AArch64InstrInfo.h

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//===- AArch64InstrInfo.h - AArch64 Instruction Information -----*- C++ -*-===//
//
// 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 contains the AArch64 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
#define LLVM_LIB_TARGET_AARCH64_AARCH64INSTRINFO_H
 
#include "AArch64.h"
#include "AArch64RegisterInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/Support/TypeSize.h"
#include <optional>
 
#define GET_INSTRINFO_HEADER
#include "AArch64GenInstrInfo.inc"
 
namespace llvm {
 
class AArch64Subtarget;
 
static const MachineMemOperand::Flags MOSuppressPair =
    MachineMemOperand::MOTargetFlag1;
static const MachineMemOperand::Flags MOStridedAccess =
    MachineMemOperand::MOTargetFlag2;
 
#define FALKOR_STRIDED_ACCESS_MD "falkor.strided.access"
 
// AArch64 MachineCombiner patterns
enum AArch64MachineCombinerPattern : unsigned {
  // These are patterns used to reduce the length of dependence chain.
  SUBADD_OP1 = MachineCombinerPattern::TARGET_PATTERN_START,
  SUBADD_OP2,
 
  // These are multiply-add patterns matched by the AArch64 machine combiner.
  MULADDW_OP1,
  MULADDW_OP2,
  MULSUBW_OP1,
  MULSUBW_OP2,
  MULADDWI_OP1,
  MULSUBWI_OP1,
  MULADDX_OP1,
  MULADDX_OP2,
  MULSUBX_OP1,
  MULSUBX_OP2,
  MULADDXI_OP1,
  MULSUBXI_OP1,
  // NEON integers vectors
  MULADDv8i8_OP1,
  MULADDv8i8_OP2,
  MULADDv16i8_OP1,
  MULADDv16i8_OP2,
  MULADDv4i16_OP1,
  MULADDv4i16_OP2,
  MULADDv8i16_OP1,
  MULADDv8i16_OP2,
  MULADDv2i32_OP1,
  MULADDv2i32_OP2,
  MULADDv4i32_OP1,
  MULADDv4i32_OP2,
 
  MULSUBv8i8_OP1,
  MULSUBv8i8_OP2,
  MULSUBv16i8_OP1,
  MULSUBv16i8_OP2,
  MULSUBv4i16_OP1,
  MULSUBv4i16_OP2,
  MULSUBv8i16_OP1,
  MULSUBv8i16_OP2,
  MULSUBv2i32_OP1,
  MULSUBv2i32_OP2,
  MULSUBv4i32_OP1,
  MULSUBv4i32_OP2,
 
  MULADDv4i16_indexed_OP1,
  MULADDv4i16_indexed_OP2,
  MULADDv8i16_indexed_OP1,
  MULADDv8i16_indexed_OP2,
  MULADDv2i32_indexed_OP1,
  MULADDv2i32_indexed_OP2,
  MULADDv4i32_indexed_OP1,
  MULADDv4i32_indexed_OP2,
 
  MULSUBv4i16_indexed_OP1,
  MULSUBv4i16_indexed_OP2,
  MULSUBv8i16_indexed_OP1,
  MULSUBv8i16_indexed_OP2,
  MULSUBv2i32_indexed_OP1,
  MULSUBv2i32_indexed_OP2,
  MULSUBv4i32_indexed_OP1,
  MULSUBv4i32_indexed_OP2,
 
  // Floating Point
  FMULADDH_OP1,
  FMULADDH_OP2,
  FMULSUBH_OP1,
  FMULSUBH_OP2,
  FMULADDS_OP1,
  FMULADDS_OP2,
  FMULSUBS_OP1,
  FMULSUBS_OP2,
  FMULADDD_OP1,
  FMULADDD_OP2,
  FMULSUBD_OP1,
  FMULSUBD_OP2,
  FNMULSUBH_OP1,
  FNMULSUBS_OP1,
  FNMULSUBD_OP1,
  FMLAv1i32_indexed_OP1,
  FMLAv1i32_indexed_OP2,
  FMLAv1i64_indexed_OP1,
  FMLAv1i64_indexed_OP2,
  FMLAv4f16_OP1,
  FMLAv4f16_OP2,
  FMLAv8f16_OP1,
  FMLAv8f16_OP2,
  FMLAv2f32_OP2,
  FMLAv2f32_OP1,
  FMLAv2f64_OP1,
  FMLAv2f64_OP2,
  FMLAv4i16_indexed_OP1,
  FMLAv4i16_indexed_OP2,
  FMLAv8i16_indexed_OP1,
  FMLAv8i16_indexed_OP2,
  FMLAv2i32_indexed_OP1,
  FMLAv2i32_indexed_OP2,
  FMLAv2i64_indexed_OP1,
  FMLAv2i64_indexed_OP2,
  FMLAv4f32_OP1,
  FMLAv4f32_OP2,
  FMLAv4i32_indexed_OP1,
  FMLAv4i32_indexed_OP2,
  FMLSv1i32_indexed_OP2,
  FMLSv1i64_indexed_OP2,
  FMLSv4f16_OP1,
  FMLSv4f16_OP2,
  FMLSv8f16_OP1,
  FMLSv8f16_OP2,
  FMLSv2f32_OP1,
  FMLSv2f32_OP2,
  FMLSv2f64_OP1,
  FMLSv2f64_OP2,
  FMLSv4i16_indexed_OP1,
  FMLSv4i16_indexed_OP2,
  FMLSv8i16_indexed_OP1,
  FMLSv8i16_indexed_OP2,
  FMLSv2i32_indexed_OP1,
  FMLSv2i32_indexed_OP2,
  FMLSv2i64_indexed_OP1,
  FMLSv2i64_indexed_OP2,
  FMLSv4f32_OP1,
  FMLSv4f32_OP2,
  FMLSv4i32_indexed_OP1,
  FMLSv4i32_indexed_OP2,
 
  FMULv2i32_indexed_OP1,
  FMULv2i32_indexed_OP2,
  FMULv2i64_indexed_OP1,
  FMULv2i64_indexed_OP2,
  FMULv4i16_indexed_OP1,
  FMULv4i16_indexed_OP2,
  FMULv4i32_indexed_OP1,
  FMULv4i32_indexed_OP2,
  FMULv8i16_indexed_OP1,
  FMULv8i16_indexed_OP2,
 
  FNMADD,
};
class AArch64InstrInfo final : public AArch64GenInstrInfo {
  const AArch64RegisterInfo RI;
  const AArch64Subtarget &Subtarget;
 
public:
  explicit AArch64InstrInfo(const AArch64Subtarget &STI);
 
  /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
  /// such, whenever a client has an instance of instruction info, it should
  /// always be able to get register info as well (through this method).
  const AArch64RegisterInfo &getRegisterInfo() const { return RI; }
 
  unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
 
  bool isAsCheapAsAMove(const MachineInstr &MI) const override;
 
  bool isCoalescableExtInstr(const MachineInstr &MI, Register &SrcReg,
                             Register &DstReg, unsigned &SubIdx) const override;
 
  bool
  areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
                                  const MachineInstr &MIb) const override;
 
  Register isLoadFromStackSlot(const MachineInstr &MI,
                               int &FrameIndex) const override;
  Register isStoreToStackSlot(const MachineInstr &MI,
                              int &FrameIndex) const override;
 
  /// Does this instruction set its full destination register to zero?
  static bool isGPRZero(const MachineInstr &MI);
 
  /// Does this instruction rename a GPR without modifying bits?
  static bool isGPRCopy(const MachineInstr &MI);
 
  /// Does this instruction rename an FPR without modifying bits?
  static bool isFPRCopy(const MachineInstr &MI);
 
  /// Return true if pairing the given load or store is hinted to be
  /// unprofitable.
  static bool isLdStPairSuppressed(const MachineInstr &MI);
 
  /// Return true if the given load or store is a strided memory access.
  static bool isStridedAccess(const MachineInstr &MI);
 
  /// Return true if it has an unscaled load/store offset.
  static bool hasUnscaledLdStOffset(unsigned Opc);
  static bool hasUnscaledLdStOffset(MachineInstr &MI) {
    return hasUnscaledLdStOffset(MI.getOpcode());
  }
 
  /// Returns the unscaled load/store for the scaled load/store opcode,
  /// if there is a corresponding unscaled variant available.
  static std::optional<unsigned> getUnscaledLdSt(unsigned Opc);
 
  /// Scaling factor for (scaled or unscaled) load or store.
  static int getMemScale(unsigned Opc);
  static int getMemScale(const MachineInstr &MI) {
    return getMemScale(MI.getOpcode());
  }
 
  /// Returns whether the instruction is a pre-indexed load.
  static bool isPreLd(const MachineInstr &MI);
 
  /// Returns whether the instruction is a pre-indexed store.
  static bool isPreSt(const MachineInstr &MI);
 
  /// Returns whether the instruction is a pre-indexed load/store.
  static bool isPreLdSt(const MachineInstr &MI);
 
  /// Returns whether the instruction is a paired load/store.
  static bool isPairedLdSt(const MachineInstr &MI);
 
  /// Returns the base register operator of a load/store.
  static const MachineOperand &getLdStBaseOp(const MachineInstr &MI);
 
  /// Returns the immediate offset operator of a load/store.
  static const MachineOperand &getLdStOffsetOp(const MachineInstr &MI);
 
  /// Returns whether the physical register is FP or NEON.
  static bool isFpOrNEON(Register Reg);
 
  /// Returns the shift amount operator of a load/store.
  static const MachineOperand &getLdStAmountOp(const MachineInstr &MI);
 
  /// Returns whether the instruction is FP or NEON.
  static bool isFpOrNEON(const MachineInstr &MI);
 
  /// Returns whether the instruction is in H form (16 bit operands)
  static bool isHForm(const MachineInstr &MI);
 
  /// Returns whether the instruction is in Q form (128 bit operands)
  static bool isQForm(const MachineInstr &MI);
 
  /// Returns whether the instruction can be compatible with non-zero BTYPE.
  static bool hasBTISemantics(const MachineInstr &MI);
 
  /// Returns the index for the immediate for a given instruction.
  static unsigned getLoadStoreImmIdx(unsigned Opc);
 
  /// Return true if pairing the given load or store may be paired with another.
  static bool isPairableLdStInst(const MachineInstr &MI);
 
  /// Returns true if MI is one of the TCRETURN* instructions.
  static bool isTailCallReturnInst(const MachineInstr &MI);
 
  /// Return the opcode that set flags when possible.  The caller is
  /// responsible for ensuring the opc has a flag setting equivalent.
  static unsigned convertToFlagSettingOpc(unsigned Opc);
 
  /// Return true if this is a load/store that can be potentially paired/merged.
  bool isCandidateToMergeOrPair(const MachineInstr &MI) const;
 
  /// Hint that pairing the given load or store is unprofitable.
  static void suppressLdStPair(MachineInstr &MI);
 
  std::optional<ExtAddrMode>
  getAddrModeFromMemoryOp(const MachineInstr &MemI,
                          const TargetRegisterInfo *TRI) const override;
 
  bool canFoldIntoAddrMode(const MachineInstr &MemI, Register Reg,
                           const MachineInstr &AddrI,
                           ExtAddrMode &AM) const override;
 
  MachineInstr *emitLdStWithAddr(MachineInstr &MemI,
                                 const ExtAddrMode &AM) const override;
 
  bool getMemOperandsWithOffsetWidth(
      const MachineInstr &MI, SmallVectorImpl<const MachineOperand *> &BaseOps,
      int64_t &Offset, bool &OffsetIsScalable, LocationSize &Width,
      const TargetRegisterInfo *TRI) const override;
 
  /// If \p OffsetIsScalable is set to 'true', the offset is scaled by `vscale`.
  /// This is true for some SVE instructions like ldr/str that have a
  /// 'reg + imm' addressing mode where the immediate is an index to the
  /// scalable vector located at 'reg + imm * vscale x #bytes'.
  bool getMemOperandWithOffsetWidth(const MachineInstr &MI,
                                    const MachineOperand *&BaseOp,
                                    int64_t &Offset, bool &OffsetIsScalable,
                                    TypeSize &Width,
                                    const TargetRegisterInfo *TRI) const;
 
  /// Return the immediate offset of the base register in a load/store \p LdSt.
  MachineOperand &getMemOpBaseRegImmOfsOffsetOperand(MachineInstr &LdSt) const;
 
  /// Returns true if opcode \p Opc is a memory operation. If it is, set
  /// \p Scale, \p Width, \p MinOffset, and \p MaxOffset accordingly.
  ///
  /// For unscaled instructions, \p Scale is set to 1. All values are in bytes.
  /// MinOffset/MaxOffset are the un-scaled limits of the immediate in the
  /// instruction, the actual offset limit is [MinOffset*Scale,
  /// MaxOffset*Scale].
  static bool getMemOpInfo(unsigned Opcode, TypeSize &Scale, TypeSize &Width,
                           int64_t &MinOffset, int64_t &MaxOffset);
 
  bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
                           int64_t Offset1, bool OffsetIsScalable1,
                           ArrayRef<const MachineOperand *> BaseOps2,
                           int64_t Offset2, bool OffsetIsScalable2,
                           unsigned ClusterSize,
                           unsigned NumBytes) const override;
 
  void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                        const DebugLoc &DL, MCRegister DestReg,
                        MCRegister SrcReg, bool KillSrc, unsigned Opcode,
                        llvm::ArrayRef<unsigned> Indices) const;
  void copyGPRRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                       const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
                       bool KillSrc, unsigned Opcode, unsigned ZeroReg,
                       llvm::ArrayRef<unsigned> Indices) const;
  void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                   const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
                   bool KillSrc, bool RenamableDest = false,
                   bool RenamableSrc = false) const override;
 
  void storeRegToStackSlot(
      MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, Register SrcReg,
      bool isKill, int FrameIndex, const TargetRegisterClass *RC,
      const TargetRegisterInfo *TRI, Register VReg,
      MachineInstr::MIFlag Flags = MachineInstr::NoFlags) const override;
 
  void loadRegFromStackSlot(
      MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
      Register DestReg, int FrameIndex, const TargetRegisterClass *RC,
      const TargetRegisterInfo *TRI, Register VReg,
      MachineInstr::MIFlag Flags = MachineInstr::NoFlags) const override;
 
  // This tells target independent code that it is okay to pass instructions
  // with subreg operands to foldMemoryOperandImpl.
  bool isSubregFoldable() const override { return true; }
 
  using TargetInstrInfo::foldMemoryOperandImpl;
  MachineInstr *
  foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
                        ArrayRef<unsigned> Ops,
                        MachineBasicBlock::iterator InsertPt, int FrameIndex,
                        LiveIntervals *LIS = nullptr,
                        VirtRegMap *VRM = nullptr) const override;
 
  /// \returns true if a branch from an instruction with opcode \p BranchOpc
  ///  bytes is capable of jumping to a position \p BrOffset bytes away.
  bool isBranchOffsetInRange(unsigned BranchOpc,
                             int64_t BrOffset) const override;
 
  MachineBasicBlock *getBranchDestBlock(const MachineInstr &MI) const override;
 
  void insertIndirectBranch(MachineBasicBlock &MBB,
                            MachineBasicBlock &NewDestBB,
                            MachineBasicBlock &RestoreBB, const DebugLoc &DL,
                            int64_t BrOffset, RegScavenger *RS) const override;
 
  bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
                     MachineBasicBlock *&FBB,
                     SmallVectorImpl<MachineOperand> &Cond,
                     bool AllowModify = false) const override;
  bool analyzeBranchPredicate(MachineBasicBlock &MBB,
                              MachineBranchPredicate &MBP,
                              bool AllowModify) const override;
  unsigned removeBranch(MachineBasicBlock &MBB,
                        int *BytesRemoved = nullptr) const override;
  unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
                        MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
                        const DebugLoc &DL,
                        int *BytesAdded = nullptr) const override;
 
  std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
  analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const override;
 
  bool
  reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
  bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
                       Register, Register, Register, int &, int &,
                       int &) const override;
  void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
                    const DebugLoc &DL, Register DstReg,
                    ArrayRef<MachineOperand> Cond, Register TrueReg,
                    Register FalseReg) const override;
 
  void insertNoop(MachineBasicBlock &MBB,
                  MachineBasicBlock::iterator MI) const override;
 
  MCInst getNop() const override;
 
  bool isSchedulingBoundary(const MachineInstr &MI,
                            const MachineBasicBlock *MBB,
                            const MachineFunction &MF) const override;
 
  /// analyzeCompare - For a comparison instruction, return the source registers
  /// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
  /// Return true if the comparison instruction can be analyzed.
  bool analyzeCompare(const MachineInstr &MI, Register &SrcReg,
                      Register &SrcReg2, int64_t &CmpMask,
                      int64_t &CmpValue) const override;
  /// optimizeCompareInstr - Convert the instruction supplying the argument to
  /// the comparison into one that sets the zero bit in the flags register.
  bool optimizeCompareInstr(MachineInstr &CmpInstr, Register SrcReg,
                            Register SrcReg2, int64_t CmpMask, int64_t CmpValue,
                            const MachineRegisterInfo *MRI) const override;
  bool optimizeCondBranch(MachineInstr &MI) const override;
 
  CombinerObjective getCombinerObjective(unsigned Pattern) const override;
  /// Return true when a code sequence can improve throughput. It
  /// should be called only for instructions in loops.
  /// \param Pattern - combiner pattern
  bool isThroughputPattern(unsigned Pattern) const override;
  /// Return true when there is potentially a faster code sequence
  /// for an instruction chain ending in ``Root``. All potential patterns are
  /// listed in the ``Patterns`` array.
  bool getMachineCombinerPatterns(MachineInstr &Root,
                                  SmallVectorImpl<unsigned> &Patterns,
                                  bool DoRegPressureReduce) const override;
  /// Return true when Inst is associative and commutative so that it can be
  /// reassociated. If Invert is true, then the inverse of Inst operation must
  /// be checked.
  bool isAssociativeAndCommutative(const MachineInstr &Inst,
                                   bool Invert) const override;
  /// When getMachineCombinerPatterns() finds patterns, this function generates
  /// the instructions that could replace the original code sequence
  void genAlternativeCodeSequence(
      MachineInstr &Root, unsigned Pattern,
      SmallVectorImpl<MachineInstr *> &InsInstrs,
      SmallVectorImpl<MachineInstr *> &DelInstrs,
      DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
  /// AArch64 supports MachineCombiner.
  bool useMachineCombiner() const override;
 
  bool expandPostRAPseudo(MachineInstr &MI) const override;
 
  std::pair<unsigned, unsigned>
  decomposeMachineOperandsTargetFlags(unsigned TF) const override;
  ArrayRef<std::pair<unsigned, const char *>>
  getSerializableDirectMachineOperandTargetFlags() const override;
  ArrayRef<std::pair<unsigned, const char *>>
  getSerializableBitmaskMachineOperandTargetFlags() const override;
  ArrayRef<std::pair<MachineMemOperand::Flags, const char *>>
  getSerializableMachineMemOperandTargetFlags() const override;
 
  bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
                                   bool OutlineFromLinkOnceODRs) const override;
  std::optional<std::unique_ptr<outliner::OutlinedFunction>>
  getOutliningCandidateInfo(
      const MachineModuleInfo &MMI,
      std::vector<outliner::Candidate> &RepeatedSequenceLocs,
      unsigned MinRepeats) const override;
  void mergeOutliningCandidateAttributes(
      Function &F, std::vector<outliner::Candidate> &Candidates) const override;
  outliner::InstrType getOutliningTypeImpl(const MachineModuleInfo &MMI,
                                           MachineBasicBlock::iterator &MIT,
                                           unsigned Flags) const override;
  SmallVector<
      std::pair<MachineBasicBlock::iterator, MachineBasicBlock::iterator>>
  getOutlinableRanges(MachineBasicBlock &MBB, unsigned &Flags) const override;
  void buildOutlinedFrame(MachineBasicBlock &MBB, MachineFunction &MF,
                          const outliner::OutlinedFunction &OF) const override;
  MachineBasicBlock::iterator
  insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
                     MachineBasicBlock::iterator &It, MachineFunction &MF,
                     outliner::Candidate &C) const override;
  bool shouldOutlineFromFunctionByDefault(MachineFunction &MF) const override;
 
  void buildClearRegister(Register Reg, MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator Iter, DebugLoc &DL,
                          bool AllowSideEffects = true) const override;
 
  /// Returns the vector element size (B, H, S or D) of an SVE opcode.
  uint64_t getElementSizeForOpcode(unsigned Opc) const;
  /// Returns true if the opcode is for an SVE instruction that sets the
  /// condition codes as if it's results had been fed to a PTEST instruction
  /// along with the same general predicate.
  bool isPTestLikeOpcode(unsigned Opc) const;
  /// Returns true if the opcode is for an SVE WHILE## instruction.
  bool isWhileOpcode(unsigned Opc) const;
  /// Returns true if the instruction has a shift by immediate that can be
  /// executed in one cycle less.
  static bool isFalkorShiftExtFast(const MachineInstr &MI);
  /// Return true if the instructions is a SEH instruciton used for unwinding
  /// on Windows.
  static bool isSEHInstruction(const MachineInstr &MI);
 
  std::optional<RegImmPair> isAddImmediate(const MachineInstr &MI,
                                           Register Reg) const override;
 
  bool isFunctionSafeToSplit(const MachineFunction &MF) const override;
 
  bool isMBBSafeToSplitToCold(const MachineBasicBlock &MBB) const override;
 
  std::optional<ParamLoadedValue>
  describeLoadedValue(const MachineInstr &MI, Register Reg) const override;
 
  unsigned int getTailDuplicateSize(CodeGenOptLevel OptLevel) const override;
 
  bool isExtendLikelyToBeFolded(MachineInstr &ExtMI,
                                MachineRegisterInfo &MRI) const override;
 
  static void decomposeStackOffsetForFrameOffsets(const StackOffset &Offset,
                                                  int64_t &NumBytes,
                                                  int64_t &NumPredicateVectors,
                                                  int64_t &NumDataVectors);
  static void decomposeStackOffsetForDwarfOffsets(const StackOffset &Offset,
                                                  int64_t &ByteSized,
                                                  int64_t &VGSized);
 
  // Return true if address of the form BaseReg + Scale * ScaledReg + Offset can
  // be used for a load/store of NumBytes. BaseReg is always present and
  // implicit.
  bool isLegalAddressingMode(unsigned NumBytes, int64_t Offset,
                             unsigned Scale) const;
 
  // Decrement the SP, issuing probes along the way. `TargetReg` is the new top
  // of the stack. `FrameSetup` is passed as true, if the allocation is a part
  // of constructing the activation frame of a function.
  MachineBasicBlock::iterator probedStackAlloc(MachineBasicBlock::iterator MBBI,
                                               Register TargetReg,
                                               bool FrameSetup) const;
 
#define GET_INSTRINFO_HELPER_DECLS
#include "AArch64GenInstrInfo.inc"
 
protected:
  /// If the specific machine instruction is an instruction that moves/copies
  /// value from one register to another register return destination and source
  /// registers as machine operands.
  std::optional<DestSourcePair>
  isCopyInstrImpl(const MachineInstr &MI) const override;
  std::optional<DestSourcePair>
  isCopyLikeInstrImpl(const MachineInstr &MI) const override;
 
private:
  unsigned getInstBundleLength(const MachineInstr &MI) const;
 
  /// Sets the offsets on outlined instructions in \p MBB which use SP
  /// so that they will be valid post-outlining.
  ///
  /// \param MBB A \p MachineBasicBlock in an outlined function.
  void fixupPostOutline(MachineBasicBlock &MBB) const;
 
  void instantiateCondBranch(MachineBasicBlock &MBB, const DebugLoc &DL,
                             MachineBasicBlock *TBB,
                             ArrayRef<MachineOperand> Cond) const;
  bool substituteCmpToZero(MachineInstr &CmpInstr, unsigned SrcReg,
                           const MachineRegisterInfo &MRI) const;
  bool removeCmpToZeroOrOne(MachineInstr &CmpInstr, unsigned SrcReg,
                            int CmpValue, const MachineRegisterInfo &MRI) const;
 
  /// Returns an unused general-purpose register which can be used for
  /// constructing an outlined call if one exists. Returns 0 otherwise.
  Register findRegisterToSaveLRTo(outliner::Candidate &C) const;
 
  /// Remove a ptest of a predicate-generating operation that already sets, or
  /// can be made to set, the condition codes in an identical manner
  bool optimizePTestInstr(MachineInstr *PTest, unsigned MaskReg,
                          unsigned PredReg,
                          const MachineRegisterInfo *MRI) const;
  std::optional<unsigned>
  canRemovePTestInstr(MachineInstr *PTest, MachineInstr *Mask,
                      MachineInstr *Pred, const MachineRegisterInfo *MRI) const;
 
  /// verifyInstruction - Perform target specific instruction verification.
  bool verifyInstruction(const MachineInstr &MI,
                         StringRef &ErrInfo) const override;
};
 
struct UsedNZCV {
  bool N = false;
  bool Z = false;
  bool C = false;
  bool V = false;
 
  UsedNZCV() = default;
 
  UsedNZCV &operator|=(const UsedNZCV &UsedFlags) {
    this->N |= UsedFlags.N;
    this->Z |= UsedFlags.Z;
    this->C |= UsedFlags.C;
    this->V |= UsedFlags.V;
    return *this;
  }
};
 
/// \returns Conditions flags used after \p CmpInstr in its MachineBB if  NZCV
/// flags are not alive in successors of the same \p CmpInstr and \p MI parent.
/// \returns std::nullopt otherwise.
///
/// Collect instructions using that flags in \p CCUseInstrs if provided.
std::optional<UsedNZCV>
examineCFlagsUse(MachineInstr &MI, MachineInstr &CmpInstr,
                 const TargetRegisterInfo &TRI,
                 SmallVectorImpl<MachineInstr *> *CCUseInstrs = nullptr);
 
/// Return true if there is an instruction /after/ \p DefMI and before \p UseMI
/// which either reads or clobbers NZCV.
bool isNZCVTouchedInInstructionRange(const MachineInstr &DefMI,
                                     const MachineInstr &UseMI,
                                     const TargetRegisterInfo *TRI);
 
MCCFIInstruction createDefCFA(const TargetRegisterInfo &TRI, unsigned FrameReg,
                              unsigned Reg, const StackOffset &Offset,
                              bool LastAdjustmentWasScalable = true);
MCCFIInstruction createCFAOffset(const TargetRegisterInfo &MRI, unsigned Reg,
                                 const StackOffset &OffsetFromDefCFA);
 
/// emitFrameOffset - Emit instructions as needed to set DestReg to SrcReg
/// plus Offset.  This is intended to be used from within the prolog/epilog
/// insertion (PEI) pass, where a virtual scratch register may be allocated
/// if necessary, to be replaced by the scavenger at the end of PEI.
void emitFrameOffset(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
                     const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
                     StackOffset Offset, const TargetInstrInfo *TII,
                     MachineInstr::MIFlag = MachineInstr::NoFlags,
                     bool SetNZCV = false, bool NeedsWinCFI = false,
                     bool *HasWinCFI = nullptr, bool EmitCFAOffset = false,
                     StackOffset InitialOffset = {},
                     unsigned FrameReg = AArch64::SP);
 
/// rewriteAArch64FrameIndex - Rewrite MI to access 'Offset' bytes from the
/// FP. Return false if the offset could not be handled directly in MI, and
/// return the left-over portion by reference.
bool rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
                              unsigned FrameReg, StackOffset &Offset,
                              const AArch64InstrInfo *TII);
 
/// Use to report the frame offset status in isAArch64FrameOffsetLegal.
enum AArch64FrameOffsetStatus {
  AArch64FrameOffsetCannotUpdate = 0x0, ///< Offset cannot apply.
  AArch64FrameOffsetIsLegal = 0x1,      ///< Offset is legal.
  AArch64FrameOffsetCanUpdate = 0x2     ///< Offset can apply, at least partly.
};
 
/// Check if the @p Offset is a valid frame offset for @p MI.
/// The returned value reports the validity of the frame offset for @p MI.
/// It uses the values defined by AArch64FrameOffsetStatus for that.
/// If result == AArch64FrameOffsetCannotUpdate, @p MI cannot be updated to
/// use an offset.eq
/// If result & AArch64FrameOffsetIsLegal, @p Offset can completely be
/// rewritten in @p MI.
/// If result & AArch64FrameOffsetCanUpdate, @p Offset contains the
/// amount that is off the limit of the legal offset.
/// If set, @p OutUseUnscaledOp will contain the whether @p MI should be
/// turned into an unscaled operator, which opcode is in @p OutUnscaledOp.
/// If set, @p EmittableOffset contains the amount that can be set in @p MI
/// (possibly with @p OutUnscaledOp if OutUseUnscaledOp is true) and that
/// is a legal offset.
int isAArch64FrameOffsetLegal(const MachineInstr &MI, StackOffset &Offset,
                              bool *OutUseUnscaledOp = nullptr,
                              unsigned *OutUnscaledOp = nullptr,
                              int64_t *EmittableOffset = nullptr);
 
static inline bool isUncondBranchOpcode(int Opc) { return Opc == AArch64::B; }
 
static inline bool isCondBranchOpcode(int Opc) {
  switch (Opc) {
  case AArch64::Bcc:
  case AArch64::CBZW:
  case AArch64::CBZX:
  case AArch64::CBNZW:
  case AArch64::CBNZX:
  case AArch64::TBZW:
  case AArch64::TBZX:
  case AArch64::TBNZW:
  case AArch64::TBNZX:
    return true;
  default:
    return false;
  }
}
 
static inline bool isIndirectBranchOpcode(int Opc) {
  switch (Opc) {
  case AArch64::BR:
  case AArch64::BRAA:
  case AArch64::BRAB:
  case AArch64::BRAAZ:
  case AArch64::BRABZ:
    return true;
  }
  return false;
}
 
static inline bool isPTrueOpcode(unsigned Opc) {
  switch (Opc) {
  case AArch64::PTRUE_B:
  case AArch64::PTRUE_H:
  case AArch64::PTRUE_S:
  case AArch64::PTRUE_D:
    return true;
  default:
    return false;
  }
}
 
/// Return opcode to be used for indirect calls.
unsigned getBLRCallOpcode(const MachineFunction &MF);
 
/// Return XPAC opcode to be used for a ptrauth strip using the given key.
static inline unsigned getXPACOpcodeForKey(AArch64PACKey::ID K) {
  using namespace AArch64PACKey;
  switch (K) {
  case IA: case IB: return AArch64::XPACI;
  case DA: case DB: return AArch64::XPACD;
  }
  llvm_unreachable("Unhandled AArch64PACKey::ID enum");
}
 
/// Return AUT opcode to be used for a ptrauth auth using the given key, or its
/// AUT*Z variant that doesn't take a discriminator operand, using zero instead.
static inline unsigned getAUTOpcodeForKey(AArch64PACKey::ID K, bool Zero) {
  using namespace AArch64PACKey;
  switch (K) {
  case IA: return Zero ? AArch64::AUTIZA : AArch64::AUTIA;
  case IB: return Zero ? AArch64::AUTIZB : AArch64::AUTIB;
  case DA: return Zero ? AArch64::AUTDZA : AArch64::AUTDA;
  case DB: return Zero ? AArch64::AUTDZB : AArch64::AUTDB;
  }
  llvm_unreachable("Unhandled AArch64PACKey::ID enum");
}
 
/// Return PAC opcode to be used for a ptrauth sign using the given key, or its
/// PAC*Z variant that doesn't take a discriminator operand, using zero instead.
static inline unsigned getPACOpcodeForKey(AArch64PACKey::ID K, bool Zero) {
  using namespace AArch64PACKey;
  switch (K) {
  case IA: return Zero ? AArch64::PACIZA : AArch64::PACIA;
  case IB: return Zero ? AArch64::PACIZB : AArch64::PACIB;
  case DA: return Zero ? AArch64::PACDZA : AArch64::PACDA;
  case DB: return Zero ? AArch64::PACDZB : AArch64::PACDB;
  }
  llvm_unreachable("Unhandled AArch64PACKey::ID enum");
}
 
// struct TSFlags {
#define TSFLAG_ELEMENT_SIZE_TYPE(X)      (X)        // 3-bits
#define TSFLAG_DESTRUCTIVE_INST_TYPE(X) ((X) << 3)  // 4-bits
#define TSFLAG_FALSE_LANE_TYPE(X)       ((X) << 7)  // 2-bits
#define TSFLAG_INSTR_FLAGS(X)           ((X) << 9)  // 2-bits
#define TSFLAG_SME_MATRIX_TYPE(X)       ((X) << 11) // 3-bits
// }
 
namespace AArch64 {
 
enum ElementSizeType {
  ElementSizeMask = TSFLAG_ELEMENT_SIZE_TYPE(0x7),
  ElementSizeNone = TSFLAG_ELEMENT_SIZE_TYPE(0x0),
  ElementSizeB    = TSFLAG_ELEMENT_SIZE_TYPE(0x1),
  ElementSizeH    = TSFLAG_ELEMENT_SIZE_TYPE(0x2),
  ElementSizeS    = TSFLAG_ELEMENT_SIZE_TYPE(0x3),
  ElementSizeD    = TSFLAG_ELEMENT_SIZE_TYPE(0x4),
};
 
enum DestructiveInstType {
  DestructiveInstTypeMask       = TSFLAG_DESTRUCTIVE_INST_TYPE(0xf),
  NotDestructive                = TSFLAG_DESTRUCTIVE_INST_TYPE(0x0),
  DestructiveOther              = TSFLAG_DESTRUCTIVE_INST_TYPE(0x1),
  DestructiveUnary              = TSFLAG_DESTRUCTIVE_INST_TYPE(0x2),
  DestructiveBinaryImm          = TSFLAG_DESTRUCTIVE_INST_TYPE(0x3),
  DestructiveBinaryShImmUnpred  = TSFLAG_DESTRUCTIVE_INST_TYPE(0x4),
  DestructiveBinary             = TSFLAG_DESTRUCTIVE_INST_TYPE(0x5),
  DestructiveBinaryComm         = TSFLAG_DESTRUCTIVE_INST_TYPE(0x6),
  DestructiveBinaryCommWithRev  = TSFLAG_DESTRUCTIVE_INST_TYPE(0x7),
  DestructiveTernaryCommWithRev = TSFLAG_DESTRUCTIVE_INST_TYPE(0x8),
  DestructiveUnaryPassthru      = TSFLAG_DESTRUCTIVE_INST_TYPE(0x9),
};
 
enum FalseLaneType {
  FalseLanesMask  = TSFLAG_FALSE_LANE_TYPE(0x3),
  FalseLanesZero  = TSFLAG_FALSE_LANE_TYPE(0x1),
  FalseLanesUndef = TSFLAG_FALSE_LANE_TYPE(0x2),
};
 
// NOTE: This is a bit field.
static const uint64_t InstrFlagIsWhile     = TSFLAG_INSTR_FLAGS(0x1);
static const uint64_t InstrFlagIsPTestLike = TSFLAG_INSTR_FLAGS(0x2);
 
enum SMEMatrixType {
  SMEMatrixTypeMask = TSFLAG_SME_MATRIX_TYPE(0x7),
  SMEMatrixNone     = TSFLAG_SME_MATRIX_TYPE(0x0),
  SMEMatrixTileB    = TSFLAG_SME_MATRIX_TYPE(0x1),
  SMEMatrixTileH    = TSFLAG_SME_MATRIX_TYPE(0x2),
  SMEMatrixTileS    = TSFLAG_SME_MATRIX_TYPE(0x3),
  SMEMatrixTileD    = TSFLAG_SME_MATRIX_TYPE(0x4),
  SMEMatrixTileQ    = TSFLAG_SME_MATRIX_TYPE(0x5),
  SMEMatrixArray    = TSFLAG_SME_MATRIX_TYPE(0x6),
};
 
#undef TSFLAG_ELEMENT_SIZE_TYPE
#undef TSFLAG_DESTRUCTIVE_INST_TYPE
#undef TSFLAG_FALSE_LANE_TYPE
#undef TSFLAG_INSTR_FLAGS
#undef TSFLAG_SME_MATRIX_TYPE
 
int getSVEPseudoMap(uint16_t Opcode);
int getSVERevInstr(uint16_t Opcode);
int getSVENonRevInstr(uint16_t Opcode);
 
int getSMEPseudoMap(uint16_t Opcode);
}
 
} // end namespace llvm
 
#endif