load into a ldN intrinsic.
///
/// E.g. Lower an interleaved load (Factor = 2):
///        %wide.vec = load <8 x i32>, <8 x i32>* %ptr
///        %v0 = shuffle %wide.vec, undef, <0, 2, 4, 6>  ; Extract even elements
///        %v1 = shuffle %wide.vec, undef, <1, 3, 5, 7>  ; Extract odd elements
///
///      Into:
///        %ld2 = { <4 x i32>, <4 x i32> } call llvm.aarch64.neon.ld2(%ptr)
///        %vec0 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 0
///        %vec1 = extractelement { <4 x i32>, <4 x i32> } %ld2, i32 1
bool AArch64TargetLowering::lowerInterleavedLoad(
    Instruction *Load, Value *Mask, ArrayRef<ShuffleVectorInst *> Shuffles,
    ArrayRef<unsigned> Indices, unsigned Factor, const APInt &GapMask) const {
  assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
         "Invalid interleave factor");
  assert(!Shuffles.empty() && "Empty shufflevector input");
  assert(Shuffles.size() == Indices.size() &&
         "Unmatched number of shufflevectors and indices");
 
  auto *LI = dyn_cast<LoadInst>(Load);
  if (!LI)
    return false;
  assert(!Mask && GapMask.popcount() == Factor && "Unexpected mask on a load");
 
  const DataLayout &DL = LI->getDataLayout();
 
  VectorType *VTy = Shuffles[0]->getType();
 
  // Skip if we do not have NEON and skip illegal vector types. We can
  // "legalize" wide vector types into multiple interleaved accesses as long as
  // the vector types are divisible by 128.
  bool UseScalable;
  if (!isLegalInterleavedAccessType(VTy, DL, UseScalable))
    return false;
 
  // Check if the interleave is a zext(shuffle), that can be better optimized
  // into shift / and masks. For the moment we do this just for uitofp (not
  // zext) to avoid issues with widening instructions.
  if (Shuffles.size() == 4 && all_of(Shuffles, [](ShuffleVectorInst *SI) {
        using namespace llvm::PatternMatch;
        return SI->hasOneUse() && match(SI->user_back(), m_UIToFP(m_Value())) &&
               SI->getType()->getScalarSizeInBits() * 4 ==
                   SI->user_back()->getType()->getScalarSizeInBits();
      }))
    return false;
 
  unsigned NumLoads = getNumInterleavedAccesses(VTy, DL, UseScalable);
 
  auto *FVTy = cast<FixedVectorType>(VTy);
 
  // A pointer vector can not be the return type of the ldN intrinsics. Need to
  // load integer vectors first and then convert to pointer vectors.
  Type *EltTy = FVTy->getElementType();
  if (EltTy->isPointerTy())
    FVTy =
        FixedVectorType::get(DL.getIntPtrType(EltTy), FVTy->getNumElements());
 
  // If we're going to generate more than one load, reset the sub-vector type
  // to something legal.
  FVTy = FixedVectorType::get(FVTy->getElementType(),
                              FVTy->getNumElements() / NumLoads);
 
  auto *LDVTy =
      UseScalable ? cast<VectorType>(getSVEContainerIRType(FVTy)) : FVTy;
 
  IRBuilder<> Builder(LI);
 
  // The base address of the load.
  Value *BaseAddr = LI->getPointerOperand();
 
  Type *PtrTy = LI->getPointerOperandType();
  Type *PredTy = VectorType::get(Type::getInt1Ty(LDVTy->getContext()),
                                 LDVTy->getElementCount());
 
  Function *LdNFunc = getStructuredLoadFunction(LI->getModule(), Factor,
                                                UseScalable, LDVTy, PtrTy);
 
  // Holds sub-vectors extracted from the load intrinsic return values. The
  // sub-vectors are associated with the shufflevector instructions they will
  // replace.
  DenseMap<ShuffleVectorInst *, SmallVector<Value *, 4>> SubVecs;
 
  Value *PTrue = nullptr;
  if (UseScalable) {
    std::optional<unsigned> PgPattern =
        getSVEPredPatternFromNumElements(FVTy->getNumElements());
    if (Subtarget->getMinSVEVectorSizeInBits() ==
            Subtarget->getMaxSVEVectorSizeInBits() &&
        Subtarget->getMinSVEVectorSizeInBits() == DL.getTypeSizeInBits(FVTy))
      PgPattern = AArch64SVEPredPattern::all;
 
    auto *PTruePat =
        ConstantInt::get(Type::getInt32Ty(LDVTy->getContext()), *PgPattern);
    PTrue = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_ptrue, {PredTy},
                                    {PTruePat});
  }
 
  for (unsigned LoadCount = 0; LoadCount < NumLoads; ++LoadCount) {
 
    // If we're generating more than one load, compute the base address of
    // subsequent loads as an offset from the previous.
    if (LoadCount > 0)
      BaseAddr = Builder.CreateConstGEP1_32(LDVTy->getElementType(), BaseAddr,
                                            FVTy->getNumElements() * Factor);
 
    CallInst *LdN;
    if (UseScalable)
      LdN = Builder.CreateCall(LdNFunc, {PTrue, BaseAddr}, "ldN");
    else
      LdN = Builder.CreateCall(LdNFunc, BaseAddr, "ldN");
 
    // Extract and store the sub-vectors returned by the load intrinsic.
    for (unsigned i = 0; i < Shuffles.size(); i++) {
      ShuffleVectorInst *SVI = Shuffles[i];
      unsigned Index = Indices[i];
 
      Value *SubVec = Builder.CreateExtractValue(LdN, Index);
 
      if (UseScalable)
        SubVec = Builder.CreateExtractVector(FVTy, SubVec, uint64_t(0));
 
      // Convert the integer vector to pointer vector if the element is pointer.
      if (EltTy->isPointerTy())
        SubVec = Builder.CreateIntToPtr(
            SubVec, FixedVectorType::get(SVI->getType()->getElementType(),
                                         FVTy->getNumElements()));
 
      SubVecs[SVI].push_back(SubVec);
    }
  }
 
  // Replace uses of the shufflevector instructions with the sub-vectors
  // returned by the load intrinsic. If a shufflevector instruction is
  // associated with more than one sub-vector, those sub-vectors will be
  // concatenated into a single wide vector.
  for (ShuffleVectorInst *SVI : Shuffles) {
    auto &SubVec = SubVecs[SVI];
    auto *WideVec =
        SubVec.size() > 1 ? concatenateVectors(Builder, SubVec) : SubVec[0];
    SVI->replaceAllUsesWith(WideVec);
  }
 
  return true;
}
 
template <typename Iter>
bool hasNearbyPairedStore(Iter It, Iter End, Value *Ptr, const DataLayout &DL) {
  int MaxLookupDist = 20;
  unsigned IdxWidth = DL.getIndexSizeInBits(0);
  APInt OffsetA(IdxWidth, 0), OffsetB(IdxWidth, 0);
  const Value *PtrA1 =
      Ptr->stripAndAccumulateInBoundsConstantOffsets(DL, OffsetA);
 
  while (++It != End) {
    if (It->isDebugOrPseudoInst())
      continue;
    if (MaxLookupDist-- == 0)
      break;
    if (const auto *SI = dyn_cast<StoreInst>(&*It)) {
      const Value *PtrB1 =
          SI->getPointerOperand()->stripAndAccumulateInBoundsConstantOffsets(
              DL, OffsetB);
      if (PtrA1 == PtrB1 &&
          (OffsetA.sextOrTrunc(IdxWidth) - OffsetB.sextOrTrunc(IdxWidth))
                  .abs() == 16)
        return true;
    }
  }
 
  return false;
}
 
/// Lower an interleaved store into a stN intrinsic.
///
/// E.g. Lower an interleaved store (Factor = 3):
///        %i.vec = shuffle <8 x i32> %v0, <8 x i32> %v1,
///                 <0, 4, 8, 1, 5, 9, 2, 6, 10, 3, 7, 11>
///        store <12 x i32> %i.vec, <12 x i32>* %ptr
///
///      Into:
///        %sub.v0 = shuffle <8 x i32> %v0, <8 x i32> v1, <0, 1, 2, 3>
///        %sub.v1 = shuffle <8 x i32> %v0, <8 x i32> v1, <4, 5, 6, 7>
///        %sub.v2 = shuffle <8 x i32> %v0, <8 x i32> v1, <8, 9, 10, 11>
///        call void llvm.aarch64.neon.st3(%sub.v0, %sub.v1, %sub.v2, %ptr)
///
/// Note that the new shufflevectors will be removed and we'll only generate one
/// st3 instruction in CodeGen.
///
/// Example for a more general valid mask (Factor 3). Lower:
///        %i.vec = shuffle <32 x i32> %v0, <32 x i32> %v1,
///                 <4, 32, 16, 5, 33, 17, 6, 34, 18, 7, 35, 19>
///        store <12 x i32> %i.vec, <12 x i32>* %ptr
///
///      Into:
///        %sub.v0 = shuffle <32 x i32> %v0, <32 x i32> v1, <4, 5, 6, 7>
///        %sub.v1 = shuffle <32 x i32> %v0, <32 x i32> v1, <32, 33, 34, 35>
///        %sub.v2 = shuffle <32 x i32> %v0, <32 x i32> v1, <16, 17, 18, 19>
///        call void llvm.aarch64.neon.st3(%sub.v0, %sub.v1, %sub.v2, %ptr)
bool AArch64TargetLowering::lowerInterleavedStore(Instruction *Store,
                                                  Value *LaneMask,
                                                  ShuffleVectorInst *SVI,
                                                  unsigned Factor,
                                                  const APInt &GapMask) const {
 
  assert(Factor >= 2 && Factor <= getMaxSupportedInterleaveFactor() &&
         "Invalid interleave factor");
  auto *SI = dyn_cast<StoreInst>(Store);
  if (!SI)
    return false;
  assert(!LaneMask && GapMask.popcount() == Factor &&
         "Unexpected mask on store");
 
  auto *VecTy = cast<FixedVectorType>(SVI->getType());
  assert(VecTy->getNumElements() % Factor == 0 && "Invalid interleaved store");
 
  unsigned LaneLen = VecTy->getNumElements() / Factor;
  Type *EltTy = VecTy->getElementType();
  auto *SubVecTy = FixedVectorType::get(EltTy, LaneLen);
 
  const DataLayout &DL = SI->getDataLayout();
  bool UseScalable;
 
  // Skip if we do not have NEON and skip illegal vector types. We can
  // "legalize" wide vector types into multiple interleaved accesses as long as
  // the vector types are divisible by 128.
  if (!isLegalInterleavedAccessType(SubVecTy, DL, UseScalable))
    return false;
 
  unsigned NumStores = getNumInterleavedAccesses(SubVecTy, DL, UseScalable);
 
  Value *Op0 = SVI->getOperand(0);
  Value *Op1 = SVI->getOperand(1);
  IRBuilder<> Builder(SI);
 
  // StN intrinsics don't support pointer vectors as arguments. Convert pointer
  // vectors to integer vectors.
  if (EltTy->isPointerTy()) {
    Type *IntTy = DL.getIntPtrType(EltTy);
    unsigned NumOpElts =
        cast<FixedVectorType>(Op0->getType())->getNumElements();
 
    // Convert to the corresponding integer vector.
    auto *IntVecTy = FixedVectorType::get(IntTy, NumOpElts);
    Op0 = Builder.CreatePtrToInt(Op0, IntVecTy);
    Op1 = Builder.CreatePtrToInt(Op1, IntVecTy);
 
    SubVecTy = FixedVectorType::get(IntTy, LaneLen);
  }
 
  // If we're going to generate more than one store, reset the lane length
  // and sub-vector type to something legal.
  LaneLen /= NumStores;
  SubVecTy = FixedVectorType::get(SubVecTy->getElementType(), LaneLen);
 
  auto *STVTy = UseScalable ? cast<VectorType>(getSVEContainerIRType(SubVecTy))
                            : SubVecTy;
 
  // The base address of the store.
  Value *BaseAddr = SI->getPointerOperand();
 
  auto Mask = SVI->getShuffleMask();
 
  // Sanity check if all the indices are NOT in range.
  // If mask is `poison`, `Mask` may be a vector of -1s.
  // If all of them are `poison`, OOB read will happen later.
  if (llvm::all_of(Mask, equal_to(PoisonMaskElem))) {
    return false;
  }
  // A 64bit st2 which does not start at element 0 will involved adding extra
  // ext elements making the st2 unprofitable, and if there is a nearby store
  // that points to BaseAddr+16 or BaseAddr-16 then it can be better left as a
  // zip;ldp pair which has higher throughput.
  if (Factor == 2 && SubVecTy->getPrimitiveSizeInBits() == 64 &&
      (Mask[0] != 0 ||
       hasNearbyPairedStore(SI->getIterator(), SI->getParent()->end(), BaseAddr,
                            DL) ||
       hasNearbyPairedStore(SI->getReverseIterator(), SI->getParent()->rend(),
                            BaseAddr, DL)))
    return false;
 
  // Conditionally skip nontemporal stores to prioritize emitting non-temporal
  // store instructions, even though AArch64 doesn't have non-temporal
  // interleaved stores.
  //
  // The check is conservative:
  //
  // - Only when not optimizing for size, as STNP lowering can increase size.
  // - Don't skip if the interleaving factor is greater than 2, as the shuffling
  //   overhead becomes higher.
  // - Don't skip if the store value types which are not directly legal.
  Function *F = SI->getFunction();
  if (Factor == 2 && SI->hasMetadata(LLVMContext::MD_nontemporal) &&
      !F->hasOptSize() && !F->hasMinSize() &&
      isLegalNTStore(SI->getValueOperand()->getType(), SI->getAlign(), DL))
    return false;
 
  Type *PtrTy = SI->getPointerOperandType();
  Type *PredTy = VectorType::get(Type::getInt1Ty(STVTy->getContext()),
                                 STVTy->getElementCount());
 
  Function *StNFunc = getStructuredStoreFunction(SI->getModule(), Factor,
                                                 UseScalable, STVTy, PtrTy);
 
  Value *PTrue = nullptr;
  if (UseScalable) {
    std::optional<unsigned> PgPattern =
        getSVEPredPatternFromNumElements(SubVecTy->getNumElements());
    if (Subtarget->getMinSVEVectorSizeInBits() ==
            Subtarget->getMaxSVEVectorSizeInBits() &&
        Subtarget->getMinSVEVectorSizeInBits() ==
            DL.getTypeSizeInBits(SubVecTy))
      PgPattern = AArch64SVEPredPattern::all;
 
    auto *PTruePat =
        ConstantInt::get(Type::getInt32Ty(STVTy->getContext()), *PgPattern);
    PTrue = Builder.CreateIntrinsic(Intrinsic::aarch64_sve_ptrue, {PredTy},
                                    {PTruePat});
  }
 
  for (unsigned StoreCount = 0; StoreCount < NumStores; ++StoreCount) {
 
    SmallVector<Value *, 5> Ops;
 
    // Split the shufflevector operands into sub vectors for the new stN call.
    for (unsigned i = 0; i < Factor; i++) {
      Value *Shuffle;
      unsigned IdxI = StoreCount * LaneLen * Factor + i;
      if (Mask[IdxI] >= 0) {
        Shuffle = Builder.CreateShuffleVector(
            Op0, Op1, createSequentialMask(Mask[IdxI], LaneLen, 0));
      } else {
        unsigned StartMask = 0;
        for (unsigned j = 1; j < LaneLen; j++) {
          unsigned IdxJ = StoreCount * LaneLen * Factor + j * Factor + i;
          if (Mask[IdxJ] >= 0) {
            StartMask = Mask[IdxJ] - j;
            break;
          }
        }
        // Note: Filling undef gaps with random elements is ok, since
        // those elements were being written anyway (with undefs).
        // In the case of all undefs we're defaulting to using elems from 0
        // Note: StartMask cannot be negative, it's checked in
        // isReInterleaveMask
        Shuffle = Builder.CreateShuffleVector(
            Op0, Op1, createSequentialMask(StartMask, LaneLen, 0));
      }
 
      if (UseScalable)
        Shuffle = Builder.CreateInsertVector(STVTy, PoisonValue::get(STVTy),
                                             Shuffle, uint64_t(0));
 
      Ops.push_back(Shuffle);
    }
 
    if (UseScalable)
      Ops.push_back(PTrue);
 
    // If we generating more than one store, we compute the base address of
    // subsequent stores as an offset from the previous.
    if (StoreCount > 0)
      BaseAddr = Builder.CreateConstGEP1_32(SubVecTy->getElementType(),
                                            BaseAddr, LaneLen * Factor);
 
    Ops.push_back(BaseAddr);
    Builder.CreateCall(StNFunc, Ops);
  }
  return true;
}
 
bool AArch64TargetLowering::lowerDeinterleaveIntrinsicToLoad(
    Instruction *Load, Value *Mask, IntrinsicInst *DI) const {
  const unsigned Factor = getDeinterleaveIntrinsicFactor(DI->getIntrinsicID());
  if (Factor != 2 && Factor != 3 && Factor != 4) {
    LLVM_DEBUG(dbgs() << "Matching ld2, ld3 and ld4 patterns failed\n");
    return false;
  }
  auto *LI = dyn_cast<LoadInst>(Load);
  if (!LI)
    return false;
  assert(!Mask && "Unexpected mask on a load\n");
 
  VectorType *VTy = getDeinterleavedVectorType(DI);
 
  const DataLayout &DL = LI->getModule()->getDataLayout();
  bool UseScalable;
  if (!isLegalInterleavedAccessType(VTy, DL, UseScalable))
    return false;
 
  // TODO: Add support for using SVE instructions with fixed types later, using
  // the code from lowerInterleavedLoad to obtain the correct container type.
  if (UseScalable && !VTy->isScalableTy())
    return false;
 
  unsigned NumLoads = getNumInterleavedAccesses(VTy, DL, UseScalable);
  VectorType *LdTy =
      VectorType::get(VTy->getElementType(),
                      VTy->getElementCount().divideCoefficientBy(NumLoads));
 
  Type *PtrTy = LI->getPointerOperandType();
  Function *LdNFunc = getStructuredLoadFunction(LI->getModule(), Factor,
                                                UseScalable, LdTy, PtrTy);
 
  IRBuilder<> Builder(LI);
  Value *Pred = nullptr;
  if (UseScalable)
    Pred =
        Builder.CreateVectorSplat(LdTy->getElementCount(), Builder.getTrue());
 
  Value *BaseAddr = LI->getPointerOperand();
  Value *Result = nullptr;
  if (NumLoads > 1) {
    // Create multiple legal small ldN.
    SmallVector<Value *, 4> ExtractedLdValues(Factor, PoisonValue::get(VTy));
    for (unsigned I = 0; I < NumLoads; ++I) {
      Value *Offset = Builder.getInt64(I * Factor);
 
      Value *Address = Builder.CreateGEP(LdTy, BaseAddr, {Offset});
      Value *LdN = nullptr;
      if (UseScalable)
        LdN = Builder.CreateCall(LdNFunc, {Pred, Address}, "ldN");
      else
        LdN = Builder.CreateCall(LdNFunc, Address, "ldN");
      Value *Idx =
          Builder.getInt64(I * LdTy->getElementCount().getKnownMinValue());
      for (unsigned J = 0; J < Factor; ++J) {
        ExtractedLdValues[J] = Builder.CreateInsertVector(
            VTy, ExtractedLdValues[J], Builder.CreateExtractValue(LdN, J), Idx);
      }
      LLVM_DEBUG(dbgs() << "LdN4 res: "; LdN->dump());
    }
 
    // Merge the values from different factors.
    Result = PoisonValue::get(DI->getType());
    for (unsigned J = 0; J < Factor; ++J)
      Result = Builder.CreateInsertValue(Result, ExtractedLdValues[J], J);
  } else {
    if (UseScalable)
      Result = Builder.CreateCall(LdNFunc, {Pred, BaseAddr}, "ldN");
    else
      Result = Builder.CreateCall(LdNFunc, BaseAddr, "ldN");
  }
 
  // Replace output of deinterleave2 intrinsic by output of ldN2/ldN4
  DI->replaceAllUsesWith(Result);
  return true;
}
 
bool AArch64TargetLowering::lowerInterleaveIntrinsicToStore(
    Instruction *Store, Value *Mask,
    ArrayRef<Value *> InterleavedValues) const {
  unsigned Factor = InterleavedValues.size();
  if (Factor != 2 && Factor != 3 && Factor != 4) {
    LLVM_DEBUG(dbgs() << "Matching st2, st3 and st4 patterns failed\n");
    return false;
  }
  StoreInst *SI = dyn_cast<StoreInst>(Store);
  if (!SI)
    return false;
  assert(!Mask && "Unexpected mask on plain store");
 
  VectorType *VTy = cast<VectorType>(InterleavedValues[0]->getType());
  const DataLayout &DL = SI->getModule()->getDataLayout();
 
  bool UseScalable;
  if (!isLegalInterleavedAccessType(VTy, DL, UseScalable))
    return false;
 
  // TODO: Add support for using SVE instructions with fixed types later, using
  // the code from lowerInterleavedStore to obtain the correct container type.
  if (UseScalable && !VTy->isScalableTy())
    return false;
 
  unsigned NumStores = getNumInterleavedAccesses(VTy, DL, UseScalable);
 
  VectorType *StTy =
      VectorType::get(VTy->getElementType(),
                      VTy->getElementCount().divideCoefficientBy(NumStores));
 
  Type *PtrTy = SI->getPointerOperandType();
  Function *StNFunc = getStructuredStoreFunction(SI->getModule(), Factor,
                                                 UseScalable, StTy, PtrTy);
 
  IRBuilder<> Builder(SI);
 
  Value *BaseAddr = SI->getPointerOperand();
  Value *Pred = nullptr;
 
  if (UseScalable)
    Pred =
        Builder.CreateVectorSplat(StTy->getElementCount(), Builder.getTrue());
 
  auto ExtractedValues = InterleavedValues;
  SmallVector<Value *, 4> StoreOperands(InterleavedValues);
  if (UseScalable)
    StoreOperands.push_back(Pred);
  StoreOperands.push_back(BaseAddr);
  for (unsigned I = 0; I < NumStores; ++I) {
    Value *Address = BaseAddr;
    if (NumStores > 1) {
      Value *Offset = Builder.getInt64(I * Factor);
      Address = Builder.CreateGEP(StTy, BaseAddr, {Offset});
      Value *Idx =
          Builder.getInt64(I * StTy->getElementCount().getKnownMinValue());
      for (unsigned J = 0; J < Factor; J++) {
        StoreOperands[J] =
            Builder.CreateExtractVector(StTy, ExtractedValues[J], Idx);
      }
      // update the address
      StoreOperands[StoreOperands.size() - 1] = Address;
    }
    Builder.CreateCall(StNFunc, StoreOperands);
  }
  return true;
}
 
EVT AArch64TargetLowering::getOptimalMemOpType(
    LLVMContext &Context, const MemOp &Op,
    const AttributeList &FuncAttributes) const {
  bool CanImplicitFloat = !FuncAttributes.hasFnAttr(Attribute::NoImplicitFloat);
  bool CanUseNEON = Subtarget->hasNEON() && CanImplicitFloat;
  bool CanUseFP = Subtarget->hasFPARMv8() && CanImplicitFloat;
  // For zero memset, only use AdvSIMD for 32-byte and above. It would have
  // taken one instruction to materialize the v2i64 zero and one store (with
  // restrictive addressing mode). Just do i64 stores.
  // For non-zero memset, use NEON even for smaller sizes as dup is efficient.
  bool IsSmallZeroMemset = Op.isMemset() && Op.size() < 32 && Op.isZeroMemset();
  auto AlignmentIsAcceptable = [&](EVT VT, Align AlignCheck) {
    if (Op.isAligned(AlignCheck))
      return true;
    unsigned Fast;
    return allowsMisalignedMemoryAccesses(VT, 0, Align(1),
                                          MachineMemOperand::MONone, &Fast) &&
           Fast;
  };
 
  // For non-zero memset, use NEON even for smaller sizes as dup + scalar store
  // is efficient
  if (CanUseNEON && Op.isMemset() && !IsSmallZeroMemset &&
      AlignmentIsAcceptable(MVT::v16i8, Align(1)))
    return MVT::v16i8;
  if (CanUseFP && !IsSmallZeroMemset &&
      AlignmentIsAcceptable(MVT::f128, Align(16)))
    return MVT::f128;
  if (Op.size() >= 8 && AlignmentIsAcceptable(MVT::i64, Align(8)))
    return MVT::i64;
  if (Op.size() >= 4 && AlignmentIsAcceptable(MVT::i32, Align(4)))
    return MVT::i32;
  return MVT::Other;
}
 
bool AArch64TargetLowering::findOptimalMemOpLowering(
    LLVMContext &Context, std::vector<EVT> &MemOps, unsigned Limit,
    const MemOp &Op, unsigned DstAS, unsigned SrcAS,
    const AttributeList &FuncAttributes, EVT *LargestVT) const {
  // For non-zero memset with v16i8, don't downgrade. We can extract smaller
  // stores (i64, i32, i16, i8) from the v16i8 splat efficiently.
  EVT VT = getOptimalMemOpType(Context, Op, FuncAttributes);
  if (VT == MVT::v16i8 && Op.isMemset() && !Op.isZeroMemset() &&
      Op.size() < 16) {
    unsigned Size = Op.size();
    unsigned RemainingSize = Size;
 
    // Break down the size into stores that we can extract from v16i8.
    // We support: i64 (8 bytes), i32 (4 bytes), i16 (2 bytes), i8 (1 byte)
    // Use the largest possible stores first to minimize the number of
    // operations.
    while (RemainingSize > 0) {
      EVT TargetVT;
 
      // Try largest stores first
      if (RemainingSize >= 8) {
        TargetVT = MVT::i64;
        RemainingSize -= 8;
      } else if (RemainingSize >= 4) {
        TargetVT = MVT::i32;
        RemainingSize -= 4;
      } else if (RemainingSize >= 2) {
        TargetVT = MVT::i16;
        RemainingSize -= 2;
      } else if (RemainingSize >= 1) {
        TargetVT = MVT::i8;
        RemainingSize -= 1;
      } else {
        // Should not reach here, but fall back to default implementation
        break;
      }
 
      MemOps.push_back(TargetVT);
    }
 
    // If we successfully decomposed the entire size, set LargestVT to v16i8
    // to ensure getMemsetValue generates the efficient vector splat (DUP).
    // We don't add v16i8 to MemOps since we only need it for value generation.
    if (RemainingSize == 0 && !MemOps.empty()) {
      if (LargestVT)
        *LargestVT = VT; // v16i8 for vector splat generation
      return true;
    }
 
    // Clear MemOps if we didn't successfully handle everything
    MemOps.clear();
  }
  // Otherwise, use the default implementation
  return TargetLowering::findOptimalMemOpLowering(
      Context, MemOps, Limit, Op, DstAS, SrcAS, FuncAttributes, LargestVT);
}
 
LLT AArch64TargetLowering::getOptimalMemOpLLT(
    const MemOp &Op, const AttributeList &FuncAttributes) const {
  bool CanImplicitFloat = !FuncAttributes.hasFnAttr(Attribute::NoImplicitFloat);
  bool CanUseNEON = Subtarget->hasNEON() && CanImplicitFloat;
  bool CanUseFP = Subtarget->hasFPARMv8() && CanImplicitFloat;
  // For zero memset, only use AdvSIMD for 32-byte and above. It would have
  // taken one instruction to materialize the v2i64 zero and one store (with
  // restrictive addressing mode). Just do i64 stores.
  // For non-zero memset, use NEON even for smaller sizes as dup is efficient.
  bool IsSmallZeroMemset = Op.isMemset() && Op.size() < 32 && Op.isZeroMemset();
  auto AlignmentIsAcceptable = [&](EVT VT, Align AlignCheck) {
    if (Op.isAligned(AlignCheck))
      return true;
    unsigned Fast;
    return allowsMisalignedMemoryAccesses(VT, 0, Align(1),
                                          MachineMemOperand::MONone, &Fast) &&
           Fast;
  };
 
  // For non-zero memset, use NEON for all sizes where it's beneficial.
  // NEON dup + scalar store works for any alignment and is efficient.
  if (CanUseNEON && Op.isMemset() && !IsSmallZeroMemset &&
      AlignmentIsAcceptable(MVT::v16i8, Align(1)))
    return LLT::fixed_vector(2, LLT::integer(64));
  if (CanUseFP && !IsSmallZeroMemset &&
      AlignmentIsAcceptable(MVT::f128, Align(16)))
    return LLT::floatIEEE(128);
  if (Op.size() >= 8 && AlignmentIsAcceptable(MVT::i64, Align(8)))
    return LLT::integer(64);
  if (Op.size() >= 4 && AlignmentIsAcceptable(MVT::i32, Align(4)))
    return LLT::integer(32);
  return LLT();
}
 
// 12-bit optionally shifted immediates are legal for adds.
bool AArch64TargetLowering::isLegalAddImmediate(int64_t Immed) const {
  if (Immed == std::numeric_limits<int64_t>::min()) {
    return false;
  }
  // Same encoding for add/sub, just flip the sign.
  return isLegalArithImmed((uint64_t)std::abs(Immed));
}
 
bool AArch64TargetLowering::isLegalAddScalableImmediate(int64_t Imm) const {
  // We will only emit addvl/inc* instructions for SVE2
  if (!Subtarget->hasSVE2())
    return false;
 
  // addvl's immediates are in terms of the number of bytes in a register.
  // Since there are 16 in the base supported size (128bits), we need to
  // divide the immediate by that much to give us a useful immediate to
  // multiply by vscale. We can't have a remainder as a result of this.
  if (Imm % 16 == 0)
    return isInt<6>(Imm / 16);
 
  // Inc[b|h|w|d] instructions take a pattern and a positive immediate
  // multiplier. For now, assume a pattern of 'all'. Incb would be a subset
  // of addvl as a result, so only take h|w|d into account.
  // Dec[h|w|d] will cover subtractions.
  // Immediates are in the range [1,16], so we can't do a 2's complement check.
  // FIXME: Can we make use of other patterns to cover other immediates?
 
  // inch|dech
  if (Imm % 8 == 0)
    return std::abs(Imm / 8) <= 16;
  // incw|decw
  if (Imm % 4 == 0)
    return std::abs(Imm / 4) <= 16;
  // incd|decd
  if (Imm % 2 == 0)
    return std::abs(Imm / 2) <= 16;
 
  return false;
}
 
// Return false to prevent folding
// (mul (add x, c1), c2) -> (add (mul x, c2), c2*c1) in DAGCombine,
// if the folding leads to worse code.
bool AArch64TargetLowering::isMulAddWithConstProfitable(
    SDValue AddNode, SDValue ConstNode) const {
  // Let the DAGCombiner decide for vector types and large types.
  const EVT VT = AddNode.getValueType();
  if (VT.isVector() || VT.getScalarSizeInBits() > 64)
    return true;
 
  // It is worse if c1 is legal add immediate, while c1*c2 is not
  // and has to be composed by at least two instructions.
  const ConstantSDNode *C1Node = cast<ConstantSDNode>(AddNode.getOperand(1));
  const ConstantSDNode *C2Node = cast<ConstantSDNode>(ConstNode);
  const int64_t C1 = C1Node->getSExtValue();
  const APInt C1C2 = C1Node->getAPIntValue() * C2Node->getAPIntValue();
  if (!isLegalAddImmediate(C1) || isLegalAddImmediate(C1C2.getSExtValue()))
    return true;
  SmallVector<AArch64_IMM::ImmInsnModel, 4> Insn;
  // Adapt to the width of a register.
  unsigned BitSize = VT.getSizeInBits() <= 32 ? 32 : 64;
  AArch64_IMM::expandMOVImm(C1C2.getZExtValue(), BitSize, Insn);
  if (Insn.size() > 1)
    return false;
 
  // Default to true and let the DAGCombiner decide.
  return true;
}
 
// Integer comparisons are implemented with ADDS/SUBS, so the range of valid
// immediates is the same as for an add or a sub.
bool AArch64TargetLowering::isLegalICmpImmediate(int64_t Immed) const {
  return isLegalAddImmediate(Immed);
}
 
/// isLegalAddressingMode - Return true if the addressing mode represented
/// by AM is legal for this target, for a load/store of the specified type.
bool AArch64TargetLowering::isLegalAddressingMode(const DataLayout &DL,
                                                  const AddrMode &AMode, Type *Ty,
                                                  unsigned AS, Instruction *I) const {
  // AArch64 has five basic addressing modes:
  //  reg
  //  reg + 9-bit signed offset
  //  reg + SIZE_IN_BYTES * 12-bit unsigned offset
  //  reg1 + reg2
  //  reg + SIZE_IN_BYTES * reg
 
  // No global is ever allowed as a base.
  if (AMode.BaseGV)
    return false;
 
  // No reg+reg+imm addressing.
  if (AMode.HasBaseReg && AMode.BaseOffs && AMode.Scale)
    return false;
 
  // Canonicalise `1*ScaledReg + imm` into `BaseReg + imm` and
  // `2*ScaledReg` into `BaseReg + ScaledReg`
  AddrMode AM = AMode;
  if (AM.Scale && !AM.HasBaseReg) {
    if (AM.Scale == 1) {
      AM.HasBaseReg = true;
      AM.Scale = 0;
    } else if (AM.Scale == 2) {
      AM.HasBaseReg = true;
      AM.Scale = 1;
    } else {
      return false;
    }
  }
 
  // A base register is required in all addressing modes.
  if (!AM.HasBaseReg)
    return false;
 
  if (Ty->isScalableTy()) {
    if (isa<ScalableVectorType>(Ty)) {
      // See if we have a foldable vscale-based offset, for vector types which
      // are either legal or smaller than the minimum; more work will be
      // required if we need to consider addressing for types which need
      // legalization by splitting.
      uint64_t VecNumBytes = DL.getTypeSizeInBits(Ty).getKnownMinValue() / 8;
      if (AM.HasBaseReg && !AM.BaseOffs && AM.ScalableOffset && !AM.Scale &&
          (AM.ScalableOffset % VecNumBytes == 0) && VecNumBytes <= 16 &&
          isPowerOf2_64(VecNumBytes))
        return isInt<4>(AM.ScalableOffset / (int64_t)VecNumBytes);
 
      uint64_t VecElemNumBytes =
          DL.getTypeSizeInBits(cast<VectorType>(Ty)->getElementType()) / 8;
      return AM.HasBaseReg && !AM.BaseOffs && !AM.ScalableOffset &&
             (AM.Scale == 0 || (uint64_t)AM.Scale == VecElemNumBytes);
    }
 
    return AM.HasBaseReg && !AM.BaseOffs && !AM.ScalableOffset && !AM.Scale;
  }
 
  // No scalable offsets allowed for non-scalable types.
  if (AM.ScalableOffset)
    return false;
 
  // check reg + imm case:
  // i.e., reg + 0, reg + imm9, reg + SIZE_IN_BYTES * uimm12
  uint64_t NumBytes = 0;
  if (Ty->isSized()) {
    uint64_t NumBits = DL.getTypeSizeInBits(Ty);
    NumBytes = NumBits / 8;
    if (!isPowerOf2_64(NumBits))
      NumBytes = 0;
  }
 
  return Subtarget->getInstrInfo()->isLegalAddressingMode(NumBytes, AM.BaseOffs,
                                                          AM.Scale);
}
 
// Check whether the 2 offsets belong to the same imm24 range, and their high
// 12bits are same, then their high part can be decoded with the offset of add.
int64_t
AArch64TargetLowering::getPreferredLargeGEPBaseOffset(int64_t MinOffset,
                                                      int64_t MaxOffset) const {
  int64_t HighPart = MinOffset & ~0xfffULL;
  if (MinOffset >> 12 == MaxOffset >> 12 && isLegalAddImmediate(HighPart)) {
    // Rebase the value to an integer multiple of imm12.
    return HighPart;
  }
 
  return 0;
}
 
bool AArch64TargetLowering::shouldConsiderGEPOffsetSplit() const {
  // Consider splitting large offset of struct or array.
  return true;
}
 
bool AArch64TargetLowering::isFMAFasterThanFMulAndFAdd(
    const MachineFunction &MF, EVT VT) const {
  EVT ScalarVT = VT.getScalarType();
 
  if (!ScalarVT.isSimple())
    return false;
 
  switch (ScalarVT.getSimpleVT().SimpleTy) {
  case MVT::f16:
    return Subtarget->hasFullFP16();
  case MVT::f32:
  case MVT::f64:
    return true;
  case MVT::bf16:
    return VT.isScalableVector() && Subtarget->hasBF16() &&
           Subtarget->isNonStreamingSVEorSME2Available();
  default:
    break;
  }
 
  return false;
}
 
bool AArch64TargetLowering::isFMAFasterThanFMulAndFAdd(const Function &F,
                                                       Type *Ty) const {
  switch (Ty->getScalarType()->getTypeID()) {
  case Type::FloatTyID:
  case Type::DoubleTyID:
    return true;
  default:
    return false;
  }
}
 
bool AArch64TargetLowering::generateFMAsInMachineCombiner(
    EVT VT, CodeGenOptLevel OptLevel) const {
  return (OptLevel >= CodeGenOptLevel::Aggressive) && !VT.isScalableVector() &&
         !useSVEForFixedLengthVectorVT(VT);
}
 
const MCPhysReg *
AArch64TargetLowering::getScratchRegisters(CallingConv::ID) const {
  // LR is a callee-save register, but we must treat it as clobbered by any call
  // site. Hence we include LR in the scratch registers, which are in turn added
  // as implicit-defs for stackmaps and patchpoints.
  static const MCPhysReg ScratchRegs[] = {
    AArch64::X16, AArch64::X17, AArch64::LR, 0
  };
  return ScratchRegs;
}
 
ArrayRef<MCPhysReg> AArch64TargetLowering::getRoundingControlRegisters() const {
  static const MCPhysReg RCRegs[] = {AArch64::FPCR};
  return RCRegs;
}
 
bool
AArch64TargetLowering::isDesirableToCommuteWithShift(const SDNode *N,
                                                     CombineLevel Level) const {
  assert((N->getOpcode() == ISD::SHL || N->getOpcode() == ISD::SRA ||
          N->getOpcode() == ISD::SRL) &&
         "Expected shift op");
 
  SDValue ShiftLHS = N->getOperand(0);
  EVT VT = N->getValueType(0);
 
  if (!ShiftLHS->hasOneUse())
    return false;
 
  if (ShiftLHS.getOpcode() == ISD::SIGN_EXTEND &&
      !ShiftLHS.getOperand(0)->hasOneUse())
    return false;
 
  // If ShiftLHS is unsigned bit extraction: ((x >> C) & mask), then do not
  // combine it with shift 'N' to let it be lowered to UBFX except:
  // ((x >> C) & mask) << C.
  if (ShiftLHS.getOpcode() == ISD::AND && (VT == MVT::i32 || VT == MVT::i64) &&
      isa<ConstantSDNode>(ShiftLHS.getOperand(1))) {
    uint64_t TruncMask = ShiftLHS.getConstantOperandVal(1);
    if (isMask_64(TruncMask)) {
      SDValue AndLHS = ShiftLHS.getOperand(0);
      if (AndLHS.getOpcode() == ISD::SRL) {
        if (auto *SRLC = dyn_cast<ConstantSDNode>(AndLHS.getOperand(1))) {
          if (N->getOpcode() == ISD::SHL)
            if (auto *SHLC = dyn_cast<ConstantSDNode>(N->getOperand(1)))
              return SRLC->getZExtValue() == SHLC->getZExtValue();
          return false;
        }
      }
    }
  }
  return true;
}
 
bool AArch64TargetLowering::isDesirableToCommuteXorWithShift(
    const SDNode *N) const {
  assert(N->getOpcode() == ISD::XOR &&
         (N->getOperand(0).getOpcode() == ISD::SHL ||
          N->getOperand(0).getOpcode() == ISD::SRL) &&
         "Expected XOR(SHIFT) pattern");
 
  // Only commute if the entire NOT mask is a hidden shifted mask.
  auto *XorC = dyn_cast<ConstantSDNode>(N->getOperand(1));
  auto *ShiftC = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1));
  if (XorC && ShiftC) {
    unsigned MaskIdx, MaskLen;
    if (XorC->getAPIntValue().isShiftedMask(MaskIdx, MaskLen)) {
      unsigned ShiftAmt = ShiftC->getZExtValue();
      unsigned BitWidth = N->getValueType(0).getScalarSizeInBits();
      if (N->getOperand(0).getOpcode() == ISD::SHL)
        return MaskIdx == ShiftAmt && MaskLen == (BitWidth - ShiftAmt);
      return MaskIdx == 0 && MaskLen == (BitWidth - ShiftAmt);
    }
  }
 
  return false;
}
 
bool AArch64TargetLowering::shouldFoldConstantShiftPairToMask(
    const SDNode *N) const {
  assert(((N->getOpcode() == ISD::SHL &&
           N->getOperand(0).getOpcode() == ISD::SRL) ||
          (N->getOpcode() == ISD::SRL &&
           N->getOperand(0).getOpcode() == ISD::SHL)) &&
         "Expected shift-shift mask");
  // Don't allow multiuse shift folding with the same shift amount.
  if (!N->getOperand(0)->hasOneUse())
    return false;
 
  // Only fold srl(shl(x,c1),c2) iff C1 >= C2 to prevent loss of UBFX patterns.
  EVT VT = N->getValueType(0);
  if (N->getOpcode() == ISD::SRL && (VT == MVT::i32 || VT == MVT::i64)) {
    auto *C1 = dyn_cast<ConstantSDNode>(N->getOperand(0).getOperand(1));
    auto *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1));
    return (!C1 || !C2 || C1->getZExtValue() >= C2->getZExtValue());
  }
 
  // We do not need to fold when this shifting used in specific load case:
  // (ldr x, (add x, (shl (srl x, c1) 2)))
  if (N->getOpcode() == ISD::SHL && N->hasOneUse()) {
    if (auto C2 = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
      unsigned ShlAmt = C2->getZExtValue();
      if (auto ShouldADD = *N->user_begin();
          ShouldADD->getOpcode() == ISD::ADD && ShouldADD->hasOneUse()) {
        if (auto Load = dyn_cast<LoadSDNode>(*ShouldADD->user_begin())) {
          EVT MemVT = Load->getMemoryVT();
 
          if (Load->getValueType(0).isScalableVector())
            return (8ULL << ShlAmt) != MemVT.getScalarSizeInBits();
 
          if (isIndexedLoadLegal(ISD::PRE_INC, MemVT))
            return (8ULL << ShlAmt) != MemVT.getFixedSizeInBits();
        }
      }
    }
  }
 
  return true;
}
 
bool AArch64TargetLowering::shouldFoldSelectWithIdentityConstant(
    unsigned BinOpcode, EVT VT, unsigned SelectOpcode, SDValue X,
    SDValue Y) const {
  return VT.isScalableVector() && isTypeLegal(VT) &&
         SelectOpcode == ISD::VSELECT;
}
 
bool AArch64TargetLowering::shouldConvertConstantLoadToIntImm(const APInt &Imm,
                                                              Type *Ty) const {
  assert(Ty->isIntegerTy());
 
  unsigned BitSize = Ty->getPrimitiveSizeInBits();
  if (BitSize == 0)
    return false;
 
  int64_t Val = Imm.getSExtValue();
  if (Val == 0 || AArch64_AM::isLogicalImmediate(Val, BitSize))
    return true;
 
  if (Val < 0)
    Val = ~Val;
  if (BitSize == 32)
    Val &= (1LL << 32) - 1;
 
  unsigned Shift = llvm::Log2_64((uint64_t)Val) / 16;
  // MOVZ is free so return true for one or fewer MOVK.
  return Shift < 3;
}
 
bool AArch64TargetLowering::isExtractSubvectorCheap(EVT ResVT, EVT SrcVT,
                                                    unsigned Index) const {
  if (!isOperationLegalOrCustom(ISD::EXTRACT_SUBVECTOR, ResVT))
    return false;
 
  return (Index == 0 || Index == ResVT.getVectorMinNumElements());
}
 
bool AArch64TargetLowering::shouldOptimizeMulOverflowWithZeroHighBits(
    LLVMContext &Context, EVT VT) const {
  if (getTypeAction(Context, VT) != TypeExpandInteger)
    return false;
 
  EVT LegalTy = EVT::getIntegerVT(Context, VT.getSizeInBits() / 2);
  return getTypeAction(Context, LegalTy) == TargetLowering::TypeLegal;
}
 
/// Turn vector tests of the signbit in the form of:
///   xor (sra X, elt_size(X)-1), -1
/// into:
///   cmge X, X, #0
static SDValue foldVectorXorShiftIntoCmp(SDNode *N, SelectionDAG &DAG,
                                         const AArch64Subtarget *Subtarget) {
  EVT VT = N->getValueType(0);
  if (!Subtarget->hasNEON() || !VT.isVector())
    return SDValue();
 
  // There must be a shift right algebraic before the xor, and the xor must be a
  // 'not' operation.
  SDValue Shift = N->getOperand(0);
  SDValue Ones = N->getOperand(1);
  if (Shift.getOpcode() != AArch64ISD::VASHR || !Shift.hasOneUse() ||
      !ISD::isBuildVectorAllOnes(Ones.getNode()))
    return SDValue();
 
  // The shift should be smearing the sign bit across each vector element.
  auto *ShiftAmt = dyn_cast<ConstantSDNode>(Shift.getOperand(1));
  EVT ShiftEltTy = Shift.getValueType().getVectorElementType();
  if (!ShiftAmt || ShiftAmt->getZExtValue() != ShiftEltTy.getSizeInBits() - 1)
    return SDValue();
 
  SDLoc DL(N);
  SDValue Zero = DAG.getConstant(0, DL, Shift.getValueType());
  return DAG.getSetCC(DL, VT, Shift.getOperand(0), Zero, ISD::SETGE);
}
 
// Given a vecreduce_add node, detect the below pattern and convert it to the
// node sequence with UABDL, [S|U]ADB and UADDLP.
//
// i32 vecreduce_add(
//  v16i32 abs(
//    v16i32 sub(
//     v16i32 [sign|zero]_extend(v16i8 a), v16i32 [sign|zero]_extend(v16i8 b))))
//
//  or
//
// i32 vecreduce_add(
//  v16i32 zext(
//   v16i16 abs(
//    v16i16 sub(
//     v16i16 [sign|zero]_extend(v16i8 a), v16i16 [sign|zero]_extend(v16i8 b))))
//
// =================>
// i32 vecreduce_add(
//   v4i32 UADDLP(
//     v8i16 add(
//       v8i16 zext(
//         v8i8 [S|U]ABD low8:v16i8 a, low8:v16i8 b
//       v8i16 zext(
//         v8i8 [S|U]ABD high8:v16i8 a, high8:v16i8 b
static SDValue performVecReduceAddCombineWithUADDLP(SDNode *N,
                                                    SelectionDAG &DAG) {
  // Assumed i32 vecreduce_add
  if (N->getValueType(0) != MVT::i32)
    return SDValue();
 
  SDValue VecReduceOp0 = N->getOperand(0);
  bool SawTrailingZext = false;
  // Look through an optional post-ABS ZEXT from v16i16 -> v16i32.
  if (VecReduceOp0.getOpcode() == ISD::ZERO_EXTEND &&
      VecReduceOp0->getValueType(0) == MVT::v16i32 &&
      VecReduceOp0->getOperand(0)->getOpcode() == ISD::ABS &&
      VecReduceOp0->getOperand(0)->getValueType(0) == MVT::v16i16) {
    SawTrailingZext = true;
    VecReduceOp0 = VecReduceOp0.getOperand(0);
  }
 
  // Peel off an optional post-ABS extend (v16i16 -> v16i32).
  MVT AbsInputVT = SawTrailingZext ? MVT::v16i16 : MVT::v16i32;
  // Assumed v16i16 or v16i32 abs input
  unsigned Opcode = VecReduceOp0.getOpcode();
  if (Opcode != ISD::ABS || VecReduceOp0->getValueType(0) != AbsInputVT)
    return SDValue();
 
  SDValue ABS = VecReduceOp0;
  // Assumed v16i16 or v16i32 sub
  if (ABS->getOperand(0)->getOpcode() != ISD::SUB ||
      ABS->getOperand(0)->getValueType(0) != AbsInputVT)
    return SDValue();
 
  SDValue SUB = ABS->getOperand(0);
  unsigned Opcode0 = SUB->getOperand(0).getOpcode();
  unsigned Opcode1 = SUB->getOperand(1).getOpcode();
  // Assumed v16i16 or v16i32 type
  if (SUB->getOperand(0)->getValueType(0) != AbsInputVT ||
      SUB->getOperand(1)->getValueType(0) != AbsInputVT)
    return SDValue();
 
  // Assumed zext or sext
  bool IsZExt = false;
  if (Opcode0 == ISD::ZERO_EXTEND && Opcode1 == ISD::ZERO_EXTEND) {
    IsZExt = true;
  } else if (Opcode0 == ISD::SIGN_EXTEND && Opcode1 == ISD::SIGN_EXTEND) {
    IsZExt = false;
  } else
    return SDValue();
 
  SDValue EXT0 = SUB->getOperand(0);
  SDValue EXT1 = SUB->getOperand(1);
  // Assumed zext's operand has v16i8 type
  if (EXT0->getOperand(0)->getValueType(0) != MVT::v16i8 ||
      EXT1->getOperand(0)->getValueType(0) != MVT::v16i8)
    return SDValue();
 
  // Pattern is detected. Let's convert it to sequence of nodes.
  SDLoc DL(N);
 
  // First, create the node pattern of UABD/SABD.
  SDValue UABDHigh8Op0 =
      DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, EXT0->getOperand(0),
                  DAG.getConstant(8, DL, MVT::i64));
  SDValue UABDHigh8Op1 =
      DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, EXT1->getOperand(0),
                  DAG.getConstant(8, DL, MVT::i64));
  SDValue UABDHigh8 = DAG.getNode(IsZExt ? ISD::ABDU : ISD::ABDS, DL, MVT::v8i8,
                                  UABDHigh8Op0, UABDHigh8Op1);
  SDValue UABDL = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::v8i16, UABDHigh8);
 
  // Second, create the node pattern of UABAL.
  SDValue UABDLo8Op0 =
      DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, EXT0->getOperand(0),
                  DAG.getConstant(0, DL, MVT::i64));
  SDValue UABDLo8Op1 =
      DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, EXT1->getOperand(0),
                  DAG.getConstant(0, DL, MVT::i64));
  SDValue UABDLo8 = DAG.getNode(IsZExt ? ISD::ABDU : ISD::ABDS, DL, MVT::v8i8,
                                UABDLo8Op0, UABDLo8Op1);
  SDValue ZExtUABD = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::v8i16, UABDLo8);
  SDValue UABAL = DAG.getNode(ISD::ADD, DL, MVT::v8i16, UABDL, ZExtUABD);
 
  // Third, create the node of UADDLP.
  SDValue UADDLP = DAG.getNode(AArch64ISD::UADDLP, DL, MVT::v4i32, UABAL);
 
  // Fourth, create the node of VECREDUCE_ADD.
  return DAG.getNode(ISD::VECREDUCE_ADD, DL, MVT::i32, UADDLP);
}
 
static SDValue
performActiveLaneMaskCombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI,
                             const AArch64Subtarget *ST) {
  if (DCI.isBeforeLegalize())
    return SDValue();
 
  if (SDValue Brk = optimizeBrk(N, DCI.DAG))
    return Brk;
 
  if (SDValue While = optimizeIncrementingWhile(N, DCI.DAG, /*IsSigned=*/false,
                                                /*IsEqual=*/false))
    return While;
 
  if (!N->getValueType(0).isScalableVector() ||
      !ST->isSVEorStreamingSVEAvailable() ||
      !(ST->hasSVE2p1() || ST->hasSME2()))
    return SDValue();
 
  // Count the number of users which are extract_vectors.
  unsigned NumExts = count_if(N->users(), [](SDNode *Use) {
    return Use->getOpcode() == ISD::EXTRACT_SUBVECTOR;
  });
 
  auto MaskEC = N->getValueType(0).getVectorElementCount();
  if (!MaskEC.isKnownMultipleOf(NumExts))
    return SDValue();
 
  ElementCount ExtMinEC = MaskEC.divideCoefficientBy(NumExts);
  if (ExtMinEC.getKnownMinValue() < 2)
    return SDValue();
 
  SmallVector<SDNode *> Extracts(NumExts, nullptr);
  for (SDNode *Use : N->users()) {
    if (Use->getOpcode() != ISD::EXTRACT_SUBVECTOR)
      continue;
 
    // Ensure the extract type is correct (e.g. if NumExts is 4 and
    // the mask return type is nxv8i1, each extract should be nxv2i1.
    if (Use->getValueType(0).getVectorElementCount() != ExtMinEC)
      return SDValue();
 
    // There should be exactly one extract for each part of the mask.
    unsigned Offset = Use->getConstantOperandVal(1);
    unsigned Part = Offset / ExtMinEC.getKnownMinValue();
    if (Extracts[Part] != nullptr)
      return SDValue();
 
    Extracts[Part] = Use;
  }
 
  SelectionDAG &DAG = DCI.DAG;
  SDLoc DL(N);
  SDValue ID =
      DAG.getTargetConstant(Intrinsic::aarch64_sve_whilelo_x2, DL, MVT::i64);
 
  SDValue Idx = N->getOperand(0);
  SDValue TC = N->getOperand(1);
  if (Idx.getValueType() != MVT::i64) {
    Idx = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, Idx);
    TC = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i64, TC);
  }
 
  // Create the whilelo_x2 intrinsics from each pair of extracts
  EVT ExtVT = Extracts[0]->getValueType(0);
  EVT DoubleExtVT = ExtVT.getDoubleNumVectorElementsVT(*DAG.getContext());
  auto R =
      DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, {ExtVT, ExtVT}, {ID, Idx, TC});
  DCI.CombineTo(Extracts[0], R.getValue(0));
  DCI.CombineTo(Extracts[1], R.getValue(1));
  SmallVector<SDValue> Concats = {DAG.getNode(
      ISD::CONCAT_VECTORS, DL, DoubleExtVT, R.getValue(0), R.getValue(1))};
 
  if (NumExts == 2) {
    assert(N->getValueType(0) == DoubleExtVT);
    return Concats[0];
  }
 
  auto Elts =
      DAG.getElementCount(DL, MVT::i64, ExtVT.getVectorElementCount() * 2);
  for (unsigned I = 2; I < NumExts; I += 2) {
    // After the first whilelo_x2, we need to increment the starting value.
    Idx = DAG.getNode(ISD::UADDSAT, DL, MVT::i64, Idx, Elts);
    R = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, DL, {ExtVT, ExtVT}, {ID, Idx, TC});
    DCI.CombineTo(Extracts[I], R.getValue(0));
    DCI.CombineTo(Extracts[I + 1], R.getValue(1));
    Concats.push_back(DAG.getNode(ISD::CONCAT_VECTORS, DL, DoubleExtVT,
                                  R.getValue(0), R.getValue(1)));
  }
 
  return DAG.getNode(ISD::CONCAT_VECTORS, DL, N->getValueType(0), Concats);
}
 
// Turn vecreduce.add(ZExt(predicate)) into cntp(predicate).
static SDValue performVecReduceAddCntpCombine(SDNode *N, SelectionDAG &DAG,
                                              const AArch64Subtarget *ST) {
  SDValue Op = N->getOperand(0);
  if (Op->getOpcode() != ISD::ZERO_EXTEND)
    return SDValue();
 
  SDValue ZExtOp = Op->getOperand(0);
  EVT VT = ZExtOp.getValueType();
  if (!VT.isScalableVector() || VT.getVectorElementType() != MVT::i1 ||
      !DAG.getTargetLoweringInfo().isTypeLegal(VT))
    return SDValue();
 
  SDLoc DL(N);
  SDValue Cntp = DAG.getNode(
      ISD::INTRINSIC_WO_CHAIN, DL, MVT::i64,
      DAG.getTargetConstant(Intrinsic::aarch64_sve_cntp, DL, MVT::i64), ZExtOp,
      ZExtOp);
  return DAG.getZExtOrTrunc(Cntp, DL, N->getValueType(0));
}
 
static SDValue performVecReduceAddCombine(SDNode *N, SelectionDAG &DAG,
                                          const AArch64Subtarget *ST) {
  if (SDValue Result = performVecReduceAddCntpCombine(N, DAG, ST))
    return Result;
 
  if (!ST->isNeonAvailable())
    return SDValue();
 
  if (!ST->hasDotProd())
    return performVecReduceAddCombineWithUADDLP(N, DAG);
 
  // Turn a v8i8/v16i8 extended vecreduce into a udot/sdot and vecreduce
  //   vecreduce.add(ext(A)) to vecreduce.add(DOT(zero, A, one))
  //   vecreduce.add(mul(ext(A), ext(B))) to vecreduce.add(DOT(zero, A, B))
  // If we have vectors larger than v16i8 we extract v16i8 vectors,
  // Follow the same steps above to get DOT instructions concatenate them
  // and generate vecreduce.add(concat_vector(DOT, DOT2, ..)).
 
  SDValue Op0 = N->getOperand(0);
  if (N->getValueType(0) != MVT::i32 || Op0.getValueType().isScalableVT() ||
      Op0.getValueType().getVectorElementType() != MVT::i32)
    return SDValue();
 
  unsigned ExtOpcode = Op0.getOpcode();
  SDValue A = Op0;
  SDValue B;
  unsigned DotOpcode;
  if (ExtOpcode == ISD::MUL) {
    A = Op0.getOperand(0);
    B = Op0.getOperand(1);
    if (A.getOperand(0).getValueType() != B.getOperand(0).getValueType())
      return SDValue();
    auto OpCodeA = A.getOpcode();
    if (OpCodeA != ISD::ZERO_EXTEND && OpCodeA != ISD::SIGN_EXTEND)
      return SDValue();
 
    auto OpCodeB = B.getOpcode();
    if (OpCodeB != ISD::ZERO_EXTEND && OpCodeB != ISD::SIGN_EXTEND)
      return SDValue();
 
    if (OpCodeA == OpCodeB) {
      DotOpcode =
          OpCodeA == ISD::ZERO_EXTEND ? AArch64ISD::UDOT : AArch64ISD::SDOT;
    } else {
      // Check USDOT support support
      if (!ST->hasMatMulInt8())
        return SDValue();
      DotOpcode = AArch64ISD::USDOT;
      if (OpCodeA == ISD::SIGN_EXTEND)
        std::swap(A, B);
    }
  } else if (ExtOpcode == ISD::ZERO_EXTEND) {
    DotOpcode = AArch64ISD::UDOT;
  } else if (ExtOpcode == ISD::SIGN_EXTEND) {
    DotOpcode = AArch64ISD::SDOT;
  } else {
    return SDValue();
  }
 
  EVT Op0VT = A.getOperand(0).getValueType();
  bool IsValidElementCount = Op0VT.getVectorNumElements() % 8 == 0;
  bool IsValidSize = Op0VT.getScalarSizeInBits() == 8;
  if (!IsValidElementCount || !IsValidSize)
    return SDValue();
 
  SDLoc DL(Op0);
  // For non-mla reductions B can be set to 1. For MLA we take the operand of
  // the extend B.
  if (!B)
    B = DAG.getConstant(1, DL, Op0VT);
  else
    B = B.getOperand(0);
 
  unsigned IsMultipleOf16 = Op0VT.getVectorNumElements() % 16 == 0;
  unsigned NumOfVecReduce;
  EVT TargetType;
  if (IsMultipleOf16) {
    NumOfVecReduce = Op0VT.getVectorNumElements() / 16;
    TargetType = MVT::v4i32;
  } else {
    NumOfVecReduce = Op0VT.getVectorNumElements() / 8;
    TargetType = MVT::v2i32;
  }
  // Handle the case where we need to generate only one Dot operation.
  if (NumOfVecReduce == 1) {
    SDValue Zeros = DAG.getConstant(0, DL, TargetType);
    SDValue Dot = DAG.getNode(DotOpcode, DL, Zeros.getValueType(), Zeros,
                              A.getOperand(0), B);
    return DAG.getNode(ISD::VECREDUCE_ADD, DL, N->getValueType(0), Dot);
  }
  // Generate Dot instructions that are multiple of 16.
  unsigned VecReduce16Num = Op0VT.getVectorNumElements() / 16;
  SmallVector<SDValue, 4> SDotVec16;
  unsigned I = 0;
  for (; I < VecReduce16Num; I += 1) {
    SDValue Zeros = DAG.getConstant(0, DL, MVT::v4i32);
    SDValue Op0 =
        DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v16i8, A.getOperand(0),
                    DAG.getConstant(I * 16, DL, MVT::i64));
    SDValue Op1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v16i8, B,
                              DAG.getConstant(I * 16, DL, MVT::i64));
    SDValue Dot =
        DAG.getNode(DotOpcode, DL, Zeros.getValueType(), Zeros, Op0, Op1);
    SDotVec16.push_back(Dot);
  }
  // Concatenate dot operations.
  EVT SDot16EVT =
      EVT::getVectorVT(*DAG.getContext(), MVT::i32, 4 * VecReduce16Num);
  SDValue ConcatSDot16 =
      DAG.getNode(ISD::CONCAT_VECTORS, DL, SDot16EVT, SDotVec16);
  SDValue VecReduceAdd16 =
      DAG.getNode(ISD::VECREDUCE_ADD, DL, N->getValueType(0), ConcatSDot16);
  unsigned VecReduce8Num = (Op0VT.getVectorNumElements() % 16) / 8;
  if (VecReduce8Num == 0)
    return VecReduceAdd16;
 
  // Generate the remainder Dot operation that is multiple of 8.
  SDValue Zeros = DAG.getConstant(0, DL, MVT::v2i32);
  SDValue Vec8Op0 =
      DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, A.getOperand(0),
                  DAG.getConstant(I * 16, DL, MVT::i64));
  SDValue Vec8Op1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, MVT::v8i8, B,
                                DAG.getConstant(I * 16, DL, MVT::i64));
  SDValue Dot =
      DAG.getNode(DotOpcode, DL, Zeros.getValueType(), Zeros, Vec8Op0, Vec8Op1);
  SDValue VecReduceAdd8 =
      DAG.getNode(ISD::VECREDUCE_ADD, DL, N->getValueType(0), Dot);
  return DAG.getNode(ISD::ADD, DL, N->getValueType(0), VecReduceAdd16,
                     VecReduceAdd8);
}
 
// Given an (integer) vecreduce, we know the order of the inputs does not
// matter. We can convert UADDV(add(zext(extract_lo(x)), zext(extract_hi(x))))
// into UADDV(UADDLP(x)). This can also happen through an extra add, where we
// transform UADDV(add(y, add(zext(extract_lo(x)), zext(extract_hi(x))))).
static SDValue performUADDVAddCombine(SDValue A, SelectionDAG &DAG) {
  auto DetectAddExtract = [&](SDValue A) {
    // Look for add(zext(extract_lo(x)), zext(extract_hi(x))), returning
    // UADDLP(x) if found.
    assert(A.getOpcode() == ISD::ADD);
    EVT VT = A.getValueType();
    SDValue Op0 = A.getOperand(0);
    SDValue Op1 = A.getOperand(1);
    if (Op0.getOpcode() != Op1.getOpcode() ||
        (Op0.getOpcode() != ISD::ZERO_EXTEND &&
         Op0.getOpcode() != ISD::SIGN_EXTEND))
      return SDValue();
    SDValue Ext0 = Op0.getOperand(0);
    SDValue Ext1 = Op1.getOperand(0);
    if (Ext0.getOpcode() != ISD::EXTRACT_SUBVECTOR ||
        Ext1.getOpcode() != ISD::EXTRACT_SUBVECTOR ||
        Ext0.getOperand(0) != Ext1.getOperand(0) ||
        Ext0.getOperand(0).getValueType().isScalableVector())
      return SDValue();
    // Check that the type is twice the add types, and the extract are from
    // upper/lower parts of the same source.
    if (Ext0.getOperand(0).getValueType().getVectorNumElements() !=
        VT.getVectorNumElements() * 2)
      return SDValue();
    if ((Ext0.getConstantOperandVal(1) != 0 ||
         Ext1.getConstantOperandVal(1) != VT.getVectorNumElements()) &&
        (Ext1.getConstantOperandVal(1) != 0 ||
         Ext0.getConstantOperandVal(1) != VT.getVectorNumElements()))
      return SDValue();
    unsigned Opcode = Op0.getOpcode() == ISD::ZERO_EXTEND ? AArch64ISD::UADDLP
                                                          : AArch64ISD::SADDLP;
    return DAG.getNode(Opcode, SDLoc(A), VT, Ext0.getOperand(0));
  };
 
  if (SDValue R = DetectAddExtract(A))
    return R;
 
  if (A.getOperand(0).getOpcode() == ISD::ADD && A.getOperand(0).hasOneUse())
    if (SDValue R = performUADDVAddCombine(A.getOperand(0), DAG))
      return DAG.getNode(ISD::ADD, SDLoc(A), A.getValueType(), R,
                         A.getOperand(1));
  if (A.getOperand(1).getOpcode() == ISD::ADD && A.getOperand(1).hasOneUse())
    if (SDValue R = performUADDVAddCombine(A.getOperand(1), DAG))
      return DAG.getNode(ISD::ADD, SDLoc(A), A.getValueType(), R,
                         A.getOperand(0));
  return SDValue();
}
 
// We can convert a UADDV(add(zext(64-bit source), zext(64-bit source))) into
// UADDLV(concat), where the concat represents the 64-bit zext sources.
static SDValue performUADDVZextCombine(SDValue A, SelectionDAG &DAG) {
  // Look for add(zext(64-bit source), zext(64-bit source)), returning
  // UADDLV(concat(zext, zext)) if found.
  assert(A.getOpcode() == ISD::ADD);
  EVT VT = A.getValueType();
  if (VT != MVT::v8i16 && VT != MVT::v4i32 && VT != MVT::v2i64)
    return SDValue();
  SDValue Op0 = A.getOperand(0);
  SDValue Op1 = A.getOperand(1);
  if (Op0.getOpcode() != ISD::ZERO_EXTEND || Op0.getOpcode() != Op1.getOpcode())
    return SDValue();
  SDValue Ext0 = Op0.getOperand(0);
  SDValue Ext1 = Op1.getOperand(0);
  EVT ExtVT0 = Ext0.getValueType();
  EVT ExtVT1 = Ext1.getValueType();
  // Check zext VTs are the same and 64-bit length.
  if (ExtVT0 != ExtVT1 ||
      VT.getScalarSizeInBits() != (2 * ExtVT0.getScalarSizeInBits()))
    return SDValue();
  // Get VT for concat of zext sources.
  EVT PairVT = ExtVT0.getDoubleNumVectorElementsVT(*DAG.getContext());
  SDValue Concat =
      DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(A), PairVT, Ext0, Ext1);
 
  switch (VT.getSimpleVT().SimpleTy) {
  case MVT::v2i64:
  case MVT::v4i32:
    return DAG.getNode(AArch64ISD::UADDLV, SDLoc(A), VT, Concat);
  case MVT::v8i16: {
    SDValue Uaddlv =
        DAG.getNode(AArch64ISD::UADDLV, SDLoc(A), MVT::v4i32, Concat);
    return DAG.getNode(AArch64ISD::NVCAST, SDLoc(A), MVT::v8i16, Uaddlv);
  }
  default:
    llvm_unreachable("Unhandled vector type");
  }
}
 
static SDValue performUADDVCombine(SDNode *N, SelectionDAG &DAG) {
  SDValue A = N->getOperand(0);
  if (A.getOpcode() == ISD::ADD) {
    if (SDValue R = performUADDVAddCombine(A, DAG))
      return DAG.getNode(N->getOpcode(), SDLoc(N), N->getValueType(0), R);
    else if (SDValue R = performUADDVZextCombine(A, DAG))
      return R;
  }
 
  // uaddv(A) --> A if all lanes of A are known to be zeros except the 0th lane.
  MVT OpVT = A.getSimpleValueType();
  assert(N->getSimpleValueType(0) == OpVT &&
         "The operand type should be consistent with the result type of UADDV");
  APInt Mask = APInt::getAllOnes(OpVT.getVectorNumElements());
  Mask.clearBit(0);
  KnownBits KnownLeadingLanes = DAG.computeKnownBits(A, Mask);
  if (KnownLeadingLanes.isZero())
    return A;
 
  return SDValue();
}
 
static SDValue performBICiCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI) {
  APInt DemandedBits =
      APInt::getAllOnes(N->getValueType(0).getScalarSizeInBits());
  APInt DemandedElts =
      APInt::getAllOnes(N->getValueType(0).getVectorNumElements());
 
  if (DAG.getTargetLoweringInfo().SimplifyDemandedBits(
          SDValue(N, 0), DemandedBits, DemandedElts, DCI))
    return SDValue(N, 0);
  return SDValue();
}
 
static SDValue performXorCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const AArch64Subtarget *Subtarget) {
  if (DCI.isBeforeLegalizeOps())
    return SDValue();
 
  return foldVectorXorShiftIntoCmp(N, DAG, Subtarget);
}
 
SDValue
AArch64TargetLowering::BuildSDIVPow2(SDNode *N, const APInt &Divisor,
                                     SelectionDAG &DAG,
                                     SmallVectorImpl<SDNode *> &Created) const {
  AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
  if (isIntDivCheap(N->getValueType(0), Attr))
    return SDValue(N, 0); // Lower SDIV as SDIV
 
  EVT VT = N->getValueType(0);
 
  // If SVE is available, we can generate
  //  sdiv(x,y) -> ptrue + asrd          , where 'y' is positive pow-2 divisor.
  //  sdiv(x,y) -> ptrue + asrd + subr   , where 'y' is negative pow-2 divisor.
  if (VT.isVector() && Subtarget->isSVEorStreamingSVEAvailable())
    return SDValue(N, 0);
 
  // fold (sdiv X, pow2)
  if ((VT != MVT::i32 && VT != MVT::i64) ||
      !(Divisor.isPowerOf2() || Divisor.isNegatedPowerOf2()))
    return SDValue();
 
  // If the divisor is 2 or -2, the default expansion is better. It will add
  // (N->getValueType(0) >> (BitWidth - 1)) to it before shifting right.
  if (Divisor == 2 ||
      Divisor == APInt(Divisor.getBitWidth(), -2, /*isSigned*/ true))
    return SDValue();
 
  return TargetLowering::buildSDIVPow2WithCMov(N, Divisor, DAG, Created);
}
 
SDValue
AArch64TargetLowering::BuildSREMPow2(SDNode *N, const APInt &Divisor,
                                     SelectionDAG &DAG,
                                     SmallVectorImpl<SDNode *> &Created) const {
  AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
  if (isIntDivCheap(N->getValueType(0), Attr))
    return SDValue(N, 0); // Lower SREM as SREM
 
  EVT VT = N->getValueType(0);
 
  // For scalable and fixed types, mark them as cheap so we can handle it much
  // later. This allows us to handle larger than legal types.
  if (VT.isScalableVector() || Subtarget->useSVEForFixedLengthVectors())
    return SDValue(N, 0);
 
  // fold (srem X, pow2)
  if ((VT != MVT::i32 && VT != MVT::i64) ||
      !(Divisor.isPowerOf2() || Divisor.isNegatedPowerOf2()))
    return SDValue();
 
  unsigned Lg2 = Divisor.countr_zero();
  if (Lg2 == 0)
    return SDValue();
 
  SDLoc DL(N);
  SDValue N0 = N->getOperand(0);
  SDValue Pow2MinusOne = DAG.getConstant((1ULL << Lg2) - 1, DL, VT);
  SDValue Zero = DAG.getConstant(0, DL, VT);
  SDValue CCVal, CSNeg;
  if (Lg2 == 1) {
    SDValue Cmp = getAArch64Cmp(N0, Zero, ISD::SETGE, CCVal, DAG, DL);
    SDValue And = DAG.getNode(ISD::AND, DL, VT, N0, Pow2MinusOne);
    CSNeg = DAG.getNode(AArch64ISD::CSNEG, DL, VT, And, And, CCVal, Cmp);
 
    Created.push_back(Cmp.getNode());
    Created.push_back(And.getNode());
  } else {
    SDValue CCVal = getCondCode(DAG, AArch64CC::MI);
    SDVTList VTs = DAG.getVTList(VT, FlagsVT);
 
    SDValue Negs = DAG.getNode(AArch64ISD::SUBS, DL, VTs, Zero, N0);
    SDValue AndPos = DAG.getNode(ISD::AND, DL, VT, N0, Pow2MinusOne);
    SDValue AndNeg = DAG.getNode(ISD::AND, DL, VT, Negs, Pow2MinusOne);
    CSNeg = DAG.getNode(AArch64ISD::CSNEG, DL, VT, AndPos, AndNeg, CCVal,
                        Negs.getValue(1));
 
    Created.push_back(Negs.getNode());
    Created.push_back(AndPos.getNode());
    Created.push_back(AndNeg.getNode());
  }
 
  return CSNeg;
}
 
static bool IsSVECntIntrinsic(SDValue S) {
  switch(getIntrinsicID(S.getNode())) {
  default:
    break;
  case Intrinsic::aarch64_sve_cntb:
  case Intrinsic::aarch64_sve_cnth:
  case Intrinsic::aarch64_sve_cntw:
  case Intrinsic::aarch64_sve_cntd:
    return true;
  }
  return false;
}
 
// Returns the maximum (scalable) value that can be returned by an SVE count
// intrinsic. Returns std::nullopt if \p Op is not aarch64_sve_cnt*.
static std::optional<ElementCount> getMaxValueForSVECntIntrinsic(SDValue Op) {
  Intrinsic::ID IID = getIntrinsicID(Op.getNode());
  if (IID == Intrinsic::aarch64_sve_cntp)
    return Op.getOperand(1).getValueType().getVectorElementCount();
  switch (IID) {
  case Intrinsic::aarch64_sve_cntd:
    return ElementCount::getScalable(2);
  case Intrinsic::aarch64_sve_cntw:
    return ElementCount::getScalable(4);
  case Intrinsic::aarch64_sve_cnth:
    return ElementCount::getScalable(8);
  case Intrinsic::aarch64_sve_cntb:
    return ElementCount::getScalable(16);
  default:
    return std::nullopt;
  }
}
 
/// Calculates what the pre-extend type is, based on the extension
/// operation node provided by \p Extend.
///
/// In the case that \p Extend is a SIGN_EXTEND or a ZERO_EXTEND, the
/// pre-extend type is pulled directly from the operand, while other extend
/// operations need a bit more inspection to get this information.
///
/// \param Extend The SDNode from the DAG that represents the extend operation
///
/// \returns The type representing the \p Extend source type, or \p MVT::Other
/// if no valid type can be determined
static EVT calculatePreExtendType(SDValue Extend) {
  switch (Extend.getOpcode()) {
  case ISD::SIGN_EXTEND:
  case ISD::ZERO_EXTEND:
  case ISD::ANY_EXTEND:
    return Extend.getOperand(0).getValueType();
  case ISD::AssertSext:
  case ISD::AssertZext:
  case ISD::SIGN_EXTEND_INREG: {
    VTSDNode *TypeNode = dyn_cast<VTSDNode>(Extend.getOperand(1));
    if (!TypeNode)
      return MVT::Other;
    return TypeNode->getVT();
  }
  case ISD::AND: {
    ConstantSDNode *Constant =
        dyn_cast<ConstantSDNode>(Extend.getOperand(1).getNode());
    if (!Constant)
      return MVT::Other;
 
    uint32_t Mask = Constant->getZExtValue();
 
    if (Mask == UCHAR_MAX)
      return MVT::i8;
    else if (Mask == USHRT_MAX)
      return MVT::i16;
    else if (Mask == UINT_MAX)
      return MVT::i32;
 
    return MVT::Other;
  }
  default:
    return MVT::Other;
  }
}
 
/// Combines a buildvector(sext/zext) or shuffle(sext/zext, undef) node pattern
/// into sext/zext(buildvector) or sext/zext(shuffle) making use of the vector
/// SExt/ZExt rather than the scalar SExt/ZExt
static SDValue performBuildShuffleExtendCombine(SDValue BV, SelectionDAG &DAG) {
  EVT VT = BV.getValueType();
  if (BV.getOpcode() != ISD::BUILD_VECTOR &&
      BV.getOpcode() != ISD::VECTOR_SHUFFLE)
    return SDValue();
 
  // Use the first item in the buildvector/shuffle to get the size of the
  // extend, and make sure it looks valid.
  SDValue Extend = BV->getOperand(0);
  unsigned ExtendOpcode = Extend.getOpcode();
  bool IsAnyExt = ExtendOpcode == ISD::ANY_EXTEND;
  bool IsSExt = ExtendOpcode == ISD::SIGN_EXTEND ||
                ExtendOpcode == ISD::SIGN_EXTEND_INREG ||
                ExtendOpcode == ISD::AssertSext;
  if (!IsAnyExt && !IsSExt && ExtendOpcode != ISD::ZERO_EXTEND &&
      ExtendOpcode != ISD::AssertZext && ExtendOpcode != ISD::AND)
    return SDValue();
  // Shuffle inputs are vector, limit to SIGN_EXTEND/ZERO_EXTEND/ANY_EXTEND to
  // ensure calculatePreExtendType will work without issue.
  if (BV.getOpcode() == ISD::VECTOR_SHUFFLE &&
      ExtendOpcode != ISD::SIGN_EXTEND && ExtendOpcode != ISD::ZERO_EXTEND &&
      ExtendOpcode != ISD::ANY_EXTEND)
    return SDValue();
 
  // Restrict valid pre-extend data type
  EVT PreExtendType = calculatePreExtendType(Extend);
  if (PreExtendType == MVT::Other ||
      PreExtendType.getScalarSizeInBits() != VT.getScalarSizeInBits() / 2)
    return SDValue();
 
  // Make sure all other operands are equally extended.
  bool SeenZExtOrSExt = !IsAnyExt;
  for (SDValue Op : drop_begin(BV->ops())) {
    if (Op.isUndef())
      continue;
 
    if (calculatePreExtendType(Op) != PreExtendType)
      return SDValue();
 
    unsigned Opc = Op.getOpcode();
    if (BV.getOpcode() == ISD::VECTOR_SHUFFLE && Opc != ISD::SIGN_EXTEND &&
        Opc != ISD::ZERO_EXTEND && Opc != ISD::ANY_EXTEND)
      return SDValue();
 
    if (Opc == ISD::ANY_EXTEND)
      continue;
 
    bool OpcIsSExt = Opc == ISD::SIGN_EXTEND || Opc == ISD::SIGN_EXTEND_INREG ||
                     Opc == ISD::AssertSext;
 
    if (SeenZExtOrSExt && OpcIsSExt != IsSExt)
      return SDValue();
 
    IsSExt = OpcIsSExt;
    SeenZExtOrSExt = true;
  }
 
  SDValue NBV;
  SDLoc DL(BV);
  if (BV.getOpcode() == ISD::BUILD_VECTOR) {
    EVT PreExtendVT =
        VT.changeVectorElementType(*DAG.getContext(), PreExtendType);
    EVT PreExtendLegalType =
        PreExtendType.getScalarSizeInBits() < 32 ? MVT::i32 : PreExtendType;
    SmallVector<SDValue, 8> NewOps;
    for (SDValue Op : BV->ops())
      NewOps.push_back(Op.isUndef() ? DAG.getPOISON(PreExtendLegalType)
                                    : DAG.getAnyExtOrTrunc(Op.getOperand(0), DL,
                                                           PreExtendLegalType));
    NBV = DAG.getNode(ISD::BUILD_VECTOR, DL, PreExtendVT, NewOps);
  } else { // BV.getOpcode() == ISD::VECTOR_SHUFFLE
    EVT PreExtendVT = VT.changeVectorElementType(*DAG.getContext(),
                                                 PreExtendType.getScalarType());
    NBV = DAG.getVectorShuffle(PreExtendVT, DL, BV.getOperand(0).getOperand(0),
                               BV.getOperand(1).isUndef()
                                   ? DAG.getPOISON(PreExtendVT)
                                   : BV.getOperand(1).getOperand(0),
                               cast<ShuffleVectorSDNode>(BV)->getMask());
  }
  unsigned ExtOpc = !SeenZExtOrSExt
                        ? ISD::ANY_EXTEND
                        : (IsSExt ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND);
  return DAG.getNode(ExtOpc, DL, VT, NBV);
}
 
/// Combines a mul(dup(sext/zext)) node pattern into mul(sext/zext(dup))
/// making use of the vector SExt/ZExt rather than the scalar SExt/ZExt
static SDValue performMulVectorExtendCombine(SDNode *Mul, SelectionDAG &DAG) {
  // If the value type isn't a vector, none of the operands are going to be dups
  EVT VT = Mul->getValueType(0);
  if (VT != MVT::v8i16 && VT != MVT::v4i32 && VT != MVT::v2i64)
    return SDValue();
 
  SDValue Op0 = performBuildShuffleExtendCombine(Mul->getOperand(0), DAG);
  SDValue Op1 = performBuildShuffleExtendCombine(Mul->getOperand(1), DAG);
 
  // Neither operands have been changed, don't make any further changes
  if (!Op0 && !Op1)
    return SDValue();
 
  SDLoc DL(Mul);
  return DAG.getNode(Mul->getOpcode(), DL, VT, Op0 ? Op0 : Mul->getOperand(0),
                     Op1 ? Op1 : Mul->getOperand(1));
}
 
// Multiplying an RDSVL value by a constant can sometimes be done cheaper by
// folding a power-of-two factor of the constant into the RDSVL immediate and
// compensating with an extra shift.
//
// We rewrite:
//   (mul (srl (rdsvl 1), w), x)
// to one of:
//   (shl (rdsvl y),  z)   if z > 0
//   (srl (rdsvl y), abs(z))   if z < 0
// where integers y, z satisfy   x = y * 2^(w + z)   and   y ∈ [-32, 31].
static SDValue performMulRdsvlCombine(SDNode *Mul, SelectionDAG &DAG) {
  SDLoc DL(Mul);
  EVT VT = Mul->getValueType(0);
  SDValue MulOp0 = Mul->getOperand(0);
  int ConstMultiplier =
      cast<ConstantSDNode>(Mul->getOperand(1))->getSExtValue();
  if ((MulOp0->getOpcode() != ISD::SRL) ||
      (MulOp0->getOperand(0).getOpcode() != AArch64ISD::RDSVL))
    return SDValue();
 
  unsigned AbsConstValue = abs(ConstMultiplier);
  unsigned OperandShift =
      cast<ConstantSDNode>(MulOp0->getOperand(1))->getZExtValue();
 
  // z ≤ ctz(|x|) - w  (largest extra shift we can take while keeping y
  // integral)
  int UpperBound = llvm::countr_zero(AbsConstValue) - OperandShift;
 
  // To keep y in range, with B = 31 for x > 0 and B = 32 for x < 0, we need:
  // 2^(w + z) ≥ ceil(x / B)  ⇒  z ≥ ceil_log2(ceil(x / B)) - w  (LowerBound).
  unsigned B = ConstMultiplier < 0 ? 32 : 31;
  unsigned CeilAxOverB = (AbsConstValue + (B - 1)) / B; // ceil(|x|/B)
  int LowerBound = llvm::Log2_32_Ceil(CeilAxOverB) - OperandShift;
 
  // No valid solution found.
  if (LowerBound > UpperBound)
    return SDValue();
 
  // Any value of z in [LowerBound, UpperBound] is valid. Prefer no extra
  // shift if possible.
  int Shift = std::min(std::max(/*prefer*/ 0, LowerBound), UpperBound);
 
  // y = x / 2^(w + z)
  int32_t RdsvlMul = (AbsConstValue >> (OperandShift + Shift)) *
                     (ConstMultiplier < 0 ? -1 : 1);
  auto Rdsvl = DAG.getNode(AArch64ISD::RDSVL, DL, MVT::i64,
                           DAG.getSignedConstant(RdsvlMul, DL, MVT::i32));
 
  if (Shift == 0)
    return Rdsvl;
  return DAG.getNode(Shift < 0 ? ISD::SRL : ISD::SHL, DL, VT, Rdsvl,
                     DAG.getConstant(abs(Shift), DL, MVT::i32),
                     SDNodeFlags::Exact);
}
 
// Combine v4i32 Mul(And(Srl(X, 15), 0x10001), 0xffff) -> v8i16 CMLTz
// Same for other types with equivalent constants.
static SDValue performMulVectorCmpZeroCombine(SDNode *N, SelectionDAG &DAG) {
  EVT VT = N->getValueType(0);
  if (VT != MVT::v2i64 && VT != MVT::v1i64 && VT != MVT::v2i32 &&
      VT != MVT::v4i32 && VT != MVT::v4i16 && VT != MVT::v8i16)
    return SDValue();
  if (N->getOperand(0).getOpcode() != ISD::AND ||
      N->getOperand(0).getOperand(0).getOpcode() != ISD::SRL)
    return SDValue();
 
  SDValue And = N->getOperand(0);
  SDValue Srl = And.getOperand(0);
 
  APInt V1, V2, V3;
  if (!ISD::isConstantSplatVector(N->getOperand(1).getNode(), V1) ||
      !ISD::isConstantSplatVector(And.getOperand(1).getNode(), V2) ||
      !ISD::isConstantSplatVector(Srl.getOperand(1).getNode(), V3))
    return SDValue();
 
  unsigned HalfSize = VT.getScalarSizeInBits() / 2;
  if (!V1.isMask(HalfSize) || V2 != (1ULL | 1ULL << HalfSize) ||
      V3 != (HalfSize - 1))
    return SDValue();
 
  EVT HalfVT = EVT::getVectorVT(*DAG.getContext(),
                                EVT::getIntegerVT(*DAG.getContext(), HalfSize),
                                VT.getVectorElementCount() * 2);
 
  SDLoc DL(N);
  SDValue In = DAG.getNode(AArch64ISD::NVCAST, DL, HalfVT, Srl.getOperand(0));
  SDValue Zero = DAG.getConstant(0, DL, In.getValueType());
  SDValue CM = DAG.getSetCC(DL, HalfVT, Zero, In, ISD::SETGT);
  return DAG.getNode(AArch64ISD::NVCAST, DL, VT, CM);
}
 
// Transform vector add(zext i8 to i32, zext i8 to i32)
//  into sext(add(zext(i8 to i16), zext(i8 to i16)) to i32)
// This allows extra uses of saddl/uaddl at the lower vector widths, and less
// extends.
static SDValue performVectorExtCombine(SDNode *N, SelectionDAG &DAG) {
  EVT VT = N->getValueType(0);
  if (!VT.isFixedLengthVector() || VT.getSizeInBits() <= 128 ||
      (N->getOperand(0).getOpcode() != ISD::ZERO_EXTEND &&
       N->getOperand(0).getOpcode() != ISD::SIGN_EXTEND) ||
      (N->getOperand(1).getOpcode() != ISD::ZERO_EXTEND &&
       N->getOperand(1).getOpcode() != ISD::SIGN_EXTEND) ||
      N->getOperand(0).getOperand(0).getValueType() !=
          N->getOperand(1).getOperand(0).getValueType())
    return SDValue();
 
  if (N->getOpcode() == ISD::MUL &&
      N->getOperand(0).getOpcode() != N->getOperand(1).getOpcode())
    return SDValue();
 
  SDValue N0 = N->getOperand(0).getOperand(0);
  SDValue N1 = N->getOperand(1).getOperand(0);
  EVT InVT = N0.getValueType();
 
  EVT S1 = InVT.getScalarType();
  EVT S2 = VT.getScalarType();
  if ((S2 == MVT::i32 && S1 == MVT::i8) ||
      (S2 == MVT::i64 && (S1 == MVT::i8 || S1 == MVT::i16))) {
    SDLoc DL(N);
    EVT HalfVT = EVT::getVectorVT(*DAG.getContext(),
                                  S2.getHalfSizedIntegerVT(*DAG.getContext()),
                                  VT.getVectorElementCount());
    SDValue NewN0 = DAG.getNode(N->getOperand(0).getOpcode(), DL, HalfVT, N0);
    SDValue NewN1 = DAG.getNode(N->getOperand(1).getOpcode(), DL, HalfVT, N1);
    SDValue NewOp = DAG.getNode(N->getOpcode(), DL, HalfVT, NewN0, NewN1);
    return DAG.getNode(N->getOpcode() == ISD::MUL ? N->getOperand(0).getOpcode()
                                                  : (unsigned)ISD::SIGN_EXTEND,
                       DL, VT, NewOp);
  }
  return SDValue();
}
 
static SDValue performMulCombine(SDNode *N, SelectionDAG &DAG,
                                 TargetLowering::DAGCombinerInfo &DCI,
                                 const AArch64Subtarget *Subtarget) {
 
  if (SDValue Ext = performMulVectorExtendCombine(N, DAG))
    return Ext;
  if (SDValue Ext = performMulVectorCmpZeroCombine(N, DAG))
    return Ext;
  if (SDValue Ext = performVectorExtCombine(N, DAG))
    return Ext;
  if (DCI.isBeforeLegalizeOps())
    return SDValue();
 
  // Canonicalize X*(Y+1) -> X*Y+X and (X+1)*Y -> X*Y+Y,
  // and in MachineCombiner pass, add+mul will be combined into madd.
  // Similarly, X*(1-Y) -> X - X*Y and (1-Y)*X -> X - Y*X.
  SDLoc DL(N);
  EVT VT = N->getValueType(0);
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);
  SDValue MulOper;
  unsigned AddSubOpc;
 
  auto IsAddSubWith1 = [&](SDValue V) -> bool {
    AddSubOpc = V->getOpcode();
    if ((AddSubOpc == ISD::ADD || AddSubOpc == ISD::SUB) && V->hasOneUse()) {
      SDValue Opnd = V->getOperand(1);
      MulOper = V->getOperand(0);
      if (AddSubOpc == ISD::SUB)
        std::swap(Opnd, MulOper);
      if (auto C = dyn_cast<ConstantSDNode>(Opnd))
        return C->isOne();
    }
    return false;
  };
 
  if (IsAddSubWith1(N0)) {
    SDValue MulVal = DAG.getNode(ISD::MUL, DL, VT, N1, MulOper);
    return DAG.getNode(AddSubOpc, DL, VT, N1, MulVal);
  }
 
  if (IsAddSubWith1(N1)) {
    SDValue MulVal = DAG.getNode(ISD::MUL, DL, VT, N0, MulOper);
    return DAG.getNode(AddSubOpc, DL, VT, N0, MulVal);
  }
 
  // The below optimizations require a constant RHS.
  if (!isa<ConstantSDNode>(N1))
    return SDValue();
 
  if (SDValue Ext = performMulRdsvlCombine(N, DAG))
    return Ext;
 
  ConstantSDNode *C = cast<ConstantSDNode>(N1);
  const APInt &ConstValue = C->getAPIntValue();
 
  // Allow the scaling to be folded into the `cnt` instruction by preventing
  // the scaling to be obscured here. This makes it easier to pattern match.
  if (IsSVECntIntrinsic(N0) ||
     (N0->getOpcode() == ISD::TRUNCATE &&
      (IsSVECntIntrinsic(N0->getOperand(0)))))
       if (ConstValue.sge(1) && ConstValue.sle(16))
         return SDValue();
 
  // Multiplication of a power of two plus/minus one can be done more
  // cheaply as shift+add/sub. For now, this is true unilaterally. If
  // future CPUs have a cheaper MADD instruction, this may need to be
  // gated on a subtarget feature. For Cyclone, 32-bit MADD is 4 cycles and
  // 64-bit is 5 cycles, so this is always a win.
  // More aggressively, some multiplications N0 * C can be lowered to
  // shift+add+shift if the constant C = A * B where A = 2^N + 1 and B = 2^M,
  // e.g. 6=3*2=(2+1)*2, 45=(1+4)*(1+8)
  // TODO: lower more cases.
 
  // TrailingZeroes is used to test if the mul can be lowered to
  // shift+add+shift.
  unsigned TrailingZeroes = ConstValue.countr_zero();
  if (TrailingZeroes) {
    // Conservatively do not lower to shift+add+shift if the mul might be
    // folded into smul or umul.
    if (N0->hasOneUse() && (isSignExtended(N0, DAG) ||
                            isZeroExtended(N0, DAG)))
      return SDValue();
    // Conservatively do not lower to shift+add+shift if the mul might be
    // folded into madd or msub.
    if (N->hasOneUse() && (N->user_begin()->getOpcode() == ISD::ADD ||
                           N->user_begin()->getOpcode() == ISD::SUB))
      return SDValue();
  }
  // Use ShiftedConstValue instead of ConstValue to support both shift+add/sub
  // and shift+add+shift.
  APInt ShiftedConstValue = ConstValue.ashr(TrailingZeroes);
  unsigned ShiftAmt;
 
  auto Shl = [&](SDValue N0, unsigned N1) {
    if (!N0.getNode())
      return SDValue();
    // If shift causes overflow, ignore this combine.
    if (N1 >= N0.getValueSizeInBits())
      return SDValue();
    SDValue RHS = DAG.getConstant(N1, DL, MVT::i64);
    return DAG.getNode(ISD::SHL, DL, VT, N0, RHS);
  };
  auto Add = [&](SDValue N0, SDValue N1) {
    if (!N0.getNode() || !N1.getNode())
      return SDValue();
    return DAG.getNode(ISD::ADD, DL, VT, N0, N1);
  };
  auto Sub = [&](SDValue N0, SDValue N1) {
    if (!N0.getNode() || !N1.getNode())
      return SDValue();
    return DAG.getNode(ISD::SUB, DL, VT, N0, N1);
  };
  auto Negate = [&](SDValue N) {
    if (!N0.getNode())
      return SDValue();
    SDValue Zero = DAG.getConstant(0, DL, VT);
    return DAG.getNode(ISD::SUB, DL, VT, Zero, N);
  };
 
  // Can the const C be decomposed into (1+2^M1)*(1+2^N1), eg:
  // C = 45 is equal to (1+4)*(1+8), we don't decompose it into (1+2)*(16-1) as
  // the (2^N - 1) can't be execused via a single instruction.
  auto isPowPlusPlusConst = [](APInt C, APInt &M, APInt &N) {
    unsigned BitWidth = C.getBitWidth();
    for (unsigned i = 1; i < BitWidth / 2; i++) {
      APInt Rem;
      APInt X(BitWidth, (1 << i) + 1);
      APInt::sdivrem(C, X, N, Rem);
      APInt NVMinus1 = N - 1;
      if (Rem == 0 && NVMinus1.isPowerOf2()) {
        M = X;
        return true;
      }
    }
    return false;
  };
 
  // Can the const C be decomposed into (2^M + 1) * 2^N + 1), eg:
  // C = 11 is equal to (1+4)*2+1, we don't decompose it into (1+2)*4-1 as
  // the (2^N - 1) can't be execused via a single instruction.
  auto isPowPlusPlusOneConst = [](APInt C, APInt &M, APInt &N) {
    APInt CVMinus1 = C - 1;
    if (CVMinus1.isNegative())
      return false;
    unsigned TrailingZeroes = CVMinus1.countr_zero();
    APInt SCVMinus1 = CVMinus1.ashr(TrailingZeroes) - 1;
    if (SCVMinus1.isPowerOf2()) {
      unsigned BitWidth = SCVMinus1.getBitWidth();
      M = APInt(BitWidth, SCVMinus1.logBase2());
      N = APInt(BitWidth, TrailingZeroes);
      return true;
    }
    return false;
  };
 
  // Can the const C be decomposed into (1 - (1 - 2^M) * 2^N), eg:
  // C = 29 is equal to 1 - (1 - 2^3) * 2^2.
  auto isPowMinusMinusOneConst = [](APInt C, APInt &M, APInt &N) {
    APInt CVMinus1 = C - 1;
    if (CVMinus1.isNegative())
      return false;
    unsigned TrailingZeroes = CVMinus1.countr_zero();
    APInt CVPlus1 = CVMinus1.ashr(TrailingZeroes) + 1;
    if (CVPlus1.isPowerOf2()) {
      unsigned BitWidth = CVPlus1.getBitWidth();
      M = APInt(BitWidth, CVPlus1.logBase2());
      N = APInt(BitWidth, TrailingZeroes);
      return true;
    }
    return false;
  };
 
  if (ConstValue.isNonNegative()) {
    // (mul x, (2^N + 1) * 2^M) => (shl (add (shl x, N), x), M)
    // (mul x, 2^N - 1) => (sub (shl x, N), x)
    // (mul x, (2^(N-M) - 1) * 2^M) => (sub (shl x, N), (shl x, M))
    // (mul x, (2^M + 1) * (2^N + 1))
    //     => MV = (add (shl x, M), x); (add (shl MV, N), MV)
    // (mul x, (2^M + 1) * 2^N + 1))
    //     =>  MV = add (shl x, M), x); add (shl MV, N), x)
    // (mul x, 1 - (1 - 2^M) * 2^N))
    //     =>  MV = sub (x - (shl x, M)); sub (x - (shl MV, N))
    APInt SCVMinus1 = ShiftedConstValue - 1;
    APInt SCVPlus1 = ShiftedConstValue + 1;
    APInt CVPlus1 = ConstValue + 1;
    APInt CVM, CVN;
    if (SCVMinus1.isPowerOf2()) {
      ShiftAmt = SCVMinus1.logBase2();
      return Shl(Add(Shl(N0, ShiftAmt), N0), TrailingZeroes);
    } else if (CVPlus1.isPowerOf2()) {
      ShiftAmt = CVPlus1.