/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Bug Summary

File:	lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Warning:	line 15644, column 1 Potential leak of memory pointed to by 'N0UsedElements.X'

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name DAGCombiner.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn325118/build-llvm/lib/CodeGen/SelectionDAG -I /build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG -I /build/llvm-toolchain-snapshot-7~svn325118/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn325118/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn325118/build-llvm/lib/CodeGen/SelectionDAG -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-02-14-150435-17243-1 -x c++ /build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

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1//===- DAGCombiner.cpp - Implement a DAG node combiner --------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This pass combines dag nodes to form fewer, simpler DAG nodes.  It can be run
11// both before and after the DAG is legalized.
12//
13// This pass is not a substitute for the LLVM IR instcombine pass. This pass is
14// primarily intended to handle simplification opportunities that are implicit
15// in the LLVM IR and exposed by the various codegen lowering phases.
16//
17//===----------------------------------------------------------------------===//

19#include "llvm/ADT/APFloat.h"
20#include "llvm/ADT/APInt.h"
21#include "llvm/ADT/ArrayRef.h"
22#include "llvm/ADT/DenseMap.h"
23#include "llvm/ADT/None.h"
24#include "llvm/ADT/Optional.h"
25#include "llvm/ADT/STLExtras.h"
26#include "llvm/ADT/SetVector.h"
27#include "llvm/ADT/SmallBitVector.h"
28#include "llvm/ADT/SmallPtrSet.h"
29#include "llvm/ADT/SmallSet.h"
30#include "llvm/ADT/SmallVector.h"
31#include "llvm/ADT/Statistic.h"
32#include "llvm/Analysis/AliasAnalysis.h"
33#include "llvm/Analysis/MemoryLocation.h"
34#include "llvm/CodeGen/DAGCombine.h"
35#include "llvm/CodeGen/ISDOpcodes.h"
36#include "llvm/CodeGen/MachineFrameInfo.h"
37#include "llvm/CodeGen/MachineFunction.h"
38#include "llvm/CodeGen/MachineMemOperand.h"
39#include "llvm/CodeGen/MachineValueType.h"
40#include "llvm/CodeGen/RuntimeLibcalls.h"
41#include "llvm/CodeGen/SelectionDAG.h"
42#include "llvm/CodeGen/SelectionDAGAddressAnalysis.h"
43#include "llvm/CodeGen/SelectionDAGNodes.h"
44#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
45#include "llvm/CodeGen/TargetLowering.h"
46#include "llvm/CodeGen/TargetRegisterInfo.h"
47#include "llvm/CodeGen/TargetSubtargetInfo.h"
48#include "llvm/CodeGen/ValueTypes.h"
49#include "llvm/IR/Attributes.h"
50#include "llvm/IR/Constant.h"
51#include "llvm/IR/DataLayout.h"
52#include "llvm/IR/DerivedTypes.h"
53#include "llvm/IR/Function.h"
54#include "llvm/IR/LLVMContext.h"
55#include "llvm/IR/Metadata.h"
56#include "llvm/Support/Casting.h"
57#include "llvm/Support/CodeGen.h"
58#include "llvm/Support/CommandLine.h"
59#include "llvm/Support/Compiler.h"
60#include "llvm/Support/Debug.h"
61#include "llvm/Support/ErrorHandling.h"
62#include "llvm/Support/KnownBits.h"
63#include "llvm/Support/MathExtras.h"
64#include "llvm/Support/raw_ostream.h"
65#include "llvm/Target/TargetMachine.h"
66#include "llvm/Target/TargetOptions.h"
67#include <algorithm>
68#include <cassert>
69#include <cstdint>
70#include <functional>
71#include <iterator>
72#include <string>
73#include <tuple>
74#include <utility>
75#include <vector>

77using namespace llvm;

79#define DEBUG_TYPE"dagcombine" "dagcombine"

81STATISTIC(NodesCombined   , "Number of dag nodes combined")static llvm::Statistic NodesCombined = {"dagcombine", "NodesCombined"
, "Number of dag nodes combined", {0}, {false}};
82STATISTIC(PreIndexedNodes , "Number of pre-indexed nodes created")static llvm::Statistic PreIndexedNodes = {"dagcombine", "PreIndexedNodes"
, "Number of pre-indexed nodes created", {0}, {false}};
83STATISTIC(PostIndexedNodes, "Number of post-indexed nodes created")static llvm::Statistic PostIndexedNodes = {"dagcombine", "PostIndexedNodes"
, "Number of post-indexed nodes created", {0}, {false}};
84STATISTIC(OpsNarrowed     , "Number of load/op/store narrowed")static llvm::Statistic OpsNarrowed = {"dagcombine", "OpsNarrowed"
, "Number of load/op/store narrowed", {0}, {false}};
85STATISTIC(LdStFP2Int      , "Number of fp load/store pairs transformed to int")static llvm::Statistic LdStFP2Int = {"dagcombine", "LdStFP2Int"
, "Number of fp load/store pairs transformed to int", {0}, {false
}};
86STATISTIC(SlicedLoads, "Number of load sliced")static llvm::Statistic SlicedLoads = {"dagcombine", "SlicedLoads"
, "Number of load sliced", {0}, {false}};

88static cl::opt<bool>
89CombinerGlobalAA("combiner-global-alias-analysis", cl::Hidden,
               cl::desc("Enable DAG combiner's use of IR alias analysis"));

92static cl::opt<bool>
93UseTBAA("combiner-use-tbaa", cl::Hidden, cl::init(true),
      cl::desc("Enable DAG combiner's use of TBAA"));

96#ifndef NDEBUG
97static cl::opt<std::string>
98CombinerAAOnlyFunc("combiner-aa-only-func", cl::Hidden,
                 cl::desc("Only use DAG-combiner alias analysis in this"
                          " function"));
101#endif

103/// Hidden option to stress test load slicing, i.e., when this option
104/// is enabled, load slicing bypasses most of its profitability guards.
105static cl::opt<bool>
106StressLoadSlicing("combiner-stress-load-slicing", cl::Hidden,
                cl::desc("Bypass the profitability model of load slicing"),
                cl::init(false));

110static cl::opt<bool>
MaySplitLoadIndex("combiner-split-load-index", cl::Hidden, cl::init(true),
                  cl::desc("DAG combiner may split indexing from loads"));

114namespace {

class DAGCombiner {
  SelectionDAG &DAG;
  const TargetLowering &TLI;
  CombineLevel Level;
  CodeGenOpt::Level OptLevel;
  bool LegalOperations = false;
  bool LegalTypes = false;
  bool ForCodeSize;

  /// \brief Worklist of all of the nodes that need to be simplified.
  ///
  /// This must behave as a stack -- new nodes to process are pushed onto the
  /// back and when processing we pop off of the back.
  ///
  /// The worklist will not contain duplicates but may contain null entries
  /// due to nodes being deleted from the underlying DAG.
  SmallVector<SDNode *, 64> Worklist;

  /// \brief Mapping from an SDNode to its position on the worklist.
  ///
  /// This is used to find and remove nodes from the worklist (by nulling
  /// them) when they are deleted from the underlying DAG. It relies on
  /// stable indices of nodes within the worklist.
  DenseMap<SDNode *, unsigned> WorklistMap;

  /// \brief Set of nodes which have been combined (at least once).
  ///
  /// This is used to allow us to reliably add any operands of a DAG node
  /// which have not yet been combined to the worklist.
  SmallPtrSet<SDNode *, 32> CombinedNodes;

  // AA - Used for DAG load/store alias analysis.
  AliasAnalysis *AA;

  /// When an instruction is simplified, add all users of the instruction to
  /// the work lists because they might get more simplified now.
  void AddUsersToWorklist(SDNode *N) {
    for (SDNode *Node : N->uses())
      AddToWorklist(Node);
  }

  /// Call the node-specific routine that folds each particular type of node.
  SDValue visit(SDNode *N);

public:
  DAGCombiner(SelectionDAG &D, AliasAnalysis *AA, CodeGenOpt::Level OL)
      : DAG(D), TLI(D.getTargetLoweringInfo()), Level(BeforeLegalizeTypes),
        OptLevel(OL), AA(AA) {
    ForCodeSize = DAG.getMachineFunction().getFunction().optForSize();

    MaximumLegalStoreInBits = 0;
    for (MVT VT : MVT::all_valuetypes())
      if (EVT(VT).isSimple() && VT != MVT::Other &&
          TLI.isTypeLegal(EVT(VT)) &&
          VT.getSizeInBits() >= MaximumLegalStoreInBits)
        MaximumLegalStoreInBits = VT.getSizeInBits();
  }

  /// Add to the worklist making sure its instance is at the back (next to be
  /// processed.)
  void AddToWorklist(SDNode *N) {
    assert(N->getOpcode() != ISD::DELETED_NODE &&(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && "Deleted Node added to Worklist") ? void (0) : __assert_fail
 ("N->getOpcode() != ISD::DELETED_NODE && \"Deleted Node added to Worklist\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 178, __extension__ __PRETTY_FUNCTION__))
           "Deleted Node added to Worklist")(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && "Deleted Node added to Worklist") ? void (0) : __assert_fail
 ("N->getOpcode() != ISD::DELETED_NODE && \"Deleted Node added to Worklist\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 178, __extension__ __PRETTY_FUNCTION__));

    // Skip handle nodes as they can't usefully be combined and confuse the
    // zero-use deletion strategy.
    if (N->getOpcode() == ISD::HANDLENODE)
      return;

    if (WorklistMap.insert(std::make_pair(N, Worklist.size())).second)
      Worklist.push_back(N);
  }

  /// Remove all instances of N from the worklist.
  void removeFromWorklist(SDNode *N) {
    CombinedNodes.erase(N);

    auto It = WorklistMap.find(N);
    if (It == WorklistMap.end())
      return; // Not in the worklist.

    // Null out the entry rather than erasing it to avoid a linear operation.
    Worklist[It->second] = nullptr;
    WorklistMap.erase(It);
  }

  void deleteAndRecombine(SDNode *N);
  bool recursivelyDeleteUnusedNodes(SDNode *N);

  /// Replaces all uses of the results of one DAG node with new values.
  SDValue CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
                    bool AddTo = true);

  /// Replaces all uses of the results of one DAG node with new values.
  SDValue CombineTo(SDNode *N, SDValue Res, bool AddTo = true) {
    return CombineTo(N, &Res, 1, AddTo);
  }

  /// Replaces all uses of the results of one DAG node with new values.
  SDValue CombineTo(SDNode *N, SDValue Res0, SDValue Res1,
                    bool AddTo = true) {
    SDValue To[] = { Res0, Res1 };
    return CombineTo(N, To, 2, AddTo);
  }

  void CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO);

private:
  unsigned MaximumLegalStoreInBits;

  /// Check the specified integer node value to see if it can be simplified or
  /// if things it uses can be simplified by bit propagation.
  /// If so, return true.
  bool SimplifyDemandedBits(SDValue Op) {
    unsigned BitWidth = Op.getScalarValueSizeInBits();
    APInt Demanded = APInt::getAllOnesValue(BitWidth);
    return SimplifyDemandedBits(Op, Demanded);
  }

  bool SimplifyDemandedBits(SDValue Op, const APInt &Demanded);

  bool CombineToPreIndexedLoadStore(SDNode *N);
  bool CombineToPostIndexedLoadStore(SDNode *N);
  SDValue SplitIndexingFromLoad(LoadSDNode *LD);
  bool SliceUpLoad(SDNode *N);

  /// \brief Replace an ISD::EXTRACT_VECTOR_ELT of a load with a narrowed
  ///   load.
  ///
  /// \param EVE ISD::EXTRACT_VECTOR_ELT to be replaced.
  /// \param InVecVT type of the input vector to EVE with bitcasts resolved.
  /// \param EltNo index of the vector element to load.
  /// \param OriginalLoad load that EVE came from to be replaced.
  /// \returns EVE on success SDValue() on failure.
  SDValue ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
      SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad);
  void ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad);
  SDValue PromoteOperand(SDValue Op, EVT PVT, bool &Replace);
  SDValue SExtPromoteOperand(SDValue Op, EVT PVT);
  SDValue ZExtPromoteOperand(SDValue Op, EVT PVT);
  SDValue PromoteIntBinOp(SDValue Op);
  SDValue PromoteIntShiftOp(SDValue Op);
  SDValue PromoteExtend(SDValue Op);
  bool PromoteLoad(SDValue Op);

  void ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
                       SDValue OrigLoad, SDValue ExtLoad,
                       const SDLoc &DL,
                       ISD::NodeType ExtType);

  /// Call the node-specific routine that knows how to fold each
  /// particular type of node. If that doesn't do anything, try the
  /// target-specific DAG combines.
  SDValue combine(SDNode *N);

  // Visitation implementation - Implement dag node combining for different
  // node types.  The semantics are as follows:
  // Return Value:
  //   SDValue.getNode() == 0 - No change was made
  //   SDValue.getNode() == N - N was replaced, is dead and has been handled.
  //   otherwise              - N should be replaced by the returned Operand.
  //
  SDValue visitTokenFactor(SDNode *N);
  SDValue visitMERGE_VALUES(SDNode *N);
  SDValue visitADD(SDNode *N);
  SDValue visitADDLike(SDValue N0, SDValue N1, SDNode *LocReference);
  SDValue visitSUB(SDNode *N);
  SDValue visitADDC(SDNode *N);
  SDValue visitUADDO(SDNode *N);
  SDValue visitUADDOLike(SDValue N0, SDValue N1, SDNode *N);
  SDValue visitSUBC(SDNode *N);
  SDValue visitUSUBO(SDNode *N);
  SDValue visitADDE(SDNode *N);
  SDValue visitADDCARRY(SDNode *N);
  SDValue visitADDCARRYLike(SDValue N0, SDValue N1, SDValue CarryIn, SDNode *N);
  SDValue visitSUBE(SDNode *N);
  SDValue visitSUBCARRY(SDNode *N);
  SDValue visitMUL(SDNode *N);
  SDValue useDivRem(SDNode *N);
  SDValue visitSDIV(SDNode *N);
  SDValue visitUDIV(SDNode *N);
  SDValue visitREM(SDNode *N);
  SDValue visitMULHU(SDNode *N);
  SDValue visitMULHS(SDNode *N);
  SDValue visitSMUL_LOHI(SDNode *N);
  SDValue visitUMUL_LOHI(SDNode *N);
  SDValue visitSMULO(SDNode *N);
  SDValue visitUMULO(SDNode *N);
  SDValue visitIMINMAX(SDNode *N);
  SDValue visitAND(SDNode *N);
  SDValue visitANDLike(SDValue N0, SDValue N1, SDNode *LocReference);
  SDValue visitOR(SDNode *N);
  SDValue visitORLike(SDValue N0, SDValue N1, SDNode *LocReference);
  SDValue visitXOR(SDNode *N);
  SDValue SimplifyVBinOp(SDNode *N);
  SDValue visitSHL(SDNode *N);
  SDValue visitSRA(SDNode *N);
  SDValue visitSRL(SDNode *N);
  SDValue visitRotate(SDNode *N);
  SDValue visitABS(SDNode *N);
  SDValue visitBSWAP(SDNode *N);
  SDValue visitBITREVERSE(SDNode *N);
  SDValue visitCTLZ(SDNode *N);
  SDValue visitCTLZ_ZERO_UNDEF(SDNode *N);
  SDValue visitCTTZ(SDNode *N);
  SDValue visitCTTZ_ZERO_UNDEF(SDNode *N);
  SDValue visitCTPOP(SDNode *N);
  SDValue visitSELECT(SDNode *N);
  SDValue visitVSELECT(SDNode *N);
  SDValue visitSELECT_CC(SDNode *N);
  SDValue visitSETCC(SDNode *N);
  SDValue visitSETCCE(SDNode *N);
  SDValue visitSETCCCARRY(SDNode *N);
  SDValue visitSIGN_EXTEND(SDNode *N);
  SDValue visitZERO_EXTEND(SDNode *N);
  SDValue visitANY_EXTEND(SDNode *N);
  SDValue visitAssertExt(SDNode *N);
  SDValue visitSIGN_EXTEND_INREG(SDNode *N);
  SDValue visitSIGN_EXTEND_VECTOR_INREG(SDNode *N);
  SDValue visitZERO_EXTEND_VECTOR_INREG(SDNode *N);
  SDValue visitTRUNCATE(SDNode *N);
  SDValue visitBITCAST(SDNode *N);
  SDValue visitBUILD_PAIR(SDNode *N);
  SDValue visitFADD(SDNode *N);
  SDValue visitFSUB(SDNode *N);
  SDValue visitFMUL(SDNode *N);
  SDValue visitFMA(SDNode *N);
  SDValue visitFDIV(SDNode *N);
  SDValue visitFREM(SDNode *N);
  SDValue visitFSQRT(SDNode *N);
  SDValue visitFCOPYSIGN(SDNode *N);
  SDValue visitSINT_TO_FP(SDNode *N);
  SDValue visitUINT_TO_FP(SDNode *N);
  SDValue visitFP_TO_SINT(SDNode *N);
  SDValue visitFP_TO_UINT(SDNode *N);
  SDValue visitFP_ROUND(SDNode *N);
  SDValue visitFP_ROUND_INREG(SDNode *N);
  SDValue visitFP_EXTEND(SDNode *N);
  SDValue visitFNEG(SDNode *N);
  SDValue visitFABS(SDNode *N);
  SDValue visitFCEIL(SDNode *N);
  SDValue visitFTRUNC(SDNode *N);
  SDValue visitFFLOOR(SDNode *N);
  SDValue visitFMINNUM(SDNode *N);
  SDValue visitFMAXNUM(SDNode *N);
  SDValue visitBRCOND(SDNode *N);
  SDValue visitBR_CC(SDNode *N);
  SDValue visitLOAD(SDNode *N);

  SDValue replaceStoreChain(StoreSDNode *ST, SDValue BetterChain);
  SDValue replaceStoreOfFPConstant(StoreSDNode *ST);

  SDValue visitSTORE(SDNode *N);
  SDValue visitINSERT_VECTOR_ELT(SDNode *N);
  SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
  SDValue visitBUILD_VECTOR(SDNode *N);
  SDValue visitCONCAT_VECTORS(SDNode *N);
  SDValue visitEXTRACT_SUBVECTOR(SDNode *N);
  SDValue visitVECTOR_SHUFFLE(SDNode *N);
  SDValue visitSCALAR_TO_VECTOR(SDNode *N);
  SDValue visitINSERT_SUBVECTOR(SDNode *N);
  SDValue visitMLOAD(SDNode *N);
  SDValue visitMSTORE(SDNode *N);
  SDValue visitMGATHER(SDNode *N);
  SDValue visitMSCATTER(SDNode *N);
  SDValue visitFP_TO_FP16(SDNode *N);
  SDValue visitFP16_TO_FP(SDNode *N);

  SDValue visitFADDForFMACombine(SDNode *N);
  SDValue visitFSUBForFMACombine(SDNode *N);
  SDValue visitFMULForFMADistributiveCombine(SDNode *N);

  SDValue XformToShuffleWithZero(SDNode *N);
  SDValue ReassociateOps(unsigned Opc, const SDLoc &DL, SDValue LHS,
                         SDValue RHS);

  SDValue visitShiftByConstant(SDNode *N, ConstantSDNode *Amt);

  SDValue foldSelectOfConstants(SDNode *N);
  SDValue foldVSelectOfConstants(SDNode *N);
  SDValue foldBinOpIntoSelect(SDNode *BO);
  bool SimplifySelectOps(SDNode *SELECT, SDValue LHS, SDValue RHS);
  SDValue SimplifyBinOpWithSameOpcodeHands(SDNode *N);
  SDValue SimplifySelect(const SDLoc &DL, SDValue N0, SDValue N1, SDValue N2);
  SDValue SimplifySelectCC(const SDLoc &DL, SDValue N0, SDValue N1,
                           SDValue N2, SDValue N3, ISD::CondCode CC,
                           bool NotExtCompare = false);
  SDValue foldSelectCCToShiftAnd(const SDLoc &DL, SDValue N0, SDValue N1,
                                 SDValue N2, SDValue N3, ISD::CondCode CC);
  SDValue foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1,
                            const SDLoc &DL);
  SDValue SimplifySetCC(EVT VT, SDValue N0, SDValue N1, ISD::CondCode Cond,
                        const SDLoc &DL, bool foldBooleans = true);

  bool isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
                         SDValue &CC) const;
  bool isOneUseSetCC(SDValue N) const;

  SDValue SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
                                       unsigned HiOp);
  SDValue CombineConsecutiveLoads(SDNode *N, EVT VT);
  SDValue CombineExtLoad(SDNode *N);
  SDValue combineRepeatedFPDivisors(SDNode *N);
  SDValue combineInsertEltToShuffle(SDNode *N, unsigned InsIndex);
  SDValue ConstantFoldBITCASTofBUILD_VECTOR(SDNode *, EVT);
  SDValue BuildSDIV(SDNode *N);
  SDValue BuildSDIVPow2(SDNode *N);
  SDValue BuildUDIV(SDNode *N);
  SDValue BuildLogBase2(SDValue Op, const SDLoc &DL);
  SDValue BuildReciprocalEstimate(SDValue Op, SDNodeFlags Flags);
  SDValue buildRsqrtEstimate(SDValue Op, SDNodeFlags Flags);
  SDValue buildSqrtEstimate(SDValue Op, SDNodeFlags Flags);
  SDValue buildSqrtEstimateImpl(SDValue Op, SDNodeFlags Flags, bool Recip);
  SDValue buildSqrtNROneConst(SDValue Op, SDValue Est, unsigned Iterations,
                              SDNodeFlags Flags, bool Reciprocal);
  SDValue buildSqrtNRTwoConst(SDValue Op, SDValue Est, unsigned Iterations,
                              SDNodeFlags Flags, bool Reciprocal);
  SDValue MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
                             bool DemandHighBits = true);
  SDValue MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1);
  SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
                            SDValue InnerPos, SDValue InnerNeg,
                            unsigned PosOpcode, unsigned NegOpcode,
                            const SDLoc &DL);
  SDNode *MatchRotate(SDValue LHS, SDValue RHS, const SDLoc &DL);
  SDValue MatchLoadCombine(SDNode *N);
  SDValue ReduceLoadWidth(SDNode *N);
  SDValue ReduceLoadOpStoreWidth(SDNode *N);
  SDValue splitMergedValStore(StoreSDNode *ST);
  SDValue TransformFPLoadStorePair(SDNode *N);
  SDValue reduceBuildVecExtToExtBuildVec(SDNode *N);
  SDValue reduceBuildVecConvertToConvertBuildVec(SDNode *N);
  SDValue reduceBuildVecToShuffle(SDNode *N);
  SDValue createBuildVecShuffle(const SDLoc &DL, SDNode *N,
                                ArrayRef<int> VectorMask, SDValue VecIn1,
                                SDValue VecIn2, unsigned LeftIdx);
  SDValue matchVSelectOpSizesWithSetCC(SDNode *N);

  /// Walk up chain skipping non-aliasing memory nodes,
  /// looking for aliasing nodes and adding them to the Aliases vector.
  void GatherAllAliases(SDNode *N, SDValue OriginalChain,
                        SmallVectorImpl<SDValue> &Aliases);

  /// Return true if there is any possibility that the two addresses overlap.
  bool isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const;

  /// Walk up chain skipping non-aliasing memory nodes, looking for a better
  /// chain (aliasing node.)
  SDValue FindBetterChain(SDNode *N, SDValue Chain);

  /// Try to replace a store and any possibly adjacent stores on
  /// consecutive chains with better chains. Return true only if St is
  /// replaced.
  ///
  /// Notice that other chains may still be replaced even if the function
  /// returns false.
  bool findBetterNeighborChains(StoreSDNode *St);

  /// Match "(X shl/srl V1) & V2" where V2 may not be present.
  bool MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask);

  /// Holds a pointer to an LSBaseSDNode as well as information on where it
  /// is located in a sequence of memory operations connected by a chain.
  struct MemOpLink {
    // Ptr to the mem node.
    LSBaseSDNode *MemNode;

    // Offset from the base ptr.
    int64_t OffsetFromBase;

    MemOpLink(LSBaseSDNode *N, int64_t Offset)
        : MemNode(N), OffsetFromBase(Offset) {}
  };

  /// This is a helper function for visitMUL to check the profitability
  /// of folding (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2).
  /// MulNode is the original multiply, AddNode is (add x, c1),
  /// and ConstNode is c2.
  bool isMulAddWithConstProfitable(SDNode *MulNode,
                                   SDValue &AddNode,
                                   SDValue &ConstNode);

  /// This is a helper function for visitAND and visitZERO_EXTEND.  Returns
  /// true if the (and (load x) c) pattern matches an extload.  ExtVT returns
  /// the type of the loaded value to be extended.
  bool isAndLoadExtLoad(ConstantSDNode *AndC, LoadSDNode *LoadN,
                        EVT LoadResultTy, EVT &ExtVT);

  /// Helper function to calculate whether the given Load can have its
  /// width reduced to ExtVT.
  bool isLegalNarrowLoad(LoadSDNode *LoadN, ISD::LoadExtType ExtType,
                         EVT &ExtVT, unsigned ShAmt = 0);

  /// Used by BackwardsPropagateMask to find suitable loads.
  bool SearchForAndLoads(SDNode *N, SmallPtrSetImpl<LoadSDNode*> &Loads,
                         SmallPtrSetImpl<SDNode*> &NodeWithConsts,
                         ConstantSDNode *Mask, SDNode *&UncombinedNode);
  /// Attempt to propagate a given AND node back to load leaves so that they
  /// can be combined into narrow loads.
  bool BackwardsPropagateMask(SDNode *N, SelectionDAG &DAG);

  /// Helper function for MergeConsecutiveStores which merges the
  /// component store chains.
  SDValue getMergeStoreChains(SmallVectorImpl<MemOpLink> &StoreNodes,
                              unsigned NumStores);

  /// This is a helper function for MergeConsecutiveStores. When the
  /// source elements of the consecutive stores are all constants or
  /// all extracted vector elements, try to merge them into one
  /// larger store introducing bitcasts if necessary.  \return True
  /// if a merged store was created.
  bool MergeStoresOfConstantsOrVecElts(SmallVectorImpl<MemOpLink> &StoreNodes,
                                       EVT MemVT, unsigned NumStores,
                                       bool IsConstantSrc, bool UseVector,
                                       bool UseTrunc);

  /// This is a helper function for MergeConsecutiveStores. Stores
  /// that potentially may be merged with St are placed in
  /// StoreNodes.
  void getStoreMergeCandidates(StoreSDNode *St,
                               SmallVectorImpl<MemOpLink> &StoreNodes);

  /// Helper function for MergeConsecutiveStores. Checks if
  /// candidate stores have indirect dependency through their
  /// operands. \return True if safe to merge.
  bool checkMergeStoreCandidatesForDependencies(
      SmallVectorImpl<MemOpLink> &StoreNodes, unsigned NumStores);

  /// Merge consecutive store operations into a wide store.
  /// This optimization uses wide integers or vectors when possible.
  /// \return number of stores that were merged into a merged store (the
  /// affected nodes are stored as a prefix in \p StoreNodes).
  bool MergeConsecutiveStores(StoreSDNode *N);

  /// \brief Try to transform a truncation where C is a constant:
  ///     (trunc (and X, C)) -> (and (trunc X), (trunc C))
  ///
  /// \p N needs to be a truncation and its first operand an AND. Other
  /// requirements are checked by the function (e.g. that trunc is
  /// single-use) and if missed an empty SDValue is returned.
  SDValue distributeTruncateThroughAnd(SDNode *N);

public:
  /// Runs the dag combiner on all nodes in the work list
  void Run(CombineLevel AtLevel);

  SelectionDAG &getDAG() const { return DAG; }

  /// Returns a type large enough to hold any valid shift amount - before type
  /// legalization these can be huge.
  EVT getShiftAmountTy(EVT LHSTy) {
    assert(LHSTy.isInteger() && "Shift amount is not an integer type!")(static_cast <bool> (LHSTy.isInteger() && "Shift amount is not an integer type!"
) ? void (0) : __assert_fail ("LHSTy.isInteger() && \"Shift amount is not an integer type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 567, __extension__ __PRETTY_FUNCTION__));
    if (LHSTy.isVector())
      return LHSTy;
    auto &DL = DAG.getDataLayout();
    return LegalTypes ? TLI.getScalarShiftAmountTy(DL, LHSTy)
                      : TLI.getPointerTy(DL);
  }

  /// This method returns true if we are running before type legalization or
  /// if the specified VT is legal.
  bool isTypeLegal(const EVT &VT) {
    if (!LegalTypes) return true;
    return TLI.isTypeLegal(VT);
  }

  /// Convenience wrapper around TargetLowering::getSetCCResultType
  EVT getSetCCResultType(EVT VT) const {
    return TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
  }
};

588/// This class is a DAGUpdateListener that removes any deleted
589/// nodes from the worklist.
590class WorklistRemover : public SelectionDAG::DAGUpdateListener {
DAGCombiner &DC;

593public:
explicit WorklistRemover(DAGCombiner &dc)
  : SelectionDAG::DAGUpdateListener(dc.getDAG()), DC(dc) {}

void NodeDeleted(SDNode *N, SDNode *E) override {
  DC.removeFromWorklist(N);
}
600};

602} // end anonymous namespace

604//===----------------------------------------------------------------------===//
605//  TargetLowering::DAGCombinerInfo implementation
606//===----------------------------------------------------------------------===//

608void TargetLowering::DAGCombinerInfo::AddToWorklist(SDNode *N) {
((DAGCombiner*)DC)->AddToWorklist(N);
610}

612SDValue TargetLowering::DAGCombinerInfo::
613CombineTo(SDNode *N, ArrayRef<SDValue> To, bool AddTo) {
return ((DAGCombiner*)DC)->CombineTo(N, &To[0], To.size(), AddTo);
615}

617SDValue TargetLowering::DAGCombinerInfo::
618CombineTo(SDNode *N, SDValue Res, bool AddTo) {
return ((DAGCombiner*)DC)->CombineTo(N, Res, AddTo);
620}

622SDValue TargetLowering::DAGCombinerInfo::
623CombineTo(SDNode *N, SDValue Res0, SDValue Res1, bool AddTo) {
return ((DAGCombiner*)DC)->CombineTo(N, Res0, Res1, AddTo);
625}

627void TargetLowering::DAGCombinerInfo::
628CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
return ((DAGCombiner*)DC)->CommitTargetLoweringOpt(TLO);
630}

632//===----------------------------------------------------------------------===//
633// Helper Functions
634//===----------------------------------------------------------------------===//

636void DAGCombiner::deleteAndRecombine(SDNode *N) {
removeFromWorklist(N);

// If the operands of this node are only used by the node, they will now be
// dead. Make sure to re-visit them and recursively delete dead nodes.
for (const SDValue &Op : N->ops())
  // For an operand generating multiple values, one of the values may
  // become dead allowing further simplification (e.g. split index
  // arithmetic from an indexed load).
  if (Op->hasOneUse() || Op->getNumValues() > 1)
    AddToWorklist(Op.getNode());

DAG.DeleteNode(N);
649}

651/// Return 1 if we can compute the negated form of the specified expression for
652/// the same cost as the expression itself, or 2 if we can compute the negated
653/// form more cheaply than the expression itself.
654static char isNegatibleForFree(SDValue Op, bool LegalOperations,
                             const TargetLowering &TLI,
                             const TargetOptions *Options,
                             unsigned Depth = 0) {
// fneg is removable even if it has multiple uses.
if (Op.getOpcode() == ISD::FNEG) return 2;

// Don't allow anything with multiple uses.
if (!Op.hasOneUse()) return 0;

// Don't recurse exponentially.
if (Depth > 6) return 0;

switch (Op.getOpcode()) {
default: return false;
case ISD::ConstantFP: {
  if (!LegalOperations)
    return 1;

  // Don't invert constant FP values after legalization unless the target says
  // the negated constant is legal.
  EVT VT = Op.getValueType();
  return TLI.isOperationLegal(ISD::ConstantFP, VT) ||
    TLI.isFPImmLegal(neg(cast<ConstantFPSDNode>(Op)->getValueAPF()), VT);
}
case ISD::FADD:
  // FIXME: determine better conditions for this xform.
  if (!Options->UnsafeFPMath) return 0;

  // After operation legalization, it might not be legal to create new FSUBs.
  if (LegalOperations &&
      !TLI.isOperationLegalOrCustom(ISD::FSUB,  Op.getValueType()))
    return 0;

  // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
  if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
                                  Options, Depth + 1))
    return V;
  // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
  return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
                            Depth + 1);
case ISD::FSUB:
  // We can't turn -(A-B) into B-A when we honor signed zeros.
  if (!Options->NoSignedZerosFPMath &&
      !Op.getNode()->getFlags().hasNoSignedZeros())
    return 0;

  // fold (fneg (fsub A, B)) -> (fsub B, A)
  return 1;

case ISD::FMUL:
case ISD::FDIV:
  if (Options->HonorSignDependentRoundingFPMath()) return 0;

  // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y) or (fmul X, (fneg Y))
  if (char V = isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI,
                                  Options, Depth + 1))
    return V;

  return isNegatibleForFree(Op.getOperand(1), LegalOperations, TLI, Options,
                            Depth + 1);

case ISD::FP_EXTEND:
case ISD::FP_ROUND:
case ISD::FSIN:
  return isNegatibleForFree(Op.getOperand(0), LegalOperations, TLI, Options,
                            Depth + 1);
}
722}

724/// If isNegatibleForFree returns true, return the newly negated expression.
725static SDValue GetNegatedExpression(SDValue Op, SelectionDAG &DAG,
                                  bool LegalOperations, unsigned Depth = 0) {
const TargetOptions &Options = DAG.getTarget().Options;
// fneg is removable even if it has multiple uses.
if (Op.getOpcode() == ISD::FNEG) return Op.getOperand(0);

// Don't allow anything with multiple uses.
assert(Op.hasOneUse() && "Unknown reuse!")(static_cast <bool> (Op.hasOneUse() && "Unknown reuse!"
) ? void (0) : __assert_fail ("Op.hasOneUse() && \"Unknown reuse!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 732, __extension__ __PRETTY_FUNCTION__));

assert(Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree")(static_cast <bool> (Depth <= 6 && "GetNegatedExpression doesn't match isNegatibleForFree"
) ? void (0) : __assert_fail ("Depth <= 6 && \"GetNegatedExpression doesn't match isNegatibleForFree\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 734, __extension__ __PRETTY_FUNCTION__));

const SDNodeFlags Flags = Op.getNode()->getFlags();

switch (Op.getOpcode()) {
default: llvm_unreachable("Unknown code")::llvm::llvm_unreachable_internal("Unknown code", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 739);
case ISD::ConstantFP: {
  APFloat V = cast<ConstantFPSDNode>(Op)->getValueAPF();
  V.changeSign();
  return DAG.getConstantFP(V, SDLoc(Op), Op.getValueType());
}
case ISD::FADD:
  // FIXME: determine better conditions for this xform.
  assert(Options.UnsafeFPMath)(static_cast <bool> (Options.UnsafeFPMath) ? void (0) :
 __assert_fail ("Options.UnsafeFPMath", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 747, __extension__ __PRETTY_FUNCTION__));

  // fold (fneg (fadd A, B)) -> (fsub (fneg A), B)
  if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
                         DAG.getTargetLoweringInfo(), &Options, Depth+1))
    return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
                       GetNegatedExpression(Op.getOperand(0), DAG,
                                            LegalOperations, Depth+1),
                       Op.getOperand(1), Flags);
  // fold (fneg (fadd A, B)) -> (fsub (fneg B), A)
  return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
                     GetNegatedExpression(Op.getOperand(1), DAG,
                                          LegalOperations, Depth+1),
                     Op.getOperand(0), Flags);
case ISD::FSUB:
  // fold (fneg (fsub 0, B)) -> B
  if (ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(Op.getOperand(0)))
    if (N0CFP->isZero())
      return Op.getOperand(1);

  // fold (fneg (fsub A, B)) -> (fsub B, A)
  return DAG.getNode(ISD::FSUB, SDLoc(Op), Op.getValueType(),
                     Op.getOperand(1), Op.getOperand(0), Flags);

case ISD::FMUL:
case ISD::FDIV:
  assert(!Options.HonorSignDependentRoundingFPMath())(static_cast <bool> (!Options.HonorSignDependentRoundingFPMath
()) ? void (0) : __assert_fail ("!Options.HonorSignDependentRoundingFPMath()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 773, __extension__ __PRETTY_FUNCTION__));

  // fold (fneg (fmul X, Y)) -> (fmul (fneg X), Y)
  if (isNegatibleForFree(Op.getOperand(0), LegalOperations,
                         DAG.getTargetLoweringInfo(), &Options, Depth+1))
    return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
                       GetNegatedExpression(Op.getOperand(0), DAG,
                                            LegalOperations, Depth+1),
                       Op.getOperand(1), Flags);

  // fold (fneg (fmul X, Y)) -> (fmul X, (fneg Y))
  return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
                     Op.getOperand(0),
                     GetNegatedExpression(Op.getOperand(1), DAG,
                                          LegalOperations, Depth+1), Flags);

case ISD::FP_EXTEND:
case ISD::FSIN:
  return DAG.getNode(Op.getOpcode(), SDLoc(Op), Op.getValueType(),
                     GetNegatedExpression(Op.getOperand(0), DAG,
                                          LegalOperations, Depth+1));
case ISD::FP_ROUND:
    return DAG.getNode(ISD::FP_ROUND, SDLoc(Op), Op.getValueType(),
                       GetNegatedExpression(Op.getOperand(0), DAG,
                                            LegalOperations, Depth+1),
                       Op.getOperand(1));
}
800}

802// APInts must be the same size for most operations, this helper
803// function zero extends the shorter of the pair so that they match.
804// We provide an Offset so that we can create bitwidths that won't overflow.
805static void zeroExtendToMatch(APInt &LHS, APInt &RHS, unsigned Offset = 0) {
unsigned Bits = Offset + std::max(LHS.getBitWidth(), RHS.getBitWidth());
LHS = LHS.zextOrSelf(Bits);
RHS = RHS.zextOrSelf(Bits);
809}

811// Return true if this node is a setcc, or is a select_cc
812// that selects between the target values used for true and false, making it
813// equivalent to a setcc. Also, set the incoming LHS, RHS, and CC references to
814// the appropriate nodes based on the type of node we are checking. This
815// simplifies life a bit for the callers.
816bool DAGCombiner::isSetCCEquivalent(SDValue N, SDValue &LHS, SDValue &RHS,
                                  SDValue &CC) const {
if (N.getOpcode() == ISD::SETCC) {
  LHS = N.getOperand(0);
  RHS = N.getOperand(1);
  CC  = N.getOperand(2);
  return true;
}

if (N.getOpcode() != ISD::SELECT_CC ||
    !TLI.isConstTrueVal(N.getOperand(2).getNode()) ||
    !TLI.isConstFalseVal(N.getOperand(3).getNode()))
  return false;

if (TLI.getBooleanContents(N.getValueType()) ==
    TargetLowering::UndefinedBooleanContent)
  return false;

LHS = N.getOperand(0);
RHS = N.getOperand(1);
CC  = N.getOperand(4);
return true;
838}

840/// Return true if this is a SetCC-equivalent operation with only one use.
841/// If this is true, it allows the users to invert the operation for free when
842/// it is profitable to do so.
843bool DAGCombiner::isOneUseSetCC(SDValue N) const {
SDValue N0, N1, N2;
if (isSetCCEquivalent(N, N0, N1, N2) && N.getNode()->hasOneUse())
  return true;
return false;
848}

850// \brief Returns the SDNode if it is a constant float BuildVector
851// or constant float.
852static SDNode *isConstantFPBuildVectorOrConstantFP(SDValue N) {
if (isa<ConstantFPSDNode>(N))
  return N.getNode();
if (ISD::isBuildVectorOfConstantFPSDNodes(N.getNode()))
  return N.getNode();
return nullptr;
858}

860// Determines if it is a constant integer or a build vector of constant
861// integers (and undefs).
862// Do not permit build vector implicit truncation.
863static bool isConstantOrConstantVector(SDValue N, bool NoOpaques = false) {
if (ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N))
  return !(Const->isOpaque() && NoOpaques);
if (N.getOpcode() != ISD::BUILD_VECTOR)
  return false;
unsigned BitWidth = N.getScalarValueSizeInBits();
for (const SDValue &Op : N->op_values()) {
  if (Op.isUndef())
    continue;
  ConstantSDNode *Const = dyn_cast<ConstantSDNode>(Op);
  if (!Const || Const->getAPIntValue().getBitWidth() != BitWidth ||
      (Const->isOpaque() && NoOpaques))
    return false;
}
return true;
878}

880// Determines if it is a constant null integer or a splatted vector of a
881// constant null integer (with no undefs).
882// Build vector implicit truncation is not an issue for null values.
883static bool isNullConstantOrNullSplatConstant(SDValue N) {
if (ConstantSDNode *Splat = isConstOrConstSplat(N))
  return Splat->isNullValue();
return false;
887}

889// Determines if it is a constant integer of one or a splatted vector of a
890// constant integer of one (with no undefs).
891// Do not permit build vector implicit truncation.
892static bool isOneConstantOrOneSplatConstant(SDValue N) {
unsigned BitWidth = N.getScalarValueSizeInBits();
if (ConstantSDNode *Splat = isConstOrConstSplat(N))
  return Splat->isOne() && Splat->getAPIntValue().getBitWidth() == BitWidth;
return false;
897}

899// Determines if it is a constant integer of all ones or a splatted vector of a
900// constant integer of all ones (with no undefs).
901// Do not permit build vector implicit truncation.
902static bool isAllOnesConstantOrAllOnesSplatConstant(SDValue N) {
unsigned BitWidth = N.getScalarValueSizeInBits();
if (ConstantSDNode *Splat = isConstOrConstSplat(N))
  return Splat->isAllOnesValue() &&
         Splat->getAPIntValue().getBitWidth() == BitWidth;
return false;
908}

910// Determines if a BUILD_VECTOR is composed of all-constants possibly mixed with
911// undef's.
912static bool isAnyConstantBuildVector(const SDNode *N) {
return ISD::isBuildVectorOfConstantSDNodes(N) ||
       ISD::isBuildVectorOfConstantFPSDNodes(N);
915}

917// Attempt to match a unary predicate against a scalar/splat constant or
918// every element of a constant BUILD_VECTOR.
919static bool matchUnaryPredicate(SDValue Op,
                              std::function<bool(ConstantSDNode *)> Match) {
if (auto *Cst = dyn_cast<ConstantSDNode>(Op))
  return Match(Cst);

if (ISD::BUILD_VECTOR != Op.getOpcode())
  return false;

EVT SVT = Op.getValueType().getScalarType();
for (unsigned i = 0, e = Op.getNumOperands(); i != e; ++i) {
  auto *Cst = dyn_cast<ConstantSDNode>(Op.getOperand(i));
  if (!Cst || Cst->getValueType(0) != SVT || !Match(Cst))
    return false;
}
return true;
934}

936// Attempt to match a binary predicate against a pair of scalar/splat constants
937// or every element of a pair of constant BUILD_VECTORs.
938static bool matchBinaryPredicate(
  SDValue LHS, SDValue RHS,
  std::function<bool(ConstantSDNode *, ConstantSDNode *)> Match) {
if (LHS.getValueType() != RHS.getValueType())
  return false;

if (auto *LHSCst = dyn_cast<ConstantSDNode>(LHS))
  if (auto *RHSCst = dyn_cast<ConstantSDNode>(RHS))
    return Match(LHSCst, RHSCst);

if (ISD::BUILD_VECTOR != LHS.getOpcode() ||
    ISD::BUILD_VECTOR != RHS.getOpcode())
  return false;

EVT SVT = LHS.getValueType().getScalarType();
for (unsigned i = 0, e = LHS.getNumOperands(); i != e; ++i) {
  auto *LHSCst = dyn_cast<ConstantSDNode>(LHS.getOperand(i));
  auto *RHSCst = dyn_cast<ConstantSDNode>(RHS.getOperand(i));
  if (!LHSCst || !RHSCst)
    return false;
  if (LHSCst->getValueType(0) != SVT ||
      LHSCst->getValueType(0) != RHSCst->getValueType(0))
    return false;
  if (!Match(LHSCst, RHSCst))
    return false;
}
return true;
965}

967SDValue DAGCombiner::ReassociateOps(unsigned Opc, const SDLoc &DL, SDValue N0,
                                  SDValue N1) {
EVT VT = N0.getValueType();
if (N0.getOpcode() == Opc) {
  if (SDNode *L = DAG.isConstantIntBuildVectorOrConstantInt(N0.getOperand(1))) {
    if (SDNode *R = DAG.isConstantIntBuildVectorOrConstantInt(N1)) {
      // reassoc. (op (op x, c1), c2) -> (op x, (op c1, c2))
      if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, L, R))
        return DAG.getNode(Opc, DL, VT, N0.getOperand(0), OpNode);
      return SDValue();
    }
    if (N0.hasOneUse()) {
      // reassoc. (op (op x, c1), y) -> (op (op x, y), c1) iff x+c1 has one
      // use
      SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0.getOperand(0), N1);
      if (!OpNode.getNode())
        return SDValue();
      AddToWorklist(OpNode.getNode());
      return DAG.getNode(Opc, DL, VT, OpNode, N0.getOperand(1));
    }
  }
}

if (N1.getOpcode() == Opc) {
  if (SDNode *R = DAG.isConstantIntBuildVectorOrConstantInt(N1.getOperand(1))) {
    if (SDNode *L = DAG.isConstantIntBuildVectorOrConstantInt(N0)) {
      // reassoc. (op c2, (op x, c1)) -> (op x, (op c1, c2))
      if (SDValue OpNode = DAG.FoldConstantArithmetic(Opc, DL, VT, R, L))
        return DAG.getNode(Opc, DL, VT, N1.getOperand(0), OpNode);
      return SDValue();
    }
    if (N1.hasOneUse()) {
      // reassoc. (op x, (op y, c1)) -> (op (op x, y), c1) iff x+c1 has one
      // use
      SDValue OpNode = DAG.getNode(Opc, SDLoc(N0), VT, N0, N1.getOperand(0));
      if (!OpNode.getNode())
        return SDValue();
      AddToWorklist(OpNode.getNode());
      return DAG.getNode(Opc, DL, VT, OpNode, N1.getOperand(1));
    }
  }
}

return SDValue();
1011}

1013SDValue DAGCombiner::CombineTo(SDNode *N, const SDValue *To, unsigned NumTo,
                             bool AddTo) {
assert(N->getNumValues() == NumTo && "Broken CombineTo call!")(static_cast <bool> (N->getNumValues() == NumTo &&
 "Broken CombineTo call!") ? void (0) : __assert_fail ("N->getNumValues() == NumTo && \"Broken CombineTo call!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1015, __extension__ __PRETTY_FUNCTION__));
++NodesCombined;
DEBUG(dbgs() << "\nReplacing.1 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.1 "; N->dump
(&DAG); dbgs() << "\nWith: "; To[0].getNode()->dump
(&DAG); dbgs() << " and " << NumTo-1 <<
 " other values\n"; } } while (false)
      N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.1 "; N->dump
(&DAG); dbgs() << "\nWith: "; To[0].getNode()->dump
(&DAG); dbgs() << " and " << NumTo-1 <<
 " other values\n"; } } while (false)
      dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.1 "; N->dump
(&DAG); dbgs() << "\nWith: "; To[0].getNode()->dump
(&DAG); dbgs() << " and " << NumTo-1 <<
 " other values\n"; } } while (false)
      To[0].getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.1 "; N->dump
(&DAG); dbgs() << "\nWith: "; To[0].getNode()->dump
(&DAG); dbgs() << " and " << NumTo-1 <<
 " other values\n"; } } while (false)
      dbgs() << " and " << NumTo-1 << " other values\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.1 "; N->dump
(&DAG); dbgs() << "\nWith: "; To[0].getNode()->dump
(&DAG); dbgs() << " and " << NumTo-1 <<
 " other values\n"; } } while (false);
for (unsigned i = 0, e = NumTo; i != e; ++i)
  assert((!To[i].getNode() ||(static_cast <bool> ((!To[i].getNode() || N->getValueType
(i) == To[i].getValueType()) && "Cannot combine value to value of different type!"
) ? void (0) : __assert_fail ("(!To[i].getNode() || N->getValueType(i) == To[i].getValueType()) && \"Cannot combine value to value of different type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1025, __extension__ __PRETTY_FUNCTION__))
          N->getValueType(i) == To[i].getValueType()) &&(static_cast <bool> ((!To[i].getNode() || N->getValueType
(i) == To[i].getValueType()) && "Cannot combine value to value of different type!"
) ? void (0) : __assert_fail ("(!To[i].getNode() || N->getValueType(i) == To[i].getValueType()) && \"Cannot combine value to value of different type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1025, __extension__ __PRETTY_FUNCTION__))
         "Cannot combine value to value of different type!")(static_cast <bool> ((!To[i].getNode() || N->getValueType
(i) == To[i].getValueType()) && "Cannot combine value to value of different type!"
) ? void (0) : __assert_fail ("(!To[i].getNode() || N->getValueType(i) == To[i].getValueType()) && \"Cannot combine value to value of different type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1025, __extension__ __PRETTY_FUNCTION__));

WorklistRemover DeadNodes(*this);
DAG.ReplaceAllUsesWith(N, To);
if (AddTo) {
  // Push the new nodes and any users onto the worklist
  for (unsigned i = 0, e = NumTo; i != e; ++i) {
    if (To[i].getNode()) {
      AddToWorklist(To[i].getNode());
      AddUsersToWorklist(To[i].getNode());
    }
  }
}

// Finally, if the node is now dead, remove it from the graph.  The node
// may not be dead if the replacement process recursively simplified to
// something else needing this node.
if (N->use_empty())
  deleteAndRecombine(N);
return SDValue(N, 0);
1045}

1047void DAGCombiner::
1048CommitTargetLoweringOpt(const TargetLowering::TargetLoweringOpt &TLO) {
// Replace all uses.  If any nodes become isomorphic to other nodes and
// are deleted, make sure to remove them from our worklist.
WorklistRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(TLO.Old, TLO.New);

// Push the new node and any (possibly new) users onto the worklist.
AddToWorklist(TLO.New.getNode());
AddUsersToWorklist(TLO.New.getNode());

// Finally, if the node is now dead, remove it from the graph.  The node
// may not be dead if the replacement process recursively simplified to
// something else needing this node.
if (TLO.Old.getNode()->use_empty())
  deleteAndRecombine(TLO.Old.getNode());
1063}

1065/// Check the specified integer node value to see if it can be simplified or if
1066/// things it uses can be simplified by bit propagation. If so, return true.
1067bool DAGCombiner::SimplifyDemandedBits(SDValue Op, const APInt &Demanded) {
TargetLowering::TargetLoweringOpt TLO(DAG, LegalTypes, LegalOperations);
KnownBits Known;
if (!TLI.SimplifyDemandedBits(Op, Demanded, Known, TLO))
  return false;

// Revisit the node.
AddToWorklist(Op.getNode());

// Replace the old value with the new one.
++NodesCombined;
DEBUG(dbgs() << "\nReplacing.2 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.2 "; TLO.Old.getNode
()->dump(&DAG); dbgs() << "\nWith: "; TLO.New.getNode
()->dump(&DAG); dbgs() << '\n'; } } while (false
)
      TLO.Old.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.2 "; TLO.Old.getNode
()->dump(&DAG); dbgs() << "\nWith: "; TLO.New.getNode
()->dump(&DAG); dbgs() << '\n'; } } while (false
)
      dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.2 "; TLO.Old.getNode
()->dump(&DAG); dbgs() << "\nWith: "; TLO.New.getNode
()->dump(&DAG); dbgs() << '\n'; } } while (false
)
      TLO.New.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.2 "; TLO.Old.getNode
()->dump(&DAG); dbgs() << "\nWith: "; TLO.New.getNode
()->dump(&DAG); dbgs() << '\n'; } } while (false
)
      dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.2 "; TLO.Old.getNode
()->dump(&DAG); dbgs() << "\nWith: "; TLO.New.getNode
()->dump(&DAG); dbgs() << '\n'; } } while (false
);

CommitTargetLoweringOpt(TLO);
return true;
1086}

1088void DAGCombiner::ReplaceLoadWithPromotedLoad(SDNode *Load, SDNode *ExtLoad) {
SDLoc DL(Load);
EVT VT = Load->getValueType(0);
SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, VT, SDValue(ExtLoad, 0));

DEBUG(dbgs() << "\nReplacing.9 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.9 "; Load->
dump(&DAG); dbgs() << "\nWith: "; Trunc.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      Load->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.9 "; Load->
dump(&DAG); dbgs() << "\nWith: "; Trunc.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.9 "; Load->
dump(&DAG); dbgs() << "\nWith: "; Trunc.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      Trunc.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.9 "; Load->
dump(&DAG); dbgs() << "\nWith: "; Trunc.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.9 "; Load->
dump(&DAG); dbgs() << "\nWith: "; Trunc.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false);
WorklistRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), Trunc);
DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 1), SDValue(ExtLoad, 1));
deleteAndRecombine(Load);
AddToWorklist(Trunc.getNode());
1103}

1105SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) {
Replace = false;
SDLoc DL(Op);
if (ISD::isUNINDEXEDLoad(Op.getNode())) {
  LoadSDNode *LD = cast<LoadSDNode>(Op);
  EVT MemVT = LD->getMemoryVT();
  ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
    ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
                                                     : ISD::EXTLOAD)
    : LD->getExtensionType();
  Replace = true;
  return DAG.getExtLoad(ExtType, DL, PVT,
                        LD->getChain(), LD->getBasePtr(),
                        MemVT, LD->getMemOperand());
}

unsigned Opc = Op.getOpcode();
switch (Opc) {
default: break;
case ISD::AssertSext:
  if (SDValue Op0 = SExtPromoteOperand(Op.getOperand(0), PVT))
    return DAG.getNode(ISD::AssertSext, DL, PVT, Op0, Op.getOperand(1));
  break;
case ISD::AssertZext:
  if (SDValue Op0 = ZExtPromoteOperand(Op.getOperand(0), PVT))
    return DAG.getNode(ISD::AssertZext, DL, PVT, Op0, Op.getOperand(1));
  break;
case ISD::Constant: {
  unsigned ExtOpc =
    Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
  return DAG.getNode(ExtOpc, DL, PVT, Op);
}
}

if (!TLI.isOperationLegal(ISD::ANY_EXTEND, PVT))
  return SDValue();
return DAG.getNode(ISD::ANY_EXTEND, DL, PVT, Op);
1142}

1144SDValue DAGCombiner::SExtPromoteOperand(SDValue Op, EVT PVT) {
if (!TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, PVT))
  return SDValue();
EVT OldVT = Op.getValueType();
SDLoc DL(Op);
bool Replace = false;
SDValue NewOp = PromoteOperand(Op, PVT, Replace);
if (!NewOp.getNode())
  return SDValue();
AddToWorklist(NewOp.getNode());

if (Replace)
  ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, NewOp.getValueType(), NewOp,
                   DAG.getValueType(OldVT));
1159}

1161SDValue DAGCombiner::ZExtPromoteOperand(SDValue Op, EVT PVT) {
EVT OldVT = Op.getValueType();
SDLoc DL(Op);
bool Replace = false;
SDValue NewOp = PromoteOperand(Op, PVT, Replace);
if (!NewOp.getNode())
  return SDValue();
AddToWorklist(NewOp.getNode());

if (Replace)
  ReplaceLoadWithPromotedLoad(Op.getNode(), NewOp.getNode());
return DAG.getZeroExtendInReg(NewOp, DL, OldVT);
1173}

1175/// Promote the specified integer binary operation if the target indicates it is
1176/// beneficial. e.g. On x86, it's usually better to promote i16 operations to
1177/// i32 since i16 instructions are longer.
1178SDValue DAGCombiner::PromoteIntBinOp(SDValue Op) {
if (!LegalOperations)
  return SDValue();

EVT VT = Op.getValueType();
if (VT.isVector() || !VT.isInteger())
  return SDValue();

// If operation type is 'undesirable', e.g. i16 on x86, consider
// promoting it.
unsigned Opc = Op.getOpcode();
if (TLI.isTypeDesirableForOp(Opc, VT))
  return SDValue();

EVT PVT = VT;
// Consult target whether it is a good idea to promote this operation and
// what's the right type to promote it to.
if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
  assert(PVT != VT && "Don't know what type to promote to!")(static_cast <bool> (PVT != VT && "Don't know what type to promote to!"
) ? void (0) : __assert_fail ("PVT != VT && \"Don't know what type to promote to!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1196, __extension__ __PRETTY_FUNCTION__));

  DEBUG(dbgs() << "\nPromoting "; Op.getNode()->dump(&DAG))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; Op.getNode(
)->dump(&DAG); } } while (false);

  bool Replace0 = false;
  SDValue N0 = Op.getOperand(0);
  SDValue NN0 = PromoteOperand(N0, PVT, Replace0);

  bool Replace1 = false;
  SDValue N1 = Op.getOperand(1);
  SDValue NN1 = PromoteOperand(N1, PVT, Replace1);
  SDLoc DL(Op);

  SDValue RV =
      DAG.getNode(ISD::TRUNCATE, DL, VT, DAG.getNode(Opc, DL, PVT, NN0, NN1));

  // We are always replacing N0/N1's use in N and only need
  // additional replacements if there are additional uses.
  Replace0 &= !N0->hasOneUse();
  Replace1 &= (N0 != N1) && !N1->hasOneUse();

  // Combine Op here so it is preserved past replacements.
  CombineTo(Op.getNode(), RV);

  // If operands have a use ordering, make sure we deal with
  // predecessor first.
  if (Replace0 && Replace1 && N0.getNode()->isPredecessorOf(N1.getNode())) {
    std::swap(N0, N1);
    std::swap(NN0, NN1);
  }

  if (Replace0) {
    AddToWorklist(NN0.getNode());
    ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());
  }
  if (Replace1) {
    AddToWorklist(NN1.getNode());
    ReplaceLoadWithPromotedLoad(N1.getNode(), NN1.getNode());
  }
  return Op;
}
return SDValue();
1238}

1240/// Promote the specified integer shift operation if the target indicates it is
1241/// beneficial. e.g. On x86, it's usually better to promote i16 operations to
1242/// i32 since i16 instructions are longer.
1243SDValue DAGCombiner::PromoteIntShiftOp(SDValue Op) {
if (!LegalOperations)
  return SDValue();

EVT VT = Op.getValueType();
if (VT.isVector() || !VT.isInteger())
  return SDValue();

// If operation type is 'undesirable', e.g. i16 on x86, consider
// promoting it.
unsigned Opc = Op.getOpcode();
if (TLI.isTypeDesirableForOp(Opc, VT))
  return SDValue();

EVT PVT = VT;
// Consult target whether it is a good idea to promote this operation and
// what's the right type to promote it to.
if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
  assert(PVT != VT && "Don't know what type to promote to!")(static_cast <bool> (PVT != VT && "Don't know what type to promote to!"
) ? void (0) : __assert_fail ("PVT != VT && \"Don't know what type to promote to!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1261, __extension__ __PRETTY_FUNCTION__));

  DEBUG(dbgs() << "\nPromoting "; Op.getNode()->dump(&DAG))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; Op.getNode(
)->dump(&DAG); } } while (false);

  bool Replace = false;
  SDValue N0 = Op.getOperand(0);
  SDValue N1 = Op.getOperand(1);
  if (Opc == ISD::SRA)
    N0 = SExtPromoteOperand(N0, PVT);
  else if (Opc == ISD::SRL)
    N0 = ZExtPromoteOperand(N0, PVT);
  else
    N0 = PromoteOperand(N0, PVT, Replace);

  if (!N0.getNode())
    return SDValue();

  SDLoc DL(Op);
  SDValue RV =
      DAG.getNode(ISD::TRUNCATE, DL, VT, DAG.getNode(Opc, DL, PVT, N0, N1));

  AddToWorklist(N0.getNode());
  if (Replace)
    ReplaceLoadWithPromotedLoad(Op.getOperand(0).getNode(), N0.getNode());

  // Deal with Op being deleted.
  if (Op && Op.getOpcode() != ISD::DELETED_NODE)
    return RV;
}
return SDValue();
1291}

1293SDValue DAGCombiner::PromoteExtend(SDValue Op) {
if (!LegalOperations)
  return SDValue();

EVT VT = Op.getValueType();
if (VT.isVector() || !VT.isInteger())
  return SDValue();

// If operation type is 'undesirable', e.g. i16 on x86, consider
// promoting it.
unsigned Opc = Op.getOpcode();
if (TLI.isTypeDesirableForOp(Opc, VT))
  return SDValue();

EVT PVT = VT;
// Consult target whether it is a good idea to promote this operation and
// what's the right type to promote it to.
if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
  assert(PVT != VT && "Don't know what type to promote to!")(static_cast <bool> (PVT != VT && "Don't know what type to promote to!"
) ? void (0) : __assert_fail ("PVT != VT && \"Don't know what type to promote to!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1311, __extension__ __PRETTY_FUNCTION__));
  // fold (aext (aext x)) -> (aext x)
  // fold (aext (zext x)) -> (zext x)
  // fold (aext (sext x)) -> (sext x)
  DEBUG(dbgs() << "\nPromoting ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; Op.getNode(
)->dump(&DAG); } } while (false)
        Op.getNode()->dump(&DAG))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; Op.getNode(
)->dump(&DAG); } } while (false);
  return DAG.getNode(Op.getOpcode(), SDLoc(Op), VT, Op.getOperand(0));
}
return SDValue();
1320}

1322bool DAGCombiner::PromoteLoad(SDValue Op) {
if (!LegalOperations)
  return false;

if (!ISD::isUNINDEXEDLoad(Op.getNode()))
  return false;

EVT VT = Op.getValueType();
if (VT.isVector() || !VT.isInteger())
  return false;

// If operation type is 'undesirable', e.g. i16 on x86, consider
// promoting it.
unsigned Opc = Op.getOpcode();
if (TLI.isTypeDesirableForOp(Opc, VT))
  return false;

EVT PVT = VT;
// Consult target whether it is a good idea to promote this operation and
// what's the right type to promote it to.
if (TLI.IsDesirableToPromoteOp(Op, PVT)) {
  assert(PVT != VT && "Don't know what type to promote to!")(static_cast <bool> (PVT != VT && "Don't know what type to promote to!"
) ? void (0) : __assert_fail ("PVT != VT && \"Don't know what type to promote to!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1343, __extension__ __PRETTY_FUNCTION__));

  SDLoc DL(Op);
  SDNode *N = Op.getNode();
  LoadSDNode *LD = cast<LoadSDNode>(N);
  EVT MemVT = LD->getMemoryVT();
  ISD::LoadExtType ExtType = ISD::isNON_EXTLoad(LD)
    ? (TLI.isLoadExtLegal(ISD::ZEXTLOAD, PVT, MemVT) ? ISD::ZEXTLOAD
                                                     : ISD::EXTLOAD)
    : LD->getExtensionType();
  SDValue NewLD = DAG.getExtLoad(ExtType, DL, PVT,
                                 LD->getChain(), LD->getBasePtr(),
                                 MemVT, LD->getMemOperand());
  SDValue Result = DAG.getNode(ISD::TRUNCATE, DL, VT, NewLD);

  DEBUG(dbgs() << "\nPromoting ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; N->dump(
&DAG); dbgs() << "\nTo: "; Result.getNode()->dump
(&DAG); dbgs() << '\n'; } } while (false)
        N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; N->dump(
&DAG); dbgs() << "\nTo: "; Result.getNode()->dump
(&DAG); dbgs() << '\n'; } } while (false)
        dbgs() << "\nTo: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; N->dump(
&DAG); dbgs() << "\nTo: "; Result.getNode()->dump
(&DAG); dbgs() << '\n'; } } while (false)
        Result.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; N->dump(
&DAG); dbgs() << "\nTo: "; Result.getNode()->dump
(&DAG); dbgs() << '\n'; } } while (false)
        dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nPromoting "; N->dump(
&DAG); dbgs() << "\nTo: "; Result.getNode()->dump
(&DAG); dbgs() << '\n'; } } while (false);
  WorklistRemover DeadNodes(*this);
  DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result);
  DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), NewLD.getValue(1));
  deleteAndRecombine(N);
  AddToWorklist(Result.getNode());
  return true;
}
return false;
1371}

1373/// \brief Recursively delete a node which has no uses and any operands for
1374/// which it is the only use.
1375///
1376/// Note that this both deletes the nodes and removes them from the worklist.
1377/// It also adds any nodes who have had a user deleted to the worklist as they
1378/// may now have only one use and subject to other combines.
1379bool DAGCombiner::recursivelyDeleteUnusedNodes(SDNode *N) {
if (!N->use_empty())
  return false;

SmallSetVector<SDNode *, 16> Nodes;
Nodes.insert(N);
do {
  N = Nodes.pop_back_val();
  if (!N)
    continue;

  if (N->use_empty()) {
    for (const SDValue &ChildN : N->op_values())
      Nodes.insert(ChildN.getNode());

    removeFromWorklist(N);
    DAG.DeleteNode(N);
  } else {
    AddToWorklist(N);
  }
} while (!Nodes.empty());
return true;
1401}

1403//===----------------------------------------------------------------------===//
1404//  Main DAG Combiner implementation
1405//===----------------------------------------------------------------------===//

1407void DAGCombiner::Run(CombineLevel AtLevel) {
// set the instance variables, so that the various visit routines may use it.
Level = AtLevel;
LegalOperations = Level >= AfterLegalizeVectorOps;
LegalTypes = Level >= AfterLegalizeTypes;

// Add all the dag nodes to the worklist.
for (SDNode &Node : DAG.allnodes())
  AddToWorklist(&Node);

// Create a dummy node (which is not added to allnodes), that adds a reference
// to the root node, preventing it from being deleted, and tracking any
// changes of the root.
HandleSDNode Dummy(DAG.getRoot());

// While the worklist isn't empty, find a node and try to combine it.
while (!WorklistMap.empty()) {
  SDNode *N;
  // The Worklist holds the SDNodes in order, but it may contain null entries.
  do {
    N = Worklist.pop_back_val();
  } while (!N);

  bool GoodWorklistEntry = WorklistMap.erase(N);
  (void)GoodWorklistEntry;
  assert(GoodWorklistEntry &&(static_cast <bool> (GoodWorklistEntry && "Found a worklist entry without a corresponding map entry!"
) ? void (0) : __assert_fail ("GoodWorklistEntry && \"Found a worklist entry without a corresponding map entry!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1433, __extension__ __PRETTY_FUNCTION__))
         "Found a worklist entry without a corresponding map entry!")(static_cast <bool> (GoodWorklistEntry && "Found a worklist entry without a corresponding map entry!"
) ? void (0) : __assert_fail ("GoodWorklistEntry && \"Found a worklist entry without a corresponding map entry!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1433, __extension__ __PRETTY_FUNCTION__));

  // If N has no uses, it is dead.  Make sure to revisit all N's operands once
  // N is deleted from the DAG, since they too may now be dead or may have a
  // reduced number of uses, allowing other xforms.
  if (recursivelyDeleteUnusedNodes(N))
    continue;

  WorklistRemover DeadNodes(*this);

  // If this combine is running after legalizing the DAG, re-legalize any
  // nodes pulled off the worklist.
  if (Level == AfterLegalizeDAG) {
    SmallSetVector<SDNode *, 16> UpdatedNodes;
    bool NIsValid = DAG.LegalizeOp(N, UpdatedNodes);

    for (SDNode *LN : UpdatedNodes) {
      AddToWorklist(LN);
      AddUsersToWorklist(LN);
    }
    if (!NIsValid)
      continue;
  }

  DEBUG(dbgs() << "\nCombining: "; N->dump(&DAG))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nCombining: "; N->dump
(&DAG); } } while (false);

  // Add any operands of the new node which have not yet been combined to the
  // worklist as well. Because the worklist uniques things already, this
  // won't repeatedly process the same operand.
  CombinedNodes.insert(N);
  for (const SDValue &ChildN : N->op_values())
    if (!CombinedNodes.count(ChildN.getNode()))
      AddToWorklist(ChildN.getNode());

  SDValue RV = combine(N);

  if (!RV.getNode())
    continue;

  ++NodesCombined;

  // If we get back the same node we passed in, rather than a new node or
  // zero, we know that the node must have defined multiple values and
  // CombineTo was used.  Since CombineTo takes care of the worklist
  // mechanics for us, we have no work to do in this case.
  if (RV.getNode() == N)
    continue;

  assert(N->getOpcode() != ISD::DELETED_NODE &&(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && RV.getOpcode() != ISD::DELETED_NODE && "Node was deleted but visit returned new node!"
) ? void (0) : __assert_fail ("N->getOpcode() != ISD::DELETED_NODE && RV.getOpcode() != ISD::DELETED_NODE && \"Node was deleted but visit returned new node!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1483, __extension__ __PRETTY_FUNCTION__))
         RV.getOpcode() != ISD::DELETED_NODE &&(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && RV.getOpcode() != ISD::DELETED_NODE && "Node was deleted but visit returned new node!"
) ? void (0) : __assert_fail ("N->getOpcode() != ISD::DELETED_NODE && RV.getOpcode() != ISD::DELETED_NODE && \"Node was deleted but visit returned new node!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1483, __extension__ __PRETTY_FUNCTION__))
         "Node was deleted but visit returned new node!")(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && RV.getOpcode() != ISD::DELETED_NODE && "Node was deleted but visit returned new node!"
) ? void (0) : __assert_fail ("N->getOpcode() != ISD::DELETED_NODE && RV.getOpcode() != ISD::DELETED_NODE && \"Node was deleted but visit returned new node!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1483, __extension__ __PRETTY_FUNCTION__));

  DEBUG(dbgs() << " ... into: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << " ... into: "; RV.getNode()
->dump(&DAG); } } while (false)
        RV.getNode()->dump(&DAG))do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << " ... into: "; RV.getNode()
->dump(&DAG); } } while (false);

  if (N->getNumValues() == RV.getNode()->getNumValues())
    DAG.ReplaceAllUsesWith(N, RV.getNode());
  else {
    assert(N->getValueType(0) == RV.getValueType() &&(static_cast <bool> (N->getValueType(0) == RV.getValueType
() && N->getNumValues() == 1 && "Type mismatch"
) ? void (0) : __assert_fail ("N->getValueType(0) == RV.getValueType() && N->getNumValues() == 1 && \"Type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1492, __extension__ __PRETTY_FUNCTION__))
           N->getNumValues() == 1 && "Type mismatch")(static_cast <bool> (N->getValueType(0) == RV.getValueType
() && N->getNumValues() == 1 && "Type mismatch"
) ? void (0) : __assert_fail ("N->getValueType(0) == RV.getValueType() && N->getNumValues() == 1 && \"Type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1492, __extension__ __PRETTY_FUNCTION__));
    DAG.ReplaceAllUsesWith(N, &RV);
  }

  // Push the new node and any users onto the worklist
  AddToWorklist(RV.getNode());
  AddUsersToWorklist(RV.getNode());

  // Finally, if the node is now dead, remove it from the graph.  The node
  // may not be dead if the replacement process recursively simplified to
  // something else needing this node. This will also take care of adding any
  // operands which have lost a user to the worklist.
  recursivelyDeleteUnusedNodes(N);
}

// If the root changed (e.g. it was a dead load, update the root).
DAG.setRoot(Dummy.getValue());
DAG.RemoveDeadNodes();
1510}

1512SDValue DAGCombiner::visit(SDNode *N) {
switch (N->getOpcode()) {
default: break;
case ISD::TokenFactor:        return visitTokenFactor(N);
case ISD::MERGE_VALUES:       return visitMERGE_VALUES(N);
case ISD::ADD:                return visitADD(N);
case ISD::SUB:                return visitSUB(N);
case ISD::ADDC:               return visitADDC(N);
case ISD::UADDO:              return visitUADDO(N);
case ISD::SUBC:               return visitSUBC(N);
case ISD::USUBO:              return visitUSUBO(N);
case ISD::ADDE:               return visitADDE(N);
case ISD::ADDCARRY:           return visitADDCARRY(N);
case ISD::SUBE:               return visitSUBE(N);
case ISD::SUBCARRY:           return visitSUBCARRY(N);
case ISD::MUL:                return visitMUL(N);
case ISD::SDIV:               return visitSDIV(N);
case ISD::UDIV:               return visitUDIV(N);
case ISD::SREM:
case ISD::UREM:               return visitREM(N);
case ISD::MULHU:              return visitMULHU(N);
case ISD::MULHS:              return visitMULHS(N);
case ISD::SMUL_LOHI:          return visitSMUL_LOHI(N);
case ISD::UMUL_LOHI:          return visitUMUL_LOHI(N);
case ISD::SMULO:              return visitSMULO(N);
case ISD::UMULO:              return visitUMULO(N);
case ISD::SMIN:
case ISD::SMAX:
case ISD::UMIN:
case ISD::UMAX:               return visitIMINMAX(N);
case ISD::AND:                return visitAND(N);
case ISD::OR:                 return visitOR(N);
case ISD::XOR:                return visitXOR(N);
case ISD::SHL:                return visitSHL(N);
case ISD::SRA:                return visitSRA(N);
case ISD::SRL:                return visitSRL(N);
case ISD::ROTR:
case ISD::ROTL:               return visitRotate(N);
case ISD::ABS:                return visitABS(N);
case ISD::BSWAP:              return visitBSWAP(N);
case ISD::BITREVERSE:         return visitBITREVERSE(N);
case ISD::CTLZ:               return visitCTLZ(N);
case ISD::CTLZ_ZERO_UNDEF:    return visitCTLZ_ZERO_UNDEF(N);
case ISD::CTTZ:               return visitCTTZ(N);
case ISD::CTTZ_ZERO_UNDEF:    return visitCTTZ_ZERO_UNDEF(N);
case ISD::CTPOP:              return visitCTPOP(N);
case ISD::SELECT:             return visitSELECT(N);
case ISD::VSELECT:            return visitVSELECT(N);
case ISD::SELECT_CC:          return visitSELECT_CC(N);
case ISD::SETCC:              return visitSETCC(N);
case ISD::SETCCE:             return visitSETCCE(N);
case ISD::SETCCCARRY:         return visitSETCCCARRY(N);
case ISD::SIGN_EXTEND:        return visitSIGN_EXTEND(N);
case ISD::ZERO_EXTEND:        return visitZERO_EXTEND(N);
case ISD::ANY_EXTEND:         return visitANY_EXTEND(N);
case ISD::AssertSext:
case ISD::AssertZext:         return visitAssertExt(N);
case ISD::SIGN_EXTEND_INREG:  return visitSIGN_EXTEND_INREG(N);
case ISD::SIGN_EXTEND_VECTOR_INREG: return visitSIGN_EXTEND_VECTOR_INREG(N);
case ISD::ZERO_EXTEND_VECTOR_INREG: return visitZERO_EXTEND_VECTOR_INREG(N);
case ISD::TRUNCATE:           return visitTRUNCATE(N);
case ISD::BITCAST:            return visitBITCAST(N);
case ISD::BUILD_PAIR:         return visitBUILD_PAIR(N);
case ISD::FADD:               return visitFADD(N);
case ISD::FSUB:               return visitFSUB(N);
case ISD::FMUL:               return visitFMUL(N);
case ISD::FMA:                return visitFMA(N);
case ISD::FDIV:               return visitFDIV(N);
case ISD::FREM:               return visitFREM(N);
case ISD::FSQRT:              return visitFSQRT(N);
case ISD::FCOPYSIGN:          return visitFCOPYSIGN(N);
case ISD::SINT_TO_FP:         return visitSINT_TO_FP(N);
case ISD::UINT_TO_FP:         return visitUINT_TO_FP(N);
case ISD::FP_TO_SINT:         return visitFP_TO_SINT(N);
case ISD::FP_TO_UINT:         return visitFP_TO_UINT(N);
case ISD::FP_ROUND:           return visitFP_ROUND(N);
case ISD::FP_ROUND_INREG:     return visitFP_ROUND_INREG(N);
case ISD::FP_EXTEND:          return visitFP_EXTEND(N);
case ISD::FNEG:               return visitFNEG(N);
case ISD::FABS:               return visitFABS(N);
case ISD::FFLOOR:             return visitFFLOOR(N);
case ISD::FMINNUM:            return visitFMINNUM(N);
case ISD::FMAXNUM:            return visitFMAXNUM(N);
case ISD::FCEIL:              return visitFCEIL(N);
case ISD::FTRUNC:             return visitFTRUNC(N);
case ISD::BRCOND:             return visitBRCOND(N);
case ISD::BR_CC:              return visitBR_CC(N);
case ISD::LOAD:               return visitLOAD(N);
case ISD::STORE:              return visitSTORE(N);
case ISD::INSERT_VECTOR_ELT:  return visitINSERT_VECTOR_ELT(N);
case ISD::EXTRACT_VECTOR_ELT: return visitEXTRACT_VECTOR_ELT(N);
case ISD::BUILD_VECTOR:       return visitBUILD_VECTOR(N);
case ISD::CONCAT_VECTORS:     return visitCONCAT_VECTORS(N);
case ISD::EXTRACT_SUBVECTOR:  return visitEXTRACT_SUBVECTOR(N);
case ISD::VECTOR_SHUFFLE:     return visitVECTOR_SHUFFLE(N);
case ISD::SCALAR_TO_VECTOR:   return visitSCALAR_TO_VECTOR(N);
case ISD::INSERT_SUBVECTOR:   return visitINSERT_SUBVECTOR(N);
case ISD::MGATHER:            return visitMGATHER(N);
case ISD::MLOAD:              return visitMLOAD(N);
case ISD::MSCATTER:           return visitMSCATTER(N);
case ISD::MSTORE:             return visitMSTORE(N);
case ISD::FP_TO_FP16:         return visitFP_TO_FP16(N);
case ISD::FP16_TO_FP:         return visitFP16_TO_FP(N);
}
return SDValue();
1617}

1619SDValue DAGCombiner::combine(SDNode *N) {
SDValue RV = visit(N);

// If nothing happened, try a target-specific DAG combine.
if (!RV.getNode()) {
  assert(N->getOpcode() != ISD::DELETED_NODE &&(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && "Node was deleted but visit returned NULL!") ? void
 (0) : __assert_fail ("N->getOpcode() != ISD::DELETED_NODE && \"Node was deleted but visit returned NULL!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1625, __extension__ __PRETTY_FUNCTION__))
         "Node was deleted but visit returned NULL!")(static_cast <bool> (N->getOpcode() != ISD::DELETED_NODE
 && "Node was deleted but visit returned NULL!") ? void
 (0) : __assert_fail ("N->getOpcode() != ISD::DELETED_NODE && \"Node was deleted but visit returned NULL!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1625, __extension__ __PRETTY_FUNCTION__));

  if (N->getOpcode() >= ISD::BUILTIN_OP_END ||
      TLI.hasTargetDAGCombine((ISD::NodeType)N->getOpcode())) {

    // Expose the DAG combiner to the target combiner impls.
    TargetLowering::DAGCombinerInfo
      DagCombineInfo(DAG, Level, false, this);

    RV = TLI.PerformDAGCombine(N, DagCombineInfo);
  }
}

// If nothing happened still, try promoting the operation.
if (!RV.getNode()) {
  switch (N->getOpcode()) {
  default: break;
  case ISD::ADD:
  case ISD::SUB:
  case ISD::MUL:
  case ISD::AND:
  case ISD::OR:
  case ISD::XOR:
    RV = PromoteIntBinOp(SDValue(N, 0));
    break;
  case ISD::SHL:
  case ISD::SRA:
  case ISD::SRL:
    RV = PromoteIntShiftOp(SDValue(N, 0));
    break;
  case ISD::SIGN_EXTEND:
  case ISD::ZERO_EXTEND:
  case ISD::ANY_EXTEND:
    RV = PromoteExtend(SDValue(N, 0));
    break;
  case ISD::LOAD:
    if (PromoteLoad(SDValue(N, 0)))
      RV = SDValue(N, 0);
    break;
  }
}

// If N is a commutative binary node, try eliminate it if the commuted
// version is already present in the DAG.
if (!RV.getNode() && TLI.isCommutativeBinOp(N->getOpcode()) &&
    N->getNumValues() == 1) {
  SDValue N0 = N->getOperand(0);
  SDValue N1 = N->getOperand(1);

  // Constant operands are canonicalized to RHS.
  if (N0 != N1 && (isa<ConstantSDNode>(N0) || !isa<ConstantSDNode>(N1))) {
    SDValue Ops[] = {N1, N0};
    SDNode *CSENode = DAG.getNodeIfExists(N->getOpcode(), N->getVTList(), Ops,
                                          N->getFlags());
    if (CSENode)
      return SDValue(CSENode, 0);
  }
}

return RV;
1685}

1687/// Given a node, return its input chain if it has one, otherwise return a null
1688/// sd operand.
1689static SDValue getInputChainForNode(SDNode *N) {
if (unsigned NumOps = N->getNumOperands()) {
  if (N->getOperand(0).getValueType() == MVT::Other)
    return N->getOperand(0);
  if (N->getOperand(NumOps-1).getValueType() == MVT::Other)
    return N->getOperand(NumOps-1);
  for (unsigned i = 1; i < NumOps-1; ++i)
    if (N->getOperand(i).getValueType() == MVT::Other)
      return N->getOperand(i);
}
return SDValue();
1700}

1702SDValue DAGCombiner::visitTokenFactor(SDNode *N) {
// If N has two operands, where one has an input chain equal to the other,
// the 'other' chain is redundant.
if (N->getNumOperands() == 2) {
  if (getInputChainForNode(N->getOperand(0).getNode()) == N->getOperand(1))
    return N->getOperand(0);
  if (getInputChainForNode(N->getOperand(1).getNode()) == N->getOperand(0))
    return N->getOperand(1);
}

SmallVector<SDNode *, 8> TFs;     // List of token factors to visit.
SmallVector<SDValue, 8> Ops;      // Ops for replacing token factor.
SmallPtrSet<SDNode*, 16> SeenOps;
bool Changed = false;             // If we should replace this token factor.

// Start out with this token factor.
TFs.push_back(N);

// Iterate through token factors.  The TFs grows when new token factors are
// encountered.
for (unsigned i = 0; i < TFs.size(); ++i) {
  SDNode *TF = TFs[i];

  // Check each of the operands.
  for (const SDValue &Op : TF->op_values()) {
    switch (Op.getOpcode()) {
    case ISD::EntryToken:
      // Entry tokens don't need to be added to the list. They are
      // redundant.
      Changed = true;
      break;

    case ISD::TokenFactor:
      if (Op.hasOneUse() && !is_contained(TFs, Op.getNode())) {
        // Queue up for processing.
        TFs.push_back(Op.getNode());
        // Clean up in case the token factor is removed.
        AddToWorklist(Op.getNode());
        Changed = true;
        break;
      }
      LLVM_FALLTHROUGH[[clang::fallthrough]];

    default:
      // Only add if it isn't already in the list.
      if (SeenOps.insert(Op.getNode()).second)
        Ops.push_back(Op);
      else
        Changed = true;
      break;
    }
  }
}

// Remove Nodes that are chained to another node in the list. Do so
// by walking up chains breath-first stopping when we've seen
// another operand. In general we must climb to the EntryNode, but we can exit
// early if we find all remaining work is associated with just one operand as
// no further pruning is possible.

// List of nodes to search through and original Ops from which they originate.
SmallVector<std::pair<SDNode *, unsigned>, 8> Worklist;
SmallVector<unsigned, 8> OpWorkCount; // Count of work for each Op.
SmallPtrSet<SDNode *, 16> SeenChains;
bool DidPruneOps = false;

unsigned NumLeftToConsider = 0;
for (const SDValue &Op : Ops) {
  Worklist.push_back(std::make_pair(Op.getNode(), NumLeftToConsider++));
  OpWorkCount.push_back(1);
}

auto AddToWorklist = [&](unsigned CurIdx, SDNode *Op, unsigned OpNumber) {
  // If this is an Op, we can remove the op from the list. Remark any
  // search associated with it as from the current OpNumber.
  if (SeenOps.count(Op) != 0) {
    Changed = true;
    DidPruneOps = true;
    unsigned OrigOpNumber = 0;
    while (OrigOpNumber < Ops.size() && Ops[OrigOpNumber].getNode() != Op)
      OrigOpNumber++;
    assert((OrigOpNumber != Ops.size()) &&(static_cast <bool> ((OrigOpNumber != Ops.size()) &&
 "expected to find TokenFactor Operand") ? void (0) : __assert_fail
 ("(OrigOpNumber != Ops.size()) && \"expected to find TokenFactor Operand\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1784, __extension__ __PRETTY_FUNCTION__))
           "expected to find TokenFactor Operand")(static_cast <bool> ((OrigOpNumber != Ops.size()) &&
 "expected to find TokenFactor Operand") ? void (0) : __assert_fail
 ("(OrigOpNumber != Ops.size()) && \"expected to find TokenFactor Operand\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1784, __extension__ __PRETTY_FUNCTION__));
    // Re-mark worklist from OrigOpNumber to OpNumber
    for (unsigned i = CurIdx + 1; i < Worklist.size(); ++i) {
      if (Worklist[i].second == OrigOpNumber) {
        Worklist[i].second = OpNumber;
      }
    }
    OpWorkCount[OpNumber] += OpWorkCount[OrigOpNumber];
    OpWorkCount[OrigOpNumber] = 0;
    NumLeftToConsider--;
  }
  // Add if it's a new chain
  if (SeenChains.insert(Op).second) {
    OpWorkCount[OpNumber]++;
    Worklist.push_back(std::make_pair(Op, OpNumber));
  }
};

for (unsigned i = 0; i < Worklist.size() && i < 1024; ++i) {
  // We need at least be consider at least 2 Ops to prune.
  if (NumLeftToConsider <= 1)
    break;
  auto CurNode = Worklist[i].first;
  auto CurOpNumber = Worklist[i].second;
  assert((OpWorkCount[CurOpNumber] > 0) &&(static_cast <bool> ((OpWorkCount[CurOpNumber] > 0) &&
 "Node should not appear in worklist") ? void (0) : __assert_fail
 ("(OpWorkCount[CurOpNumber] > 0) && \"Node should not appear in worklist\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1809, __extension__ __PRETTY_FUNCTION__))
         "Node should not appear in worklist")(static_cast <bool> ((OpWorkCount[CurOpNumber] > 0) &&
 "Node should not appear in worklist") ? void (0) : __assert_fail
 ("(OpWorkCount[CurOpNumber] > 0) && \"Node should not appear in worklist\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1809, __extension__ __PRETTY_FUNCTION__));
  switch (CurNode->getOpcode()) {
  case ISD::EntryToken:
    // Hitting EntryToken is the only way for the search to terminate without
    // hitting
    // another operand's search. Prevent us from marking this operand
    // considered.
    NumLeftToConsider++;
    break;
  case ISD::TokenFactor:
    for (const SDValue &Op : CurNode->op_values())
      AddToWorklist(i, Op.getNode(), CurOpNumber);
    break;
  case ISD::CopyFromReg:
  case ISD::CopyToReg:
    AddToWorklist(i, CurNode->getOperand(0).getNode(), CurOpNumber);
    break;
  default:
    if (auto *MemNode = dyn_cast<MemSDNode>(CurNode))
      AddToWorklist(i, MemNode->getChain().getNode(), CurOpNumber);
    break;
  }
  OpWorkCount[CurOpNumber]--;
  if (OpWorkCount[CurOpNumber] == 0)
    NumLeftToConsider--;
}

// If we've changed things around then replace token factor.
if (Changed) {
  SDValue Result;
  if (Ops.empty()) {
    // The entry token is the only possible outcome.
    Result = DAG.getEntryNode();
  } else {
    if (DidPruneOps) {
      SmallVector<SDValue, 8> PrunedOps;
      //
      for (const SDValue &Op : Ops) {
        if (SeenChains.count(Op.getNode()) == 0)
          PrunedOps.push_back(Op);
      }
      Result = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, PrunedOps);
    } else {
      Result = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Ops);
    }
  }
  return Result;
}
return SDValue();
1858}

1860/// MERGE_VALUES can always be eliminated.
1861SDValue DAGCombiner::visitMERGE_VALUES(SDNode *N) {
WorklistRemover DeadNodes(*this);
// Replacing results may cause a different MERGE_VALUES to suddenly
// be CSE'd with N, and carry its uses with it. Iterate until no
// uses remain, to ensure that the node can be safely deleted.
// First add the users of this node to the work list so that they
// can be tried again once they have new operands.
AddUsersToWorklist(N);
do {
  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
    DAG.ReplaceAllUsesOfValueWith(SDValue(N, i), N->getOperand(i));
} while (!N->use_empty());
deleteAndRecombine(N);
return SDValue(N, 0);   // Return N so it doesn't get rechecked!
1875}

1877/// If \p N is a ConstantSDNode with isOpaque() == false return it casted to a
1878/// ConstantSDNode pointer else nullptr.
1879static ConstantSDNode *getAsNonOpaqueConstant(SDValue N) {
ConstantSDNode *Const = dyn_cast<ConstantSDNode>(N);
return Const != nullptr && !Const->isOpaque() ? Const : nullptr;
1882}

1884SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
auto BinOpcode = BO->getOpcode();
assert((BinOpcode == ISD::ADD || BinOpcode == ISD::SUB ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::UREM || BinOpcode == ISD::AND ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::OR || BinOpcode == ISD::XOR ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::SHL || BinOpcode == ISD::SRL ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::SRA || BinOpcode == ISD::FADD ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL ||(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
        BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) &&(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__))
       "Unexpected binary operator")(static_cast <bool> ((BinOpcode == ISD::ADD || BinOpcode
 == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV
 || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode
 == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR
 || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode
 == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD
 || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode
 == ISD::FDIV || BinOpcode == ISD::FREM) && "Unexpected binary operator"
) ? void (0) : __assert_fail ("(BinOpcode == ISD::ADD || BinOpcode == ISD::SUB || BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV || BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM || BinOpcode == ISD::UREM || BinOpcode == ISD::AND || BinOpcode == ISD::OR || BinOpcode == ISD::XOR || BinOpcode == ISD::SHL || BinOpcode == ISD::SRL || BinOpcode == ISD::SRA || BinOpcode == ISD::FADD || BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL || BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) && \"Unexpected binary operator\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 1895, __extension__ __PRETTY_FUNCTION__));

// Bail out if any constants are opaque because we can't constant fold those.
SDValue C1 = BO->getOperand(1);
if (!isConstantOrConstantVector(C1, true) &&
    !isConstantFPBuildVectorOrConstantFP(C1))
  return SDValue();

// Don't do this unless the old select is going away. We want to eliminate the
// binary operator, not replace a binop with a select.
// TODO: Handle ISD::SELECT_CC.
SDValue Sel = BO->getOperand(0);
if (Sel.getOpcode() != ISD::SELECT || !Sel.hasOneUse())
  return SDValue();

SDValue CT = Sel.getOperand(1);
if (!isConstantOrConstantVector(CT, true) &&
    !isConstantFPBuildVectorOrConstantFP(CT))
  return SDValue();

SDValue CF = Sel.getOperand(2);
if (!isConstantOrConstantVector(CF, true) &&
    !isConstantFPBuildVectorOrConstantFP(CF))
  return SDValue();

// We have a select-of-constants followed by a binary operator with a
// constant. Eliminate the binop by pulling the constant math into the select.
// Example: add (select Cond, CT, CF), C1 --> select Cond, CT + C1, CF + C1
EVT VT = Sel.getValueType();
SDLoc DL(Sel);
SDValue NewCT = DAG.getNode(BinOpcode, DL, VT, CT, C1);
if (!NewCT.isUndef() &&
    !isConstantOrConstantVector(NewCT, true) &&
    !isConstantFPBuildVectorOrConstantFP(NewCT))
  return SDValue();

SDValue NewCF = DAG.getNode(BinOpcode, DL, VT, CF, C1);
if (!NewCF.isUndef() &&
    !isConstantOrConstantVector(NewCF, true) &&
    !isConstantFPBuildVectorOrConstantFP(NewCF))
  return SDValue();

return DAG.getSelect(DL, VT, Sel.getOperand(0), NewCT, NewCF);
1938}

1940SDValue DAGCombiner::visitADD(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
SDLoc DL(N);

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  // fold (add x, 0) -> x, vector edition
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N0;
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    return N1;
}

// fold (add x, undef) -> undef
if (N0.isUndef())
  return N0;

if (N1.isUndef())
  return N1;

if (DAG.isConstantIntBuildVectorOrConstantInt(N0)) {
  // canonicalize constant to RHS
  if (!DAG.isConstantIntBuildVectorOrConstantInt(N1))
    return DAG.getNode(ISD::ADD, DL, VT, N1, N0);
  // fold (add c1, c2) -> c1+c2
  return DAG.FoldConstantArithmetic(ISD::ADD, DL, VT, N0.getNode(),
                                    N1.getNode());
}

// fold (add x, 0) -> x
if (isNullConstant(N1))
  return N0;

if (isConstantOrConstantVector(N1, /* NoOpaque */ true)) {
  // fold ((c1-A)+c2) -> (c1+c2)-A
  if (N0.getOpcode() == ISD::SUB &&
      isConstantOrConstantVector(N0.getOperand(0), /* NoOpaque */ true)) {
    // FIXME: Adding 2 constants should be handled by FoldConstantArithmetic.
    return DAG.getNode(ISD::SUB, DL, VT,
                       DAG.getNode(ISD::ADD, DL, VT, N1, N0.getOperand(0)),
                       N0.getOperand(1));
  }

  // add (sext i1 X), 1 -> zext (not i1 X)
  // We don't transform this pattern:
  //   add (zext i1 X), -1 -> sext (not i1 X)
  // because most (?) targets generate better code for the zext form.
  if (N0.getOpcode() == ISD::SIGN_EXTEND && N0.hasOneUse() &&
      isOneConstantOrOneSplatConstant(N1)) {
    SDValue X = N0.getOperand(0);
    if ((!LegalOperations ||
         (TLI.isOperationLegal(ISD::XOR, X.getValueType()) &&
          TLI.isOperationLegal(ISD::ZERO_EXTEND, VT))) &&
        X.getScalarValueSizeInBits() == 1) {
      SDValue Not = DAG.getNOT(DL, X, X.getValueType());
      return DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Not);
    }
  }

  // Undo the add -> or combine to merge constant offsets from a frame index.
  if (N0.getOpcode() == ISD::OR &&
      isa<FrameIndexSDNode>(N0.getOperand(0)) &&
      isa<ConstantSDNode>(N0.getOperand(1)) &&
      DAG.haveNoCommonBitsSet(N0.getOperand(0), N0.getOperand(1))) {
    SDValue Add0 = DAG.getNode(ISD::ADD, DL, VT, N1, N0.getOperand(1));
    return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0), Add0);
  }
}

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// reassociate add
if (SDValue RADD = ReassociateOps(ISD::ADD, DL, N0, N1))
  return RADD;

// fold ((0-A) + B) -> B-A
if (N0.getOpcode() == ISD::SUB &&
    isNullConstantOrNullSplatConstant(N0.getOperand(0)))
  return DAG.getNode(ISD::SUB, DL, VT, N1, N0.getOperand(1));

// fold (A + (0-B)) -> A-B
if (N1.getOpcode() == ISD::SUB &&
    isNullConstantOrNullSplatConstant(N1.getOperand(0)))
  return DAG.getNode(ISD::SUB, DL, VT, N0, N1.getOperand(1));

// fold (A+(B-A)) -> B
if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(1))
  return N1.getOperand(0);

// fold ((B-A)+A) -> B
if (N0.getOpcode() == ISD::SUB && N1 == N0.getOperand(1))
  return N0.getOperand(0);

// fold (A+(B-(A+C))) to (B-C)
if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
    N0 == N1.getOperand(1).getOperand(0))
  return DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(0),
                     N1.getOperand(1).getOperand(1));

// fold (A+(B-(C+A))) to (B-C)
if (N1.getOpcode() == ISD::SUB && N1.getOperand(1).getOpcode() == ISD::ADD &&
    N0 == N1.getOperand(1).getOperand(1))
  return DAG.getNode(ISD::SUB, DL, VT, N1.getOperand(0),
                     N1.getOperand(1).getOperand(0));

// fold (A+((B-A)+or-C)) to (B+or-C)
if ((N1.getOpcode() == ISD::SUB || N1.getOpcode() == ISD::ADD) &&
    N1.getOperand(0).getOpcode() == ISD::SUB &&
    N0 == N1.getOperand(0).getOperand(1))
  return DAG.getNode(N1.getOpcode(), DL, VT, N1.getOperand(0).getOperand(0),
                     N1.getOperand(1));

// fold (A-B)+(C-D) to (A+C)-(B+D) when A or C is constant
if (N0.getOpcode() == ISD::SUB && N1.getOpcode() == ISD::SUB) {
  SDValue N00 = N0.getOperand(0);
  SDValue N01 = N0.getOperand(1);
  SDValue N10 = N1.getOperand(0);
  SDValue N11 = N1.getOperand(1);

  if (isConstantOrConstantVector(N00) || isConstantOrConstantVector(N10))
    return DAG.getNode(ISD::SUB, DL, VT,
                       DAG.getNode(ISD::ADD, SDLoc(N0), VT, N00, N10),
                       DAG.getNode(ISD::ADD, SDLoc(N1), VT, N01, N11));
}

if (SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// fold (a+b) -> (a|b) iff a and b share no bits.
if ((!LegalOperations || TLI.isOperationLegal(ISD::OR, VT)) &&
    DAG.haveNoCommonBitsSet(N0, N1))
  return DAG.getNode(ISD::OR, DL, VT, N0, N1);

if (SDValue Combined = visitADDLike(N0, N1, N))
  return Combined;

if (SDValue Combined = visitADDLike(N1, N0, N))
  return Combined;

return SDValue();
2086}

2088static SDValue getAsCarry(const TargetLowering &TLI, SDValue V) {
bool Masked = false;

// First, peel away TRUNCATE/ZERO_EXTEND/AND nodes due to legalization.
while (true) {
  if (V.getOpcode() == ISD::TRUNCATE || V.getOpcode() == ISD::ZERO_EXTEND) {
    V = V.getOperand(0);
    continue;
  }

  if (V.getOpcode() == ISD::AND && isOneConstant(V.getOperand(1))) {
    Masked = true;
    V = V.getOperand(0);
    continue;
  }

  break;
}

// If this is not a carry, return.
if (V.getResNo() != 1)
  return SDValue();

if (V.getOpcode() != ISD::ADDCARRY && V.getOpcode() != ISD::SUBCARRY &&
    V.getOpcode() != ISD::UADDO && V.getOpcode() != ISD::USUBO)
  return SDValue();

// If the result is masked, then no matter what kind of bool it is we can
// return. If it isn't, then we need to make sure the bool type is either 0 or
// 1 and not other values.
if (Masked ||
    TLI.getBooleanContents(V.getValueType()) ==
        TargetLoweringBase::ZeroOrOneBooleanContent)
  return V;

return SDValue();
2124}

2126SDValue DAGCombiner::visitADDLike(SDValue N0, SDValue N1, SDNode *LocReference) {
EVT VT = N0.getValueType();
SDLoc DL(LocReference);

// fold (add x, shl(0 - y, n)) -> sub(x, shl(y, n))
if (N1.getOpcode() == ISD::SHL && N1.getOperand(0).getOpcode() == ISD::SUB &&
    isNullConstantOrNullSplatConstant(N1.getOperand(0).getOperand(0)))
  return DAG.getNode(ISD::SUB, DL, VT, N0,
                     DAG.getNode(ISD::SHL, DL, VT,
                                 N1.getOperand(0).getOperand(1),
                                 N1.getOperand(1)));

if (N1.getOpcode() == ISD::AND) {
  SDValue AndOp0 = N1.getOperand(0);
  unsigned NumSignBits = DAG.ComputeNumSignBits(AndOp0);
  unsigned DestBits = VT.getScalarSizeInBits();

  // (add z, (and (sbbl x, x), 1)) -> (sub z, (sbbl x, x))
  // and similar xforms where the inner op is either ~0 or 0.
  if (NumSignBits == DestBits &&
      isOneConstantOrOneSplatConstant(N1->getOperand(1)))
    return DAG.getNode(ISD::SUB, DL, VT, N0, AndOp0);
}

// add (sext i1), X -> sub X, (zext i1)
if (N0.getOpcode() == ISD::SIGN_EXTEND &&
    N0.getOperand(0).getValueType() == MVT::i1 &&
    !TLI.isOperationLegal(ISD::SIGN_EXTEND, MVT::i1)) {
  SDValue ZExt = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0));
  return DAG.getNode(ISD::SUB, DL, VT, N1, ZExt);
}

// add X, (sextinreg Y i1) -> sub X, (and Y 1)
if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
  VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
  if (TN->getVT() == MVT::i1) {
    SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
                               DAG.getConstant(1, DL, VT));
    return DAG.getNode(ISD::SUB, DL, VT, N0, ZExt);
  }
}

// (add X, (addcarry Y, 0, Carry)) -> (addcarry X, Y, Carry)
if (N1.getOpcode() == ISD::ADDCARRY && isNullConstant(N1.getOperand(1)) &&
    N1.getResNo() == 0)
  return DAG.getNode(ISD::ADDCARRY, DL, N1->getVTList(),
                     N0, N1.getOperand(0), N1.getOperand(2));

// (add X, Carry) -> (addcarry X, 0, Carry)
if (TLI.isOperationLegalOrCustom(ISD::ADDCARRY, VT))
  if (SDValue Carry = getAsCarry(TLI, N1))
    return DAG.getNode(ISD::ADDCARRY, DL,
                       DAG.getVTList(VT, Carry.getValueType()), N0,
                       DAG.getConstant(0, DL, VT), Carry);

return SDValue();
2182}

2184SDValue DAGCombiner::visitADDC(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
SDLoc DL(N);

// If the flag result is dead, turn this into an ADD.
if (!N->hasAnyUseOfValue(1))
  return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1),
                   DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

// canonicalize constant to RHS.
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
if (N0C && !N1C)
  return DAG.getNode(ISD::ADDC, DL, N->getVTList(), N1, N0);

// fold (addc x, 0) -> x + no carry out
if (isNullConstant(N1))
  return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE,
                                      DL, MVT::Glue));

// If it cannot overflow, transform into an add.
if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never)
  return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1),
                   DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

return SDValue();
2212}

2214SDValue DAGCombiner::visitUADDO(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
if (VT.isVector())
  return SDValue();

EVT CarryVT = N->getValueType(1);
SDLoc DL(N);

// If the flag result is dead, turn this into an ADD.
if (!N->hasAnyUseOfValue(1))
  return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1),
                   DAG.getUNDEF(CarryVT));

// canonicalize constant to RHS.
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
if (N0C && !N1C)
  return DAG.getNode(ISD::UADDO, DL, N->getVTList(), N1, N0);

// fold (uaddo x, 0) -> x + no carry out
if (isNullConstant(N1))
  return CombineTo(N, N0, DAG.getConstant(0, DL, CarryVT));

// If it cannot overflow, transform into an add.
if (DAG.computeOverflowKind(N0, N1) == SelectionDAG::OFK_Never)
  return CombineTo(N, DAG.getNode(ISD::ADD, DL, VT, N0, N1),
                   DAG.getConstant(0, DL, CarryVT));

if (SDValue Combined = visitUADDOLike(N0, N1, N))
  return Combined;

if (SDValue Combined = visitUADDOLike(N1, N0, N))
  return Combined;

return SDValue();
2251}

2253SDValue DAGCombiner::visitUADDOLike(SDValue N0, SDValue N1, SDNode *N) {
auto VT = N0.getValueType();

// (uaddo X, (addcarry Y, 0, Carry)) -> (addcarry X, Y, Carry)
// If Y + 1 cannot overflow.
if (N1.getOpcode() == ISD::ADDCARRY && isNullConstant(N1.getOperand(1))) {
  SDValue Y = N1.getOperand(0);
  SDValue One = DAG.getConstant(1, SDLoc(N), Y.getValueType());
  if (DAG.computeOverflowKind(Y, One) == SelectionDAG::OFK_Never)
    return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), N0, Y,
                       N1.getOperand(2));
}

// (uaddo X, Carry) -> (addcarry X, 0, Carry)
if (TLI.isOperationLegalOrCustom(ISD::ADDCARRY, VT))
  if (SDValue Carry = getAsCarry(TLI, N1))
    return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), N0,
                       DAG.getConstant(0, SDLoc(N), VT), Carry);

return SDValue();
2273}

2275SDValue DAGCombiner::visitADDE(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue CarryIn = N->getOperand(2);

// canonicalize constant to RHS
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
if (N0C && !N1C)
  return DAG.getNode(ISD::ADDE, SDLoc(N), N->getVTList(),
                     N1, N0, CarryIn);

// fold (adde x, y, false) -> (addc x, y)
if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
  return DAG.getNode(ISD::ADDC, SDLoc(N), N->getVTList(), N0, N1);

return SDValue();
2292}

2294SDValue DAGCombiner::visitADDCARRY(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue CarryIn = N->getOperand(2);
SDLoc DL(N);

// canonicalize constant to RHS
ConstantSDNode *N0C = dyn_cast<ConstantSDNode>(N0);
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
if (N0C && !N1C)
  return DAG.getNode(ISD::ADDCARRY, DL, N->getVTList(), N1, N0, CarryIn);

// fold (addcarry x, y, false) -> (uaddo x, y)
if (isNullConstant(CarryIn))
  return DAG.getNode(ISD::UADDO, DL, N->getVTList(), N0, N1);

// fold (addcarry 0, 0, X) -> (and (ext/trunc X), 1) and no carry.
if (isNullConstant(N0) && isNullConstant(N1)) {
  EVT VT = N0.getValueType();
  EVT CarryVT = CarryIn.getValueType();
  SDValue CarryExt = DAG.getBoolExtOrTrunc(CarryIn, DL, VT, CarryVT);
  AddToWorklist(CarryExt.getNode());
  return CombineTo(N, DAG.getNode(ISD::AND, DL, VT, CarryExt,
                                  DAG.getConstant(1, DL, VT)),
                   DAG.getConstant(0, DL, CarryVT));
}

if (SDValue Combined = visitADDCARRYLike(N0, N1, CarryIn, N))
  return Combined;

if (SDValue Combined = visitADDCARRYLike(N1, N0, CarryIn, N))
  return Combined;

return SDValue();
2328}

2330SDValue DAGCombiner::visitADDCARRYLike(SDValue N0, SDValue N1, SDValue CarryIn,
                                     SDNode *N) {
// Iff the flag result is dead:
// (addcarry (add|uaddo X, Y), 0, Carry) -> (addcarry X, Y, Carry)
if ((N0.getOpcode() == ISD::ADD ||
     (N0.getOpcode() == ISD::UADDO && N0.getResNo() == 0)) &&
    isNullConstant(N1) && !N->hasAnyUseOfValue(1))
  return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(),
                     N0.getOperand(0), N0.getOperand(1), CarryIn);

/**
 * When one of the addcarry argument is itself a carry, we may be facing
 * a diamond carry propagation. In which case we try to transform the DAG
 * to ensure linear carry propagation if that is possible.
 *
 * We are trying to get:
 *   (addcarry X, 0, (addcarry A, B, Z):Carry)
 */
if (auto Y = getAsCarry(TLI, N1)) {
  /**
   *            (uaddo A, B)
   *             /       \
   *          Carry      Sum
   *            |          \
   *            | (addcarry *, 0, Z)
   *            |       /
   *             \   Carry
   *              |   /
   * (addcarry X, *, *)
   */
  if (Y.getOpcode() == ISD::UADDO &&
      CarryIn.getResNo() == 1 &&
      CarryIn.getOpcode() == ISD::ADDCARRY &&
      isNullConstant(CarryIn.getOperand(1)) &&
      CarryIn.getOperand(0) == Y.getValue(0)) {
    auto NewY = DAG.getNode(ISD::ADDCARRY, SDLoc(N), Y->getVTList(),
                            Y.getOperand(0), Y.getOperand(1),
                            CarryIn.getOperand(2));
    AddToWorklist(NewY.getNode());
    return DAG.getNode(ISD::ADDCARRY, SDLoc(N), N->getVTList(), N0,
                       DAG.getConstant(0, SDLoc(N), N0.getValueType()),
                       NewY.getValue(1));
  }
}

return SDValue();
2376}

2378// Since it may not be valid to emit a fold to zero for vector initializers
2379// check if we can before folding.
2380static SDValue tryFoldToZero(const SDLoc &DL, const TargetLowering &TLI, EVT VT,
                           SelectionDAG &DAG, bool LegalOperations,
                           bool LegalTypes) {
if (!VT.isVector())
  return DAG.getConstant(0, DL, VT);
if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
  return DAG.getConstant(0, DL, VT);
return SDValue();
2388}

2390SDValue DAGCombiner::visitSUB(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
SDLoc DL(N);

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  // fold (sub x, 0) -> x, vector edition
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N0;
}

// fold (sub x, x) -> 0
// FIXME: Refactor this and xor and other similar operations together.
if (N0 == N1)
  return tryFoldToZero(DL, TLI, VT, DAG, LegalOperations, LegalTypes);
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
    DAG.isConstantIntBuildVectorOrConstantInt(N1)) {
  // fold (sub c1, c2) -> c1-c2
  return DAG.FoldConstantArithmetic(ISD::SUB, DL, VT, N0.getNode(),
                                    N1.getNode());
}

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);

// fold (sub x, c) -> (add x, -c)
if (N1C) {
  return DAG.getNode(ISD::ADD, DL, VT, N0,
                     DAG.getConstant(-N1C->getAPIntValue(), DL, VT));
}

if (isNullConstantOrNullSplatConstant(N0)) {
  unsigned BitWidth = VT.getScalarSizeInBits();
  // Right-shifting everything out but the sign bit followed by negation is
  // the same as flipping arithmetic/logical shift type without the negation:
  // -(X >>u 31) -> (X >>s 31)
  // -(X >>s 31) -> (X >>u 31)
  if (N1->getOpcode() == ISD::SRA || N1->getOpcode() == ISD::SRL) {
    ConstantSDNode *ShiftAmt = isConstOrConstSplat(N1.getOperand(1));
    if (ShiftAmt && ShiftAmt->getZExtValue() == BitWidth - 1) {
      auto NewSh = N1->getOpcode() == ISD::SRA ? ISD::SRL : ISD::SRA;
      if (!LegalOperations || TLI.isOperationLegal(NewSh, VT))
        return DAG.getNode(NewSh, DL, VT, N1.getOperand(0), N1.getOperand(1));
    }
  }

  // 0 - X --> 0 if the sub is NUW.
  if (N->getFlags().hasNoUnsignedWrap())
    return N0;

  if (DAG.MaskedValueIsZero(N1, ~APInt::getSignMask(BitWidth))) {
    // N1 is either 0 or the minimum signed value. If the sub is NSW, then
    // N1 must be 0 because negating the minimum signed value is undefined.
    if (N->getFlags().hasNoSignedWrap())
      return N0;

    // 0 - X --> X if X is 0 or the minimum signed value.
    return N1;
  }
}

// Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1)
if (isAllOnesConstantOrAllOnesSplatConstant(N0))
  return DAG.getNode(ISD::XOR, DL, VT, N1, N0);

// fold A-(A-B) -> B
if (N1.getOpcode() == ISD::SUB && N0 == N1.getOperand(0))
  return N1.getOperand(1);

// fold (A+B)-A -> B
if (N0.getOpcode() == ISD::ADD && N0.getOperand(0) == N1)
  return N0.getOperand(1);

// fold (A+B)-B -> A
if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1)
  return N0.getOperand(0);

// fold C2-(A+C1) -> (C2-C1)-A
if (N1.getOpcode() == ISD::ADD) {
  SDValue N11 = N1.getOperand(1);
  if (isConstantOrConstantVector(N0, /* NoOpaques */ true) &&
      isConstantOrConstantVector(N11, /* NoOpaques */ true)) {
    SDValue NewC = DAG.getNode(ISD::SUB, DL, VT, N0, N11);
    return DAG.getNode(ISD::SUB, DL, VT, NewC, N1.getOperand(0));
  }
}

// fold ((A+(B+or-C))-B) -> A+or-C
if (N0.getOpcode() == ISD::ADD &&
    (N0.getOperand(1).getOpcode() == ISD::SUB ||
     N0.getOperand(1).getOpcode() == ISD::ADD) &&
    N0.getOperand(1).getOperand(0) == N1)
  return DAG.getNode(N0.getOperand(1).getOpcode(), DL, VT, N0.getOperand(0),
                     N0.getOperand(1).getOperand(1));

// fold ((A+(C+B))-B) -> A+C
if (N0.getOpcode() == ISD::ADD && N0.getOperand(1).getOpcode() == ISD::ADD &&
    N0.getOperand(1).getOperand(1) == N1)
  return DAG.getNode(ISD::ADD, DL, VT, N0.getOperand(0),
                     N0.getOperand(1).getOperand(0));

// fold ((A-(B-C))-C) -> A-B
if (N0.getOpcode() == ISD::SUB && N0.getOperand(1).getOpcode() == ISD::SUB &&
    N0.getOperand(1).getOperand(1) == N1)
  return DAG.getNode(ISD::SUB, DL, VT, N0.getOperand(0),
                     N0.getOperand(1).getOperand(0));

// If either operand of a sub is undef, the result is undef
if (N0.isUndef())
  return N0;
if (N1.isUndef())
  return N1;

// If the relocation model supports it, consider symbol offsets.
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(N0))
  if (!LegalOperations && TLI.isOffsetFoldingLegal(GA)) {
    // fold (sub Sym, c) -> Sym-c
    if (N1C && GA->getOpcode() == ISD::GlobalAddress)
      return DAG.getGlobalAddress(GA->getGlobal(), SDLoc(N1C), VT,
                                  GA->getOffset() -
                                      (uint64_t)N1C->getSExtValue());
    // fold (sub Sym+c1, Sym+c2) -> c1-c2
    if (GlobalAddressSDNode *GB = dyn_cast<GlobalAddressSDNode>(N1))
      if (GA->getGlobal() == GB->getGlobal())
        return DAG.getConstant((uint64_t)GA->getOffset() - GB->getOffset(),
                               DL, VT);
  }

// sub X, (sextinreg Y i1) -> add X, (and Y 1)
if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) {
  VTSDNode *TN = cast<VTSDNode>(N1.getOperand(1));
  if (TN->getVT() == MVT::i1) {
    SDValue ZExt = DAG.getNode(ISD::AND, DL, VT, N1.getOperand(0),
                               DAG.getConstant(1, DL, VT));
    return DAG.getNode(ISD::ADD, DL, VT, N0, ZExt);
  }
}

return SDValue();
2536}

2538SDValue DAGCombiner::visitSUBC(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
SDLoc DL(N);

// If the flag result is dead, turn this into an SUB.
if (!N->hasAnyUseOfValue(1))
  return CombineTo(N, DAG.getNode(ISD::SUB, DL, VT, N0, N1),
                   DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

// fold (subc x, x) -> 0 + no borrow
if (N0 == N1)
  return CombineTo(N, DAG.getConstant(0, DL, VT),
                   DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

// fold (subc x, 0) -> x + no borrow
if (isNullConstant(N1))
  return CombineTo(N, N0, DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

// Canonicalize (sub -1, x) -> ~x, i.e. (xor x, -1) + no borrow
if (isAllOnesConstant(N0))
  return CombineTo(N, DAG.getNode(ISD::XOR, DL, VT, N1, N0),
                   DAG.getNode(ISD::CARRY_FALSE, DL, MVT::Glue));

return SDValue();
2564}

2566SDValue DAGCombiner::visitUSUBO(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
if (VT.isVector())
  return SDValue();

EVT CarryVT = N->getValueType(1);
SDLoc DL(N);

// If the flag result is dead, turn this into an SUB.
if (!N->hasAnyUseOfValue(1))
  return CombineTo(N, DAG.getNode(ISD::SUB, DL, VT, N0, N1),
                   DAG.getUNDEF(CarryVT));

// fold (usubo x, x) -> 0 + no borrow
if (N0 == N1)
  return CombineTo(N, DAG.getConstant(0, DL, VT),
                   DAG.getConstant(0, DL, CarryVT));

// fold (usubo x, 0) -> x + no borrow
if (isNullConstant(N1))
  return CombineTo(N, N0, DAG.getConstant(0, DL, CarryVT));

// Canonicalize (usubo -1, x) -> ~x, i.e. (xor x, -1) + no borrow
if (isAllOnesConstant(N0))
  return CombineTo(N, DAG.getNode(ISD::XOR, DL, VT, N1, N0),
                   DAG.getConstant(0, DL, CarryVT));

return SDValue();
2596}

2598SDValue DAGCombiner::visitSUBE(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue CarryIn = N->getOperand(2);

// fold (sube x, y, false) -> (subc x, y)
if (CarryIn.getOpcode() == ISD::CARRY_FALSE)
  return DAG.getNode(ISD::SUBC, SDLoc(N), N->getVTList(), N0, N1);

return SDValue();
2608}

2610SDValue DAGCombiner::visitSUBCARRY(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue CarryIn = N->getOperand(2);

// fold (subcarry x, y, false) -> (usubo x, y)
if (isNullConstant(CarryIn))
  return DAG.getNode(ISD::USUBO, SDLoc(N), N->getVTList(), N0, N1);

return SDValue();
2620}

2622SDValue DAGCombiner::visitMUL(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();

// fold (mul x, undef) -> 0
if (N0.isUndef() || N1.isUndef())
  return DAG.getConstant(0, SDLoc(N), VT);

bool N0IsConst = false;
bool N1IsConst = false;
bool N1IsOpaqueConst = false;
bool N0IsOpaqueConst = false;
APInt ConstValue0, ConstValue1;
// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  N0IsConst = ISD::isConstantSplatVector(N0.getNode(), ConstValue0);
  N1IsConst = ISD::isConstantSplatVector(N1.getNode(), ConstValue1);
  assert((!N0IsConst ||(static_cast <bool> ((!N0IsConst || ConstValue0.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N0IsConst || ConstValue0.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2645, __extension__ __PRETTY_FUNCTION__))
          ConstValue0.getBitWidth() == VT.getScalarSizeInBits()) &&(static_cast <bool> ((!N0IsConst || ConstValue0.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N0IsConst || ConstValue0.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2645, __extension__ __PRETTY_FUNCTION__))
         "Splat APInt should be element width")(static_cast <bool> ((!N0IsConst || ConstValue0.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N0IsConst || ConstValue0.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2645, __extension__ __PRETTY_FUNCTION__));
  assert((!N1IsConst ||(static_cast <bool> ((!N1IsConst || ConstValue1.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N1IsConst || ConstValue1.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2648, __extension__ __PRETTY_FUNCTION__))
          ConstValue1.getBitWidth() == VT.getScalarSizeInBits()) &&(static_cast <bool> ((!N1IsConst || ConstValue1.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N1IsConst || ConstValue1.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2648, __extension__ __PRETTY_FUNCTION__))
         "Splat APInt should be element width")(static_cast <bool> ((!N1IsConst || ConstValue1.getBitWidth
() == VT.getScalarSizeInBits()) && "Splat APInt should be element width"
) ? void (0) : __assert_fail ("(!N1IsConst || ConstValue1.getBitWidth() == VT.getScalarSizeInBits()) && \"Splat APInt should be element width\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2648, __extension__ __PRETTY_FUNCTION__));
} else {
  N0IsConst = isa<ConstantSDNode>(N0);
  if (N0IsConst) {
    ConstValue0 = cast<ConstantSDNode>(N0)->getAPIntValue();
    N0IsOpaqueConst = cast<ConstantSDNode>(N0)->isOpaque();
  }
  N1IsConst = isa<ConstantSDNode>(N1);
  if (N1IsConst) {
    ConstValue1 = cast<ConstantSDNode>(N1)->getAPIntValue();
    N1IsOpaqueConst = cast<ConstantSDNode>(N1)->isOpaque();
  }
}

// fold (mul c1, c2) -> c1*c2
if (N0IsConst && N1IsConst && !N0IsOpaqueConst && !N1IsOpaqueConst)
  return DAG.FoldConstantArithmetic(ISD::MUL, SDLoc(N), VT,
                                    N0.getNode(), N1.getNode());

// canonicalize constant to RHS (vector doesn't have to splat)
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
   !DAG.isConstantIntBuildVectorOrConstantInt(N1))
  return DAG.getNode(ISD::MUL, SDLoc(N), VT, N1, N0);
// fold (mul x, 0) -> 0
if (N1IsConst && ConstValue1.isNullValue())
  return N1;
// fold (mul x, 1) -> x
if (N1IsConst && ConstValue1.isOneValue())
  return N0;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (mul x, -1) -> 0-x
if (N1IsConst && ConstValue1.isAllOnesValue()) {
  SDLoc DL(N);
  return DAG.getNode(ISD::SUB, DL, VT,
                     DAG.getConstant(0, DL, VT), N0);
}
// fold (mul x, (1 << c)) -> x << c
if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) &&
    DAG.isKnownToBeAPowerOfTwo(N1) &&
    (!VT.isVector() || Level <= AfterLegalizeVectorOps)) {
  SDLoc DL(N);
  SDValue LogBase2 = BuildLogBase2(N1, DL);
  AddToWorklist(LogBase2.getNode());

  EVT ShiftVT = getShiftAmountTy(N0.getValueType());
  SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ShiftVT);
  AddToWorklist(Trunc.getNode());
  return DAG.getNode(ISD::SHL, DL, VT, N0, Trunc);
}
// fold (mul x, -(1 << c)) -> -(x << c) or (-x) << c
if (N1IsConst && !N1IsOpaqueConst && (-ConstValue1).isPowerOf2()) {
  unsigned Log2Val = (-ConstValue1).logBase2();
  SDLoc DL(N);
  // FIXME: If the input is something that is easily negated (e.g. a
  // single-use add), we should put the negate there.
  return DAG.getNode(ISD::SUB, DL, VT,
                     DAG.getConstant(0, DL, VT),
                     DAG.getNode(ISD::SHL, DL, VT, N0,
                          DAG.getConstant(Log2Val, DL,
                                    getShiftAmountTy(N0.getValueType()))));
}

// (mul (shl X, c1), c2) -> (mul X, c2 << c1)
if (N0.getOpcode() == ISD::SHL &&
    isConstantOrConstantVector(N1, /* NoOpaques */ true) &&
    isConstantOrConstantVector(N0.getOperand(1), /* NoOpaques */ true)) {
  SDValue C3 = DAG.getNode(ISD::SHL, SDLoc(N), VT, N1, N0.getOperand(1));
  if (isConstantOrConstantVector(C3))
    return DAG.getNode(ISD::MUL, SDLoc(N), VT, N0.getOperand(0), C3);
}

// Change (mul (shl X, C), Y) -> (shl (mul X, Y), C) when the shift has one
// use.
{
  SDValue Sh(nullptr, 0), Y(nullptr, 0);

  // Check for both (mul (shl X, C), Y)  and  (mul Y, (shl X, C)).
  if (N0.getOpcode() == ISD::SHL &&
      isConstantOrConstantVector(N0.getOperand(1)) &&
      N0.getNode()->hasOneUse()) {
    Sh = N0; Y = N1;
  } else if (N1.getOpcode() == ISD::SHL &&
             isConstantOrConstantVector(N1.getOperand(1)) &&
             N1.getNode()->hasOneUse()) {
    Sh = N1; Y = N0;
  }

  if (Sh.getNode()) {
    SDValue Mul = DAG.getNode(ISD::MUL, SDLoc(N), VT, Sh.getOperand(0), Y);
    return DAG.getNode(ISD::SHL, SDLoc(N), VT, Mul, Sh.getOperand(1));
  }
}

// fold (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2)
if (DAG.isConstantIntBuildVectorOrConstantInt(N1) &&
    N0.getOpcode() == ISD::ADD &&
    DAG.isConstantIntBuildVectorOrConstantInt(N0.getOperand(1)) &&
    isMulAddWithConstProfitable(N, N0, N1))
    return DAG.getNode(ISD::ADD, SDLoc(N), VT,
                       DAG.getNode(ISD::MUL, SDLoc(N0), VT,
                                   N0.getOperand(0), N1),
                       DAG.getNode(ISD::MUL, SDLoc(N1), VT,
                                   N0.getOperand(1), N1));

// reassociate mul
if (SDValue RMUL = ReassociateOps(ISD::MUL, SDLoc(N), N0, N1))
  return RMUL;

return SDValue();
2760}

2762/// Return true if divmod libcall is available.
2763static bool isDivRemLibcallAvailable(SDNode *Node, bool isSigned,
                                   const TargetLowering &TLI) {
RTLIB::Libcall LC;
EVT NodeType = Node->getValueType(0);
if (!NodeType.isSimple())
  return false;
switch (NodeType.getSimpleVT().SimpleTy) {
default: return false; // No libcall for vector types.
case MVT::i8:   LC= isSigned ? RTLIB::SDIVREM_I8  : RTLIB::UDIVREM_I8;  break;
case MVT::i16:  LC= isSigned ? RTLIB::SDIVREM_I16 : RTLIB::UDIVREM_I16; break;
case MVT::i32:  LC= isSigned ? RTLIB::SDIVREM_I32 : RTLIB::UDIVREM_I32; break;
case MVT::i64:  LC= isSigned ? RTLIB::SDIVREM_I64 : RTLIB::UDIVREM_I64; break;
case MVT::i128: LC= isSigned ? RTLIB::SDIVREM_I128:RTLIB::UDIVREM_I128; break;
}

return TLI.getLibcallName(LC) != nullptr;
2779}

2781/// Issue divrem if both quotient and remainder are needed.
2782SDValue DAGCombiner::useDivRem(SDNode *Node) {
if (Node->use_empty())
  return SDValue(); // This is a dead node, leave it alone.

unsigned Opcode = Node->getOpcode();
bool isSigned = (Opcode == ISD::SDIV) || (Opcode == ISD::SREM);
unsigned DivRemOpc = isSigned ? ISD::SDIVREM : ISD::UDIVREM;

// DivMod lib calls can still work on non-legal types if using lib-calls.
EVT VT = Node->getValueType(0);
if (VT.isVector() || !VT.isInteger())
  return SDValue();

if (!TLI.isTypeLegal(VT) && !TLI.isOperationCustom(DivRemOpc, VT))
  return SDValue();

// If DIVREM is going to get expanded into a libcall,
// but there is no libcall available, then don't combine.
if (!TLI.isOperationLegalOrCustom(DivRemOpc, VT) &&
    !isDivRemLibcallAvailable(Node, isSigned, TLI))
  return SDValue();

// If div is legal, it's better to do the normal expansion
unsigned OtherOpcode = 0;
if ((Opcode == ISD::SDIV) || (Opcode == ISD::UDIV)) {
  OtherOpcode = isSigned ? ISD::SREM : ISD::UREM;
  if (TLI.isOperationLegalOrCustom(Opcode, VT))
    return SDValue();
} else {
  OtherOpcode = isSigned ? ISD::SDIV : ISD::UDIV;
  if (TLI.isOperationLegalOrCustom(OtherOpcode, VT))
    return SDValue();
}

SDValue Op0 = Node->getOperand(0);
SDValue Op1 = Node->getOperand(1);
SDValue combined;
for (SDNode::use_iterator UI = Op0.getNode()->use_begin(),
       UE = Op0.getNode()->use_end(); UI != UE; ++UI) {
  SDNode *User = *UI;
  if (User == Node || User->use_empty())
    continue;
  // Convert the other matching node(s), too;
  // otherwise, the DIVREM may get target-legalized into something
  // target-specific that we won't be able to recognize.
  unsigned UserOpc = User->getOpcode();
  if ((UserOpc == Opcode || UserOpc == OtherOpcode || UserOpc == DivRemOpc) &&
      User->getOperand(0) == Op0 &&
      User->getOperand(1) == Op1) {
    if (!combined) {
      if (UserOpc == OtherOpcode) {
        SDVTList VTs = DAG.getVTList(VT, VT);
        combined = DAG.getNode(DivRemOpc, SDLoc(Node), VTs, Op0, Op1);
      } else if (UserOpc == DivRemOpc) {
        combined = SDValue(User, 0);
      } else {
        assert(UserOpc == Opcode)(static_cast <bool> (UserOpc == Opcode) ? void (0) : __assert_fail
 ("UserOpc == Opcode", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 2838, __extension__ __PRETTY_FUNCTION__));
        continue;
      }
    }
    if (UserOpc == ISD::SDIV || UserOpc == ISD::UDIV)
      CombineTo(User, combined);
    else if (UserOpc == ISD::SREM || UserOpc == ISD::UREM)
      CombineTo(User, combined.getValue(1));
  }
}
return combined;
2849}

2851static SDValue simplifyDivRem(SDNode *N, SelectionDAG &DAG) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc DL(N);

if (DAG.isUndef(N->getOpcode(), {N0, N1}))
  return DAG.getUNDEF(VT);

// undef / X -> 0
// undef % X -> 0
if (N0.isUndef())
  return DAG.getConstant(0, DL, VT);

return SDValue();
2866}

2868SDValue DAGCombiner::visitSDIV(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

SDLoc DL(N);

// fold (sdiv c1, c2) -> c1/c2
ConstantSDNode *N0C = isConstOrConstSplat(N0);
ConstantSDNode *N1C = isConstOrConstSplat(N1);
if (N0C && N1C && !N0C->isOpaque() && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::SDIV, DL, VT, N0C, N1C);
// fold (sdiv X, 1) -> X
if (N1C && N1C->isOne())
  return N0;
// fold (sdiv X, -1) -> 0-X
if (N1C && N1C->isAllOnesValue())
  return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), N0);

if (SDValue V = simplifyDivRem(N, DAG))
  return V;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// If we know the sign bits of both operands are zero, strength reduce to a
// udiv instead.  Handles (X&15) /s 4 -> X&15 >> 2
if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
  return DAG.getNode(ISD::UDIV, DL, N1.getValueType(), N0, N1);

// fold (sdiv X, pow2) -> simple ops after legalize
// FIXME: We check for the exact bit here because the generic lowering gives
// better results in that case. The target-specific lowering should learn how
// to handle exact sdivs efficiently.
if (N1C && !N1C->isNullValue() && !N1C->isOpaque() &&
    !N->getFlags().hasExact() && (N1C->getAPIntValue().isPowerOf2() ||
                                  (-N1C->getAPIntValue()).isPowerOf2())) {
  // Target-specific implementation of sdiv x, pow2.
  if (SDValue Res = BuildSDIVPow2(N))
    return Res;

  unsigned lg2 = N1C->getAPIntValue().countTrailingZeros();

  // Splat the sign bit into the register
  SDValue SGN =
      DAG.getNode(ISD::SRA, DL, VT, N0,
                  DAG.getConstant(VT.getScalarSizeInBits() - 1, DL,
                                  getShiftAmountTy(N0.getValueType())));
  AddToWorklist(SGN.getNode());

  // Add (N0 < 0) ? abs2 - 1 : 0;
  SDValue SRL =
      DAG.getNode(ISD::SRL, DL, VT, SGN,
                  DAG.getConstant(VT.getScalarSizeInBits() - lg2, DL,
                                  getShiftAmountTy(SGN.getValueType())));
  SDValue ADD = DAG.getNode(ISD::ADD, DL, VT, N0, SRL);
  AddToWorklist(SRL.getNode());
  AddToWorklist(ADD.getNode());    // Divide by pow2
  SDValue SRA = DAG.getNode(ISD::SRA, DL, VT, ADD,
                DAG.getConstant(lg2, DL,
                                getShiftAmountTy(ADD.getValueType())));

  // If we're dividing by a positive value, we're done.  Otherwise, we must
  // negate the result.
  if (N1C->getAPIntValue().isNonNegative())
    return SRA;

  AddToWorklist(SRA.getNode());
  return DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), SRA);
}

// If integer divide is expensive and we satisfy the requirements, emit an
// alternate sequence.  Targets may check function attributes for size/speed
// trade-offs.
AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
if (N1C && !TLI.isIntDivCheap(N->getValueType(0), Attr))
  if (SDValue Op = BuildSDIV(N))
    return Op;

// sdiv, srem -> sdivrem
// If the divisor is constant, then return DIVREM only if isIntDivCheap() is
// true.  Otherwise, we break the simplification logic in visitREM().
if (!N1C || TLI.isIntDivCheap(N->getValueType(0), Attr))
  if (SDValue DivRem = useDivRem(N))
      return DivRem;

return SDValue();
2960}

2962SDValue DAGCombiner::visitUDIV(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

SDLoc DL(N);

// fold (udiv c1, c2) -> c1/c2
ConstantSDNode *N0C = isConstOrConstSplat(N0);
ConstantSDNode *N1C = isConstOrConstSplat(N1);
if (N0C && N1C)
  if (SDValue Folded = DAG.FoldConstantArithmetic(ISD::UDIV, DL, VT,
                                                  N0C, N1C))
    return Folded;

if (SDValue V = simplifyDivRem(N, DAG))
  return V;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (udiv x, (1 << c)) -> x >>u c
if (isConstantOrConstantVector(N1, /*NoOpaques*/ true) &&
    DAG.isKnownToBeAPowerOfTwo(N1)) {
  SDValue LogBase2 = BuildLogBase2(N1, DL);
  AddToWorklist(LogBase2.getNode());

  EVT ShiftVT = getShiftAmountTy(N0.getValueType());
  SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ShiftVT);
  AddToWorklist(Trunc.getNode());
  return DAG.getNode(ISD::SRL, DL, VT, N0, Trunc);
}

// fold (udiv x, (shl c, y)) -> x >>u (log2(c)+y) iff c is power of 2
if (N1.getOpcode() == ISD::SHL) {
  SDValue N10 = N1.getOperand(0);
  if (isConstantOrConstantVector(N10, /*NoOpaques*/ true) &&
      DAG.isKnownToBeAPowerOfTwo(N10)) {
    SDValue LogBase2 = BuildLogBase2(N10, DL);
    AddToWorklist(LogBase2.getNode());

    EVT ADDVT = N1.getOperand(1).getValueType();
    SDValue Trunc = DAG.getZExtOrTrunc(LogBase2, DL, ADDVT);
    AddToWorklist(Trunc.getNode());
    SDValue Add = DAG.getNode(ISD::ADD, DL, ADDVT, N1.getOperand(1), Trunc);
    AddToWorklist(Add.getNode());
    return DAG.getNode(ISD::SRL, DL, VT, N0, Add);
  }
}

// fold (udiv x, c) -> alternate
AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();
if (N1C && !TLI.isIntDivCheap(N->getValueType(0), Attr))
  if (SDValue Op = BuildUDIV(N))
    return Op;

// sdiv, srem -> sdivrem
// If the divisor is constant, then return DIVREM only if isIntDivCheap() is
// true.  Otherwise, we break the simplification logic in visitREM().
if (!N1C || TLI.isIntDivCheap(N->getValueType(0), Attr))
  if (SDValue DivRem = useDivRem(N))
      return DivRem;

return SDValue();
3031}

3033// handles ISD::SREM and ISD::UREM
3034SDValue DAGCombiner::visitREM(SDNode *N) {
unsigned Opcode = N->getOpcode();
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
bool isSigned = (Opcode == ISD::SREM);
SDLoc DL(N);

// fold (rem c1, c2) -> c1%c2
ConstantSDNode *N0C = isConstOrConstSplat(N0);
ConstantSDNode *N1C = isConstOrConstSplat(N1);
if (N0C && N1C)
  if (SDValue Folded = DAG.FoldConstantArithmetic(Opcode, DL, VT, N0C, N1C))
    return Folded;

if (SDValue V = simplifyDivRem(N, DAG))
  return V;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

if (isSigned) {
  // If we know the sign bits of both operands are zero, strength reduce to a
  // urem instead.  Handles (X & 0x0FFFFFFF) %s 16 -> X&15
  if (DAG.SignBitIsZero(N1) && DAG.SignBitIsZero(N0))
    return DAG.getNode(ISD::UREM, DL, VT, N0, N1);
} else {
  SDValue NegOne = DAG.getAllOnesConstant(DL, VT);
  if (DAG.isKnownToBeAPowerOfTwo(N1)) {
    // fold (urem x, pow2) -> (and x, pow2-1)
    SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N1, NegOne);
    AddToWorklist(Add.getNode());
    return DAG.getNode(ISD::AND, DL, VT, N0, Add);
  }
  if (N1.getOpcode() == ISD::SHL &&
      DAG.isKnownToBeAPowerOfTwo(N1.getOperand(0))) {
    // fold (urem x, (shl pow2, y)) -> (and x, (add (shl pow2, y), -1))
    SDValue Add = DAG.getNode(ISD::ADD, DL, VT, N1, NegOne);
    AddToWorklist(Add.getNode());
    return DAG.getNode(ISD::AND, DL, VT, N0, Add);
  }
}

AttributeList Attr = DAG.getMachineFunction().getFunction().getAttributes();

// If X/C can be simplified by the division-by-constant logic, lower
// X%C to the equivalent of X-X/C*C.
// To avoid mangling nodes, this simplification requires that the combine()
// call for the speculative DIV must not cause a DIVREM conversion.  We guard
// against this by skipping the simplification if isIntDivCheap().  When
// div is not cheap, combine will not return a DIVREM.  Regardless,
// checking cheapness here makes sense since the simplification results in
// fatter code.
if (N1C && !N1C->isNullValue() && !TLI.isIntDivCheap(VT, Attr)) {
  unsigned DivOpcode = isSigned ? ISD::SDIV : ISD::UDIV;
  SDValue Div = DAG.getNode(DivOpcode, DL, VT, N0, N1);
  AddToWorklist(Div.getNode());
  SDValue OptimizedDiv = combine(Div.getNode());
  if (OptimizedDiv.getNode() && OptimizedDiv.getNode() != Div.getNode()) {
    assert((OptimizedDiv.getOpcode() != ISD::UDIVREM) &&(static_cast <bool> ((OptimizedDiv.getOpcode() != ISD::
UDIVREM) && (OptimizedDiv.getOpcode() != ISD::SDIVREM
)) ? void (0) : __assert_fail ("(OptimizedDiv.getOpcode() != ISD::UDIVREM) && (OptimizedDiv.getOpcode() != ISD::SDIVREM)"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3094, __extension__ __PRETTY_FUNCTION__))
           (OptimizedDiv.getOpcode() != ISD::SDIVREM))(static_cast <bool> ((OptimizedDiv.getOpcode() != ISD::
UDIVREM) && (OptimizedDiv.getOpcode() != ISD::SDIVREM
)) ? void (0) : __assert_fail ("(OptimizedDiv.getOpcode() != ISD::UDIVREM) && (OptimizedDiv.getOpcode() != ISD::SDIVREM)"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3094, __extension__ __PRETTY_FUNCTION__));
    SDValue Mul = DAG.getNode(ISD::MUL, DL, VT, OptimizedDiv, N1);
    SDValue Sub = DAG.getNode(ISD::SUB, DL, VT, N0, Mul);
    AddToWorklist(Mul.getNode());
    return Sub;
  }
}

// sdiv, srem -> sdivrem
if (SDValue DivRem = useDivRem(N))
  return DivRem.getValue(1);

return SDValue();
3107}

3109SDValue DAGCombiner::visitMULHS(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc DL(N);

if (VT.isVector()) {
  // fold (mulhs x, 0) -> 0
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N1;
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    return N0;
}

// fold (mulhs x, 0) -> 0
if (isNullConstant(N1))
  return N1;
// fold (mulhs x, 1) -> (sra x, size(x)-1)
if (isOneConstant(N1))
  return DAG.getNode(ISD::SRA, DL, N0.getValueType(), N0,
                     DAG.getConstant(N0.getValueSizeInBits() - 1, DL,
                                     getShiftAmountTy(N0.getValueType())));

// fold (mulhs x, undef) -> 0
if (N0.isUndef() || N1.isUndef())
  return DAG.getConstant(0, DL, VT);

// If the type twice as wide is legal, transform the mulhs to a wider multiply
// plus a shift.
if (VT.isSimple() && !VT.isVector()) {
  MVT Simple = VT.getSimpleVT();
  unsigned SimpleSize = Simple.getSizeInBits();
  EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
  if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
    N0 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N0);
    N1 = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N1);
    N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
    N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
          DAG.getConstant(SimpleSize, DL,
                          getShiftAmountTy(N1.getValueType())));
    return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
  }
}

return SDValue();
3154}

3156SDValue DAGCombiner::visitMULHU(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc DL(N);

if (VT.isVector()) {
  // fold (mulhu x, 0) -> 0
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N1;
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    return N0;
}

// fold (mulhu x, 0) -> 0
if (isNullConstant(N1))
  return N1;
// fold (mulhu x, 1) -> 0
if (isOneConstant(N1))
  return DAG.getConstant(0, DL, N0.getValueType());
// fold (mulhu x, undef) -> 0
if (N0.isUndef() || N1.isUndef())
  return DAG.getConstant(0, DL, VT);

// If the type twice as wide is legal, transform the mulhu to a wider multiply
// plus a shift.
if (VT.isSimple() && !VT.isVector()) {
  MVT Simple = VT.getSimpleVT();
  unsigned SimpleSize = Simple.getSizeInBits();
  EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
  if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
    N0 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N0);
    N1 = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N1);
    N1 = DAG.getNode(ISD::MUL, DL, NewVT, N0, N1);
    N1 = DAG.getNode(ISD::SRL, DL, NewVT, N1,
          DAG.getConstant(SimpleSize, DL,
                          getShiftAmountTy(N1.getValueType())));
    return DAG.getNode(ISD::TRUNCATE, DL, VT, N1);
  }
}

return SDValue();
3198}

3200/// Perform optimizations common to nodes that compute two values. LoOp and HiOp
3201/// give the opcodes for the two computations that are being performed. Return
3202/// true if a simplification was made.
3203SDValue DAGCombiner::SimplifyNodeWithTwoResults(SDNode *N, unsigned LoOp,
                                              unsigned HiOp) {
// If the high half is not needed, just compute the low half.
bool HiExists = N->hasAnyUseOfValue(1);
if (!HiExists &&
    (!LegalOperations ||
     TLI.isOperationLegalOrCustom(LoOp, N->getValueType(0)))) {
  SDValue Res = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
  return CombineTo(N, Res, Res);
}

// If the low half is not needed, just compute the high half.
bool LoExists = N->hasAnyUseOfValue(0);
if (!LoExists &&
    (!LegalOperations ||
     TLI.isOperationLegal(HiOp, N->getValueType(1)))) {
  SDValue Res = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
  return CombineTo(N, Res, Res);
}

// If both halves are used, return as it is.
if (LoExists && HiExists)
  return SDValue();

// If the two computed results can be simplified separately, separate them.
if (LoExists) {
  SDValue Lo = DAG.getNode(LoOp, SDLoc(N), N->getValueType(0), N->ops());
  AddToWorklist(Lo.getNode());
  SDValue LoOpt = combine(Lo.getNode());
  if (LoOpt.getNode() && LoOpt.getNode() != Lo.getNode() &&
      (!LegalOperations ||
       TLI.isOperationLegal(LoOpt.getOpcode(), LoOpt.getValueType())))
    return CombineTo(N, LoOpt, LoOpt);
}

if (HiExists) {
  SDValue Hi = DAG.getNode(HiOp, SDLoc(N), N->getValueType(1), N->ops());
  AddToWorklist(Hi.getNode());
  SDValue HiOpt = combine(Hi.getNode());
  if (HiOpt.getNode() && HiOpt != Hi &&
      (!LegalOperations ||
       TLI.isOperationLegal(HiOpt.getOpcode(), HiOpt.getValueType())))
    return CombineTo(N, HiOpt, HiOpt);
}

return SDValue();
3249}

3251SDValue DAGCombiner::visitSMUL_LOHI(SDNode *N) {
if (SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHS))
  return Res;

EVT VT = N->getValueType(0);
SDLoc DL(N);

// If the type is twice as wide is legal, transform the mulhu to a wider
// multiply plus a shift.
if (VT.isSimple() && !VT.isVector()) {
  MVT Simple = VT.getSimpleVT();
  unsigned SimpleSize = Simple.getSizeInBits();
  EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
  if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
    SDValue Lo = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(0));
    SDValue Hi = DAG.getNode(ISD::SIGN_EXTEND, DL, NewVT, N->getOperand(1));
    Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
    // Compute the high part as N1.
    Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
          DAG.getConstant(SimpleSize, DL,
                          getShiftAmountTy(Lo.getValueType())));
    Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
    // Compute the low part as N0.
    Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
    return CombineTo(N, Lo, Hi);
  }
}

return SDValue();
3280}

3282SDValue DAGCombiner::visitUMUL_LOHI(SDNode *N) {
if (SDValue Res = SimplifyNodeWithTwoResults(N, ISD::MUL, ISD::MULHU))
  return Res;

EVT VT = N->getValueType(0);
SDLoc DL(N);

// If the type is twice as wide is legal, transform the mulhu to a wider
// multiply plus a shift.
if (VT.isSimple() && !VT.isVector()) {
  MVT Simple = VT.getSimpleVT();
  unsigned SimpleSize = Simple.getSizeInBits();
  EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), SimpleSize*2);
  if (TLI.isOperationLegal(ISD::MUL, NewVT)) {
    SDValue Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(0));
    SDValue Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, NewVT, N->getOperand(1));
    Lo = DAG.getNode(ISD::MUL, DL, NewVT, Lo, Hi);
    // Compute the high part as N1.
    Hi = DAG.getNode(ISD::SRL, DL, NewVT, Lo,
          DAG.getConstant(SimpleSize, DL,
                          getShiftAmountTy(Lo.getValueType())));
    Hi = DAG.getNode(ISD::TRUNCATE, DL, VT, Hi);
    // Compute the low part as N0.
    Lo = DAG.getNode(ISD::TRUNCATE, DL, VT, Lo);
    return CombineTo(N, Lo, Hi);
  }
}

return SDValue();
3311}

3313SDValue DAGCombiner::visitSMULO(SDNode *N) {
// (smulo x, 2) -> (saddo x, x)
if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
  if (C2->getAPIntValue() == 2)
    return DAG.getNode(ISD::SADDO, SDLoc(N), N->getVTList(),
                       N->getOperand(0), N->getOperand(0));

return SDValue();
3321}

3323SDValue DAGCombiner::visitUMULO(SDNode *N) {
// (umulo x, 2) -> (uaddo x, x)
if (ConstantSDNode *C2 = dyn_cast<ConstantSDNode>(N->getOperand(1)))
  if (C2->getAPIntValue() == 2)
    return DAG.getNode(ISD::UADDO, SDLoc(N), N->getVTList(),
                       N->getOperand(0), N->getOperand(0));

return SDValue();
3331}

3333SDValue DAGCombiner::visitIMINMAX(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

// fold operation with constant operands.
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
if (N0C && N1C)
  return DAG.FoldConstantArithmetic(N->getOpcode(), SDLoc(N), VT, N0C, N1C);

// canonicalize constant to RHS
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
   !DAG.isConstantIntBuildVectorOrConstantInt(N1))
  return DAG.getNode(N->getOpcode(), SDLoc(N), VT, N1, N0);

// Is sign bits are zero, flip between UMIN/UMAX and SMIN/SMAX.
// Only do this if the current op isn't legal and the flipped is.
unsigned Opcode = N->getOpcode();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (!TLI.isOperationLegal(Opcode, VT) &&
    (N0.isUndef() || DAG.SignBitIsZero(N0)) &&
    (N1.isUndef() || DAG.SignBitIsZero(N1))) {
  unsigned AltOpcode;
  switch (Opcode) {
  case ISD::SMIN: AltOpcode = ISD::UMIN; break;
  case ISD::SMAX: AltOpcode = ISD::UMAX; break;
  case ISD::UMIN: AltOpcode = ISD::SMIN; break;
  case ISD::UMAX: AltOpcode = ISD::SMAX; break;
  default: llvm_unreachable("Unknown MINMAX opcode")::llvm::llvm_unreachable_internal("Unknown MINMAX opcode", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3367);
  }
  if (TLI.isOperationLegal(AltOpcode, VT))
    return DAG.getNode(AltOpcode, SDLoc(N), VT, N0, N1);
}

return SDValue();
3374}

3376/// If this is a binary operator with two operands of the same opcode, try to
3377/// simplify it.
3378SDValue DAGCombiner::SimplifyBinOpWithSameOpcodeHands(SDNode *N) {
SDValue N0 = N->getOperand(0), N1 = N->getOperand(1);
EVT VT = N0.getValueType();
assert(N0.getOpcode() == N1.getOpcode() && "Bad input!")(static_cast <bool> (N0.getOpcode() == N1.getOpcode() &&
 "Bad input!") ? void (0) : __assert_fail ("N0.getOpcode() == N1.getOpcode() && \"Bad input!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3381, __extension__ __PRETTY_FUNCTION__));

// Bail early if none of these transforms apply.
if (N0.getNumOperands() == 0) return SDValue();

// For each of OP in AND/OR/XOR:
// fold (OP (zext x), (zext y)) -> (zext (OP x, y))
// fold (OP (sext x), (sext y)) -> (sext (OP x, y))
// fold (OP (aext x), (aext y)) -> (aext (OP x, y))
// fold (OP (bswap x), (bswap y)) -> (bswap (OP x, y))
// fold (OP (trunc x), (trunc y)) -> (trunc (OP x, y)) (if trunc isn't free)
//
// do not sink logical op inside of a vector extend, since it may combine
// into a vsetcc.
EVT Op0VT = N0.getOperand(0).getValueType();
if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
     N0.getOpcode() == ISD::SIGN_EXTEND ||
     N0.getOpcode() == ISD::BSWAP ||
     // Avoid infinite looping with PromoteIntBinOp.
     (N0.getOpcode() == ISD::ANY_EXTEND &&
      (!LegalTypes || TLI.isTypeDesirableForOp(N->getOpcode(), Op0VT))) ||
     (N0.getOpcode() == ISD::TRUNCATE &&
      (!TLI.isZExtFree(VT, Op0VT) ||
       !TLI.isTruncateFree(Op0VT, VT)) &&
      TLI.isTypeLegal(Op0VT))) &&
    !VT.isVector() &&
    Op0VT == N1.getOperand(0).getValueType() &&
    (!LegalOperations || TLI.isOperationLegal(N->getOpcode(), Op0VT))) {
  SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
                               N0.getOperand(0).getValueType(),
                               N0.getOperand(0), N1.getOperand(0));
  AddToWorklist(ORNode.getNode());
  return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, ORNode);
}

// For each of OP in SHL/SRL/SRA/AND...
//   fold (and (OP x, z), (OP y, z)) -> (OP (and x, y), z)
//   fold (or  (OP x, z), (OP y, z)) -> (OP (or  x, y), z)
//   fold (xor (OP x, z), (OP y, z)) -> (OP (xor x, y), z)
if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL ||
     N0.getOpcode() == ISD::SRA || N0.getOpcode() == ISD::AND) &&
    N0.getOperand(1) == N1.getOperand(1)) {
  SDValue ORNode = DAG.getNode(N->getOpcode(), SDLoc(N0),
                               N0.getOperand(0).getValueType(),
                               N0.getOperand(0), N1.getOperand(0));
  AddToWorklist(ORNode.getNode());
  return DAG.getNode(N0.getOpcode(), SDLoc(N), VT,
                     ORNode, N0.getOperand(1));
}

// Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B))
// Only perform this optimization up until type legalization, before
// LegalizeVectorOprs. LegalizeVectorOprs promotes vector operations by
// adding bitcasts. For example (xor v4i32) is promoted to (v2i64), and
// we don't want to undo this promotion.
// We also handle SCALAR_TO_VECTOR because xor/or/and operations are cheaper
// on scalars.
if ((N0.getOpcode() == ISD::BITCAST ||
     N0.getOpcode() == ISD::SCALAR_TO_VECTOR) &&
     Level <= AfterLegalizeTypes) {
  SDValue In0 = N0.getOperand(0);
  SDValue In1 = N1.getOperand(0);
  EVT In0Ty = In0.getValueType();
  EVT In1Ty = In1.getValueType();
  SDLoc DL(N);
  // If both incoming values are integers, and the original types are the
  // same.
  if (In0Ty.isInteger() && In1Ty.isInteger() && In0Ty == In1Ty) {
    SDValue Op = DAG.getNode(N->getOpcode(), DL, In0Ty, In0, In1);
    SDValue BC = DAG.getNode(N0.getOpcode(), DL, VT, Op);
    AddToWorklist(Op.getNode());
    return BC;
  }
}

// Xor/and/or are indifferent to the swizzle operation (shuffle of one value).
// Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A,B))
// If both shuffles use the same mask, and both shuffle within a single
// vector, then it is worthwhile to move the swizzle after the operation.
// The type-legalizer generates this pattern when loading illegal
// vector types from memory. In many cases this allows additional shuffle
// optimizations.
// There are other cases where moving the shuffle after the xor/and/or
// is profitable even if shuffles don't perform a swizzle.
// If both shuffles use the same mask, and both shuffles have the same first
// or second operand, then it might still be profitable to move the shuffle
// after the xor/and/or operation.
if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG) {
  ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(N0);
  ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(N1);

  assert(N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() &&(static_cast <bool> (N0.getOperand(0).getValueType() ==
 N1.getOperand(0).getValueType() && "Inputs to shuffles are not the same type"
) ? void (0) : __assert_fail ("N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() && \"Inputs to shuffles are not the same type\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3473, __extension__ __PRETTY_FUNCTION__))
         "Inputs to shuffles are not the same type")(static_cast <bool> (N0.getOperand(0).getValueType() ==
 N1.getOperand(0).getValueType() && "Inputs to shuffles are not the same type"
) ? void (0) : __assert_fail ("N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType() && \"Inputs to shuffles are not the same type\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3473, __extension__ __PRETTY_FUNCTION__));

  // Check that both shuffles use the same mask. The masks are known to be of
  // the same length because the result vector type is the same.
  // Check also that shuffles have only one use to avoid introducing extra
  // instructions.
  if (SVN0->hasOneUse() && SVN1->hasOneUse() &&
      SVN0->getMask().equals(SVN1->getMask())) {
    SDValue ShOp = N0->getOperand(1);

    // Don't try to fold this node if it requires introducing a
    // build vector of all zeros that might be illegal at this stage.
    if (N->getOpcode() == ISD::XOR && !ShOp.isUndef()) {
      if (!LegalTypes)
        ShOp = DAG.getConstant(0, SDLoc(N), VT);
      else
        ShOp = SDValue();
    }

    // (AND (shuf (A, C), shuf (B, C)) -> shuf (AND (A, B), C)
    // (OR  (shuf (A, C), shuf (B, C)) -> shuf (OR  (A, B), C)
    // (XOR (shuf (A, C), shuf (B, C)) -> shuf (XOR (A, B), V_0)
    if (N0.getOperand(1) == N1.getOperand(1) && ShOp.getNode()) {
      SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
                                    N0->getOperand(0), N1->getOperand(0));
      AddToWorklist(NewNode.getNode());
      return DAG.getVectorShuffle(VT, SDLoc(N), NewNode, ShOp,
                                  SVN0->getMask());
    }

    // Don't try to fold this node if it requires introducing a
    // build vector of all zeros that might be illegal at this stage.
    ShOp = N0->getOperand(0);
    if (N->getOpcode() == ISD::XOR && !ShOp.isUndef()) {
      if (!LegalTypes)
        ShOp = DAG.getConstant(0, SDLoc(N), VT);
      else
        ShOp = SDValue();
    }

    // (AND (shuf (C, A), shuf (C, B)) -> shuf (C, AND (A, B))
    // (OR  (shuf (C, A), shuf (C, B)) -> shuf (C, OR  (A, B))
    // (XOR (shuf (C, A), shuf (C, B)) -> shuf (V_0, XOR (A, B))
    if (N0->getOperand(0) == N1->getOperand(0) && ShOp.getNode()) {
      SDValue NewNode = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
                                    N0->getOperand(1), N1->getOperand(1));
      AddToWorklist(NewNode.getNode());
      return DAG.getVectorShuffle(VT, SDLoc(N), ShOp, NewNode,
                                  SVN0->getMask());
    }
  }
}

return SDValue();
3527}

3529/// Try to make (and/or setcc (LL, LR), setcc (RL, RR)) more efficient.
3530SDValue DAGCombiner::foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1,
                                     const SDLoc &DL) {
SDValue LL, LR, RL, RR, N0CC, N1CC;
if (!isSetCCEquivalent(N0, LL, LR, N0CC) ||
    !isSetCCEquivalent(N1, RL, RR, N1CC))
  return SDValue();

assert(N0.getValueType() == N1.getValueType() &&(static_cast <bool> (N0.getValueType() == N1.getValueType
() && "Unexpected operand types for bitwise logic op"
) ? void (0) : __assert_fail ("N0.getValueType() == N1.getValueType() && \"Unexpected operand types for bitwise logic op\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3538, __extension__ __PRETTY_FUNCTION__))
       "Unexpected operand types for bitwise logic op")(static_cast <bool> (N0.getValueType() == N1.getValueType
() && "Unexpected operand types for bitwise logic op"
) ? void (0) : __assert_fail ("N0.getValueType() == N1.getValueType() && \"Unexpected operand types for bitwise logic op\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3538, __extension__ __PRETTY_FUNCTION__));
assert(LL.getValueType() == LR.getValueType() &&(static_cast <bool> (LL.getValueType() == LR.getValueType
() && RL.getValueType() == RR.getValueType() &&
 "Unexpected operand types for setcc") ? void (0) : __assert_fail
 ("LL.getValueType() == LR.getValueType() && RL.getValueType() == RR.getValueType() && \"Unexpected operand types for setcc\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3541, __extension__ __PRETTY_FUNCTION__))
       RL.getValueType() == RR.getValueType() &&(static_cast <bool> (LL.getValueType() == LR.getValueType
() && RL.getValueType() == RR.getValueType() &&
 "Unexpected operand types for setcc") ? void (0) : __assert_fail
 ("LL.getValueType() == LR.getValueType() && RL.getValueType() == RR.getValueType() && \"Unexpected operand types for setcc\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3541, __extension__ __PRETTY_FUNCTION__))
       "Unexpected operand types for setcc")(static_cast <bool> (LL.getValueType() == LR.getValueType
() && RL.getValueType() == RR.getValueType() &&
 "Unexpected operand types for setcc") ? void (0) : __assert_fail
 ("LL.getValueType() == LR.getValueType() && RL.getValueType() == RR.getValueType() && \"Unexpected operand types for setcc\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3541, __extension__ __PRETTY_FUNCTION__));

// If we're here post-legalization or the logic op type is not i1, the logic
// op type must match a setcc result type. Also, all folds require new
// operations on the left and right operands, so those types must match.
EVT VT = N0.getValueType();
EVT OpVT = LL.getValueType();
if (LegalOperations || VT.getScalarType() != MVT::i1)
  if (VT != getSetCCResultType(OpVT))
    return SDValue();
if (OpVT != RL.getValueType())
  return SDValue();

ISD::CondCode CC0 = cast<CondCodeSDNode>(N0CC)->get();
ISD::CondCode CC1 = cast<CondCodeSDNode>(N1CC)->get();
bool IsInteger = OpVT.isInteger();
if (LR == RR && CC0 == CC1 && IsInteger) {
  bool IsZero = isNullConstantOrNullSplatConstant(LR);
  bool IsNeg1 = isAllOnesConstantOrAllOnesSplatConstant(LR);

  // All bits clear?
  bool AndEqZero = IsAnd && CC1 == ISD::SETEQ && IsZero;
  // All sign bits clear?
  bool AndGtNeg1 = IsAnd && CC1 == ISD::SETGT && IsNeg1;
  // Any bits set?
  bool OrNeZero = !IsAnd && CC1 == ISD::SETNE && IsZero;
  // Any sign bits set?
  bool OrLtZero = !IsAnd && CC1 == ISD::SETLT && IsZero;

  // (and (seteq X,  0), (seteq Y,  0)) --> (seteq (or X, Y),  0)
  // (and (setgt X, -1), (setgt Y, -1)) --> (setgt (or X, Y), -1)
  // (or  (setne X,  0), (setne Y,  0)) --> (setne (or X, Y),  0)
  // (or  (setlt X,  0), (setlt Y,  0)) --> (setlt (or X, Y),  0)
  if (AndEqZero || AndGtNeg1 || OrNeZero || OrLtZero) {
    SDValue Or = DAG.getNode(ISD::OR, SDLoc(N0), OpVT, LL, RL);
    AddToWorklist(Or.getNode());
    return DAG.getSetCC(DL, VT, Or, LR, CC1);
  }

  // All bits set?
  bool AndEqNeg1 = IsAnd && CC1 == ISD::SETEQ && IsNeg1;
  // All sign bits set?
  bool AndLtZero = IsAnd && CC1 == ISD::SETLT && IsZero;
  // Any bits clear?
  bool OrNeNeg1 = !IsAnd && CC1 == ISD::SETNE && IsNeg1;
  // Any sign bits clear?
  bool OrGtNeg1 = !IsAnd && CC1 == ISD::SETGT && IsNeg1;

  // (and (seteq X, -1), (seteq Y, -1)) --> (seteq (and X, Y), -1)
  // (and (setlt X,  0), (setlt Y,  0)) --> (setlt (and X, Y),  0)
  // (or  (setne X, -1), (setne Y, -1)) --> (setne (and X, Y), -1)
  // (or  (setgt X, -1), (setgt Y  -1)) --> (setgt (and X, Y), -1)
  if (AndEqNeg1 || AndLtZero || OrNeNeg1 || OrGtNeg1) {
    SDValue And = DAG.getNode(ISD::AND, SDLoc(N0), OpVT, LL, RL);
    AddToWorklist(And.getNode());
    return DAG.getSetCC(DL, VT, And, LR, CC1);
  }
}

// TODO: What is the 'or' equivalent of this fold?
// (and (setne X, 0), (setne X, -1)) --> (setuge (add X, 1), 2)
if (IsAnd && LL == RL && CC0 == CC1 && OpVT.getScalarSizeInBits() > 1 &&
    IsInteger && CC0 == ISD::SETNE &&
    ((isNullConstant(LR) && isAllOnesConstant(RR)) ||
     (isAllOnesConstant(LR) && isNullConstant(RR)))) {
  SDValue One = DAG.getConstant(1, DL, OpVT);
  SDValue Two = DAG.getConstant(2, DL, OpVT);
  SDValue Add = DAG.getNode(ISD::ADD, SDLoc(N0), OpVT, LL, One);
  AddToWorklist(Add.getNode());
  return DAG.getSetCC(DL, VT, Add, Two, ISD::SETUGE);
}

// Try more general transforms if the predicates match and the only user of
// the compares is the 'and' or 'or'.
if (IsInteger && TLI.convertSetCCLogicToBitwiseLogic(OpVT) && CC0 == CC1 &&
    N0.hasOneUse() && N1.hasOneUse()) {
  // and (seteq A, B), (seteq C, D) --> seteq (or (xor A, B), (xor C, D)), 0
  // or  (setne A, B), (setne C, D) --> setne (or (xor A, B), (xor C, D)), 0
  if ((IsAnd && CC1 == ISD::SETEQ) || (!IsAnd && CC1 == ISD::SETNE)) {
    SDValue XorL = DAG.getNode(ISD::XOR, SDLoc(N0), OpVT, LL, LR);
    SDValue XorR = DAG.getNode(ISD::XOR, SDLoc(N1), OpVT, RL, RR);
    SDValue Or = DAG.getNode(ISD::OR, DL, OpVT, XorL, XorR);
    SDValue Zero = DAG.getConstant(0, DL, OpVT);
    return DAG.getSetCC(DL, VT, Or, Zero, CC1);
  }
}

// Canonicalize equivalent operands to LL == RL.
if (LL == RR && LR == RL) {
  CC1 = ISD::getSetCCSwappedOperands(CC1);
  std::swap(RL, RR);
}

// (and (setcc X, Y, CC0), (setcc X, Y, CC1)) --> (setcc X, Y, NewCC)
// (or  (setcc X, Y, CC0), (setcc X, Y, CC1)) --> (setcc X, Y, NewCC)
if (LL == RL && LR == RR) {
  ISD::CondCode NewCC = IsAnd ? ISD::getSetCCAndOperation(CC0, CC1, IsInteger)
                              : ISD::getSetCCOrOperation(CC0, CC1, IsInteger);
  if (NewCC != ISD::SETCC_INVALID &&
      (!LegalOperations ||
       (TLI.isCondCodeLegal(NewCC, LL.getSimpleValueType()) &&
        TLI.isOperationLegal(ISD::SETCC, OpVT))))
    return DAG.getSetCC(DL, VT, LL, LR, NewCC);
}

return SDValue();
3647}

3649/// This contains all DAGCombine rules which reduce two values combined by
3650/// an And operation to a single value. This makes them reusable in the context
3651/// of visitSELECT(). Rules involving constants are not included as
3652/// visitSELECT() already handles those cases.
3653SDValue DAGCombiner::visitANDLike(SDValue N0, SDValue N1, SDNode *N) {
EVT VT = N1.getValueType();
SDLoc DL(N);

// fold (and x, undef) -> 0
if (N0.isUndef() || N1.isUndef())
  return DAG.getConstant(0, DL, VT);

if (SDValue V = foldLogicOfSetCCs(true, N0, N1, DL))
  return V;

if (N0.getOpcode() == ISD::ADD && N1.getOpcode() == ISD::SRL &&
    VT.getSizeInBits() <= 64) {
  if (ConstantSDNode *ADDI = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
    if (ConstantSDNode *SRLI = dyn_cast<ConstantSDNode>(N1.getOperand(1))) {
      // Look for (and (add x, c1), (lshr y, c2)). If C1 wasn't a legal
      // immediate for an add, but it is legal if its top c2 bits are set,
      // transform the ADD so the immediate doesn't need to be materialized
      // in a register.
      APInt ADDC = ADDI->getAPIntValue();
      APInt SRLC = SRLI->getAPIntValue();
      if (ADDC.getMinSignedBits() <= 64 &&
          SRLC.ult(VT.getSizeInBits()) &&
          !TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
        APInt Mask = APInt::getHighBitsSet(VT.getSizeInBits(),
                                           SRLC.getZExtValue());
        if (DAG.MaskedValueIsZero(N0.getOperand(1), Mask)) {
          ADDC |= Mask;
          if (TLI.isLegalAddImmediate(ADDC.getSExtValue())) {
            SDLoc DL0(N0);
            SDValue NewAdd =
              DAG.getNode(ISD::ADD, DL0, VT,
                          N0.getOperand(0), DAG.getConstant(ADDC, DL, VT));
            CombineTo(N0.getNode(), NewAdd);
            // Return N so it doesn't get rechecked!
            return SDValue(N, 0);
          }
        }
      }
    }
  }
}

// Reduce bit extract of low half of an integer to the narrower type.
// (and (srl i64:x, K), KMask) ->
//   (i64 zero_extend (and (srl (i32 (trunc i64:x)), K)), KMask)
if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
  if (ConstantSDNode *CAnd = dyn_cast<ConstantSDNode>(N1)) {
    if (ConstantSDNode *CShift = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
      unsigned Size = VT.getSizeInBits();
      const APInt &AndMask = CAnd->getAPIntValue();
      unsigned ShiftBits = CShift->getZExtValue();

      // Bail out, this node will probably disappear anyway.
      if (ShiftBits == 0)
        return SDValue();

      unsigned MaskBits = AndMask.countTrailingOnes();
      EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), Size / 2);

      if (AndMask.isMask() &&
          // Required bits must not span the two halves of the integer and
          // must fit in the half size type.
          (ShiftBits + MaskBits <= Size / 2) &&
          TLI.isNarrowingProfitable(VT, HalfVT) &&
          TLI.isTypeDesirableForOp(ISD::AND, HalfVT) &&
          TLI.isTypeDesirableForOp(ISD::SRL, HalfVT) &&
          TLI.isTruncateFree(VT, HalfVT) &&
          TLI.isZExtFree(HalfVT, VT)) {
        // The isNarrowingProfitable is to avoid regressions on PPC and
        // AArch64 which match a few 64-bit bit insert / bit extract patterns
        // on downstream users of this. Those patterns could probably be
        // extended to handle extensions mixed in.

        SDValue SL(N0);
        assert(MaskBits <= Size)(static_cast <bool> (MaskBits <= Size) ? void (0) : __assert_fail
 ("MaskBits <= Size", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3728, __extension__ __PRETTY_FUNCTION__));

        // Extracting the highest bit of the low half.
        EVT ShiftVT = TLI.getShiftAmountTy(HalfVT, DAG.getDataLayout());
        SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, HalfVT,
                                    N0.getOperand(0));

        SDValue NewMask = DAG.getConstant(AndMask.trunc(Size / 2), SL, HalfVT);
        SDValue ShiftK = DAG.getConstant(ShiftBits, SL, ShiftVT);
        SDValue Shift = DAG.getNode(ISD::SRL, SL, HalfVT, Trunc, ShiftK);
        SDValue And = DAG.getNode(ISD::AND, SL, HalfVT, Shift, NewMask);
        return DAG.getNode(ISD::ZERO_EXTEND, SL, VT, And);
      }
    }
  }
}

return SDValue();
3746}

3748bool DAGCombiner::isAndLoadExtLoad(ConstantSDNode *AndC, LoadSDNode *LoadN,
                                 EVT LoadResultTy, EVT &ExtVT) {
if (!AndC->getAPIntValue().isMask())
  return false;

unsigned ActiveBits = AndC->getAPIntValue().countTrailingOnes();

ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
EVT LoadedVT = LoadN->getMemoryVT();

if (ExtVT == LoadedVT &&
    (!LegalOperations ||
     TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy, ExtVT))) {
  // ZEXTLOAD will match without needing to change the size of the value being
  // loaded.
  return true;
}

// Do not change the width of a volatile load.
if (LoadN->isVolatile())
  return false;

// Do not generate loads of non-round integer types since these can
// be expensive (and would be wrong if the type is not byte sized).
if (!LoadedVT.bitsGT(ExtVT) || !ExtVT.isRound())
  return false;

if (LegalOperations &&
    !TLI.isLoadExtLegal(ISD::ZEXTLOAD, LoadResultTy, ExtVT))
  return false;

if (!TLI.shouldReduceLoadWidth(LoadN, ISD::ZEXTLOAD, ExtVT))
  return false;

return true;
3783}

3785bool DAGCombiner::isLegalNarrowLoad(LoadSDNode *LoadN, ISD::LoadExtType ExtType,
                                  EVT &ExtVT, unsigned ShAmt) {
// Don't transform one with multiple uses, this would require adding a new
// load.
if (!SDValue(LoadN, 0).hasOneUse())
  return false;

if (LegalOperations &&
    !TLI.isLoadExtLegal(ExtType, LoadN->getValueType(0), ExtVT))
  return false;

// Do not generate loads of non-round integer types since these can
// be expensive (and would be wrong if the type is not byte sized).
if (!ExtVT.isRound())
  return false;

// Don't change the width of a volatile load.
if (LoadN->isVolatile())
  return false;

// Verify that we are actually reducing a load width here.
if (LoadN->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits())
  return false;

// For the transform to be legal, the load must produce only two values
// (the value loaded and the chain).  Don't transform a pre-increment
// load, for example, which produces an extra value.  Otherwise the
// transformation is not equivalent, and the downstream logic to replace
// uses gets things wrong.
if (LoadN->getNumValues() > 2)
  return false;

// If the load that we're shrinking is an extload and we're not just
// discarding the extension we can't simply shrink the load. Bail.
// TODO: It would be possible to merge the extensions in some cases.
if (LoadN->getExtensionType() != ISD::NON_EXTLOAD &&
    LoadN->getMemoryVT().getSizeInBits() < ExtVT.getSizeInBits() + ShAmt)
  return false;

if (!TLI.shouldReduceLoadWidth(LoadN, ExtType, ExtVT))
  return false;

// It's not possible to generate a constant of extended or untyped type.
EVT PtrType = LoadN->getOperand(1).getValueType();
if (PtrType == MVT::Untyped || PtrType.isExtended())
  return false;

return true;
3833}

3835bool DAGCombiner::SearchForAndLoads(SDNode *N,
                                  SmallPtrSetImpl<LoadSDNode*> &Loads,
                                  SmallPtrSetImpl<SDNode*> &NodesWithConsts,
                                  ConstantSDNode *Mask,
                                  SDNode *&NodeToMask) {
// Recursively search for the operands, looking for loads which can be
// narrowed.
for (unsigned i = 0, e = N->getNumOperands(); i < e; ++i) {
  SDValue Op = N->getOperand(i);

  if (Op.getValueType().isVector())
    return false;

  // Some constants may need fixing up later if they are too large.
  if (auto *C = dyn_cast<ConstantSDNode>(Op)) {
    if ((N->getOpcode() == ISD::OR || N->getOpcode() == ISD::XOR) &&
        (Mask->getAPIntValue() & C->getAPIntValue()) != C->getAPIntValue())
      NodesWithConsts.insert(N);
    continue;
  }

  if (!Op.hasOneUse())
    return false;

  switch(Op.getOpcode()) {
  case ISD::LOAD: {
    auto *Load = cast<LoadSDNode>(Op);
    EVT ExtVT;
    if (isAndLoadExtLoad(Mask, Load, Load->getValueType(0), ExtVT) &&
        isLegalNarrowLoad(Load, ISD::ZEXTLOAD, ExtVT)) {

      // ZEXTLOAD is already small enough.
      if (Load->getExtensionType() == ISD::ZEXTLOAD &&
          ExtVT.bitsGE(Load->getMemoryVT()))
        continue;

      // Use LE to convert equal sized loads to zext.
      if (ExtVT.bitsLE(Load->getMemoryVT()))
        Loads.insert(Load);

      continue;
    }
    return false;
  }
  case ISD::ZERO_EXTEND:
  case ISD::AssertZext: {
    unsigned ActiveBits = Mask->getAPIntValue().countTrailingOnes();
    EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
    EVT VT = Op.getOpcode() == ISD::AssertZext ?
      cast<VTSDNode>(Op.getOperand(1))->getVT() :
      Op.getOperand(0).getValueType();

    // We can accept extending nodes if the mask is wider or an equal
    // width to the original type.
    if (ExtVT.bitsGE(VT))
      continue;
    break;
  }
  case ISD::OR:
  case ISD::XOR:
  case ISD::AND:
    if (!SearchForAndLoads(Op.getNode(), Loads, NodesWithConsts, Mask,
                           NodeToMask))
      return false;
    continue;
  }

  // Allow one node which will masked along with any loads found.
  if (NodeToMask)
    return false;
  NodeToMask = Op.getNode();
}
return true;
3908}

3910bool DAGCombiner::BackwardsPropagateMask(SDNode *N, SelectionDAG &DAG) {
auto *Mask = dyn_cast<ConstantSDNode>(N->getOperand(1));
if (!Mask)
  return false;

if (!Mask->getAPIntValue().isMask())
  return false;

// No need to do anything if the and directly uses a load.
if (isa<LoadSDNode>(N->getOperand(0)))
  return false;

SmallPtrSet<LoadSDNode*, 8> Loads;
SmallPtrSet<SDNode*, 2> NodesWithConsts;
SDNode *FixupNode = nullptr;
if (SearchForAndLoads(N, Loads, NodesWithConsts, Mask, FixupNode)) {
  if (Loads.size() == 0)
    return false;

  DEBUG(dbgs() << "Backwards propagate AND: "; N->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "Backwards propagate AND: "
; N->dump(); } } while (false);
  SDValue MaskOp = N->getOperand(1);

  // If it exists, fixup the single node we allow in the tree that needs
  // masking.
  if (FixupNode) {
    DEBUG(dbgs() << "First, need to fix up: "; FixupNode->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "First, need to fix up: "; FixupNode
->dump(); } } while (false);
    SDValue And = DAG.getNode(ISD::AND, SDLoc(FixupNode),
                              FixupNode->getValueType(0),
                              SDValue(FixupNode, 0), MaskOp);
    DAG.ReplaceAllUsesOfValueWith(SDValue(FixupNode, 0), And);
    DAG.UpdateNodeOperands(And.getNode(), SDValue(FixupNode, 0),
                           MaskOp);
  }

  // Narrow any constants that need it.
  for (auto *LogicN : NodesWithConsts) {
    SDValue Op0 = LogicN->getOperand(0);
    SDValue Op1 = LogicN->getOperand(1);

    if (isa<ConstantSDNode>(Op0))
        std::swap(Op0, Op1);

    SDValue And = DAG.getNode(ISD::AND, SDLoc(Op1), Op1.getValueType(),
                              Op1, MaskOp);

    DAG.UpdateNodeOperands(LogicN, Op0, And);
  }

  // Create narrow loads.
  for (auto *Load : Loads) {
    DEBUG(dbgs() << "Propagate AND back to: "; Load->dump())do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "Propagate AND back to: "; Load
->dump(); } } while (false);
    SDValue And = DAG.getNode(ISD::AND, SDLoc(Load), Load->getValueType(0),
                              SDValue(Load, 0), MaskOp);
    DAG.ReplaceAllUsesOfValueWith(SDValue(Load, 0), And);
    DAG.UpdateNodeOperands(And.getNode(), SDValue(Load, 0), MaskOp);
    SDValue NewLoad = ReduceLoadWidth(And.getNode());
    assert(NewLoad &&(static_cast <bool> (NewLoad && "Shouldn't be masking the load if it can't be narrowed"
) ? void (0) : __assert_fail ("NewLoad && \"Shouldn't be masking the load if it can't be narrowed\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3967, __extension__ __PRETTY_FUNCTION__))
           "Shouldn't be masking the load if it can't be narrowed")(static_cast <bool> (NewLoad && "Shouldn't be masking the load if it can't be narrowed"
) ? void (0) : __assert_fail ("NewLoad && \"Shouldn't be masking the load if it can't be narrowed\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 3967, __extension__ __PRETTY_FUNCTION__));
    CombineTo(Load, NewLoad, NewLoad.getValue(1));
  }
  DAG.ReplaceAllUsesWith(N, N->getOperand(0).getNode());
  return true;
}
return false;
3974}

3976SDValue DAGCombiner::visitAND(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N1.getValueType();

// x & x --> x
if (N0 == N1)
  return N0;

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  // fold (and x, 0) -> 0, vector edition
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    // do not return N0, because undef node may exist in N0
    return DAG.getConstant(APInt::getNullValue(N0.getScalarValueSizeInBits()),
                           SDLoc(N), N0.getValueType());
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    // do not return N1, because undef node may exist in N1
    return DAG.getConstant(APInt::getNullValue(N1.getScalarValueSizeInBits()),
                           SDLoc(N), N1.getValueType());

  // fold (and x, -1) -> x, vector edition
  if (ISD::isBuildVectorAllOnes(N0.getNode()))
    return N1;
  if (ISD::isBuildVectorAllOnes(N1.getNode()))
    return N0;
}

// fold (and c1, c2) -> c1&c2
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
ConstantSDNode *N1C = isConstOrConstSplat(N1);
if (N0C && N1C && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::AND, SDLoc(N), VT, N0C, N1C);
// canonicalize constant to RHS
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
   !DAG.isConstantIntBuildVectorOrConstantInt(N1))
  return DAG.getNode(ISD::AND, SDLoc(N), VT, N1, N0);
// fold (and x, -1) -> x
if (isAllOnesConstant(N1))
  return N0;
// if (and x, c) is known to be zero, return 0
unsigned BitWidth = VT.getScalarSizeInBits();
if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
                                 APInt::getAllOnesValue(BitWidth)))
  return DAG.getConstant(0, SDLoc(N), VT);

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// reassociate and
if (SDValue RAND = ReassociateOps(ISD::AND, SDLoc(N), N0, N1))
  return RAND;

// Try to convert a constant mask AND into a shuffle clear mask.
if (VT.isVector())
  if (SDValue Shuffle = XformToShuffleWithZero(N))
    return Shuffle;

// fold (and (or x, C), D) -> D if (C & D) == D
auto MatchSubset = [](ConstantSDNode *LHS, ConstantSDNode *RHS) {
  return RHS->getAPIntValue().isSubsetOf(LHS->getAPIntValue());
};
if (N0.getOpcode() == ISD::OR &&
    matchBinaryPredicate(N0.getOperand(1), N1, MatchSubset))
  return N1;
// fold (and (any_ext V), c) -> (zero_ext V) if 'and' only clears top bits.
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
  SDValue N0Op0 = N0.getOperand(0);
  APInt Mask = ~N1C->getAPIntValue();
  Mask = Mask.trunc(N0Op0.getScalarValueSizeInBits());
  if (DAG.MaskedValueIsZero(N0Op0, Mask)) {
    SDValue Zext = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N),
                               N0.getValueType(), N0Op0);

    // Replace uses of the AND with uses of the Zero extend node.
    CombineTo(N, Zext);

    // We actually want to replace all uses of the any_extend with the
    // zero_extend, to avoid duplicating things.  This will later cause this
    // AND to be folded.
    CombineTo(N0.getNode(), Zext);
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}
// similarly fold (and (X (load ([non_ext|any_ext|zero_ext] V))), c) ->
// (X (load ([non_ext|zero_ext] V))) if 'and' only clears top bits which must
// already be zero by virtue of the width of the base type of the load.
//
// the 'X' node here can either be nothing or an extract_vector_elt to catch
// more cases.
if ((N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
     N0.getValueSizeInBits() == N0.getOperand(0).getScalarValueSizeInBits() &&
     N0.getOperand(0).getOpcode() == ISD::LOAD &&
     N0.getOperand(0).getResNo() == 0) ||
    (N0.getOpcode() == ISD::LOAD && N0.getResNo() == 0)) {
  LoadSDNode *Load = cast<LoadSDNode>( (N0.getOpcode() == ISD::LOAD) ?
                                       N0 : N0.getOperand(0) );

  // Get the constant (if applicable) the zero'th operand is being ANDed with.
  // This can be a pure constant or a vector splat, in which case we treat the
  // vector as a scalar and use the splat value.
  APInt Constant = APInt::getNullValue(1);
  if (const ConstantSDNode *C = dyn_cast<ConstantSDNode>(N1)) {
    Constant = C->getAPIntValue();
  } else if (BuildVectorSDNode *Vector = dyn_cast<BuildVectorSDNode>(N1)) {
    APInt SplatValue, SplatUndef;
    unsigned SplatBitSize;
    bool HasAnyUndefs;
    bool IsSplat = Vector->isConstantSplat(SplatValue, SplatUndef,
                                           SplatBitSize, HasAnyUndefs);
    if (IsSplat) {
      // Undef bits can contribute to a possible optimisation if set, so
      // set them.
      SplatValue |= SplatUndef;

      // The splat value may be something like "0x00FFFFFF", which means 0 for
      // the first vector value and FF for the rest, repeating. We need a mask
      // that will apply equally to all members of the vector, so AND all the
      // lanes of the constant together.
      EVT VT = Vector->getValueType(0);
      unsigned BitWidth = VT.getScalarSizeInBits();

      // If the splat value has been compressed to a bitlength lower
      // than the size of the vector lane, we need to re-expand it to
      // the lane size.
      if (BitWidth > SplatBitSize)
        for (SplatValue = SplatValue.zextOrTrunc(BitWidth);
             SplatBitSize < BitWidth;
             SplatBitSize = SplatBitSize * 2)
          SplatValue |= SplatValue.shl(SplatBitSize);

      // Make sure that variable 'Constant' is only set if 'SplatBitSize' is a
      // multiple of 'BitWidth'. Otherwise, we could propagate a wrong value.
      if (SplatBitSize % BitWidth == 0) {
        Constant = APInt::getAllOnesValue(BitWidth);
        for (unsigned i = 0, n = SplatBitSize/BitWidth; i < n; ++i)
          Constant &= SplatValue.lshr(i*BitWidth).zextOrTrunc(BitWidth);
      }
    }
  }

  // If we want to change an EXTLOAD to a ZEXTLOAD, ensure a ZEXTLOAD is
  // actually legal and isn't going to get expanded, else this is a false
  // optimisation.
  bool CanZextLoadProfitably = TLI.isLoadExtLegal(ISD::ZEXTLOAD,
                                                  Load->getValueType(0),
                                                  Load->getMemoryVT());

  // Resize the constant to the same size as the original memory access before
  // extension. If it is still the AllOnesValue then this AND is completely
  // unneeded.
  Constant = Constant.zextOrTrunc(Load->getMemoryVT().getScalarSizeInBits());

  bool B;
  switch (Load->getExtensionType()) {
  default: B = false; break;
  case ISD::EXTLOAD: B = CanZextLoadProfitably; break;
  case ISD::ZEXTLOAD:
  case ISD::NON_EXTLOAD: B = true; break;
  }

  if (B && Constant.isAllOnesValue()) {
    // If the load type was an EXTLOAD, convert to ZEXTLOAD in order to
    // preserve semantics once we get rid of the AND.
    SDValue NewLoad(Load, 0);

    // Fold the AND away. NewLoad may get replaced immediately.
    CombineTo(N, (N0.getNode() == Load) ? NewLoad : N0);

    if (Load->getExtensionType() == ISD::EXTLOAD) {
      NewLoad = DAG.getLoad(Load->getAddressingMode(), ISD::ZEXTLOAD,
                            Load->getValueType(0), SDLoc(Load),
                            Load->getChain(), Load->getBasePtr(),
                            Load->getOffset(), Load->getMemoryVT(),
                            Load->getMemOperand());
      // Replace uses of the EXTLOAD with the new ZEXTLOAD.
      if (Load->getNumValues() == 3) {
        // PRE/POST_INC loads have 3 values.
        SDValue To[] = { NewLoad.getValue(0), NewLoad.getValue(1),
                         NewLoad.getValue(2) };
        CombineTo(Load, To, 3, true);
      } else {
        CombineTo(Load, NewLoad.getValue(0), NewLoad.getValue(1));
      }
    }

    return SDValue(N, 0); // Return N so it doesn't get rechecked!
  }
}

// fold (and (load x), 255) -> (zextload x, i8)
// fold (and (extload x, i16), 255) -> (zextload x, i8)
// fold (and (any_ext (extload x, i16)), 255) -> (zextload x, i8)
if (!VT.isVector() && N1C && (N0.getOpcode() == ISD::LOAD ||
                              (N0.getOpcode() == ISD::ANY_EXTEND &&
                               N0.getOperand(0).getOpcode() == ISD::LOAD))) {
  if (SDValue Res = ReduceLoadWidth(N)) {
    LoadSDNode *LN0 = N0->getOpcode() == ISD::ANY_EXTEND
      ? cast<LoadSDNode>(N0.getOperand(0)) : cast<LoadSDNode>(N0);

    AddToWorklist(N);
    CombineTo(LN0, Res, Res.getValue(1));
    return SDValue(N, 0);
  }
}

if (Level >= AfterLegalizeTypes) {
  // Attempt to propagate the AND back up to the leaves which, if they're
  // loads, can be combined to narrow loads and the AND node can be removed.
  // Perform after legalization so that extend nodes will already be
  // combined into the loads.
  if (BackwardsPropagateMask(N, DAG)) {
    return SDValue(N, 0);
  }
}

if (SDValue Combined = visitANDLike(N0, N1, N))
  return Combined;

// Simplify: (and (op x...), (op y...))  -> (op (and x, y))
if (N0.getOpcode() == N1.getOpcode())
  if (SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N))
    return Tmp;

// Masking the negated extension of a boolean is just the zero-extended
// boolean:
// and (sub 0, zext(bool X)), 1 --> zext(bool X)
// and (sub 0, sext(bool X)), 1 --> zext(bool X)
//
// Note: the SimplifyDemandedBits fold below can make an information-losing
// transform, and then we have no way to find this better fold.
if (N1C && N1C->isOne() && N0.getOpcode() == ISD::SUB) {
  if (isNullConstantOrNullSplatConstant(N0.getOperand(0))) {
    SDValue SubRHS = N0.getOperand(1);
    if (SubRHS.getOpcode() == ISD::ZERO_EXTEND &&
        SubRHS.getOperand(0).getScalarValueSizeInBits() == 1)
      return SubRHS;
    if (SubRHS.getOpcode() == ISD::SIGN_EXTEND &&
        SubRHS.getOperand(0).getScalarValueSizeInBits() == 1)
      return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, SubRHS.getOperand(0));
  }
}

// fold (and (sign_extend_inreg x, i16 to i32), 1) -> (and x, 1)
// fold (and (sra)) -> (and (srl)) when possible.
if (SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// fold (zext_inreg (extload x)) -> (zextload x)
if (ISD::isEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode())) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  EVT MemVT = LN0->getMemoryVT();
  // If we zero all the possible extended bits, then we can turn this into
  // a zextload if we are running before legalize or the operation is legal.
  unsigned BitWidth = N1.getScalarValueSizeInBits();
  if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
                         BitWidth - MemVT.getScalarSizeInBits())) &&
      ((!LegalOperations && !LN0->isVolatile()) ||
       TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
    SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
                                     LN0->getChain(), LN0->getBasePtr(),
                                     MemVT, LN0->getMemOperand());
    AddToWorklist(N);
    CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}
// fold (zext_inreg (sextload x)) -> (zextload x) iff load has one use
if (ISD::isSEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
    N0.hasOneUse()) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  EVT MemVT = LN0->getMemoryVT();
  // If we zero all the possible extended bits, then we can turn this into
  // a zextload if we are running before legalize or the operation is legal.
  unsigned BitWidth = N1.getScalarValueSizeInBits();
  if (DAG.MaskedValueIsZero(N1, APInt::getHighBitsSet(BitWidth,
                         BitWidth - MemVT.getScalarSizeInBits())) &&
      ((!LegalOperations && !LN0->isVolatile()) ||
       TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT))) {
    SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N0), VT,
                                     LN0->getChain(), LN0->getBasePtr(),
                                     MemVT, LN0->getMemOperand());
    AddToWorklist(N);
    CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}
// fold (and (or (srl N, 8), (shl N, 8)), 0xffff) -> (srl (bswap N), const)
if (N1C && N1C->getAPIntValue() == 0xffff && N0.getOpcode() == ISD::OR) {
  if (SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
                                         N0.getOperand(1), false))
    return BSwap;
}

return SDValue();
4274}

4276/// Match (a >> 8) | (a << 8) as (bswap a) >> 16.
4277SDValue DAGCombiner::MatchBSwapHWordLow(SDNode *N, SDValue N0, SDValue N1,
                                      bool DemandHighBits) {
if (!LegalOperations)
  return SDValue();

EVT VT = N->getValueType(0);
if (VT != MVT::i64 && VT != MVT::i32 && VT != MVT::i16)
  return SDValue();
if (!TLI.isOperationLegalOrCustom(ISD::BSWAP, VT))
  return SDValue();

// Recognize (and (shl a, 8), 0xff00), (and (srl a, 8), 0xff)
bool LookPassAnd0 = false;
bool LookPassAnd1 = false;
if (N0.getOpcode() == ISD::AND && N0.getOperand(0).getOpcode() == ISD::SRL)
    std::swap(N0, N1);
if (N1.getOpcode() == ISD::AND && N1.getOperand(0).getOpcode() == ISD::SHL)
    std::swap(N0, N1);
if (N0.getOpcode() == ISD::AND) {
  if (!N0.getNode()->hasOneUse())
    return SDValue();
  ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
  if (!N01C || N01C->getZExtValue() != 0xFF00)
    return SDValue();
  N0 = N0.getOperand(0);
  LookPassAnd0 = true;
}

if (N1.getOpcode() == ISD::AND) {
  if (!N1.getNode()->hasOneUse())
    return SDValue();
  ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
  if (!N11C || N11C->getZExtValue() != 0xFF)
    return SDValue();
  N1 = N1.getOperand(0);
  LookPassAnd1 = true;
}

if (N0.getOpcode() == ISD::SRL && N1.getOpcode() == ISD::SHL)
  std::swap(N0, N1);
if (N0.getOpcode() != ISD::SHL || N1.getOpcode() != ISD::SRL)
  return SDValue();
if (!N0.getNode()->hasOneUse() || !N1.getNode()->hasOneUse())
  return SDValue();

ConstantSDNode *N01C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1));
if (!N01C || !N11C)
  return SDValue();
if (N01C->getZExtValue() != 8 || N11C->getZExtValue() != 8)
  return SDValue();

// Look for (shl (and a, 0xff), 8), (srl (and a, 0xff00), 8)
SDValue N00 = N0->getOperand(0);
if (!LookPassAnd0 && N00.getOpcode() == ISD::AND) {
  if (!N00.getNode()->hasOneUse())
    return SDValue();
  ConstantSDNode *N001C = dyn_cast<ConstantSDNode>(N00.getOperand(1));
  if (!N001C || N001C->getZExtValue() != 0xFF)
    return SDValue();
  N00 = N00.getOperand(0);
  LookPassAnd0 = true;
}

SDValue N10 = N1->getOperand(0);
if (!LookPassAnd1 && N10.getOpcode() == ISD::AND) {
  if (!N10.getNode()->hasOneUse())
    return SDValue();
  ConstantSDNode *N101C = dyn_cast<ConstantSDNode>(N10.getOperand(1));
  if (!N101C || N101C->getZExtValue() != 0xFF00)
    return SDValue();
  N10 = N10.getOperand(0);
  LookPassAnd1 = true;
}

if (N00 != N10)
  return SDValue();

// Make sure everything beyond the low halfword gets set to zero since the SRL
// 16 will clear the top bits.
unsigned OpSizeInBits = VT.getSizeInBits();
if (DemandHighBits && OpSizeInBits > 16) {
  // If the left-shift isn't masked out then the only way this is a bswap is
  // if all bits beyond the low 8 are 0. In that case the entire pattern
  // reduces to a left shift anyway: leave it for other parts of the combiner.
  if (!LookPassAnd0)
    return SDValue();

  // However, if the right shift isn't masked out then it might be because
  // it's not needed. See if we can spot that too.
  if (!LookPassAnd1 &&
      !DAG.MaskedValueIsZero(
          N10, APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - 16)))
    return SDValue();
}

SDValue Res = DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N00);
if (OpSizeInBits > 16) {
  SDLoc DL(N);
  Res = DAG.getNode(ISD::SRL, DL, VT, Res,
                    DAG.getConstant(OpSizeInBits - 16, DL,
                                    getShiftAmountTy(VT)));
}
return Res;
4381}

4383/// Return true if the specified node is an element that makes up a 32-bit
4384/// packed halfword byteswap.
4385/// ((x & 0x000000ff) << 8) |
4386/// ((x & 0x0000ff00) >> 8) |
4387/// ((x & 0x00ff0000) << 8) |
4388/// ((x & 0xff000000) >> 8)
4389static bool isBSwapHWordElement(SDValue N, MutableArrayRef<SDNode *> Parts) {
if (!N.getNode()->hasOneUse())
  return false;

unsigned Opc = N.getOpcode();
if (Opc != ISD::AND && Opc != ISD::SHL && Opc != ISD::SRL)
  return false;

SDValue N0 = N.getOperand(0);
unsigned Opc0 = N0.getOpcode();
if (Opc0 != ISD::AND && Opc0 != ISD::SHL && Opc0 != ISD::SRL)
  return false;

ConstantSDNode *N1C = nullptr;
// SHL or SRL: look upstream for AND mask operand
if (Opc == ISD::AND)
  N1C = dyn_cast<ConstantSDNode>(N.getOperand(1));
else if (Opc0 == ISD::AND)
  N1C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
if (!N1C)
  return false;

unsigned MaskByteOffset;
switch (N1C->getZExtValue()) {
default:
  return false;
case 0xFF:       MaskByteOffset = 0; break;
case 0xFF00:     MaskByteOffset = 1; break;
case 0xFF0000:   MaskByteOffset = 2; break;
case 0xFF000000: MaskByteOffset = 3; break;
}

// Look for (x & 0xff) << 8 as well as ((x << 8) & 0xff00).
if (Opc == ISD::AND) {
  if (MaskByteOffset == 0 || MaskByteOffset == 2) {
    // (x >> 8) & 0xff
    // (x >> 8) & 0xff0000
    if (Opc0 != ISD::SRL)
      return false;
    ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
    if (!C || C->getZExtValue() != 8)
      return false;
  } else {
    // (x << 8) & 0xff00
    // (x << 8) & 0xff000000
    if (Opc0 != ISD::SHL)
      return false;
    ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));
    if (!C || C->getZExtValue() != 8)
      return false;
  }
} else if (Opc == ISD::SHL) {
  // (x & 0xff) << 8
  // (x & 0xff0000) << 8
  if (MaskByteOffset != 0 && MaskByteOffset != 2)
    return false;
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
  if (!C || C->getZExtValue() != 8)
    return false;
} else { // Opc == ISD::SRL
  // (x & 0xff00) >> 8
  // (x & 0xff000000) >> 8
  if (MaskByteOffset != 1 && MaskByteOffset != 3)
    return false;
  ConstantSDNode *C = dyn_cast<ConstantSDNode>(N.getOperand(1));
  if (!C || C->getZExtValue() != 8)
    return false;
}

if (Parts[MaskByteOffset])
  return false;

Parts[MaskByteOffset] = N0.getOperand(0).getNode();
return true;
4463}

4465/// Match a 32-bit packed halfword bswap. That is
4466/// ((x & 0x000000ff) << 8) |
4467/// ((x & 0x0000ff00) >> 8) |
4468/// ((x & 0x00ff0000) << 8) |
4469/// ((x & 0xff000000) >> 8)
4470/// => (rotl (bswap x), 16)
4471SDValue DAGCombiner::MatchBSwapHWord(SDNode *N, SDValue N0, SDValue N1) {
if (!LegalOperations)
  return SDValue();

EVT VT = N->getValueType(0);
if (VT != MVT::i32)
  return SDValue();
if (!TLI.isOperationLegalOrCustom(ISD::BSWAP, VT))
  return SDValue();

// Look for either
// (or (or (and), (and)), (or (and), (and)))
// (or (or (or (and), (and)), (and)), (and))
if (N0.getOpcode() != ISD::OR)
  return SDValue();
SDValue N00 = N0.getOperand(0);
SDValue N01 = N0.getOperand(1);
SDNode *Parts[4] = {};

if (N1.getOpcode() == ISD::OR &&
    N00.getNumOperands() == 2 && N01.getNumOperands() == 2) {
  // (or (or (and), (and)), (or (and), (and)))
  if (!isBSwapHWordElement(N00, Parts))
    return SDValue();

  if (!isBSwapHWordElement(N01, Parts))
    return SDValue();
  SDValue N10 = N1.getOperand(0);
  if (!isBSwapHWordElement(N10, Parts))
    return SDValue();
  SDValue N11 = N1.getOperand(1);
  if (!isBSwapHWordElement(N11, Parts))
    return SDValue();
} else {
  // (or (or (or (and), (and)), (and)), (and))
  if (!isBSwapHWordElement(N1, Parts))
    return SDValue();
  if (!isBSwapHWordElement(N01, Parts))
    return SDValue();
  if (N00.getOpcode() != ISD::OR)
    return SDValue();
  SDValue N000 = N00.getOperand(0);
  if (!isBSwapHWordElement(N000, Parts))
    return SDValue();
  SDValue N001 = N00.getOperand(1);
  if (!isBSwapHWordElement(N001, Parts))
    return SDValue();
}

// Make sure the parts are all coming from the same node.
if (Parts[0] != Parts[1] || Parts[0] != Parts[2] || Parts[0] != Parts[3])
  return SDValue();

SDLoc DL(N);
SDValue BSwap = DAG.getNode(ISD::BSWAP, DL, VT,
                            SDValue(Parts[0], 0));

// Result of the bswap should be rotated by 16. If it's not legal, then
// do  (x << 16) | (x >> 16).
SDValue ShAmt = DAG.getConstant(16, DL, getShiftAmountTy(VT));
if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT))
  return DAG.getNode(ISD::ROTL, DL, VT, BSwap, ShAmt);
if (TLI.isOperationLegalOrCustom(ISD::ROTR, VT))
  return DAG.getNode(ISD::ROTR, DL, VT, BSwap, ShAmt);
return DAG.getNode(ISD::OR, DL, VT,
                   DAG.getNode(ISD::SHL, DL, VT, BSwap, ShAmt),
                   DAG.getNode(ISD::SRL, DL, VT, BSwap, ShAmt));
4538}

4540/// This contains all DAGCombine rules which reduce two values combined by
4541/// an Or operation to a single value \see visitANDLike().
4542SDValue DAGCombiner::visitORLike(SDValue N0, SDValue N1, SDNode *N) {
EVT VT = N1.getValueType();
SDLoc DL(N);

// fold (or x, undef) -> -1
if (!LegalOperations && (N0.isUndef() || N1.isUndef()))
  return DAG.getAllOnesConstant(DL, VT);

if (SDValue V = foldLogicOfSetCCs(false, N0, N1, DL))
  return V;

// (or (and X, C1), (and Y, C2))  -> (and (or X, Y), C3) if possible.
if (N0.getOpcode() == ISD::AND && N1.getOpcode() == ISD::AND &&
    // Don't increase # computations.
    (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
  // We can only do this xform if we know that bits from X that are set in C2
  // but not in C1 are already zero.  Likewise for Y.
  if (const ConstantSDNode *N0O1C =
      getAsNonOpaqueConstant(N0.getOperand(1))) {
    if (const ConstantSDNode *N1O1C =
        getAsNonOpaqueConstant(N1.getOperand(1))) {
      // We can only do this xform if we know that bits from X that are set in
      // C2 but not in C1 are already zero.  Likewise for Y.
      const APInt &LHSMask = N0O1C->getAPIntValue();
      const APInt &RHSMask = N1O1C->getAPIntValue();

      if (DAG.MaskedValueIsZero(N0.getOperand(0), RHSMask&~LHSMask) &&
          DAG.MaskedValueIsZero(N1.getOperand(0), LHSMask&~RHSMask)) {
        SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
                                N0.getOperand(0), N1.getOperand(0));
        return DAG.getNode(ISD::AND, DL, VT, X,
                           DAG.getConstant(LHSMask | RHSMask, DL, VT));
      }
    }
  }
}

// (or (and X, M), (and X, N)) -> (and X, (or M, N))
if (N0.getOpcode() == ISD::AND &&
    N1.getOpcode() == ISD::AND &&
    N0.getOperand(0) == N1.getOperand(0) &&
    // Don't increase # computations.
    (N0.getNode()->hasOneUse() || N1.getNode()->hasOneUse())) {
  SDValue X = DAG.getNode(ISD::OR, SDLoc(N0), VT,
                          N0.getOperand(1), N1.getOperand(1));
  return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0), X);
}

return SDValue();
4591}

4593SDValue DAGCombiner::visitOR(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N1.getValueType();

// x | x --> x
if (N0 == N1)
  return N0;

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  // fold (or x, 0) -> x, vector edition
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    return N1;
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N0;

  // fold (or x, -1) -> -1, vector edition
  if (ISD::isBuildVectorAllOnes(N0.getNode()))
    // do not return N0, because undef node may exist in N0
    return DAG.getAllOnesConstant(SDLoc(N), N0.getValueType());
  if (ISD::isBuildVectorAllOnes(N1.getNode()))
    // do not return N1, because undef node may exist in N1
    return DAG.getAllOnesConstant(SDLoc(N), N1.getValueType());

  // fold (or (shuf A, V_0, MA), (shuf B, V_0, MB)) -> (shuf A, B, Mask)
  // Do this only if the resulting shuffle is legal.
  if (isa<ShuffleVectorSDNode>(N0) &&
      isa<ShuffleVectorSDNode>(N1) &&
      // Avoid folding a node with illegal type.
      TLI.isTypeLegal(VT)) {
    bool ZeroN00 = ISD::isBuildVectorAllZeros(N0.getOperand(0).getNode());
    bool ZeroN01 = ISD::isBuildVectorAllZeros(N0.getOperand(1).getNode());
    bool ZeroN10 = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());
    bool ZeroN11 = ISD::isBuildVectorAllZeros(N1.getOperand(1).getNode());
    // Ensure both shuffles have a zero input.
    if ((ZeroN00 != ZeroN01) && (ZeroN10 != ZeroN11)) {
      assert((!ZeroN00 || !ZeroN01) && "Both inputs zero!")(static_cast <bool> ((!ZeroN00 || !ZeroN01) && "Both inputs zero!"
) ? void (0) : __assert_fail ("(!ZeroN00 || !ZeroN01) && \"Both inputs zero!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 4633, __extension__ __PRETTY_FUNCTION__));
      assert((!ZeroN10 || !ZeroN11) && "Both inputs zero!")(static_cast <bool> ((!ZeroN10 || !ZeroN11) && "Both inputs zero!"
) ? void (0) : __assert_fail ("(!ZeroN10 || !ZeroN11) && \"Both inputs zero!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 4634, __extension__ __PRETTY_FUNCTION__));
      const ShuffleVectorSDNode *SV0 = cast<ShuffleVectorSDNode>(N0);
      const ShuffleVectorSDNode *SV1 = cast<ShuffleVectorSDNode>(N1);
      bool CanFold = true;
      int NumElts = VT.getVectorNumElements();
      SmallVector<int, 4> Mask(NumElts);

      for (int i = 0; i != NumElts; ++i) {
        int M0 = SV0->getMaskElt(i);
        int M1 = SV1->getMaskElt(i);

        // Determine if either index is pointing to a zero vector.
        bool M0Zero = M0 < 0 || (ZeroN00 == (M0 < NumElts));
        bool M1Zero = M1 < 0 || (ZeroN10 == (M1 < NumElts));

        // If one element is zero and the otherside is undef, keep undef.
        // This also handles the case that both are undef.
        if ((M0Zero && M1 < 0) || (M1Zero && M0 < 0)) {
          Mask[i] = -1;
          continue;
        }

        // Make sure only one of the elements is zero.
        if (M0Zero == M1Zero) {
          CanFold = false;
          break;
        }

        assert((M0 >= 0 || M1 >= 0) && "Undef index!")(static_cast <bool> ((M0 >= 0 || M1 >= 0) &&
 "Undef index!") ? void (0) : __assert_fail ("(M0 >= 0 || M1 >= 0) && \"Undef index!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 4662, __extension__ __PRETTY_FUNCTION__));

        // We have a zero and non-zero element. If the non-zero came from
        // SV0 make the index a LHS index. If it came from SV1, make it
        // a RHS index. We need to mod by NumElts because we don't care
        // which operand it came from in the original shuffles.
        Mask[i] = M1Zero ? M0 % NumElts : (M1 % NumElts) + NumElts;
      }

      if (CanFold) {
        SDValue NewLHS = ZeroN00 ? N0.getOperand(1) : N0.getOperand(0);
        SDValue NewRHS = ZeroN10 ? N1.getOperand(1) : N1.getOperand(0);

        bool LegalMask = TLI.isShuffleMaskLegal(Mask, VT);
        if (!LegalMask) {
          std::swap(NewLHS, NewRHS);
          ShuffleVectorSDNode::commuteMask(Mask);
          LegalMask = TLI.isShuffleMaskLegal(Mask, VT);
        }

        if (LegalMask)
          return DAG.getVectorShuffle(VT, SDLoc(N), NewLHS, NewRHS, Mask);
      }
    }
  }
}

// fold (or c1, c2) -> c1|c2
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1);
if (N0C && N1C && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::OR, SDLoc(N), VT, N0C, N1C);
// canonicalize constant to RHS
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
   !DAG.isConstantIntBuildVectorOrConstantInt(N1))
  return DAG.getNode(ISD::OR, SDLoc(N), VT, N1, N0);
// fold (or x, 0) -> x
if (isNullConstant(N1))
  return N0;
// fold (or x, -1) -> -1
if (isAllOnesConstant(N1))
  return N1;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (or x, c) -> c iff (x & ~c) == 0
if (N1C && DAG.MaskedValueIsZero(N0, ~N1C->getAPIntValue()))
  return N1;

if (SDValue Combined = visitORLike(N0, N1, N))
  return Combined;

// Recognize halfword bswaps as (bswap + rotl 16) or (bswap + shl 16)
if (SDValue BSwap = MatchBSwapHWord(N, N0, N1))
  return BSwap;
if (SDValue BSwap = MatchBSwapHWordLow(N, N0, N1))
  return BSwap;

// reassociate or
if (SDValue ROR = ReassociateOps(ISD::OR, SDLoc(N), N0, N1))
  return ROR;

// Canonicalize (or (and X, c1), c2) -> (and (or X, c2), c1|c2)
// iff (c1 & c2) != 0.
auto MatchIntersect = [](ConstantSDNode *LHS, ConstantSDNode *RHS) {
  return LHS->getAPIntValue().intersects(RHS->getAPIntValue());
};
if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
    matchBinaryPredicate(N0.getOperand(1), N1, MatchIntersect)) {
  if (SDValue COR = DAG.FoldConstantArithmetic(
          ISD::OR, SDLoc(N1), VT, N1.getNode(), N0.getOperand(1).getNode())) {
    SDValue IOR = DAG.getNode(ISD::OR, SDLoc(N0), VT, N0.getOperand(0), N1);
    AddToWorklist(IOR.getNode());
    return DAG.getNode(ISD::AND, SDLoc(N), VT, COR, IOR);
  }
}

// Simplify: (or (op x...), (op y...))  -> (op (or x, y))
if (N0.getOpcode() == N1.getOpcode())
  if (SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N))
    return Tmp;

// See if this is some rotate idiom.
if (SDNode *Rot = MatchRotate(N0, N1, SDLoc(N)))
  return SDValue(Rot, 0);

if (SDValue Load = MatchLoadCombine(N))
  return Load;

// Simplify the operands using demanded-bits information.
if (SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

return SDValue();
4757}

4759/// Match "(X shl/srl V1) & V2" where V2 may not be present.
4760bool DAGCombiner::MatchRotateHalf(SDValue Op, SDValue &Shift, SDValue &Mask) {
if (Op.getOpcode() == ISD::AND) {
  if (DAG.isConstantIntBuildVectorOrConstantInt(Op.getOperand(1))) {
    Mask = Op.getOperand(1);
    Op = Op.getOperand(0);
  } else {
    return false;
  }
}

if (Op.getOpcode() == ISD::SRL || Op.getOpcode() == ISD::SHL) {
  Shift = Op;
  return true;
}

return false;
4776}

4778// Return true if we can prove that, whenever Neg and Pos are both in the
4779// range [0, EltSize), Neg == (Pos == 0 ? 0 : EltSize - Pos).  This means that
4780// for two opposing shifts shift1 and shift2 and a value X with OpBits bits:
4781//
4782//     (or (shift1 X, Neg), (shift2 X, Pos))
4783//
4784// reduces to a rotate in direction shift2 by Pos or (equivalently) a rotate
4785// in direction shift1 by Neg.  The range [0, EltSize) means that we only need
4786// to consider shift amounts with defined behavior.
4787static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned EltSize) {
// If EltSize is a power of 2 then:
//
//  (a) (Pos == 0 ? 0 : EltSize - Pos) == (EltSize - Pos) & (EltSize - 1)
//  (b) Neg == Neg & (EltSize - 1) whenever Neg is in [0, EltSize).
//
// So if EltSize is a power of 2 and Neg is (and Neg', EltSize-1), we check
// for the stronger condition:
//
//     Neg & (EltSize - 1) == (EltSize - Pos) & (EltSize - 1)    [A]
//
// for all Neg and Pos.  Since Neg & (EltSize - 1) == Neg' & (EltSize - 1)
// we can just replace Neg with Neg' for the rest of the function.
//
// In other cases we check for the even stronger condition:
//
//     Neg == EltSize - Pos                                    [B]
//
// for all Neg and Pos.  Note that the (or ...) then invokes undefined
// behavior if Pos == 0 (and consequently Neg == EltSize).
//
// We could actually use [A] whenever EltSize is a power of 2, but the
// only extra cases that it would match are those uninteresting ones
// where Neg and Pos are never in range at the same time.  E.g. for
// EltSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
// as well as (sub 32, Pos), but:
//
//     (or (shift1 X, (sub 64, Pos)), (shift2 X, Pos))
//
// always invokes undefined behavior for 32-bit X.
//
// Below, Mask == EltSize - 1 when using [A] and is all-ones otherwise.
unsigned MaskLoBits = 0;
if (Neg.getOpcode() == ISD::AND && isPowerOf2_64(EltSize)) {
  if (ConstantSDNode *NegC = isConstOrConstSplat(Neg.getOperand(1))) {
    if (NegC->getAPIntValue() == EltSize - 1) {
      Neg = Neg.getOperand(0);
      MaskLoBits = Log2_64(EltSize);
    }
  }
}

// Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
if (Neg.getOpcode() != ISD::SUB)
  return false;
ConstantSDNode *NegC = isConstOrConstSplat(Neg.getOperand(0));
if (!NegC)
  return false;
SDValue NegOp1 = Neg.getOperand(1);

// On the RHS of [A], if Pos is Pos' & (EltSize - 1), just replace Pos with
// Pos'.  The truncation is redundant for the purpose of the equality.
if (MaskLoBits && Pos.getOpcode() == ISD::AND)
  if (ConstantSDNode *PosC = isConstOrConstSplat(Pos.getOperand(1)))
    if (PosC->getAPIntValue() == EltSize - 1)
      Pos = Pos.getOperand(0);

// The condition we need is now:
//
//     (NegC - NegOp1) & Mask == (EltSize - Pos) & Mask
//
// If NegOp1 == Pos then we need:
//
//              EltSize & Mask == NegC & Mask
//
// (because "x & Mask" is a truncation and distributes through subtraction).
APInt Width;
if (Pos == NegOp1)
  Width = NegC->getAPIntValue();

// Check for cases where Pos has the form (add NegOp1, PosC) for some PosC.
// Then the condition we want to prove becomes:
//
//     (NegC - NegOp1) & Mask == (EltSize - (NegOp1 + PosC)) & Mask
//
// which, again because "x & Mask" is a truncation, becomes:
//
//                NegC & Mask == (EltSize - PosC) & Mask
//             EltSize & Mask == (NegC + PosC) & Mask
else if (Pos.getOpcode() == ISD::ADD && Pos.getOperand(0) == NegOp1) {
  if (ConstantSDNode *PosC = isConstOrConstSplat(Pos.getOperand(1)))
    Width = PosC->getAPIntValue() + NegC->getAPIntValue();
  else
    return false;
} else
  return false;

// Now we just need to check that EltSize & Mask == Width & Mask.
if (MaskLoBits)
  // EltSize & Mask is 0 since Mask is EltSize - 1.
  return Width.getLoBits(MaskLoBits) == 0;
return Width == EltSize;
4879}

4881// A subroutine of MatchRotate used once we have found an OR of two opposite
4882// shifts of Shifted.  If Neg == <operand size> - Pos then the OR reduces
4883// to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
4884// former being preferred if supported.  InnerPos and InnerNeg are Pos and
4885// Neg with outer conversions stripped away.
4886SDNode *DAGCombiner::MatchRotatePosNeg(SDValue Shifted, SDValue Pos,
                                     SDValue Neg, SDValue InnerPos,
                                     SDValue InnerNeg, unsigned PosOpcode,
                                     unsigned NegOpcode, const SDLoc &DL) {
// fold (or (shl x, (*ext y)),
//          (srl x, (*ext (sub 32, y)))) ->
//   (rotl x, y) or (rotr x, (sub 32, y))
//
// fold (or (shl x, (*ext (sub 32, y))),
//          (srl x, (*ext y))) ->
//   (rotr x, y) or (rotl x, (sub 32, y))
EVT VT = Shifted.getValueType();
if (matchRotateSub(InnerPos, InnerNeg, VT.getScalarSizeInBits())) {
  bool HasPos = TLI.isOperationLegalOrCustom(PosOpcode, VT);
  return DAG.getNode(HasPos ? PosOpcode : NegOpcode, DL, VT, Shifted,
                     HasPos ? Pos : Neg).getNode();
}

return nullptr;
4905}

4907// MatchRotate - Handle an 'or' of two operands.  If this is one of the many
4908// idioms for rotate, and if the target supports rotation instructions, generate
4909// a rot[lr].
4910SDNode *DAGCombiner::MatchRotate(SDValue LHS, SDValue RHS, const SDLoc &DL) {
// Must be a legal type.  Expanded 'n promoted things won't work with rotates.
EVT VT = LHS.getValueType();
if (!TLI.isTypeLegal(VT)) return nullptr;

// The target must have at least one rotate flavor.
bool HasROTL = TLI.isOperationLegalOrCustom(ISD::ROTL, VT);
bool HasROTR = TLI.isOperationLegalOrCustom(ISD::ROTR, VT);
if (!HasROTL && !HasROTR) return nullptr;

// Check for truncated rotate.
if (LHS.getOpcode() == ISD::TRUNCATE && RHS.getOpcode() == ISD::TRUNCATE &&
    LHS.getOperand(0).getValueType() == RHS.getOperand(0).getValueType()) {
  assert(LHS.getValueType() == RHS.getValueType())(static_cast <bool> (LHS.getValueType() == RHS.getValueType
()) ? void (0) : __assert_fail ("LHS.getValueType() == RHS.getValueType()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 4923, __extension__ __PRETTY_FUNCTION__));
  if (SDNode *Rot = MatchRotate(LHS.getOperand(0), RHS.getOperand(0), DL)) {
    return DAG.getNode(ISD::TRUNCATE, SDLoc(LHS), LHS.getValueType(),
                       SDValue(Rot, 0)).getNode();
  }
}

// Match "(X shl/srl V1) & V2" where V2 may not be present.
SDValue LHSShift;   // The shift.
SDValue LHSMask;    // AND value if any.
if (!MatchRotateHalf(LHS, LHSShift, LHSMask))
  return nullptr; // Not part of a rotate.

SDValue RHSShift;   // The shift.
SDValue RHSMask;    // AND value if any.
if (!MatchRotateHalf(RHS, RHSShift, RHSMask))
  return nullptr; // Not part of a rotate.

if (LHSShift.getOperand(0) != RHSShift.getOperand(0))
  return nullptr;   // Not shifting the same value.

if (LHSShift.getOpcode() == RHSShift.getOpcode())
  return nullptr;   // Shifts must disagree.

// Canonicalize shl to left side in a shl/srl pair.
if (RHSShift.getOpcode() == ISD::SHL) {
  std::swap(LHS, RHS);
  std::swap(LHSShift, RHSShift);
  std::swap(LHSMask, RHSMask);
}

unsigned EltSizeInBits = VT.getScalarSizeInBits();
SDValue LHSShiftArg = LHSShift.getOperand(0);
SDValue LHSShiftAmt = LHSShift.getOperand(1);
SDValue RHSShiftArg = RHSShift.getOperand(0);
SDValue RHSShiftAmt = RHSShift.getOperand(1);

// fold (or (shl x, C1), (srl x, C2)) -> (rotl x, C1)
// fold (or (shl x, C1), (srl x, C2)) -> (rotr x, C2)
auto MatchRotateSum = [EltSizeInBits](ConstantSDNode *LHS,
                                      ConstantSDNode *RHS) {
  return (LHS->getAPIntValue() + RHS->getAPIntValue()) == EltSizeInBits;
};
if (matchBinaryPredicate(LHSShiftAmt, RHSShiftAmt, MatchRotateSum)) {
  SDValue Rot = DAG.getNode(HasROTL ? ISD::ROTL : ISD::ROTR, DL, VT,
                            LHSShiftArg, HasROTL ? LHSShiftAmt : RHSShiftAmt);

  // If there is an AND of either shifted operand, apply it to the result.
  if (LHSMask.getNode() || RHSMask.getNode()) {
    SDValue AllOnes = DAG.getAllOnesConstant(DL, VT);
    SDValue Mask = AllOnes;

    if (LHSMask.getNode()) {
      SDValue RHSBits = DAG.getNode(ISD::SRL, DL, VT, AllOnes, RHSShiftAmt);
      Mask = DAG.getNode(ISD::AND, DL, VT, Mask,
                         DAG.getNode(ISD::OR, DL, VT, LHSMask, RHSBits));
    }
    if (RHSMask.getNode()) {
      SDValue LHSBits = DAG.getNode(ISD::SHL, DL, VT, AllOnes, LHSShiftAmt);
      Mask = DAG.getNode(ISD::AND, DL, VT, Mask,
                         DAG.getNode(ISD::OR, DL, VT, RHSMask, LHSBits));
    }

    Rot = DAG.getNode(ISD::AND, DL, VT, Rot, Mask);
  }

  return Rot.getNode();
}

// If there is a mask here, and we have a variable shift, we can't be sure
// that we're masking out the right stuff.
if (LHSMask.getNode() || RHSMask.getNode())
  return nullptr;

// If the shift amount is sign/zext/any-extended just peel it off.
SDValue LExtOp0 = LHSShiftAmt;
SDValue RExtOp0 = RHSShiftAmt;
if ((LHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
     LHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
     LHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
     LHSShiftAmt.getOpcode() == ISD::TRUNCATE) &&
    (RHSShiftAmt.getOpcode() == ISD::SIGN_EXTEND ||
     RHSShiftAmt.getOpcode() == ISD::ZERO_EXTEND ||
     RHSShiftAmt.getOpcode() == ISD::ANY_EXTEND ||
     RHSShiftAmt.getOpcode() == ISD::TRUNCATE)) {
  LExtOp0 = LHSShiftAmt.getOperand(0);
  RExtOp0 = RHSShiftAmt.getOperand(0);
}

SDNode *TryL = MatchRotatePosNeg(LHSShiftArg, LHSShiftAmt, RHSShiftAmt,
                                 LExtOp0, RExtOp0, ISD::ROTL, ISD::ROTR, DL);
if (TryL)
  return TryL;

SDNode *TryR = MatchRotatePosNeg(RHSShiftArg, RHSShiftAmt, LHSShiftAmt,
                                 RExtOp0, LExtOp0, ISD::ROTR, ISD::ROTL, DL);
if (TryR)
  return TryR;

return nullptr;
5023}

5025namespace {

5027/// Represents known origin of an individual byte in load combine pattern. The
5028/// value of the byte is either constant zero or comes from memory.
5029struct ByteProvider {
// For constant zero providers Load is set to nullptr. For memory providers
// Load represents the node which loads the byte from memory.
// ByteOffset is the offset of the byte in the value produced by the load.
LoadSDNode *Load = nullptr;
unsigned ByteOffset = 0;

ByteProvider() = default;

static ByteProvider getMemory(LoadSDNode *Load, unsigned ByteOffset) {
  return ByteProvider(Load, ByteOffset);
}

static ByteProvider getConstantZero() { return ByteProvider(nullptr, 0); }

bool isConstantZero() const { return !Load; }
bool isMemory() const { return Load; }

bool operator==(const ByteProvider &Other) const {
  return Other.Load == Load && Other.ByteOffset == ByteOffset;
}

5051private:
ByteProvider(LoadSDNode *Load, unsigned ByteOffset)
    : Load(Load), ByteOffset(ByteOffset) {}
5054};

5056} // end anonymous namespace

5058/// Recursively traverses the expression calculating the origin of the requested
5059/// byte of the given value. Returns None if the provider can't be calculated.
5060///
5061/// For all the values except the root of the expression verifies that the value
5062/// has exactly one use and if it's not true return None. This way if the origin
5063/// of the byte is returned it's guaranteed that the values which contribute to
5064/// the byte are not used outside of this expression.
5065///
5066/// Because the parts of the expression are not allowed to have more than one
5067/// use this function iterates over trees, not DAGs. So it never visits the same
5068/// node more than once.
5069static const Optional<ByteProvider>
5070calculateByteProvider(SDValue Op, unsigned Index, unsigned Depth,
                    bool Root = false) {
// Typical i64 by i8 pattern requires recursion up to 8 calls depth
if (Depth == 10)
  return None;

if (!Root && !Op.hasOneUse())
  return None;

assert(Op.getValueType().isScalarInteger() && "can't handle other types")(static_cast <bool> (Op.getValueType().isScalarInteger(
) && "can't handle other types") ? void (0) : __assert_fail
 ("Op.getValueType().isScalarInteger() && \"can't handle other types\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5079, __extension__ __PRETTY_FUNCTION__));
unsigned BitWidth = Op.getValueSizeInBits();
if (BitWidth % 8 != 0)
  return None;
unsigned ByteWidth = BitWidth / 8;
assert(Index < ByteWidth && "invalid index requested")(static_cast <bool> (Index < ByteWidth && "invalid index requested"
) ? void (0) : __assert_fail ("Index < ByteWidth && \"invalid index requested\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5084, __extension__ __PRETTY_FUNCTION__));
(void) ByteWidth;

switch (Op.getOpcode()) {
case ISD::OR: {
  auto LHS = calculateByteProvider(Op->getOperand(0), Index, Depth + 1);
  if (!LHS)
    return None;
  auto RHS = calculateByteProvider(Op->getOperand(1), Index, Depth + 1);
  if (!RHS)
    return None;

  if (LHS->isConstantZero())
    return RHS;
  if (RHS->isConstantZero())
    return LHS;
  return None;
}
case ISD::SHL: {
  auto ShiftOp = dyn_cast<ConstantSDNode>(Op->getOperand(1));
  if (!ShiftOp)
    return None;

  uint64_t BitShift = ShiftOp->getZExtValue();
  if (BitShift % 8 != 0)
    return None;
  uint64_t ByteShift = BitShift / 8;

  return Index < ByteShift
             ? ByteProvider::getConstantZero()
             : calculateByteProvider(Op->getOperand(0), Index - ByteShift,
                                     Depth + 1);
}
case ISD::ANY_EXTEND:
case ISD::SIGN_EXTEND:
case ISD::ZERO_EXTEND: {
  SDValue NarrowOp = Op->getOperand(0);
  unsigned NarrowBitWidth = NarrowOp.getScalarValueSizeInBits();
  if (NarrowBitWidth % 8 != 0)
    return None;
  uint64_t NarrowByteWidth = NarrowBitWidth / 8;

  if (Index >= NarrowByteWidth)
    return Op.getOpcode() == ISD::ZERO_EXTEND
               ? Optional<ByteProvider>(ByteProvider::getConstantZero())
               : None;
  return calculateByteProvider(NarrowOp, Index, Depth + 1);
}
case ISD::BSWAP:
  return calculateByteProvider(Op->getOperand(0), ByteWidth - Index - 1,
                               Depth + 1);
case ISD::LOAD: {
  auto L = cast<LoadSDNode>(Op.getNode());
  if (L->isVolatile() || L->isIndexed())
    return None;

  unsigned NarrowBitWidth = L->getMemoryVT().getSizeInBits();
  if (NarrowBitWidth % 8 != 0)
    return None;
  uint64_t NarrowByteWidth = NarrowBitWidth / 8;

  if (Index >= NarrowByteWidth)
    return L->getExtensionType() == ISD::ZEXTLOAD
               ? Optional<ByteProvider>(ByteProvider::getConstantZero())
               : None;
  return ByteProvider::getMemory(L, Index);
}
}

return None;
5154}

5156/// Match a pattern where a wide type scalar value is loaded by several narrow
5157/// loads and combined by shifts and ors. Fold it into a single load or a load
5158/// and a BSWAP if the targets supports it.
5159///
5160/// Assuming little endian target:
5161///  i8 *a = ...
5162///  i32 val = a[0] | (a[1] << 8) | (a[2] << 16) | (a[3] << 24)
5163/// =>
5164///  i32 val = *((i32)a)
5165///
5166///  i8 *a = ...
5167///  i32 val = (a[0] << 24) | (a[1] << 16) | (a[2] << 8) | a[3]
5168/// =>
5169///  i32 val = BSWAP(*((i32)a))
5170///
5171/// TODO: This rule matches complex patterns with OR node roots and doesn't
5172/// interact well with the worklist mechanism. When a part of the pattern is
5173/// updated (e.g. one of the loads) its direct users are put into the worklist,
5174/// but the root node of the pattern which triggers the load combine is not
5175/// necessarily a direct user of the changed node. For example, once the address
5176/// of t28 load is reassociated load combine won't be triggered:
5177///             t25: i32 = add t4, Constant:i32<2>
5178///           t26: i64 = sign_extend t25
5179///        t27: i64 = add t2, t26
5180///       t28: i8,ch = load<LD1[%tmp9]> t0, t27, undef:i64
5181///     t29: i32 = zero_extend t28
5182///   t32: i32 = shl t29, Constant:i8<8>
5183/// t33: i32 = or t23, t32
5184/// As a possible fix visitLoad can check if the load can be a part of a load
5185/// combine pattern and add corresponding OR roots to the worklist.
5186SDValue DAGCombiner::MatchLoadCombine(SDNode *N) {
assert(N->getOpcode() == ISD::OR &&(static_cast <bool> (N->getOpcode() == ISD::OR &&
 "Can only match load combining against OR nodes") ? void (0)
 : __assert_fail ("N->getOpcode() == ISD::OR && \"Can only match load combining against OR nodes\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5188, __extension__ __PRETTY_FUNCTION__))
       "Can only match load combining against OR nodes")(static_cast <bool> (N->getOpcode() == ISD::OR &&
 "Can only match load combining against OR nodes") ? void (0)
 : __assert_fail ("N->getOpcode() == ISD::OR && \"Can only match load combining against OR nodes\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5188, __extension__ __PRETTY_FUNCTION__));

// Handles simple types only
EVT VT = N->getValueType(0);
if (VT != MVT::i16 && VT != MVT::i32 && VT != MVT::i64)
  return SDValue();
unsigned ByteWidth = VT.getSizeInBits() / 8;

const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Before legalize we can introduce too wide illegal loads which will be later
// split into legal sized loads. This enables us to combine i64 load by i8
// patterns to a couple of i32 loads on 32 bit targets.
if (LegalOperations && !TLI.isOperationLegal(ISD::LOAD, VT))
  return SDValue();

std::function<unsigned(unsigned, unsigned)> LittleEndianByteAt = [](
  unsigned BW, unsigned i) { return i; };
std::function<unsigned(unsigned, unsigned)> BigEndianByteAt = [](
  unsigned BW, unsigned i) { return BW - i - 1; };

bool IsBigEndianTarget = DAG.getDataLayout().isBigEndian();
auto MemoryByteOffset = [&] (ByteProvider P) {
  assert(P.isMemory() && "Must be a memory byte provider")(static_cast <bool> (P.isMemory() && "Must be a memory byte provider"
) ? void (0) : __assert_fail ("P.isMemory() && \"Must be a memory byte provider\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5210, __extension__ __PRETTY_FUNCTION__));
  unsigned LoadBitWidth = P.Load->getMemoryVT().getSizeInBits();
  assert(LoadBitWidth % 8 == 0 &&(static_cast <bool> (LoadBitWidth % 8 == 0 && "can only analyze providers for individual bytes not bit"
) ? void (0) : __assert_fail ("LoadBitWidth % 8 == 0 && \"can only analyze providers for individual bytes not bit\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5213, __extension__ __PRETTY_FUNCTION__))
         "can only analyze providers for individual bytes not bit")(static_cast <bool> (LoadBitWidth % 8 == 0 && "can only analyze providers for individual bytes not bit"
) ? void (0) : __assert_fail ("LoadBitWidth % 8 == 0 && \"can only analyze providers for individual bytes not bit\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5213, __extension__ __PRETTY_FUNCTION__));
  unsigned LoadByteWidth = LoadBitWidth / 8;
  return IsBigEndianTarget
          ? BigEndianByteAt(LoadByteWidth, P.ByteOffset)
          : LittleEndianByteAt(LoadByteWidth, P.ByteOffset);
};

Optional<BaseIndexOffset> Base;
SDValue Chain;

SmallSet<LoadSDNode *, 8> Loads;
Optional<ByteProvider> FirstByteProvider;
int64_t FirstOffset = INT64_MAX(9223372036854775807L);

// Check if all the bytes of the OR we are looking at are loaded from the same
// base address. Collect bytes offsets from Base address in ByteOffsets.
SmallVector<int64_t, 4> ByteOffsets(ByteWidth);
for (unsigned i = 0; i < ByteWidth; i++) {
  auto P = calculateByteProvider(SDValue(N, 0), i, 0, /*Root=*/true);
  if (!P || !P->isMemory()) // All the bytes must be loaded from memory
    return SDValue();

  LoadSDNode *L = P->Load;
  assert(L->hasNUsesOfValue(1, 0) && !L->isVolatile() && !L->isIndexed() &&(static_cast <bool> (L->hasNUsesOfValue(1, 0) &&
 !L->isVolatile() && !L->isIndexed() &&
 "Must be enforced by calculateByteProvider") ? void (0) : __assert_fail
 ("L->hasNUsesOfValue(1, 0) && !L->isVolatile() && !L->isIndexed() && \"Must be enforced by calculateByteProvider\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5237, __extension__ __PRETTY_FUNCTION__))
         "Must be enforced by calculateByteProvider")(static_cast <bool> (L->hasNUsesOfValue(1, 0) &&
 !L->isVolatile() && !L->isIndexed() &&
 "Must be enforced by calculateByteProvider") ? void (0) : __assert_fail
 ("L->hasNUsesOfValue(1, 0) && !L->isVolatile() && !L->isIndexed() && \"Must be enforced by calculateByteProvider\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5237, __extension__ __PRETTY_FUNCTION__));
  assert(L->getOffset().isUndef() && "Unindexed load must have undef offset")(static_cast <bool> (L->getOffset().isUndef() &&
 "Unindexed load must have undef offset") ? void (0) : __assert_fail
 ("L->getOffset().isUndef() && \"Unindexed load must have undef offset\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5238, __extension__ __PRETTY_FUNCTION__));

  // All loads must share the same chain
  SDValue LChain = L->getChain();
  if (!Chain)
    Chain = LChain;
  else if (Chain != LChain)
    return SDValue();

  // Loads must share the same base address
  BaseIndexOffset Ptr = BaseIndexOffset::match(L, DAG);
  int64_t ByteOffsetFromBase = 0;
  if (!Base)
    Base = Ptr;
  else if (!Base->equalBaseIndex(Ptr, DAG, ByteOffsetFromBase))
    return SDValue();

  // Calculate the offset of the current byte from the base address
  ByteOffsetFromBase += MemoryByteOffset(*P);
  ByteOffsets[i] = ByteOffsetFromBase;

  // Remember the first byte load
  if (ByteOffsetFromBase < FirstOffset) {
    FirstByteProvider = P;
    FirstOffset = ByteOffsetFromBase;
  }

  Loads.insert(L);
}
assert(!Loads.empty() && "All the bytes of the value must be loaded from "(static_cast <bool> (!Loads.empty() && "All the bytes of the value must be loaded from "
 "memory, so there must be at least one load which produces the value"
) ? void (0) : __assert_fail ("!Loads.empty() && \"All the bytes of the value must be loaded from \" \"memory, so there must be at least one load which produces the value\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5268, __extension__ __PRETTY_FUNCTION__))
       "memory, so there must be at least one load which produces the value")(static_cast <bool> (!Loads.empty() && "All the bytes of the value must be loaded from "
 "memory, so there must be at least one load which produces the value"
) ? void (0) : __assert_fail ("!Loads.empty() && \"All the bytes of the value must be loaded from \" \"memory, so there must be at least one load which produces the value\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5268, __extension__ __PRETTY_FUNCTION__));
assert(Base && "Base address of the accessed memory location must be set")(static_cast <bool> (Base && "Base address of the accessed memory location must be set"
) ? void (0) : __assert_fail ("Base && \"Base address of the accessed memory location must be set\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5269, __extension__ __PRETTY_FUNCTION__));
assert(FirstOffset != INT64_MAX && "First byte offset must be set")(static_cast <bool> (FirstOffset != (9223372036854775807L
) && "First byte offset must be set") ? void (0) : __assert_fail
 ("FirstOffset != INT64_MAX && \"First byte offset must be set\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5270, __extension__ __PRETTY_FUNCTION__));

// Check if the bytes of the OR we are looking at match with either big or
// little endian value load
bool BigEndian = true, LittleEndian = true;
for (unsigned i = 0; i < ByteWidth; i++) {
  int64_t CurrentByteOffset = ByteOffsets[i] - FirstOffset;
  LittleEndian &= CurrentByteOffset == LittleEndianByteAt(ByteWidth, i);
  BigEndian &= CurrentByteOffset == BigEndianByteAt(ByteWidth, i);
  if (!BigEndian && !LittleEndian)
    return SDValue();
}
assert((BigEndian != LittleEndian) && "should be either or")(static_cast <bool> ((BigEndian != LittleEndian) &&
 "should be either or") ? void (0) : __assert_fail ("(BigEndian != LittleEndian) && \"should be either or\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5282, __extension__ __PRETTY_FUNCTION__));
assert(FirstByteProvider && "must be set")(static_cast <bool> (FirstByteProvider && "must be set"
) ? void (0) : __assert_fail ("FirstByteProvider && \"must be set\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5283, __extension__ __PRETTY_FUNCTION__));

// Ensure that the first byte is loaded from zero offset of the first load.
// So the combined value can be loaded from the first load address.
if (MemoryByteOffset(*FirstByteProvider) != 0)
  return SDValue();
LoadSDNode *FirstLoad = FirstByteProvider->Load;

// The node we are looking at matches with the pattern, check if we can
// replace it with a single load and bswap if needed.

// If the load needs byte swap check if the target supports it
bool NeedsBswap = IsBigEndianTarget != BigEndian;

// Before legalize we can introduce illegal bswaps which will be later
// converted to an explicit bswap sequence. This way we end up with a single
// load and byte shuffling instead of several loads and byte shuffling.
if (NeedsBswap && LegalOperations && !TLI.isOperationLegal(ISD::BSWAP, VT))
  return SDValue();

// Check that a load of the wide type is both allowed and fast on the target
bool Fast = false;
bool Allowed = TLI.allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(),
                                      VT, FirstLoad->getAddressSpace(),
                                      FirstLoad->getAlignment(), &Fast);
if (!Allowed || !Fast)
  return SDValue();

SDValue NewLoad =
    DAG.getLoad(VT, SDLoc(N), Chain, FirstLoad->getBasePtr(),
                FirstLoad->getPointerInfo(), FirstLoad->getAlignment());

// Transfer chain users from old loads to the new load.
for (LoadSDNode *L : Loads)
  DAG.ReplaceAllUsesOfValueWith(SDValue(L, 1), SDValue(NewLoad.getNode(), 1));

return NeedsBswap ? DAG.getNode(ISD::BSWAP, SDLoc(N), VT, NewLoad) : NewLoad;
5320}

5322SDValue DAGCombiner::visitXOR(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  // fold (xor x, 0) -> x, vector edition
  if (ISD::isBuildVectorAllZeros(N0.getNode()))
    return N1;
  if (ISD::isBuildVectorAllZeros(N1.getNode()))
    return N0;
}

// fold (xor undef, undef) -> 0. This is a common idiom (misuse).
if (N0.isUndef() && N1.isUndef())
  return DAG.getConstant(0, SDLoc(N), VT);
// fold (xor x, undef) -> undef
if (N0.isUndef())
  return N0;
if (N1.isUndef())
  return N1;
// fold (xor c1, c2) -> c1^c2
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
ConstantSDNode *N1C = getAsNonOpaqueConstant(N1);
if (N0C && N1C)
  return DAG.FoldConstantArithmetic(ISD::XOR, SDLoc(N), VT, N0C, N1C);
// canonicalize constant to RHS
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
   !DAG.isConstantIntBuildVectorOrConstantInt(N1))
  return DAG.getNode(ISD::XOR, SDLoc(N), VT, N1, N0);
// fold (xor x, 0) -> x
if (isNullConstant(N1))
  return N0;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// reassociate xor
if (SDValue RXOR = ReassociateOps(ISD::XOR, SDLoc(N), N0, N1))
  return RXOR;

// fold !(x cc y) -> (x !cc y)
SDValue LHS, RHS, CC;
if (TLI.isConstTrueVal(N1.getNode()) && isSetCCEquivalent(N0, LHS, RHS, CC)) {
  bool isInt = LHS.getValueType().isInteger();
  ISD::CondCode NotCC = ISD::getSetCCInverse(cast<CondCodeSDNode>(CC)->get(),
                                             isInt);

  if (!LegalOperations ||
      TLI.isCondCodeLegal(NotCC, LHS.getSimpleValueType())) {
    switch (N0.getOpcode()) {
    default:
      llvm_unreachable("Unhandled SetCC Equivalent!")::llvm::llvm_unreachable_internal("Unhandled SetCC Equivalent!"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5378);
    case ISD::SETCC:
      return DAG.getSetCC(SDLoc(N0), VT, LHS, RHS, NotCC);
    case ISD::SELECT_CC:
      return DAG.getSelectCC(SDLoc(N0), LHS, RHS, N0.getOperand(2),
                             N0.getOperand(3), NotCC);
    }
  }
}

// fold (not (zext (setcc x, y))) -> (zext (not (setcc x, y)))
if (isOneConstant(N1) && N0.getOpcode() == ISD::ZERO_EXTEND &&
    N0.getNode()->hasOneUse() &&
    isSetCCEquivalent(N0.getOperand(0), LHS, RHS, CC)){
  SDValue V = N0.getOperand(0);
  SDLoc DL(N0);
  V = DAG.getNode(ISD::XOR, DL, V.getValueType(), V,
                  DAG.getConstant(1, DL, V.getValueType()));
  AddToWorklist(V.getNode());
  return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT, V);
}

// fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are setcc
if (isOneConstant(N1) && VT == MVT::i1 && N0.hasOneUse() &&
    (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
  SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
  if (isOneUseSetCC(RHS) || isOneUseSetCC(LHS)) {
    unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
    LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
    RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
    AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
    return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
  }
}
// fold (not (or x, y)) -> (and (not x), (not y)) iff x or y are constants
if (isAllOnesConstant(N1) && N0.hasOneUse() &&
    (N0.getOpcode() == ISD::OR || N0.getOpcode() == ISD::AND)) {
  SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
  if (isa<ConstantSDNode>(RHS) || isa<ConstantSDNode>(LHS)) {
    unsigned NewOpcode = N0.getOpcode() == ISD::AND ? ISD::OR : ISD::AND;
    LHS = DAG.getNode(ISD::XOR, SDLoc(LHS), VT, LHS, N1); // LHS = ~LHS
    RHS = DAG.getNode(ISD::XOR, SDLoc(RHS), VT, RHS, N1); // RHS = ~RHS
    AddToWorklist(LHS.getNode()); AddToWorklist(RHS.getNode());
    return DAG.getNode(NewOpcode, SDLoc(N), VT, LHS, RHS);
  }
}
// fold (xor (and x, y), y) -> (and (not x), y)
if (N0.getOpcode() == ISD::AND && N0.getNode()->hasOneUse() &&
    N0->getOperand(1) == N1) {
  SDValue X = N0->getOperand(0);
  SDValue NotX = DAG.getNOT(SDLoc(X), X, VT);
  AddToWorklist(NotX.getNode());
  return DAG.getNode(ISD::AND, SDLoc(N), VT, NotX, N1);
}

// fold Y = sra (X, size(X)-1); xor (add (X, Y), Y) -> (abs X)
unsigned OpSizeInBits = VT.getScalarSizeInBits();
if (N0.getOpcode() == ISD::ADD && N0.getOperand(1) == N1 &&
    N1.getOpcode() == ISD::SRA && N1.getOperand(0) == N0.getOperand(0) &&
    TLI.isOperationLegalOrCustom(ISD::ABS, VT)) {
  if (ConstantSDNode *C = isConstOrConstSplat(N1.getOperand(1)))
    if (C->getAPIntValue() == (OpSizeInBits - 1))
      return DAG.getNode(ISD::ABS, SDLoc(N), VT, N0.getOperand(0));
}

// fold (xor x, x) -> 0
if (N0 == N1)
  return tryFoldToZero(SDLoc(N), TLI, VT, DAG, LegalOperations, LegalTypes);

// fold (xor (shl 1, x), -1) -> (rotl ~1, x)
// Here is a concrete example of this equivalence:
// i16   x ==  14
// i16 shl ==   1 << 14  == 16384 == 0b0100000000000000
// i16 xor == ~(1 << 14) == 49151 == 0b1011111111111111
//
// =>
//
// i16     ~1      == 0b1111111111111110
// i16 rol(~1, 14) == 0b1011111111111111
//
// Some additional tips to help conceptualize this transform:
// - Try to see the operation as placing a single zero in a value of all ones.
// - There exists no value for x which would allow the result to contain zero.
// - Values of x larger than the bitwidth are undefined and do not require a
//   consistent result.
// - Pushing the zero left requires shifting one bits in from the right.
// A rotate left of ~1 is a nice way of achieving the desired result.
if (TLI.isOperationLegalOrCustom(ISD::ROTL, VT) && N0.getOpcode() == ISD::SHL
    && isAllOnesConstant(N1) && isOneConstant(N0.getOperand(0))) {
  SDLoc DL(N);
  return DAG.getNode(ISD::ROTL, DL, VT, DAG.getConstant(~1, DL, VT),
                     N0.getOperand(1));
}

// Simplify: xor (op x...), (op y...)  -> (op (xor x, y))
if (N0.getOpcode() == N1.getOpcode())
  if (SDValue Tmp = SimplifyBinOpWithSameOpcodeHands(N))
    return Tmp;

// Simplify the expression using non-local knowledge.
if (SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

return SDValue();
5482}

5484/// Handle transforms common to the three shifts, when the shift amount is a
5485/// constant.
5486SDValue DAGCombiner::visitShiftByConstant(SDNode *N, ConstantSDNode *Amt) {
SDNode *LHS = N->getOperand(0).getNode();
if (!LHS->hasOneUse()) return SDValue();

// We want to pull some binops through shifts, so that we have (and (shift))
// instead of (shift (and)), likewise for add, or, xor, etc.  This sort of
// thing happens with address calculations, so it's important to canonicalize
// it.
bool HighBitSet = false;  // Can we transform this if the high bit is set?

switch (LHS->getOpcode()) {
default: return SDValue();
case ISD::OR:
case ISD::XOR:
  HighBitSet = false; // We can only transform sra if the high bit is clear.
  break;
case ISD::AND:
  HighBitSet = true;  // We can only transform sra if the high bit is set.
  break;
case ISD::ADD:
  if (N->getOpcode() != ISD::SHL)
    return SDValue(); // only shl(add) not sr[al](add).
  HighBitSet = false; // We can only transform sra if the high bit is clear.
  break;
}

// We require the RHS of the binop to be a constant and not opaque as well.
ConstantSDNode *BinOpCst = getAsNonOpaqueConstant(LHS->getOperand(1));
if (!BinOpCst) return SDValue();

// FIXME: disable this unless the input to the binop is a shift by a constant
// or is copy/select.Enable this in other cases when figure out it's exactly profitable.
SDNode *BinOpLHSVal = LHS->getOperand(0).getNode();
bool isShift = BinOpLHSVal->getOpcode() == ISD::SHL ||
               BinOpLHSVal->getOpcode() == ISD::SRA ||
               BinOpLHSVal->getOpcode() == ISD::SRL;
bool isCopyOrSelect = BinOpLHSVal->getOpcode() == ISD::CopyFromReg ||
                      BinOpLHSVal->getOpcode() == ISD::SELECT;

if ((!isShift || !isa<ConstantSDNode>(BinOpLHSVal->getOperand(1))) &&
    !isCopyOrSelect)
  return SDValue();

if (isCopyOrSelect && N->hasOneUse())
  return SDValue();

EVT VT = N->getValueType(0);

// If this is a signed shift right, and the high bit is modified by the
// logical operation, do not perform the transformation. The highBitSet
// boolean indicates the value of the high bit of the constant which would
// cause it to be modified for this operation.
if (N->getOpcode() == ISD::SRA) {
  bool BinOpRHSSignSet = BinOpCst->getAPIntValue().isNegative();
  if (BinOpRHSSignSet != HighBitSet)
    return SDValue();
}

if (!TLI.isDesirableToCommuteWithShift(LHS))
  return SDValue();

// Fold the constants, shifting the binop RHS by the shift amount.
SDValue NewRHS = DAG.getNode(N->getOpcode(), SDLoc(LHS->getOperand(1)),
                             N->getValueType(0),
                             LHS->getOperand(1), N->getOperand(1));
assert(isa<ConstantSDNode>(NewRHS) && "Folding was not successful!")(static_cast <bool> (isa<ConstantSDNode>(NewRHS) &&
 "Folding was not successful!") ? void (0) : __assert_fail ("isa<ConstantSDNode>(NewRHS) && \"Folding was not successful!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5551, __extension__ __PRETTY_FUNCTION__));

// Create the new shift.
SDValue NewShift = DAG.getNode(N->getOpcode(),
                               SDLoc(LHS->getOperand(0)),
                               VT, LHS->getOperand(0), N->getOperand(1));

// Create the new binop.
return DAG.getNode(LHS->getOpcode(), SDLoc(N), VT, NewShift, NewRHS);
5560}

5562SDValue DAGCombiner::distributeTruncateThroughAnd(SDNode *N) {
assert(N->getOpcode() == ISD::TRUNCATE)(static_cast <bool> (N->getOpcode() == ISD::TRUNCATE
) ? void (0) : __assert_fail ("N->getOpcode() == ISD::TRUNCATE"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5563, __extension__ __PRETTY_FUNCTION__));
assert(N->getOperand(0).getOpcode() == ISD::AND)(static_cast <bool> (N->getOperand(0).getOpcode() ==
 ISD::AND) ? void (0) : __assert_fail ("N->getOperand(0).getOpcode() == ISD::AND"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 5564, __extension__ __PRETTY_FUNCTION__));

// (truncate:TruncVT (and N00, N01C)) -> (and (truncate:TruncVT N00), TruncC)
if (N->hasOneUse() && N->getOperand(0).hasOneUse()) {
  SDValue N01 = N->getOperand(0).getOperand(1);
  if (isConstantOrConstantVector(N01, /* NoOpaques */ true)) {
    SDLoc DL(N);
    EVT TruncVT = N->getValueType(0);
    SDValue N00 = N->getOperand(0).getOperand(0);
    SDValue Trunc00 = DAG.getNode(ISD::TRUNCATE, DL, TruncVT, N00);
    SDValue Trunc01 = DAG.getNode(ISD::TRUNCATE, DL, TruncVT, N01);
    AddToWorklist(Trunc00.getNode());
    AddToWorklist(Trunc01.getNode());
    return DAG.getNode(ISD::AND, DL, TruncVT, Trunc00, Trunc01);
  }
}

return SDValue();
5582}

5584SDValue DAGCombiner::visitRotate(SDNode *N) {
SDLoc dl(N);
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
unsigned Bitsize = VT.getScalarSizeInBits();

// fold (rot x, 0) -> x
if (isNullConstantOrNullSplatConstant(N1))
  return N0;

// fold (rot x, c) -> (rot x, c % BitSize)
if (ConstantSDNode *Cst = isConstOrConstSplat(N1)) {
  if (Cst->getAPIntValue().uge(Bitsize)) {
    uint64_t RotAmt = Cst->getAPIntValue().urem(Bitsize);
    return DAG.getNode(N->getOpcode(), dl, VT, N0,
                       DAG.getConstant(RotAmt, dl, N1.getValueType()));
  }
}

// fold (rot* x, (trunc (and y, c))) -> (rot* x, (and (trunc y), (trunc c))).
if (N1.getOpcode() == ISD::TRUNCATE &&
    N1.getOperand(0).getOpcode() == ISD::AND) {
  if (SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode()))
    return DAG.getNode(N->getOpcode(), dl, VT, N0, NewOp1);
}

unsigned NextOp = N0.getOpcode();
// fold (rot* (rot* x, c2), c1) -> (rot* x, c1 +- c2 % bitsize)
if (NextOp == ISD::ROTL || NextOp == ISD::ROTR) {
  SDNode *C1 = DAG.isConstantIntBuildVectorOrConstantInt(N1);
  SDNode *C2 = DAG.isConstantIntBuildVectorOrConstantInt(N0.getOperand(1));
  if (C1 && C2 && C1->getValueType(0) == C2->getValueType(0)) {
    EVT ShiftVT = C1->getValueType(0);
    bool SameSide = (N->getOpcode() == NextOp);
    unsigned CombineOp = SameSide ? ISD::ADD : ISD::SUB;
    if (SDValue CombinedShift =
            DAG.FoldConstantArithmetic(CombineOp, dl, ShiftVT, C1, C2)) {
      SDValue BitsizeC = DAG.getConstant(Bitsize, dl, ShiftVT);
      SDValue CombinedShiftNorm = DAG.FoldConstantArithmetic(
          ISD::SREM, dl, ShiftVT, CombinedShift.getNode(),
          BitsizeC.getNode());
      return DAG.getNode(N->getOpcode(), dl, VT, N0->getOperand(0),
                         CombinedShiftNorm);
    }
  }
}
return SDValue();
5632}

5634SDValue DAGCombiner::visitSHL(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarSizeInBits();

// fold vector ops
if (VT.isVector()) {
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

  BuildVectorSDNode *N1CV = dyn_cast<BuildVectorSDNode>(N1);
  // If setcc produces all-one true value then:
  // (shl (and (setcc) N01CV) N1CV) -> (and (setcc) N01CV<<N1CV)
  if (N1CV && N1CV->isConstant()) {
    if (N0.getOpcode() == ISD::AND) {
      SDValue N00 = N0->getOperand(0);
      SDValue N01 = N0->getOperand(1);
      BuildVectorSDNode *N01CV = dyn_cast<BuildVectorSDNode>(N01);

      if (N01CV && N01CV->isConstant() && N00.getOpcode() == ISD::SETCC &&
          TLI.getBooleanContents(N00.getOperand(0).getValueType()) ==
              TargetLowering::ZeroOrNegativeOneBooleanContent) {
        if (SDValue C = DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT,
                                                   N01CV, N1CV))
          return DAG.getNode(ISD::AND, SDLoc(N), VT, N00, C);
      }
    }
  }
}

ConstantSDNode *N1C = isConstOrConstSplat(N1);

// fold (shl c1, c2) -> c1<<c2
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
if (N0C && N1C && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::SHL, SDLoc(N), VT, N0C, N1C);
// fold (shl 0, x) -> 0
if (isNullConstantOrNullSplatConstant(N0))
  return N0;
// fold (shl x, c >= size(x)) -> undef
// NOTE: ALL vector elements must be too big to avoid partial UNDEFs.
auto MatchShiftTooBig = [OpSizeInBits](ConstantSDNode *Val) {
  return Val->getAPIntValue().uge(OpSizeInBits);
};
if (matchUnaryPredicate(N1, MatchShiftTooBig))
  return DAG.getUNDEF(VT);
// fold (shl x, 0) -> x
if (N1C && N1C->isNullValue())
  return N0;
// fold (shl undef, x) -> 0
if (N0.isUndef())
  return DAG.getConstant(0, SDLoc(N), VT);

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// if (shl x, c) is known to be zero, return 0
if (DAG.MaskedValueIsZero(SDValue(N, 0),
                          APInt::getAllOnesValue(OpSizeInBits)))
  return DAG.getConstant(0, SDLoc(N), VT);
// fold (shl x, (trunc (and y, c))) -> (shl x, (and (trunc y), (trunc c))).
if (N1.getOpcode() == ISD::TRUNCATE &&
    N1.getOperand(0).getOpcode() == ISD::AND) {
  if (SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode()))
    return DAG.getNode(ISD::SHL, SDLoc(N), VT, N0, NewOp1);
}

if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// fold (shl (shl x, c1), c2) -> 0 or (shl x, (add c1, c2))
if (N0.getOpcode() == ISD::SHL) {
  auto MatchOutOfRange = [OpSizeInBits](ConstantSDNode *LHS,
                                        ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).uge(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchOutOfRange))
    return DAG.getConstant(0, SDLoc(N), VT);

  auto MatchInRange = [OpSizeInBits](ConstantSDNode *LHS,
                                     ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).ult(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchInRange)) {
    SDLoc DL(N);
    EVT ShiftVT = N1.getValueType();
    SDValue Sum = DAG.getNode(ISD::ADD, DL, ShiftVT, N1, N0.getOperand(1));
    return DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0), Sum);
  }
}

// fold (shl (ext (shl x, c1)), c2) -> (ext (shl x, (add c1, c2)))
// For this to be valid, the second form must not preserve any of the bits
// that are shifted out by the inner shift in the first form.  This means
// the outer shift size must be >= the number of bits added by the ext.
// As a corollary, we don't care what kind of ext it is.
if (N1C && (N0.getOpcode() == ISD::ZERO_EXTEND ||
            N0.getOpcode() == ISD::ANY_EXTEND ||
            N0.getOpcode() == ISD::SIGN_EXTEND) &&
    N0.getOperand(0).getOpcode() == ISD::SHL) {
  SDValue N0Op0 = N0.getOperand(0);
  if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
    APInt c1 = N0Op0C1->getAPIntValue();
    APInt c2 = N1C->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);

    EVT InnerShiftVT = N0Op0.getValueType();
    uint64_t InnerShiftSize = InnerShiftVT.getScalarSizeInBits();
    if (c2.uge(OpSizeInBits - InnerShiftSize)) {
      SDLoc DL(N0);
      APInt Sum = c1 + c2;
      if (Sum.uge(OpSizeInBits))
        return DAG.getConstant(0, DL, VT);

      return DAG.getNode(
          ISD::SHL, DL, VT,
          DAG.getNode(N0.getOpcode(), DL, VT, N0Op0->getOperand(0)),
          DAG.getConstant(Sum.getZExtValue(), DL, N1.getValueType()));
    }
  }
}

// fold (shl (zext (srl x, C)), C) -> (zext (shl (srl x, C), C))
// Only fold this if the inner zext has no other uses to avoid increasing
// the total number of instructions.
if (N1C && N0.getOpcode() == ISD::ZERO_EXTEND && N0.hasOneUse() &&
    N0.getOperand(0).getOpcode() == ISD::SRL) {
  SDValue N0Op0 = N0.getOperand(0);
  if (ConstantSDNode *N0Op0C1 = isConstOrConstSplat(N0Op0.getOperand(1))) {
    if (N0Op0C1->getAPIntValue().ult(VT.getScalarSizeInBits())) {
      uint64_t c1 = N0Op0C1->getZExtValue();
      uint64_t c2 = N1C->getZExtValue();
      if (c1 == c2) {
        SDValue NewOp0 = N0.getOperand(0);
        EVT CountVT = NewOp0.getOperand(1).getValueType();
        SDLoc DL(N);
        SDValue NewSHL = DAG.getNode(ISD::SHL, DL, NewOp0.getValueType(),
                                     NewOp0,
                                     DAG.getConstant(c2, DL, CountVT));
        AddToWorklist(NewSHL.getNode());
        return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N0), VT, NewSHL);
      }
    }
  }
}

// fold (shl (sr[la] exact X,  C1), C2) -> (shl    X, (C2-C1)) if C1 <= C2
// fold (shl (sr[la] exact X,  C1), C2) -> (sr[la] X, (C2-C1)) if C1  > C2
if (N1C && (N0.getOpcode() == ISD::SRL || N0.getOpcode() == ISD::SRA) &&
    N0->getFlags().hasExact()) {
  if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
    uint64_t C1 = N0C1->getZExtValue();
    uint64_t C2 = N1C->getZExtValue();
    SDLoc DL(N);
    if (C1 <= C2)
      return DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
                         DAG.getConstant(C2 - C1, DL, N1.getValueType()));
    return DAG.getNode(N0.getOpcode(), DL, VT, N0.getOperand(0),
                       DAG.getConstant(C1 - C2, DL, N1.getValueType()));
  }
}

// fold (shl (srl x, c1), c2) -> (and (shl x, (sub c2, c1), MASK) or
//                               (and (srl x, (sub c1, c2), MASK)
// Only fold this if the inner shift has no other uses -- if it does, folding
// this will increase the total number of instructions.
if (N1C && N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
  if (ConstantSDNode *N0C1 = isConstOrConstSplat(N0.getOperand(1))) {
    uint64_t c1 = N0C1->getZExtValue();
    if (c1 < OpSizeInBits) {
      uint64_t c2 = N1C->getZExtValue();
      APInt Mask = APInt::getHighBitsSet(OpSizeInBits, OpSizeInBits - c1);
      SDValue Shift;
      if (c2 > c1) {
        Mask <<= c2 - c1;
        SDLoc DL(N);
        Shift = DAG.getNode(ISD::SHL, DL, VT, N0.getOperand(0),
                            DAG.getConstant(c2 - c1, DL, N1.getValueType()));
      } else {
        Mask.lshrInPlace(c1 - c2);
        SDLoc DL(N);
        Shift = DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0),
                            DAG.getConstant(c1 - c2, DL, N1.getValueType()));
      }
      SDLoc DL(N0);
      return DAG.getNode(ISD::AND, DL, VT, Shift,
                         DAG.getConstant(Mask, DL, VT));
    }
  }
}

// fold (shl (sra x, c1), c1) -> (and x, (shl -1, c1))
if (N0.getOpcode() == ISD::SRA && N1 == N0.getOperand(1) &&
    isConstantOrConstantVector(N1, /* No Opaques */ true)) {
  SDLoc DL(N);
  SDValue AllBits = DAG.getAllOnesConstant(DL, VT);
  SDValue HiBitsMask = DAG.getNode(ISD::SHL, DL, VT, AllBits, N1);
  return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0), HiBitsMask);
}

// fold (shl (add x, c1), c2) -> (add (shl x, c2), c1 << c2)
// fold (shl (or x, c1), c2) -> (or (shl x, c2), c1 << c2)
// Variant of version done on multiply, except mul by a power of 2 is turned
// into a shift.
if ((N0.getOpcode() == ISD::ADD || N0.getOpcode() == ISD::OR) &&
    N0.getNode()->hasOneUse() &&
    isConstantOrConstantVector(N1, /* No Opaques */ true) &&
    isConstantOrConstantVector(N0.getOperand(1), /* No Opaques */ true)) {
  SDValue Shl0 = DAG.getNode(ISD::SHL, SDLoc(N0), VT, N0.getOperand(0), N1);
  SDValue Shl1 = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
  AddToWorklist(Shl0.getNode());
  AddToWorklist(Shl1.getNode());
  return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, Shl0, Shl1);
}

// fold (shl (mul x, c1), c2) -> (mul x, c1 << c2)
if (N0.getOpcode() == ISD::MUL && N0.getNode()->hasOneUse() &&
    isConstantOrConstantVector(N1, /* No Opaques */ true) &&
    isConstantOrConstantVector(N0.getOperand(1), /* No Opaques */ true)) {
  SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N1), VT, N0.getOperand(1), N1);
  if (isConstantOrConstantVector(Shl))
    return DAG.getNode(ISD::MUL, SDLoc(N), VT, N0.getOperand(0), Shl);
}

if (N1C && !N1C->isOpaque())
  if (SDValue NewSHL = visitShiftByConstant(N, N1C))
    return NewSHL;

return SDValue();
5870}

5872SDValue DAGCombiner::visitSRA(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarSizeInBits();

// Arithmetic shifting an all-sign-bit value is a no-op.
// fold (sra 0, x) -> 0
// fold (sra -1, x) -> -1
if (DAG.ComputeNumSignBits(N0) == OpSizeInBits)
  return N0;

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

ConstantSDNode *N1C = isConstOrConstSplat(N1);

// fold (sra c1, c2) -> (sra c1, c2)
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
if (N0C && N1C && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::SRA, SDLoc(N), VT, N0C, N1C);
// fold (sra x, c >= size(x)) -> undef
// NOTE: ALL vector elements must be too big to avoid partial UNDEFs.
auto MatchShiftTooBig = [OpSizeInBits](ConstantSDNode *Val) {
  return Val->getAPIntValue().uge(OpSizeInBits);
};
if (matchUnaryPredicate(N1, MatchShiftTooBig))
  return DAG.getUNDEF(VT);
// fold (sra x, 0) -> x
if (N1C && N1C->isNullValue())
  return N0;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (sra (shl x, c1), c1) -> sext_inreg for some c1 and target supports
// sext_inreg.
if (N1C && N0.getOpcode() == ISD::SHL && N1 == N0.getOperand(1)) {
  unsigned LowBits = OpSizeInBits - (unsigned)N1C->getZExtValue();
  EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), LowBits);
  if (VT.isVector())
    ExtVT = EVT::getVectorVT(*DAG.getContext(),
                             ExtVT, VT.getVectorNumElements());
  if ((!LegalOperations ||
       TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, ExtVT)))
    return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
                       N0.getOperand(0), DAG.getValueType(ExtVT));
}

// fold (sra (sra x, c1), c2) -> (sra x, (add c1, c2))
if (N0.getOpcode() == ISD::SRA) {
  SDLoc DL(N);
  EVT ShiftVT = N1.getValueType();

  auto MatchOutOfRange = [OpSizeInBits](ConstantSDNode *LHS,
                                        ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).uge(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchOutOfRange))
    return DAG.getNode(ISD::SRA, DL, VT, N0.getOperand(0),
                       DAG.getConstant(OpSizeInBits - 1, DL, ShiftVT));

  auto MatchInRange = [OpSizeInBits](ConstantSDNode *LHS,
                                     ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).ult(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchInRange)) {
    SDValue Sum = DAG.getNode(ISD::ADD, DL, ShiftVT, N1, N0.getOperand(1));
    return DAG.getNode(ISD::SRA, DL, VT, N0.getOperand(0), Sum);
  }
}

// fold (sra (shl X, m), (sub result_size, n))
// -> (sign_extend (trunc (shl X, (sub (sub result_size, n), m)))) for
// result_size - n != m.
// If truncate is free for the target sext(shl) is likely to result in better
// code.
if (N0.getOpcode() == ISD::SHL && N1C) {
  // Get the two constanst of the shifts, CN0 = m, CN = n.
  const ConstantSDNode *N01C = isConstOrConstSplat(N0.getOperand(1));
  if (N01C) {
    LLVMContext &Ctx = *DAG.getContext();
    // Determine what the truncate's result bitsize and type would be.
    EVT TruncVT = EVT::getIntegerVT(Ctx, OpSizeInBits - N1C->getZExtValue());

    if (VT.isVector())
      TruncVT = EVT::getVectorVT(Ctx, TruncVT, VT.getVectorNumElements());

    // Determine the residual right-shift amount.
    int ShiftAmt = N1C->getZExtValue() - N01C->getZExtValue();

    // If the shift is not a no-op (in which case this should be just a sign
    // extend already), the truncated to type is legal, sign_extend is legal
    // on that type, and the truncate to that type is both legal and free,
    // perform the transform.
    if ((ShiftAmt > 0) &&
        TLI.isOperationLegalOrCustom(ISD::SIGN_EXTEND, TruncVT) &&
        TLI.isOperationLegalOrCustom(ISD::TRUNCATE, VT) &&
        TLI.isTruncateFree(VT, TruncVT)) {
      SDLoc DL(N);
      SDValue Amt = DAG.getConstant(ShiftAmt, DL,
          getShiftAmountTy(N0.getOperand(0).getValueType()));
      SDValue Shift = DAG.getNode(ISD::SRL, DL, VT,
                                  N0.getOperand(0), Amt);
      SDValue Trunc = DAG.getNode(ISD::TRUNCATE, DL, TruncVT,
                                  Shift);
      return DAG.getNode(ISD::SIGN_EXTEND, DL,
                         N->getValueType(0), Trunc);
    }
  }
}

// fold (sra x, (trunc (and y, c))) -> (sra x, (and (trunc y), (trunc c))).
if (N1.getOpcode() == ISD::TRUNCATE &&
    N1.getOperand(0).getOpcode() == ISD::AND) {
  if (SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode()))
    return DAG.getNode(ISD::SRA, SDLoc(N), VT, N0, NewOp1);
}

// fold (sra (trunc (srl x, c1)), c2) -> (trunc (sra x, c1 + c2))
//      if c1 is equal to the number of bits the trunc removes
if (N0.getOpcode() == ISD::TRUNCATE &&
    (N0.getOperand(0).getOpcode() == ISD::SRL ||
     N0.getOperand(0).getOpcode() == ISD::SRA) &&
    N0.getOperand(0).hasOneUse() &&
    N0.getOperand(0).getOperand(1).hasOneUse() &&
    N1C) {
  SDValue N0Op0 = N0.getOperand(0);
  if (ConstantSDNode *LargeShift = isConstOrConstSplat(N0Op0.getOperand(1))) {
    unsigned LargeShiftVal = LargeShift->getZExtValue();
    EVT LargeVT = N0Op0.getValueType();

    if (LargeVT.getScalarSizeInBits() - OpSizeInBits == LargeShiftVal) {
      SDLoc DL(N);
      SDValue Amt =
        DAG.getConstant(LargeShiftVal + N1C->getZExtValue(), DL,
                        getShiftAmountTy(N0Op0.getOperand(0).getValueType()));
      SDValue SRA = DAG.getNode(ISD::SRA, DL, LargeVT,
                                N0Op0.getOperand(0), Amt);
      return DAG.getNode(ISD::TRUNCATE, DL, VT, SRA);
    }
  }
}

// Simplify, based on bits shifted out of the LHS.
if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// If the sign bit is known to be zero, switch this to a SRL.
if (DAG.SignBitIsZero(N0))
  return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, N1);

if (N1C && !N1C->isOpaque())
  if (SDValue NewSRA = visitShiftByConstant(N, N1C))
    return NewSRA;

return SDValue();
6037}

6039SDValue DAGCombiner::visitSRL(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N0.getValueType();
unsigned OpSizeInBits = VT.getScalarSizeInBits();

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

ConstantSDNode *N1C = isConstOrConstSplat(N1);

// fold (srl c1, c2) -> c1 >>u c2
ConstantSDNode *N0C = getAsNonOpaqueConstant(N0);
if (N0C && N1C && !N1C->isOpaque())
  return DAG.FoldConstantArithmetic(ISD::SRL, SDLoc(N), VT, N0C, N1C);
// fold (srl 0, x) -> 0
if (isNullConstantOrNullSplatConstant(N0))
  return N0;
// fold (srl x, c >= size(x)) -> undef
// NOTE: ALL vector elements must be too big to avoid partial UNDEFs.
auto MatchShiftTooBig = [OpSizeInBits](ConstantSDNode *Val) {
  return Val->getAPIntValue().uge(OpSizeInBits);
};
if (matchUnaryPredicate(N1, MatchShiftTooBig))
  return DAG.getUNDEF(VT);
// fold (srl x, 0) -> x
if (N1C && N1C->isNullValue())
  return N0;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// if (srl x, c) is known to be zero, return 0
if (N1C && DAG.MaskedValueIsZero(SDValue(N, 0),
                                 APInt::getAllOnesValue(OpSizeInBits)))
  return DAG.getConstant(0, SDLoc(N), VT);

// fold (srl (srl x, c1), c2) -> 0 or (srl x, (add c1, c2))
if (N0.getOpcode() == ISD::SRL) {
  auto MatchOutOfRange = [OpSizeInBits](ConstantSDNode *LHS,
                                        ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).uge(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchOutOfRange))
    return DAG.getConstant(0, SDLoc(N), VT);

  auto MatchInRange = [OpSizeInBits](ConstantSDNode *LHS,
                                     ConstantSDNode *RHS) {
    APInt c1 = LHS->getAPIntValue();
    APInt c2 = RHS->getAPIntValue();
    zeroExtendToMatch(c1, c2, 1 /* Overflow Bit */);
    return (c1 + c2).ult(OpSizeInBits);
  };
  if (matchBinaryPredicate(N1, N0.getOperand(1), MatchInRange)) {
    SDLoc DL(N);
    EVT ShiftVT = N1.getValueType();
    SDValue Sum = DAG.getNode(ISD::ADD, DL, ShiftVT, N1, N0.getOperand(1));
    return DAG.getNode(ISD::SRL, DL, VT, N0.getOperand(0), Sum);
  }
}

// fold (srl (trunc (srl x, c1)), c2) -> 0 or (trunc (srl x, (add c1, c2)))
if (N1C && N0.getOpcode() == ISD::TRUNCATE &&
    N0.getOperand(0).getOpcode() == ISD::SRL) {
  if (auto N001C = isConstOrConstSplat(N0.getOperand(0).getOperand(1))) {
    uint64_t c1 = N001C->getZExtValue();
    uint64_t c2 = N1C->getZExtValue();
    EVT InnerShiftVT = N0.getOperand(0).getValueType();
    EVT ShiftCountVT = N0.getOperand(0).getOperand(1).getValueType();
    uint64_t InnerShiftSize = InnerShiftVT.getScalarSizeInBits();
    // This is only valid if the OpSizeInBits + c1 = size of inner shift.
    if (c1 + OpSizeInBits == InnerShiftSize) {
      SDLoc DL(N0);
      if (c1 + c2 >= InnerShiftSize)
        return DAG.getConstant(0, DL, VT);
      return DAG.getNode(ISD::TRUNCATE, DL, VT,
                         DAG.getNode(ISD::SRL, DL, InnerShiftVT,
                                     N0.getOperand(0).getOperand(0),
                                     DAG.getConstant(c1 + c2, DL,
                                                     ShiftCountVT)));
    }
  }
}

// fold (srl (shl x, c), c) -> (and x, cst2)
if (N0.getOpcode() == ISD::SHL && N0.getOperand(1) == N1 &&
    isConstantOrConstantVector(N1, /* NoOpaques */ true)) {
  SDLoc DL(N);
  SDValue Mask =
      DAG.getNode(ISD::SRL, DL, VT, DAG.getAllOnesConstant(DL, VT), N1);
  AddToWorklist(Mask.getNode());
  return DAG.getNode(ISD::AND, DL, VT, N0.getOperand(0), Mask);
}

// fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
  // Shifting in all undef bits?
  EVT SmallVT = N0.getOperand(0).getValueType();
  unsigned BitSize = SmallVT.getScalarSizeInBits();
  if (N1C->getZExtValue() >= BitSize)
    return DAG.getUNDEF(VT);

  if (!LegalTypes || TLI.isTypeDesirableForOp(ISD::SRL, SmallVT)) {
    uint64_t ShiftAmt = N1C->getZExtValue();
    SDLoc DL0(N0);
    SDValue SmallShift = DAG.getNode(ISD::SRL, DL0, SmallVT,
                                     N0.getOperand(0),
                        DAG.getConstant(ShiftAmt, DL0,
                                        getShiftAmountTy(SmallVT)));
    AddToWorklist(SmallShift.getNode());
    APInt Mask = APInt::getLowBitsSet(OpSizeInBits, OpSizeInBits - ShiftAmt);
    SDLoc DL(N);
    return DAG.getNode(ISD::AND, DL, VT,
                       DAG.getNode(ISD::ANY_EXTEND, DL, VT, SmallShift),
                       DAG.getConstant(Mask, DL, VT));
  }
}

// fold (srl (sra X, Y), 31) -> (srl X, 31).  This srl only looks at the sign
// bit, which is unmodified by sra.
if (N1C && N1C->getZExtValue() + 1 == OpSizeInBits) {
  if (N0.getOpcode() == ISD::SRA)
    return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0.getOperand(0), N1);
}

// fold (srl (ctlz x), "5") -> x  iff x has one bit set (the low bit).
if (N1C && N0.getOpcode() == ISD::CTLZ &&
    N1C->getAPIntValue() == Log2_32(OpSizeInBits)) {
  KnownBits Known;
  DAG.computeKnownBits(N0.getOperand(0), Known);

  // If any of the input bits are KnownOne, then the input couldn't be all
  // zeros, thus the result of the srl will always be zero.
  if (Known.One.getBoolValue()) return DAG.getConstant(0, SDLoc(N0), VT);

  // If all of the bits input the to ctlz node are known to be zero, then
  // the result of the ctlz is "32" and the result of the shift is one.
  APInt UnknownBits = ~Known.Zero;
  if (UnknownBits == 0) return DAG.getConstant(1, SDLoc(N0), VT);

  // Otherwise, check to see if there is exactly one bit input to the ctlz.
  if (UnknownBits.isPowerOf2()) {
    // Okay, we know that only that the single bit specified by UnknownBits
    // could be set on input to the CTLZ node. If this bit is set, the SRL
    // will return 0, if it is clear, it returns 1. Change the CTLZ/SRL pair
    // to an SRL/XOR pair, which is likely to simplify more.
    unsigned ShAmt = UnknownBits.countTrailingZeros();
    SDValue Op = N0.getOperand(0);

    if (ShAmt) {
      SDLoc DL(N0);
      Op = DAG.getNode(ISD::SRL, DL, VT, Op,
                DAG.getConstant(ShAmt, DL,
                                getShiftAmountTy(Op.getValueType())));
      AddToWorklist(Op.getNode());
    }

    SDLoc DL(N);
    return DAG.getNode(ISD::XOR, DL, VT,
                       Op, DAG.getConstant(1, DL, VT));
  }
}

// fold (srl x, (trunc (and y, c))) -> (srl x, (and (trunc y), (trunc c))).
if (N1.getOpcode() == ISD::TRUNCATE &&
    N1.getOperand(0).getOpcode() == ISD::AND) {
  if (SDValue NewOp1 = distributeTruncateThroughAnd(N1.getNode()))
    return DAG.getNode(ISD::SRL, SDLoc(N), VT, N0, NewOp1);
}

// fold operands of srl based on knowledge that the low bits are not
// demanded.
if (N1C && SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

if (N1C && !N1C->isOpaque())
  if (SDValue NewSRL = visitShiftByConstant(N, N1C))
    return NewSRL;

// Attempt to convert a srl of a load into a narrower zero-extending load.
if (SDValue NarrowLoad = ReduceLoadWidth(N))
  return NarrowLoad;

// Here is a common situation. We want to optimize:
//
//   %a = ...
//   %b = and i32 %a, 2
//   %c = srl i32 %b, 1
//   brcond i32 %c ...
//
// into
//
//   %a = ...
//   %b = and %a, 2
//   %c = setcc eq %b, 0
//   brcond %c ...
//
// However when after the source operand of SRL is optimized into AND, the SRL
// itself may not be optimized further. Look for it and add the BRCOND into
// the worklist.
if (N->hasOneUse()) {
  SDNode *Use = *N->use_begin();
  if (Use->getOpcode() == ISD::BRCOND)
    AddToWorklist(Use);
  else if (Use->getOpcode() == ISD::TRUNCATE && Use->hasOneUse()) {
    // Also look pass the truncate.
    Use = *Use->use_begin();
    if (Use->getOpcode() == ISD::BRCOND)
      AddToWorklist(Use);
  }
}

return SDValue();
6257}

6259SDValue DAGCombiner::visitABS(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (abs c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::ABS, SDLoc(N), VT, N0);
// fold (abs (abs x)) -> (abs x)
if (N0.getOpcode() == ISD::ABS)
  return N0;
// fold (abs x) -> x iff not-negative
if (DAG.SignBitIsZero(N0))
  return N0;
return SDValue();
6273}

6275SDValue DAGCombiner::visitBSWAP(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (bswap c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::BSWAP, SDLoc(N), VT, N0);
// fold (bswap (bswap x)) -> x
if (N0.getOpcode() == ISD::BSWAP)
  return N0->getOperand(0);
return SDValue();
6286}

6288SDValue DAGCombiner::visitBITREVERSE(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (bitreverse c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::BITREVERSE, SDLoc(N), VT, N0);
// fold (bitreverse (bitreverse x)) -> x
if (N0.getOpcode() == ISD::BITREVERSE)
  return N0.getOperand(0);
return SDValue();
6299}

6301SDValue DAGCombiner::visitCTLZ(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (ctlz c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::CTLZ, SDLoc(N), VT, N0);

// If the value is known never to be zero, switch to the undef version.
if (!LegalOperations || TLI.isOperationLegal(ISD::CTLZ_ZERO_UNDEF, VT)) {
  if (DAG.isKnownNeverZero(N0))
    return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
}

return SDValue();
6316}

6318SDValue DAGCombiner::visitCTLZ_ZERO_UNDEF(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (ctlz_zero_undef c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SDLoc(N), VT, N0);
return SDValue();
6326}

6328SDValue DAGCombiner::visitCTTZ(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (cttz c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::CTTZ, SDLoc(N), VT, N0);

// If the value is known never to be zero, switch to the undef version.
if (!LegalOperations || TLI.isOperationLegal(ISD::CTTZ_ZERO_UNDEF, VT)) {
  if (DAG.isKnownNeverZero(N0))
    return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
}

return SDValue();
6343}

6345SDValue DAGCombiner::visitCTTZ_ZERO_UNDEF(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (cttz_zero_undef c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::CTTZ_ZERO_UNDEF, SDLoc(N), VT, N0);
return SDValue();
6353}

6355SDValue DAGCombiner::visitCTPOP(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (ctpop c1) -> c2
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::CTPOP, SDLoc(N), VT, N0);
return SDValue();
6363}

6365/// \brief Generate Min/Max node
6366static SDValue combineMinNumMaxNum(const SDLoc &DL, EVT VT, SDValue LHS,
                                 SDValue RHS, SDValue True, SDValue False,
                                 ISD::CondCode CC, const TargetLowering &TLI,
                                 SelectionDAG &DAG) {
if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
  return SDValue();

switch (CC) {
case ISD::SETOLT:
case ISD::SETOLE:
case ISD::SETLT:
case ISD::SETLE:
case ISD::SETULT:
case ISD::SETULE: {
  unsigned Opcode = (LHS == True) ? ISD::FMINNUM : ISD::FMAXNUM;
  if (TLI.isOperationLegal(Opcode, VT))
    return DAG.getNode(Opcode, DL, VT, LHS, RHS);
  return SDValue();
}
case ISD::SETOGT:
case ISD::SETOGE:
case ISD::SETGT:
case ISD::SETGE:
case ISD::SETUGT:
case ISD::SETUGE: {
  unsigned Opcode = (LHS == True) ? ISD::FMAXNUM : ISD::FMINNUM;
  if (TLI.isOperationLegal(Opcode, VT))
    return DAG.getNode(Opcode, DL, VT, LHS, RHS);
  return SDValue();
}
default:
  return SDValue();
}
6399}

6401SDValue DAGCombiner::foldSelectOfConstants(SDNode *N) {
SDValue Cond = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
EVT VT = N->getValueType(0);
EVT CondVT = Cond.getValueType();
SDLoc DL(N);

if (!VT.isInteger())
  return SDValue();

auto *C1 = dyn_cast<ConstantSDNode>(N1);
auto *C2 = dyn_cast<ConstantSDNode>(N2);
if (!C1 || !C2)
  return SDValue();

// Only do this before legalization to avoid conflicting with target-specific
// transforms in the other direction (create a select from a zext/sext). There
// is also a target-independent combine here in DAGCombiner in the other
// direction for (select Cond, -1, 0) when the condition is not i1.
if (CondVT == MVT::i1 && !LegalOperations) {
  if (C1->isNullValue() && C2->isOne()) {
    // select Cond, 0, 1 --> zext (!Cond)
    SDValue NotCond = DAG.getNOT(DL, Cond, MVT::i1);
    if (VT != MVT::i1)
      NotCond = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, NotCond);
    return NotCond;
  }
  if (C1->isNullValue() && C2->isAllOnesValue()) {
    // select Cond, 0, -1 --> sext (!Cond)
    SDValue NotCond = DAG.getNOT(DL, Cond, MVT::i1);
    if (VT != MVT::i1)
      NotCond = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, NotCond);
    return NotCond;
  }
  if (C1->isOne() && C2->isNullValue()) {
    // select Cond, 1, 0 --> zext (Cond)
    if (VT != MVT::i1)
      Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Cond);
    return Cond;
  }
  if (C1->isAllOnesValue() && C2->isNullValue()) {
    // select Cond, -1, 0 --> sext (Cond)
    if (VT != MVT::i1)
      Cond = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Cond);
    return Cond;
  }

  // For any constants that differ by 1, we can transform the select into an
  // extend and add. Use a target hook because some targets may prefer to
  // transform in the other direction.
  if (TLI.convertSelectOfConstantsToMath(VT)) {
    if (C1->getAPIntValue() - 1 == C2->getAPIntValue()) {
      // select Cond, C1, C1-1 --> add (zext Cond), C1-1
      if (VT != MVT::i1)
        Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Cond);
      return DAG.getNode(ISD::ADD, DL, VT, Cond, N2);
    }
    if (C1->getAPIntValue() + 1 == C2->getAPIntValue()) {
      // select Cond, C1, C1+1 --> add (sext Cond), C1+1
      if (VT != MVT::i1)
        Cond = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Cond);
      return DAG.getNode(ISD::ADD, DL, VT, Cond, N2);
    }
  }

  return SDValue();
}

// fold (select Cond, 0, 1) -> (xor Cond, 1)
// We can't do this reliably if integer based booleans have different contents
// to floating point based booleans. This is because we can't tell whether we
// have an integer-based boolean or a floating-point-based boolean unless we
// can find the SETCC that produced it and inspect its operands. This is
// fairly easy if C is the SETCC node, but it can potentially be
// undiscoverable (or not reasonably discoverable). For example, it could be
// in another basic block or it could require searching a complicated
// expression.
if (CondVT.isInteger() &&
    TLI.getBooleanContents(false, true) ==
        TargetLowering::ZeroOrOneBooleanContent &&
    TLI.getBooleanContents(false, false) ==
        TargetLowering::ZeroOrOneBooleanContent &&
    C1->isNullValue() && C2->isOne()) {
  SDValue NotCond =
      DAG.getNode(ISD::XOR, DL, CondVT, Cond, DAG.getConstant(1, DL, CondVT));
  if (VT.bitsEq(CondVT))
    return NotCond;
  return DAG.getZExtOrTrunc(NotCond, DL, VT);
}

return SDValue();
6493}

6495SDValue DAGCombiner::visitSELECT(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
EVT VT = N->getValueType(0);
EVT VT0 = N0.getValueType();
SDLoc DL(N);

// fold (select C, X, X) -> X
if (N1 == N2)
  return N1;

if (const ConstantSDNode *N0C = dyn_cast<const ConstantSDNode>(N0)) {
  // fold (select true, X, Y) -> X
  // fold (select false, X, Y) -> Y
  return !N0C->isNullValue() ? N1 : N2;
}

// fold (select X, X, Y) -> (or X, Y)
// fold (select X, 1, Y) -> (or C, Y)
if (VT == VT0 && VT == MVT::i1 && (N0 == N1 || isOneConstant(N1)))
  return DAG.getNode(ISD::OR, DL, VT, N0, N2);

if (SDValue V = foldSelectOfConstants(N))
  return V;

// fold (select C, 0, X) -> (and (not C), X)
if (VT == VT0 && VT == MVT::i1 && isNullConstant(N1)) {
  SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
  AddToWorklist(NOTNode.getNode());
  return DAG.getNode(ISD::AND, DL, VT, NOTNode, N2);
}
// fold (select C, X, 1) -> (or (not C), X)
if (VT == VT0 && VT == MVT::i1 && isOneConstant(N2)) {
  SDValue NOTNode = DAG.getNOT(SDLoc(N0), N0, VT);
  AddToWorklist(NOTNode.getNode());
  return DAG.getNode(ISD::OR, DL, VT, NOTNode, N1);
}
// fold (select X, Y, X) -> (and X, Y)
// fold (select X, Y, 0) -> (and X, Y)
if (VT == VT0 && VT == MVT::i1 && (N0 == N2 || isNullConstant(N2)))
  return DAG.getNode(ISD::AND, DL, VT, N0, N1);

// If we can fold this based on the true/false value, do so.
if (SimplifySelectOps(N, N1, N2))
  return SDValue(N, 0); // Don't revisit N.

if (VT0 == MVT::i1) {
  // The code in this block deals with the following 2 equivalences:
  //    select(C0|C1, x, y) <=> select(C0, x, select(C1, x, y))
  //    select(C0&C1, x, y) <=> select(C0, select(C1, x, y), y)
  // The target can specify its preferred form with the
  // shouldNormalizeToSelectSequence() callback. However we always transform
  // to the right anyway if we find the inner select exists in the DAG anyway
  // and we always transform to the left side if we know that we can further
  // optimize the combination of the conditions.
  bool normalizeToSequence =
      TLI.shouldNormalizeToSelectSequence(*DAG.getContext(), VT);
  // select (and Cond0, Cond1), X, Y
  //   -> select Cond0, (select Cond1, X, Y), Y
  if (N0->getOpcode() == ISD::AND && N0->hasOneUse()) {
    SDValue Cond0 = N0->getOperand(0);
    SDValue Cond1 = N0->getOperand(1);
    SDValue InnerSelect =
        DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Cond1, N1, N2);
    if (normalizeToSequence || !InnerSelect.use_empty())
      return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Cond0,
                         InnerSelect, N2);
  }
  // select (or Cond0, Cond1), X, Y -> select Cond0, X, (select Cond1, X, Y)
  if (N0->getOpcode() == ISD::OR && N0->hasOneUse()) {
    SDValue Cond0 = N0->getOperand(0);
    SDValue Cond1 = N0->getOperand(1);
    SDValue InnerSelect =
        DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Cond1, N1, N2);
    if (normalizeToSequence || !InnerSelect.use_empty())
      return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Cond0, N1,
                         InnerSelect);
  }

  // select Cond0, (select Cond1, X, Y), Y -> select (and Cond0, Cond1), X, Y
  if (N1->getOpcode() == ISD::SELECT && N1->hasOneUse()) {
    SDValue N1_0 = N1->getOperand(0);
    SDValue N1_1 = N1->getOperand(1);
    SDValue N1_2 = N1->getOperand(2);
    if (N1_2 == N2 && N0.getValueType() == N1_0.getValueType()) {
      // Create the actual and node if we can generate good code for it.
      if (!normalizeToSequence) {
        SDValue And = DAG.getNode(ISD::AND, DL, N0.getValueType(), N0, N1_0);
        return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), And, N1_1, N2);
      }
      // Otherwise see if we can optimize the "and" to a better pattern.
      if (SDValue Combined = visitANDLike(N0, N1_0, N))
        return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Combined, N1_1,
                           N2);
    }
  }
  // select Cond0, X, (select Cond1, X, Y) -> select (or Cond0, Cond1), X, Y
  if (N2->getOpcode() == ISD::SELECT && N2->hasOneUse()) {
    SDValue N2_0 = N2->getOperand(0);
    SDValue N2_1 = N2->getOperand(1);
    SDValue N2_2 = N2->getOperand(2);
    if (N2_1 == N1 && N0.getValueType() == N2_0.getValueType()) {
      // Create the actual or node if we can generate good code for it.
      if (!normalizeToSequence) {
        SDValue Or = DAG.getNode(ISD::OR, DL, N0.getValueType(), N0, N2_0);
        return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Or, N1, N2_2);
      }
      // Otherwise see if we can optimize to a better pattern.
      if (SDValue Combined = visitORLike(N0, N2_0, N))
        return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Combined, N1,
                           N2_2);
    }
  }
}

// select (xor Cond, 1), X, Y -> select Cond, Y, X
if (VT0 == MVT::i1) {
  if (N0->getOpcode() == ISD::XOR) {
    if (auto *C = dyn_cast<ConstantSDNode>(N0->getOperand(1))) {
      SDValue Cond0 = N0->getOperand(0);
      if (C->isOne())
        return DAG.getNode(ISD::SELECT, DL, N1.getValueType(), Cond0, N2, N1);
    }
  }
}

// fold selects based on a setcc into other things, such as min/max/abs
if (N0.getOpcode() == ISD::SETCC) {
  // select x, y (fcmp lt x, y) -> fminnum x, y
  // select x, y (fcmp gt x, y) -> fmaxnum x, y
  //
  // This is OK if we don't care about what happens if either operand is a
  // NaN.
  //

  // FIXME: Instead of testing for UnsafeFPMath, this should be checking for
  // no signed zeros as well as no nans.
  const TargetOptions &Options = DAG.getTarget().Options;
  if (Options.UnsafeFPMath && VT.isFloatingPoint() && N0.hasOneUse() &&
      DAG.isKnownNeverNaN(N1) && DAG.isKnownNeverNaN(N2)) {
    ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();

    if (SDValue FMinMax = combineMinNumMaxNum(
            DL, VT, N0.getOperand(0), N0.getOperand(1), N1, N2, CC, TLI, DAG))
      return FMinMax;
  }

  if ((!LegalOperations &&
       TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT)) ||
      TLI.isOperationLegal(ISD::SELECT_CC, VT))
    return DAG.getNode(ISD::SELECT_CC, DL, VT, N0.getOperand(0),
                       N0.getOperand(1), N1, N2, N0.getOperand(2));
  return SimplifySelect(DL, N0, N1, N2);
}

return SDValue();
6652}

6654static
6655std::pair<SDValue, SDValue> SplitVSETCC(const SDNode *N, SelectionDAG &DAG) {
SDLoc DL(N);
EVT LoVT, HiVT;
std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(N->getValueType(0));

// Split the inputs.
SDValue Lo, Hi, LL, LH, RL, RH;
std::tie(LL, LH) = DAG.SplitVectorOperand(N, 0);
std::tie(RL, RH) = DAG.SplitVectorOperand(N, 1);

Lo = DAG.getNode(N->getOpcode(), DL, LoVT, LL, RL, N->getOperand(2));
Hi = DAG.getNode(N->getOpcode(), DL, HiVT, LH, RH, N->getOperand(2));

return std::make_pair(Lo, Hi);
6669}

6671// This function assumes all the vselect's arguments are CONCAT_VECTOR
6672// nodes and that the condition is a BV of ConstantSDNodes (or undefs).
6673static SDValue ConvertSelectToConcatVector(SDNode *N, SelectionDAG &DAG) {
SDLoc DL(N);
SDValue Cond = N->getOperand(0);
SDValue LHS = N->getOperand(1);
SDValue RHS = N->getOperand(2);
EVT VT = N->getValueType(0);
int NumElems = VT.getVectorNumElements();
assert(LHS.getOpcode() == ISD::CONCAT_VECTORS &&(static_cast <bool> (LHS.getOpcode() == ISD::CONCAT_VECTORS
 && RHS.getOpcode() == ISD::CONCAT_VECTORS &&
 Cond.getOpcode() == ISD::BUILD_VECTOR) ? void (0) : __assert_fail
 ("LHS.getOpcode() == ISD::CONCAT_VECTORS && RHS.getOpcode() == ISD::CONCAT_VECTORS && Cond.getOpcode() == ISD::BUILD_VECTOR"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6682, __extension__ __PRETTY_FUNCTION__))
       RHS.getOpcode() == ISD::CONCAT_VECTORS &&(static_cast <bool> (LHS.getOpcode() == ISD::CONCAT_VECTORS
 && RHS.getOpcode() == ISD::CONCAT_VECTORS &&
 Cond.getOpcode() == ISD::BUILD_VECTOR) ? void (0) : __assert_fail
 ("LHS.getOpcode() == ISD::CONCAT_VECTORS && RHS.getOpcode() == ISD::CONCAT_VECTORS && Cond.getOpcode() == ISD::BUILD_VECTOR"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6682, __extension__ __PRETTY_FUNCTION__))
       Cond.getOpcode() == ISD::BUILD_VECTOR)(static_cast <bool> (LHS.getOpcode() == ISD::CONCAT_VECTORS
 && RHS.getOpcode() == ISD::CONCAT_VECTORS &&
 Cond.getOpcode() == ISD::BUILD_VECTOR) ? void (0) : __assert_fail
 ("LHS.getOpcode() == ISD::CONCAT_VECTORS && RHS.getOpcode() == ISD::CONCAT_VECTORS && Cond.getOpcode() == ISD::BUILD_VECTOR"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6682, __extension__ __PRETTY_FUNCTION__));

// CONCAT_VECTOR can take an arbitrary number of arguments. We only care about
// binary ones here.
if (LHS->getNumOperands() != 2 || RHS->getNumOperands() != 2)
  return SDValue();

// We're sure we have an even number of elements due to the
// concat_vectors we have as arguments to vselect.
// Skip BV elements until we find one that's not an UNDEF
// After we find an UNDEF element, keep looping until we get to half the
// length of the BV and see if all the non-undef nodes are the same.
ConstantSDNode *BottomHalf = nullptr;
for (int i = 0; i < NumElems / 2; ++i) {
  if (Cond->getOperand(i)->isUndef())
    continue;

  if (BottomHalf == nullptr)
    BottomHalf = cast<ConstantSDNode>(Cond.getOperand(i));
  else if (Cond->getOperand(i).getNode() != BottomHalf)
    return SDValue();
}

// Do the same for the second half of the BuildVector
ConstantSDNode *TopHalf = nullptr;
for (int i = NumElems / 2; i < NumElems; ++i) {
  if (Cond->getOperand(i)->isUndef())
    continue;

  if (TopHalf == nullptr)
    TopHalf = cast<ConstantSDNode>(Cond.getOperand(i));
  else if (Cond->getOperand(i).getNode() != TopHalf)
    return SDValue();
}

assert(TopHalf && BottomHalf &&(static_cast <bool> (TopHalf && BottomHalf &&
 "One half of the selector was all UNDEFs and the other was all the "
 "same value. This should have been addressed before this function."
) ? void (0) : __assert_fail ("TopHalf && BottomHalf && \"One half of the selector was all UNDEFs and the other was all the \" \"same value. This should have been addressed before this function.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6719, __extension__ __PRETTY_FUNCTION__))
       "One half of the selector was all UNDEFs and the other was all the "(static_cast <bool> (TopHalf && BottomHalf &&
 "One half of the selector was all UNDEFs and the other was all the "
 "same value. This should have been addressed before this function."
) ? void (0) : __assert_fail ("TopHalf && BottomHalf && \"One half of the selector was all UNDEFs and the other was all the \" \"same value. This should have been addressed before this function.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6719, __extension__ __PRETTY_FUNCTION__))
       "same value. This should have been addressed before this function.")(static_cast <bool> (TopHalf && BottomHalf &&
 "One half of the selector was all UNDEFs and the other was all the "
 "same value. This should have been addressed before this function."
) ? void (0) : __assert_fail ("TopHalf && BottomHalf && \"One half of the selector was all UNDEFs and the other was all the \" \"same value. This should have been addressed before this function.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 6719, __extension__ __PRETTY_FUNCTION__));
return DAG.getNode(
    ISD::CONCAT_VECTORS, DL, VT,
    BottomHalf->isNullValue() ? RHS->getOperand(0) : LHS->getOperand(0),
    TopHalf->isNullValue() ? RHS->getOperand(1) : LHS->getOperand(1));
6724}

6726SDValue DAGCombiner::visitMSCATTER(SDNode *N) {
if (Level >= AfterLegalizeTypes)
  return SDValue();

MaskedScatterSDNode *MSC = cast<MaskedScatterSDNode>(N);
SDValue Mask = MSC->getMask();
SDValue Data  = MSC->getValue();
SDLoc DL(N);

// If the MSCATTER data type requires splitting and the mask is provided by a
// SETCC, then split both nodes and its operands before legalization. This
// prevents the type legalizer from unrolling SETCC into scalar comparisons
// and enables future optimizations (e.g. min/max pattern matching on X86).
if (Mask.getOpcode() != ISD::SETCC)
  return SDValue();

// Check if any splitting is required.
if (TLI.getTypeAction(*DAG.getContext(), Data.getValueType()) !=
    TargetLowering::TypeSplitVector)
  return SDValue();
SDValue MaskLo, MaskHi, Lo, Hi;
std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);

EVT LoVT, HiVT;
std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MSC->getValueType(0));

SDValue Chain = MSC->getChain();

EVT MemoryVT = MSC->getMemoryVT();
unsigned Alignment = MSC->getOriginalAlignment();

EVT LoMemVT, HiMemVT;
std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);

SDValue DataLo, DataHi;
std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);

SDValue Scale = MSC->getScale();
SDValue BasePtr = MSC->getBasePtr();
SDValue IndexLo, IndexHi;
std::tie(IndexLo, IndexHi) = DAG.SplitVector(MSC->getIndex(), DL);

MachineMemOperand *MMO = DAG.getMachineFunction().
  getMachineMemOperand(MSC->getPointerInfo(),
                        MachineMemOperand::MOStore,  LoMemVT.getStoreSize(),
                        Alignment, MSC->getAAInfo(), MSC->getRanges());

SDValue OpsLo[] = { Chain, DataLo, MaskLo, BasePtr, IndexLo, Scale };
Lo = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataLo.getValueType(),
                          DL, OpsLo, MMO);

SDValue OpsHi[] = { Chain, DataHi, MaskHi, BasePtr, IndexHi, Scale };
Hi = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), DataHi.getValueType(),
                          DL, OpsHi, MMO);

AddToWorklist(Lo.getNode());
AddToWorklist(Hi.getNode());

return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
6785}

6787SDValue DAGCombiner::visitMSTORE(SDNode *N) {
if (Level >= AfterLegalizeTypes)
  return SDValue();

MaskedStoreSDNode *MST = dyn_cast<MaskedStoreSDNode>(N);
SDValue Mask = MST->getMask();
SDValue Data  = MST->getValue();
EVT VT = Data.getValueType();
SDLoc DL(N);

// If the MSTORE data type requires splitting and the mask is provided by a
// SETCC, then split both nodes and its operands before legalization. This
// prevents the type legalizer from unrolling SETCC into scalar comparisons
// and enables future optimizations (e.g. min/max pattern matching on X86).
if (Mask.getOpcode() == ISD::SETCC) {
  // Check if any splitting is required.
  if (TLI.getTypeAction(*DAG.getContext(), VT) !=
      TargetLowering::TypeSplitVector)
    return SDValue();

  SDValue MaskLo, MaskHi, Lo, Hi;
  std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);

  SDValue Chain = MST->getChain();
  SDValue Ptr   = MST->getBasePtr();

  EVT MemoryVT = MST->getMemoryVT();
  unsigned Alignment = MST->getOriginalAlignment();

  // if Alignment is equal to the vector size,
  // take the half of it for the second part
  unsigned SecondHalfAlignment =
    (Alignment == VT.getSizeInBits() / 8) ? Alignment / 2 : Alignment;

  EVT LoMemVT, HiMemVT;
  std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);

  SDValue DataLo, DataHi;
  std::tie(DataLo, DataHi) = DAG.SplitVector(Data, DL);

  MachineMemOperand *MMO = DAG.getMachineFunction().
    getMachineMemOperand(MST->getPointerInfo(),
                         MachineMemOperand::MOStore,  LoMemVT.getStoreSize(),
                         Alignment, MST->getAAInfo(), MST->getRanges());

  Lo = DAG.getMaskedStore(Chain, DL, DataLo, Ptr, MaskLo, LoMemVT, MMO,
                          MST->isTruncatingStore(),
                          MST->isCompressingStore());

  Ptr = TLI.IncrementMemoryAddress(Ptr, MaskLo, DL, LoMemVT, DAG,
                                   MST->isCompressingStore());

  MMO = DAG.getMachineFunction().
    getMachineMemOperand(MST->getPointerInfo(),
                         MachineMemOperand::MOStore,  HiMemVT.getStoreSize(),
                         SecondHalfAlignment, MST->getAAInfo(),
                         MST->getRanges());

  Hi = DAG.getMaskedStore(Chain, DL, DataHi, Ptr, MaskHi, HiMemVT, MMO,
                          MST->isTruncatingStore(),
                          MST->isCompressingStore());

  AddToWorklist(Lo.getNode());
  AddToWorklist(Hi.getNode());

  return DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo, Hi);
}
return SDValue();
6855}

6857SDValue DAGCombiner::visitMGATHER(SDNode *N) {
if (Level >= AfterLegalizeTypes)
  return SDValue();

MaskedGatherSDNode *MGT = cast<MaskedGatherSDNode>(N);
SDValue Mask = MGT->getMask();
SDLoc DL(N);

// If the MGATHER result requires splitting and the mask is provided by a
// SETCC, then split both nodes and its operands before legalization. This
// prevents the type legalizer from unrolling SETCC into scalar comparisons
// and enables future optimizations (e.g. min/max pattern matching on X86).

if (Mask.getOpcode() != ISD::SETCC)
  return SDValue();

EVT VT = N->getValueType(0);

// Check if any splitting is required.
if (TLI.getTypeAction(*DAG.getContext(), VT) !=
    TargetLowering::TypeSplitVector)
  return SDValue();

SDValue MaskLo, MaskHi, Lo, Hi;
std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);

SDValue Src0 = MGT->getValue();
SDValue Src0Lo, Src0Hi;
std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);

EVT LoVT, HiVT;
std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(VT);

SDValue Chain = MGT->getChain();
EVT MemoryVT = MGT->getMemoryVT();
unsigned Alignment = MGT->getOriginalAlignment();

EVT LoMemVT, HiMemVT;
std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);

SDValue Scale = MGT->getScale();
SDValue BasePtr = MGT->getBasePtr();
SDValue Index = MGT->getIndex();
SDValue IndexLo, IndexHi;
std::tie(IndexLo, IndexHi) = DAG.SplitVector(Index, DL);

MachineMemOperand *MMO = DAG.getMachineFunction().
  getMachineMemOperand(MGT->getPointerInfo(),
                        MachineMemOperand::MOLoad,  LoMemVT.getStoreSize(),
                        Alignment, MGT->getAAInfo(), MGT->getRanges());

SDValue OpsLo[] = { Chain, Src0Lo, MaskLo, BasePtr, IndexLo, Scale };
Lo = DAG.getMaskedGather(DAG.getVTList(LoVT, MVT::Other), LoVT, DL, OpsLo,
                         MMO);

SDValue OpsHi[] = { Chain, Src0Hi, MaskHi, BasePtr, IndexHi, Scale };
Hi = DAG.getMaskedGather(DAG.getVTList(HiVT, MVT::Other), HiVT, DL, OpsHi,
                         MMO);

AddToWorklist(Lo.getNode());
AddToWorklist(Hi.getNode());

// Build a factor node to remember that this load is independent of the
// other one.
Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
                    Hi.getValue(1));

// Legalized the chain result - switch anything that used the old chain to
// use the new one.
DAG.ReplaceAllUsesOfValueWith(SDValue(MGT, 1), Chain);

SDValue GatherRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);

SDValue RetOps[] = { GatherRes, Chain };
return DAG.getMergeValues(RetOps, DL);
6932}

6934SDValue DAGCombiner::visitMLOAD(SDNode *N) {
if (Level >= AfterLegalizeTypes)
  return SDValue();

MaskedLoadSDNode *MLD = dyn_cast<MaskedLoadSDNode>(N);
SDValue Mask = MLD->getMask();
SDLoc DL(N);

// If the MLOAD result requires splitting and the mask is provided by a
// SETCC, then split both nodes and its operands before legalization. This
// prevents the type legalizer from unrolling SETCC into scalar comparisons
// and enables future optimizations (e.g. min/max pattern matching on X86).
if (Mask.getOpcode() == ISD::SETCC) {
  EVT VT = N->getValueType(0);

  // Check if any splitting is required.
  if (TLI.getTypeAction(*DAG.getContext(), VT) !=
      TargetLowering::TypeSplitVector)
    return SDValue();

  SDValue MaskLo, MaskHi, Lo, Hi;
  std::tie(MaskLo, MaskHi) = SplitVSETCC(Mask.getNode(), DAG);

  SDValue Src0 = MLD->getSrc0();
  SDValue Src0Lo, Src0Hi;
  std::tie(Src0Lo, Src0Hi) = DAG.SplitVector(Src0, DL);

  EVT LoVT, HiVT;
  std::tie(LoVT, HiVT) = DAG.GetSplitDestVTs(MLD->getValueType(0));

  SDValue Chain = MLD->getChain();
  SDValue Ptr   = MLD->getBasePtr();
  EVT MemoryVT = MLD->getMemoryVT();
  unsigned Alignment = MLD->getOriginalAlignment();

  // if Alignment is equal to the vector size,
  // take the half of it for the second part
  unsigned SecondHalfAlignment =
    (Alignment == MLD->getValueType(0).getSizeInBits()/8) ?
       Alignment/2 : Alignment;

  EVT LoMemVT, HiMemVT;
  std::tie(LoMemVT, HiMemVT) = DAG.GetSplitDestVTs(MemoryVT);

  MachineMemOperand *MMO = DAG.getMachineFunction().
  getMachineMemOperand(MLD->getPointerInfo(),
                       MachineMemOperand::MOLoad,  LoMemVT.getStoreSize(),
                       Alignment, MLD->getAAInfo(), MLD->getRanges());

  Lo = DAG.getMaskedLoad(LoVT, DL, Chain, Ptr, MaskLo, Src0Lo, LoMemVT, MMO,
                         ISD::NON_EXTLOAD, MLD->isExpandingLoad());

  Ptr = TLI.IncrementMemoryAddress(Ptr, MaskLo, DL, LoMemVT, DAG,
                                   MLD->isExpandingLoad());

  MMO = DAG.getMachineFunction().
  getMachineMemOperand(MLD->getPointerInfo(),
                       MachineMemOperand::MOLoad,  HiMemVT.getStoreSize(),
                       SecondHalfAlignment, MLD->getAAInfo(), MLD->getRanges());

  Hi = DAG.getMaskedLoad(HiVT, DL, Chain, Ptr, MaskHi, Src0Hi, HiMemVT, MMO,
                         ISD::NON_EXTLOAD, MLD->isExpandingLoad());

  AddToWorklist(Lo.getNode());
  AddToWorklist(Hi.getNode());

  // Build a factor node to remember that this load is independent of the
  // other one.
  Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Lo.getValue(1),
                      Hi.getValue(1));

  // Legalized the chain result - switch anything that used the old chain to
  // use the new one.
  DAG.ReplaceAllUsesOfValueWith(SDValue(MLD, 1), Chain);

  SDValue LoadRes = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi);

  SDValue RetOps[] = { LoadRes, Chain };
  return DAG.getMergeValues(RetOps, DL);
}
return SDValue();
7015}

7017/// A vector select of 2 constant vectors can be simplified to math/logic to
7018/// avoid a variable select instruction and possibly avoid constant loads.
7019SDValue DAGCombiner::foldVSelectOfConstants(SDNode *N) {
SDValue Cond = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
EVT VT = N->getValueType(0);
if (!Cond.hasOneUse() || Cond.getScalarValueSizeInBits() != 1 ||
    !TLI.convertSelectOfConstantsToMath(VT) ||
    !ISD::isBuildVectorOfConstantSDNodes(N1.getNode()) ||
    !ISD::isBuildVectorOfConstantSDNodes(N2.getNode()))
  return SDValue();

// Check if we can use the condition value to increment/decrement a single
// constant value. This simplifies a select to an add and removes a constant
// load/materialization from the general case.
bool AllAddOne = true;
bool AllSubOne = true;
unsigned Elts = VT.getVectorNumElements();
for (unsigned i = 0; i != Elts; ++i) {
  SDValue N1Elt = N1.getOperand(i);
  SDValue N2Elt = N2.getOperand(i);
  if (N1Elt.isUndef() || N2Elt.isUndef())
    continue;

  const APInt &C1 = cast<ConstantSDNode>(N1Elt)->getAPIntValue();
  const APInt &C2 = cast<ConstantSDNode>(N2Elt)->getAPIntValue();
  if (C1 != C2 + 1)
    AllAddOne = false;
  if (C1 != C2 - 1)
    AllSubOne = false;
}

// Further simplifications for the extra-special cases where the constants are
// all 0 or all -1 should be implemented as folds of these patterns.
SDLoc DL(N);
if (AllAddOne || AllSubOne) {
  // vselect <N x i1> Cond, C+1, C --> add (zext Cond), C
  // vselect <N x i1> Cond, C-1, C --> add (sext Cond), C
  auto ExtendOpcode = AllAddOne ? ISD::ZERO_EXTEND : ISD::SIGN_EXTEND;
  SDValue ExtendedCond = DAG.getNode(ExtendOpcode, DL, VT, Cond);
  return DAG.getNode(ISD::ADD, DL, VT, ExtendedCond, N2);
}

// The general case for select-of-constants:
// vselect <N x i1> Cond, C1, C2 --> xor (and (sext Cond), (C1^C2)), C2
// ...but that only makes sense if a vselect is slower than 2 logic ops, so
// leave that to a machine-specific pass.
return SDValue();
7066}

7068SDValue DAGCombiner::visitVSELECT(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
SDLoc DL(N);

// fold (vselect C, X, X) -> X
if (N1 == N2)
  return N1;

// Canonicalize integer abs.
// vselect (setg[te] X,  0),  X, -X ->
// vselect (setgt    X, -1),  X, -X ->
// vselect (setl[te] X,  0), -X,  X ->
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
if (N0.getOpcode() == ISD::SETCC) {
  SDValue LHS = N0.getOperand(0), RHS = N0.getOperand(1);
  ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
  bool isAbs = false;
  bool RHSIsAllZeros = ISD::isBuildVectorAllZeros(RHS.getNode());

  if (((RHSIsAllZeros && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
       (ISD::isBuildVectorAllOnes(RHS.getNode()) && CC == ISD::SETGT)) &&
      N1 == LHS && N2.getOpcode() == ISD::SUB && N1 == N2.getOperand(1))
    isAbs = ISD::isBuildVectorAllZeros(N2.getOperand(0).getNode());
  else if ((RHSIsAllZeros && (CC == ISD::SETLT || CC == ISD::SETLE)) &&
           N2 == LHS && N1.getOpcode() == ISD::SUB && N2 == N1.getOperand(1))
    isAbs = ISD::isBuildVectorAllZeros(N1.getOperand(0).getNode());

  if (isAbs) {
    EVT VT = LHS.getValueType();
    if (TLI.isOperationLegalOrCustom(ISD::ABS, VT))
      return DAG.getNode(ISD::ABS, DL, VT, LHS);

    SDValue Shift = DAG.getNode(
        ISD::SRA, DL, VT, LHS,
        DAG.getConstant(VT.getScalarSizeInBits() - 1, DL, VT));
    SDValue Add = DAG.getNode(ISD::ADD, DL, VT, LHS, Shift);
    AddToWorklist(Shift.getNode());
    AddToWorklist(Add.getNode());
    return DAG.getNode(ISD::XOR, DL, VT, Add, Shift);
  }
}

if (SimplifySelectOps(N, N1, N2))
  return SDValue(N, 0);  // Don't revisit N.

// Fold (vselect (build_vector all_ones), N1, N2) -> N1
if (ISD::isBuildVectorAllOnes(N0.getNode()))
  return N1;
// Fold (vselect (build_vector all_zeros), N1, N2) -> N2
if (ISD::isBuildVectorAllZeros(N0.getNode()))
  return N2;

// The ConvertSelectToConcatVector function is assuming both the above
// checks for (vselect (build_vector all{ones,zeros) ...) have been made
// and addressed.
if (N1.getOpcode() == ISD::CONCAT_VECTORS &&
    N2.getOpcode() == ISD::CONCAT_VECTORS &&
    ISD::isBuildVectorOfConstantSDNodes(N0.getNode())) {
  if (SDValue CV = ConvertSelectToConcatVector(N, DAG))
    return CV;
}

if (SDValue V = foldVSelectOfConstants(N))
  return V;

return SDValue();
7136}

7138SDValue DAGCombiner::visitSELECT_CC(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
SDValue N3 = N->getOperand(3);
SDValue N4 = N->getOperand(4);
ISD::CondCode CC = cast<CondCodeSDNode>(N4)->get();

// fold select_cc lhs, rhs, x, x, cc -> x
if (N2 == N3)
  return N2;

// Determine if the condition we're dealing with is constant
if (SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()), N0, N1,
                                CC, SDLoc(N), false)) {
  AddToWorklist(SCC.getNode());

  if (ConstantSDNode *SCCC = dyn_cast<ConstantSDNode>(SCC.getNode())) {
    if (!SCCC->isNullValue())
      return N2;    // cond always true -> true val
    else
      return N3;    // cond always false -> false val
  } else if (SCC->isUndef()) {
    // When the condition is UNDEF, just return the first operand. This is
    // coherent the DAG creation, no setcc node is created in this case
    return N2;
  } else if (SCC.getOpcode() == ISD::SETCC) {
    // Fold to a simpler select_cc
    return DAG.getNode(ISD::SELECT_CC, SDLoc(N), N2.getValueType(),
                       SCC.getOperand(0), SCC.getOperand(1), N2, N3,
                       SCC.getOperand(2));
  }
}

// If we can fold this based on the true/false value, do so.
if (SimplifySelectOps(N, N2, N3))
  return SDValue(N, 0);  // Don't revisit N.

// fold select_cc into other things, such as min/max/abs
return SimplifySelectCC(SDLoc(N), N0, N1, N2, N3, CC);
7178}

7180SDValue DAGCombiner::visitSETCC(SDNode *N) {
return SimplifySetCC(N->getValueType(0), N->getOperand(0), N->getOperand(1),
                     cast<CondCodeSDNode>(N->getOperand(2))->get(),
                     SDLoc(N));
7184}

7186SDValue DAGCombiner::visitSETCCE(SDNode *N) {
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
SDValue Carry = N->getOperand(2);
SDValue Cond = N->getOperand(3);

// If Carry is false, fold to a regular SETCC.
if (Carry.getOpcode() == ISD::CARRY_FALSE)
  return DAG.getNode(ISD::SETCC, SDLoc(N), N->getVTList(), LHS, RHS, Cond);

return SDValue();
7197}

7199SDValue DAGCombiner::visitSETCCCARRY(SDNode *N) {
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
SDValue Carry = N->getOperand(2);
SDValue Cond = N->getOperand(3);

// If Carry is false, fold to a regular SETCC.
if (isNullConstant(Carry))
  return DAG.getNode(ISD::SETCC, SDLoc(N), N->getVTList(), LHS, RHS, Cond);

return SDValue();
7210}

7212/// Try to fold a sext/zext/aext dag node into a ConstantSDNode or
7213/// a build_vector of constants.
7214/// This function is called by the DAGCombiner when visiting sext/zext/aext
7215/// dag nodes (see for example method DAGCombiner::visitSIGN_EXTEND).
7216/// Vector extends are not folded if operations are legal; this is to
7217/// avoid introducing illegal build_vector dag nodes.
7218static SDNode *tryToFoldExtendOfConstant(SDNode *N, const TargetLowering &TLI,
                                       SelectionDAG &DAG, bool LegalTypes,
                                       bool LegalOperations) {
unsigned Opcode = N->getOpcode();
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

assert((Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND ||(static_cast <bool> ((Opcode == ISD::SIGN_EXTEND || Opcode
 == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode ==
 ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG
) && "Expected EXTEND dag node in input!") ? void (0)
 : __assert_fail ("(Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG) && \"Expected EXTEND dag node in input!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__))
       Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG ||(static_cast <bool> ((Opcode == ISD::SIGN_EXTEND || Opcode
 == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode ==
 ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG
) && "Expected EXTEND dag node in input!") ? void (0)
 : __assert_fail ("(Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG) && \"Expected EXTEND dag node in input!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__))
       Opcode == ISD::ZERO_EXTEND_VECTOR_INREG)(static_cast <bool> ((Opcode == ISD::SIGN_EXTEND || Opcode
 == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode ==
 ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG
) && "Expected EXTEND dag node in input!") ? void (0)
 : __assert_fail ("(Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG) && \"Expected EXTEND dag node in input!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__))
       && "Expected EXTEND dag node in input!")(static_cast <bool> ((Opcode == ISD::SIGN_EXTEND || Opcode
 == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode ==
 ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG
) && "Expected EXTEND dag node in input!") ? void (0)
 : __assert_fail ("(Opcode == ISD::SIGN_EXTEND || Opcode == ISD::ZERO_EXTEND || Opcode == ISD::ANY_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG || Opcode == ISD::ZERO_EXTEND_VECTOR_INREG) && \"Expected EXTEND dag node in input!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7228, __extension__ __PRETTY_FUNCTION__));

// fold (sext c1) -> c1
// fold (zext c1) -> c1
// fold (aext c1) -> c1
if (isa<ConstantSDNode>(N0))
  return DAG.getNode(Opcode, SDLoc(N), VT, N0).getNode();

// fold (sext (build_vector AllConstants) -> (build_vector AllConstants)
// fold (zext (build_vector AllConstants) -> (build_vector AllConstants)
// fold (aext (build_vector AllConstants) -> (build_vector AllConstants)
EVT SVT = VT.getScalarType();
if (!(VT.isVector() &&
    (!LegalTypes || (!LegalOperations && TLI.isTypeLegal(SVT))) &&
    ISD::isBuildVectorOfConstantSDNodes(N0.getNode())))
  return nullptr;

// We can fold this node into a build_vector.
unsigned VTBits = SVT.getSizeInBits();
unsigned EVTBits = N0->getValueType(0).getScalarSizeInBits();
SmallVector<SDValue, 8> Elts;
unsigned NumElts = VT.getVectorNumElements();
SDLoc DL(N);

for (unsigned i=0; i != NumElts; ++i) {
  SDValue Op = N0->getOperand(i);
  if (Op->isUndef()) {
    Elts.push_back(DAG.getUNDEF(SVT));
    continue;
  }

  SDLoc DL(Op);
  // Get the constant value and if needed trunc it to the size of the type.
  // Nodes like build_vector might have constants wider than the scalar type.
  APInt C = cast<ConstantSDNode>(Op)->getAPIntValue().zextOrTrunc(EVTBits);
  if (Opcode == ISD::SIGN_EXTEND || Opcode == ISD::SIGN_EXTEND_VECTOR_INREG)
    Elts.push_back(DAG.getConstant(C.sext(VTBits), DL, SVT));
  else
    Elts.push_back(DAG.getConstant(C.zext(VTBits), DL, SVT));
}

return DAG.getBuildVector(VT, DL, Elts).getNode();
7270}

7272// ExtendUsesToFormExtLoad - Trying to extend uses of a load to enable this:
7273// "fold ({s|z|a}ext (load x)) -> ({s|z|a}ext (truncate ({s|z|a}extload x)))"
7274// transformation. Returns true if extension are possible and the above
7275// mentioned transformation is profitable.
7276static bool ExtendUsesToFormExtLoad(SDNode *N, SDValue N0,
                                  unsigned ExtOpc,
                                  SmallVectorImpl<SDNode *> &ExtendNodes,
                                  const TargetLowering &TLI) {
bool HasCopyToRegUses = false;
bool isTruncFree = TLI.isTruncateFree(N->getValueType(0), N0.getValueType());
for (SDNode::use_iterator UI = N0.getNode()->use_begin(),
                          UE = N0.getNode()->use_end();
     UI != UE; ++UI) {
  SDNode *User = *UI;
  if (User == N)
    continue;
  if (UI.getUse().getResNo() != N0.getResNo())
    continue;
  // FIXME: Only extend SETCC N, N and SETCC N, c for now.
  if (ExtOpc != ISD::ANY_EXTEND && User->getOpcode() == ISD::SETCC) {
    ISD::CondCode CC = cast<CondCodeSDNode>(User->getOperand(2))->get();
    if (ExtOpc == ISD::ZERO_EXTEND && ISD::isSignedIntSetCC(CC))
      // Sign bits will be lost after a zext.
      return false;
    bool Add = false;
    for (unsigned i = 0; i != 2; ++i) {
      SDValue UseOp = User->getOperand(i);
      if (UseOp == N0)
        continue;
      if (!isa<ConstantSDNode>(UseOp))
        return false;
      Add = true;
    }
    if (Add)
      ExtendNodes.push_back(User);
    continue;
  }
  // If truncates aren't free and there are users we can't
  // extend, it isn't worthwhile.
  if (!isTruncFree)
    return false;
  // Remember if this value is live-out.
  if (User->getOpcode() == ISD::CopyToReg)
    HasCopyToRegUses = true;
}

if (HasCopyToRegUses) {
  bool BothLiveOut = false;
  for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
       UI != UE; ++UI) {
    SDUse &Use = UI.getUse();
    if (Use.getResNo() == 0 && Use.getUser()->getOpcode() == ISD::CopyToReg) {
      BothLiveOut = true;
      break;
    }
  }
  if (BothLiveOut)
    // Both unextended and extended values are live out. There had better be
    // a good reason for the transformation.
    return ExtendNodes.size();
}
return true;
7334}

7336void DAGCombiner::ExtendSetCCUses(const SmallVectorImpl<SDNode *> &SetCCs,
                                SDValue OrigLoad, SDValue ExtLoad,
                                const SDLoc &DL, ISD::NodeType ExtType) {
// Extend SetCC uses if necessary.
for (unsigned i = 0, e = SetCCs.size(); i != e; ++i) {
  SDNode *SetCC = SetCCs[i];
  SmallVector<SDValue, 4> Ops;

  for (unsigned j = 0; j != 2; ++j) {
    SDValue SOp = SetCC->getOperand(j);
    if (SOp == OrigLoad)
      Ops.push_back(ExtLoad);
    else
      Ops.push_back(DAG.getNode(ExtType, DL, ExtLoad->getValueType(0), SOp));
  }

  Ops.push_back(SetCC->getOperand(2));
  CombineTo(SetCC, DAG.getNode(ISD::SETCC, DL, SetCC->getValueType(0), Ops));
}
7355}

7357// FIXME: Bring more similar combines here, common to sext/zext (maybe aext?).
7358SDValue DAGCombiner::CombineExtLoad(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT DstVT = N->getValueType(0);
EVT SrcVT = N0.getValueType();

assert((N->getOpcode() == ISD::SIGN_EXTEND ||(static_cast <bool> ((N->getOpcode() == ISD::SIGN_EXTEND
 || N->getOpcode() == ISD::ZERO_EXTEND) && "Unexpected node type (not an extend)!"
) ? void (0) : __assert_fail ("(N->getOpcode() == ISD::SIGN_EXTEND || N->getOpcode() == ISD::ZERO_EXTEND) && \"Unexpected node type (not an extend)!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7365, __extension__ __PRETTY_FUNCTION__))
        N->getOpcode() == ISD::ZERO_EXTEND) &&(static_cast <bool> ((N->getOpcode() == ISD::SIGN_EXTEND
 || N->getOpcode() == ISD::ZERO_EXTEND) && "Unexpected node type (not an extend)!"
) ? void (0) : __assert_fail ("(N->getOpcode() == ISD::SIGN_EXTEND || N->getOpcode() == ISD::ZERO_EXTEND) && \"Unexpected node type (not an extend)!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7365, __extension__ __PRETTY_FUNCTION__))
       "Unexpected node type (not an extend)!")(static_cast <bool> ((N->getOpcode() == ISD::SIGN_EXTEND
 || N->getOpcode() == ISD::ZERO_EXTEND) && "Unexpected node type (not an extend)!"
) ? void (0) : __assert_fail ("(N->getOpcode() == ISD::SIGN_EXTEND || N->getOpcode() == ISD::ZERO_EXTEND) && \"Unexpected node type (not an extend)!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7365, __extension__ __PRETTY_FUNCTION__));

// fold (sext (load x)) to multiple smaller sextloads; same for zext.
// For example, on a target with legal v4i32, but illegal v8i32, turn:
//   (v8i32 (sext (v8i16 (load x))))
// into:
//   (v8i32 (concat_vectors (v4i32 (sextload x)),
//                          (v4i32 (sextload (x + 16)))))
// Where uses of the original load, i.e.:
//   (v8i16 (load x))
// are replaced with:
//   (v8i16 (truncate
//     (v8i32 (concat_vectors (v4i32 (sextload x)),
//                            (v4i32 (sextload (x + 16)))))))
//
// This combine is only applicable to illegal, but splittable, vectors.
// All legal types, and illegal non-vector types, are handled elsewhere.
// This combine is controlled by TargetLowering::isVectorLoadExtDesirable.
//
if (N0->getOpcode() != ISD::LOAD)
  return SDValue();

LoadSDNode *LN0 = cast<LoadSDNode>(N0);

if (!ISD::isNON_EXTLoad(LN0) || !ISD::isUNINDEXEDLoad(LN0) ||
    !N0.hasOneUse() || LN0->isVolatile() || !DstVT.isVector() ||
    !DstVT.isPow2VectorType() || !TLI.isVectorLoadExtDesirable(SDValue(N, 0)))
  return SDValue();

SmallVector<SDNode *, 4> SetCCs;
if (!ExtendUsesToFormExtLoad(N, N0, N->getOpcode(), SetCCs, TLI))
  return SDValue();

ISD::LoadExtType ExtType =
    N->getOpcode() == ISD::SIGN_EXTEND ? ISD::SEXTLOAD : ISD::ZEXTLOAD;

// Try to split the vector types to get down to legal types.
EVT SplitSrcVT = SrcVT;
EVT SplitDstVT = DstVT;
while (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT) &&
       SplitSrcVT.getVectorNumElements() > 1) {
  SplitDstVT = DAG.GetSplitDestVTs(SplitDstVT).first;
  SplitSrcVT = DAG.GetSplitDestVTs(SplitSrcVT).first;
}

if (!TLI.isLoadExtLegalOrCustom(ExtType, SplitDstVT, SplitSrcVT))
  return SDValue();

SDLoc DL(N);
const unsigned NumSplits =
    DstVT.getVectorNumElements() / SplitDstVT.getVectorNumElements();
const unsigned Stride = SplitSrcVT.getStoreSize();
SmallVector<SDValue, 4> Loads;
SmallVector<SDValue, 4> Chains;

SDValue BasePtr = LN0->getBasePtr();
for (unsigned Idx = 0; Idx < NumSplits; Idx++) {
  const unsigned Offset = Idx * Stride;
  const unsigned Align = MinAlign(LN0->getAlignment(), Offset);

  SDValue SplitLoad = DAG.getExtLoad(
      ExtType, DL, SplitDstVT, LN0->getChain(), BasePtr,
      LN0->getPointerInfo().getWithOffset(Offset), SplitSrcVT, Align,
      LN0->getMemOperand()->getFlags(), LN0->getAAInfo());

  BasePtr = DAG.getNode(ISD::ADD, DL, BasePtr.getValueType(), BasePtr,
                        DAG.getConstant(Stride, DL, BasePtr.getValueType()));

  Loads.push_back(SplitLoad.getValue(0));
  Chains.push_back(SplitLoad.getValue(1));
}

SDValue NewChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other, Chains);
SDValue NewValue = DAG.getNode(ISD::CONCAT_VECTORS, DL, DstVT, Loads);

// Simplify TF.
AddToWorklist(NewChain.getNode());

CombineTo(N, NewValue);

// Replace uses of the original load (before extension)
// with a truncate of the concatenated sextloaded vectors.
SDValue Trunc =
    DAG.getNode(ISD::TRUNCATE, SDLoc(N0), N0.getValueType(), NewValue);
ExtendSetCCUses(SetCCs, N0, NewValue, DL,
                (ISD::NodeType)N->getOpcode());
CombineTo(N0.getNode(), Trunc, NewChain);
return SDValue(N, 0); // Return N so it doesn't get rechecked!
7453}

7455/// If we're narrowing or widening the result of a vector select and the final
7456/// size is the same size as a setcc (compare) feeding the select, then try to
7457/// apply the cast operation to the select's operands because matching vector
7458/// sizes for a select condition and other operands should be more efficient.
7459SDValue DAGCombiner::matchVSelectOpSizesWithSetCC(SDNode *Cast) {
unsigned CastOpcode = Cast->getOpcode();
assert((CastOpcode == ISD::SIGN_EXTEND || CastOpcode == ISD::ZERO_EXTEND ||(static_cast <bool> ((CastOpcode == ISD::SIGN_EXTEND ||
 CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE
 || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND
) && "Unexpected opcode for vector select narrowing/widening"
) ? void (0) : __assert_fail ("(CastOpcode == ISD::SIGN_EXTEND || CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND) && \"Unexpected opcode for vector select narrowing/widening\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7464, __extension__ __PRETTY_FUNCTION__))
        CastOpcode == ISD::TRUNCATE || CastOpcode == ISD::FP_EXTEND ||(static_cast <bool> ((CastOpcode == ISD::SIGN_EXTEND ||
 CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE
 || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND
) && "Unexpected opcode for vector select narrowing/widening"
) ? void (0) : __assert_fail ("(CastOpcode == ISD::SIGN_EXTEND || CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND) && \"Unexpected opcode for vector select narrowing/widening\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7464, __extension__ __PRETTY_FUNCTION__))
        CastOpcode == ISD::FP_ROUND) &&(static_cast <bool> ((CastOpcode == ISD::SIGN_EXTEND ||
 CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE
 || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND
) && "Unexpected opcode for vector select narrowing/widening"
) ? void (0) : __assert_fail ("(CastOpcode == ISD::SIGN_EXTEND || CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND) && \"Unexpected opcode for vector select narrowing/widening\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7464, __extension__ __PRETTY_FUNCTION__))
       "Unexpected opcode for vector select narrowing/widening")(static_cast <bool> ((CastOpcode == ISD::SIGN_EXTEND ||
 CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE
 || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND
) && "Unexpected opcode for vector select narrowing/widening"
) ? void (0) : __assert_fail ("(CastOpcode == ISD::SIGN_EXTEND || CastOpcode == ISD::ZERO_EXTEND || CastOpcode == ISD::TRUNCATE || CastOpcode == ISD::FP_EXTEND || CastOpcode == ISD::FP_ROUND) && \"Unexpected opcode for vector select narrowing/widening\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7464, __extension__ __PRETTY_FUNCTION__));

// We only do this transform before legal ops because the pattern may be
// obfuscated by target-specific operations after legalization. Do not create
// an illegal select op, however, because that may be difficult to lower.
EVT VT = Cast->getValueType(0);
if (LegalOperations || !TLI.isOperationLegalOrCustom(ISD::VSELECT, VT))
  return SDValue();

SDValue VSel = Cast->getOperand(0);
if (VSel.getOpcode() != ISD::VSELECT || !VSel.hasOneUse() ||
    VSel.getOperand(0).getOpcode() != ISD::SETCC)
  return SDValue();

// Does the setcc have the same vector size as the casted select?
SDValue SetCC = VSel.getOperand(0);
EVT SetCCVT = getSetCCResultType(SetCC.getOperand(0).getValueType());
if (SetCCVT.getSizeInBits() != VT.getSizeInBits())
  return SDValue();

// cast (vsel (setcc X), A, B) --> vsel (setcc X), (cast A), (cast B)
SDValue A = VSel.getOperand(1);
SDValue B = VSel.getOperand(2);
SDValue CastA, CastB;
SDLoc DL(Cast);
if (CastOpcode == ISD::FP_ROUND) {
  // FP_ROUND (fptrunc) has an extra flag operand to pass along.
  CastA = DAG.getNode(CastOpcode, DL, VT, A, Cast->getOperand(1));
  CastB = DAG.getNode(CastOpcode, DL, VT, B, Cast->getOperand(1));
} else {
  CastA = DAG.getNode(CastOpcode, DL, VT, A);
  CastB = DAG.getNode(CastOpcode, DL, VT, B);
}
return DAG.getNode(ISD::VSELECT, DL, VT, SetCC, CastA, CastB);
7498}

7500SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
SDLoc DL(N);

if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
                                            LegalOperations))
  return SDValue(Res, 0);

// fold (sext (sext x)) -> (sext x)
// fold (sext (aext x)) -> (sext x)
if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
  return DAG.getNode(ISD::SIGN_EXTEND, DL, VT, N0.getOperand(0));

if (N0.getOpcode() == ISD::TRUNCATE) {
  // fold (sext (truncate (load x))) -> (sext (smaller load x))
  // fold (sext (truncate (srl (load x), c))) -> (sext (smaller load (x+c/n)))
  if (SDValue NarrowLoad = ReduceLoadWidth(N0.getNode())) {
    SDNode *oye = N0.getOperand(0).getNode();
    if (NarrowLoad.getNode() != N0.getNode()) {
      CombineTo(N0.getNode(), NarrowLoad);
      // CombineTo deleted the truncate, if needed, but not what's under it.
      AddToWorklist(oye);
    }
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }

  // See if the value being truncated is already sign extended.  If so, just
  // eliminate the trunc/sext pair.
  SDValue Op = N0.getOperand(0);
  unsigned OpBits   = Op.getScalarValueSizeInBits();
  unsigned MidBits  = N0.getScalarValueSizeInBits();
  unsigned DestBits = VT.getScalarSizeInBits();
  unsigned NumSignBits = DAG.ComputeNumSignBits(Op);

  if (OpBits == DestBits) {
    // Op is i32, Mid is i8, and Dest is i32.  If Op has more than 24 sign
    // bits, it is already ready.
    if (NumSignBits > DestBits-MidBits)
      return Op;
  } else if (OpBits < DestBits) {
    // Op is i32, Mid is i8, and Dest is i64.  If Op has more than 24 sign
    // bits, just sext from i32.
    if (NumSignBits > OpBits-MidBits)
      return DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Op);
  } else {
    // Op is i64, Mid is i8, and Dest is i32.  If Op has more than 56 sign
    // bits, just truncate to i32.
    if (NumSignBits > OpBits-MidBits)
      return DAG.getNode(ISD::TRUNCATE, DL, VT, Op);
  }

  // fold (sext (truncate x)) -> (sextinreg x).
  if (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG,
                                               N0.getValueType())) {
    if (OpBits < DestBits)
      Op = DAG.getNode(ISD::ANY_EXTEND, SDLoc(N0), VT, Op);
    else if (OpBits > DestBits)
      Op = DAG.getNode(ISD::TRUNCATE, SDLoc(N0), VT, Op);
    return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Op,
                       DAG.getValueType(N0.getValueType()));
  }
}

// fold (sext (load x)) -> (sext (truncate (sextload x)))
// Only generate vector extloads when 1) they're legal, and 2) they are
// deemed desirable by the target.
if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
    ((!LegalOperations && !VT.isVector() &&
      !cast<LoadSDNode>(N0)->isVolatile()) ||
     TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, N0.getValueType()))) {
  bool DoXform = true;
  SmallVector<SDNode*, 4> SetCCs;
  if (!N0.hasOneUse())
    DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::SIGN_EXTEND, SetCCs, TLI);
  if (VT.isVector())
    DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
  if (DoXform) {
    LoadSDNode *LN0 = cast<LoadSDNode>(N0);
    SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, DL, VT, LN0->getChain(),
                                     LN0->getBasePtr(), N0.getValueType(),
                                     LN0->getMemOperand());
    ExtendSetCCUses(SetCCs, N0, ExtLoad, DL, ISD::SIGN_EXTEND);
    // If the load value is used only by N, replace it via CombineTo N.
    bool NoReplaceTrunc = SDValue(LN0, 0).hasOneUse();
    CombineTo(N, ExtLoad);
    if (NoReplaceTrunc) {
      DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    } else {
      SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
                                  N0.getValueType(), ExtLoad);
      CombineTo(LN0, Trunc, ExtLoad.getValue(1));
    }
    return SDValue(N, 0);
  }
}

// fold (sext (load x)) to multiple smaller sextloads.
// Only on illegal but splittable vectors.
if (SDValue ExtLoad = CombineExtLoad(N))
  return ExtLoad;

// fold (sext (sextload x)) -> (sext (truncate (sextload x)))
// fold (sext ( extload x)) -> (sext (truncate (sextload x)))
if ((ISD::isSEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
    ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  EVT MemVT = LN0->getMemoryVT();
  if ((!LegalOperations && !LN0->isVolatile()) ||
      TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, MemVT)) {
    SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, DL, VT, LN0->getChain(),
                                     LN0->getBasePtr(), MemVT,
                                     LN0->getMemOperand());
    CombineTo(N, ExtLoad);
    DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}

// fold (sext (and/or/xor (load x), cst)) ->
//      (and/or/xor (sextload x), (sext cst))
if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
     N0.getOpcode() == ISD::XOR) &&
    isa<LoadSDNode>(N0.getOperand(0)) &&
    N0.getOperand(1).getOpcode() == ISD::Constant &&
    (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
  LoadSDNode *LN00 = cast<LoadSDNode>(N0.getOperand(0));
  EVT MemVT = LN00->getMemoryVT();
  if (TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, MemVT) &&
    LN00->getExtensionType() != ISD::ZEXTLOAD && LN00->isUnindexed()) {
    bool DoXform = true;
    SmallVector<SDNode*, 4> SetCCs;
    if (!N0.hasOneUse())
      DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0), ISD::SIGN_EXTEND,
                                        SetCCs, TLI);
    if (DoXform) {
      SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(LN00), VT,
                                       LN00->getChain(), LN00->getBasePtr(),
                                       LN00->getMemoryVT(),
                                       LN00->getMemOperand());
      APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
      Mask = Mask.sext(VT.getSizeInBits());
      SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
                                ExtLoad, DAG.getConstant(Mask, DL, VT));
      ExtendSetCCUses(SetCCs, N0.getOperand(0), ExtLoad, DL,
                      ISD::SIGN_EXTEND);
      bool NoReplaceTruncAnd = !N0.hasOneUse();
      bool NoReplaceTrunc = SDValue(LN00, 0).hasOneUse();
      CombineTo(N, And);
      // If N0 has multiple uses, change other uses as well.
      if (NoReplaceTruncAnd) {
        SDValue TruncAnd =
            DAG.getNode(ISD::TRUNCATE, DL, N0.getValueType(), And);
        CombineTo(N0.getNode(), TruncAnd);
      }
      if (NoReplaceTrunc) {
        DAG.ReplaceAllUsesOfValueWith(SDValue(LN00, 1), ExtLoad.getValue(1));
      } else {
        SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(LN00),
                                    LN00->getValueType(0), ExtLoad);
        CombineTo(LN00, Trunc, ExtLoad.getValue(1));
      }
      return SDValue(N,0); // Return N so it doesn't get rechecked!
    }
  }
}

if (N0.getOpcode() == ISD::SETCC) {
  SDValue N00 = N0.getOperand(0);
  SDValue N01 = N0.getOperand(1);
  ISD::CondCode CC = cast<CondCodeSDNode>(N0.getOperand(2))->get();
  EVT N00VT = N0.getOperand(0).getValueType();

  // sext(setcc) -> sext_in_reg(vsetcc) for vectors.
  // Only do this before legalize for now.
  if (VT.isVector() && !LegalOperations &&
      TLI.getBooleanContents(N00VT) ==
          TargetLowering::ZeroOrNegativeOneBooleanContent) {
    // On some architectures (such as SSE/NEON/etc) the SETCC result type is
    // of the same size as the compared operands. Only optimize sext(setcc())
    // if this is the case.
    EVT SVT = getSetCCResultType(N00VT);

    // We know that the # elements of the results is the same as the
    // # elements of the compare (and the # elements of the compare result
    // for that matter).  Check to see that they are the same size.  If so,
    // we know that the element size of the sext'd result matches the
    // element size of the compare operands.
    if (VT.getSizeInBits() == SVT.getSizeInBits())
      return DAG.getSetCC(DL, VT, N00, N01, CC);

    // If the desired elements are smaller or larger than the source
    // elements, we can use a matching integer vector type and then
    // truncate/sign extend.
    EVT MatchingVecType = N00VT.changeVectorElementTypeToInteger();
    if (SVT == MatchingVecType) {
      SDValue VsetCC = DAG.getSetCC(DL, MatchingVecType, N00, N01, CC);
      return DAG.getSExtOrTrunc(VsetCC, DL, VT);
    }
  }

  // sext(setcc x, y, cc) -> (select (setcc x, y, cc), T, 0)
  // Here, T can be 1 or -1, depending on the type of the setcc and
  // getBooleanContents().
  unsigned SetCCWidth = N0.getScalarValueSizeInBits();

  // To determine the "true" side of the select, we need to know the high bit
  // of the value returned by the setcc if it evaluates to true.
  // If the type of the setcc is i1, then the true case of the select is just
  // sext(i1 1), that is, -1.
  // If the type of the setcc is larger (say, i8) then the value of the high
  // bit depends on getBooleanContents(), so ask TLI for a real "true" value
  // of the appropriate width.
  SDValue ExtTrueVal = (SetCCWidth == 1)
                           ? DAG.getAllOnesConstant(DL, VT)
                           : DAG.getBoolConstant(true, DL, VT, N00VT);
  SDValue Zero = DAG.getConstant(0, DL, VT);
  if (SDValue SCC =
          SimplifySelectCC(DL, N00, N01, ExtTrueVal, Zero, CC, true))
    return SCC;

  if (!VT.isVector() && !TLI.convertSelectOfConstantsToMath(VT)) {
    EVT SetCCVT = getSetCCResultType(N00VT);
    // Don't do this transform for i1 because there's a select transform
    // that would reverse it.
    // TODO: We should not do this transform at all without a target hook
    // because a sext is likely cheaper than a select?
    if (SetCCVT.getScalarSizeInBits() != 1 &&
        (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, N00VT))) {
      SDValue SetCC = DAG.getSetCC(DL, SetCCVT, N00, N01, CC);
      return DAG.getSelect(DL, VT, SetCC, ExtTrueVal, Zero);
    }
  }
}

// fold (sext x) -> (zext x) if the sign bit is known zero.
if ((!LegalOperations || TLI.isOperationLegal(ISD::ZERO_EXTEND, VT)) &&
    DAG.SignBitIsZero(N0))
  return DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0);

if (SDValue NewVSel = matchVSelectOpSizesWithSetCC(N))
  return NewVSel;

return SDValue();
7744}

7746// isTruncateOf - If N is a truncate of some other value, return true, record
7747// the value being truncated in Op and which of Op's bits are zero/one in Known.
7748// This function computes KnownBits to avoid a duplicated call to
7749// computeKnownBits in the caller.
7750static bool isTruncateOf(SelectionDAG &DAG, SDValue N, SDValue &Op,
                       KnownBits &Known) {
if (N->getOpcode() == ISD::TRUNCATE) {
  Op = N->getOperand(0);
  DAG.computeKnownBits(Op, Known);
  return true;
}

if (N->getOpcode() != ISD::SETCC || N->getValueType(0) != MVT::i1 ||
    cast<CondCodeSDNode>(N->getOperand(2))->get() != ISD::SETNE)
  return false;

SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
assert(Op0.getValueType() == Op1.getValueType())(static_cast <bool> (Op0.getValueType() == Op1.getValueType
()) ? void (0) : __assert_fail ("Op0.getValueType() == Op1.getValueType()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 7764, __extension__ __PRETTY_FUNCTION__));

if (isNullConstant(Op0))
  Op = Op1;
else if (isNullConstant(Op1))
  Op = Op0;
else
  return false;

DAG.computeKnownBits(Op, Known);

if (!(Known.Zero | 1).isAllOnesValue())
  return false;

return true;
7779}

7781SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
                                            LegalOperations))
  return SDValue(Res, 0);

// fold (zext (zext x)) -> (zext x)
// fold (zext (aext x)) -> (zext x)
if (N0.getOpcode() == ISD::ZERO_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND)
  return DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N), VT,
                     N0.getOperand(0));

// fold (zext (truncate x)) -> (zext x) or
//      (zext (truncate x)) -> (truncate x)
// This is valid when the truncated bits of x are already zero.
// FIXME: We should extend this to work for vectors too.
SDValue Op;
KnownBits Known;
if (!VT.isVector() && isTruncateOf(DAG, N0, Op, Known)) {
  APInt TruncatedBits =
    (Op.getValueSizeInBits() == N0.getValueSizeInBits()) ?
    APInt(Op.getValueSizeInBits(), 0) :
    APInt::getBitsSet(Op.getValueSizeInBits(),
                      N0.getValueSizeInBits(),
                      std::min(Op.getValueSizeInBits(),
                               VT.getSizeInBits()));
  if (TruncatedBits.isSubsetOf(Known.Zero))
    return DAG.getZExtOrTrunc(Op, SDLoc(N), VT);
}

// fold (zext (truncate x)) -> (and x, mask)
if (N0.getOpcode() == ISD::TRUNCATE) {
  // fold (zext (truncate (load x))) -> (zext (smaller load x))
  // fold (zext (truncate (srl (load x), c))) -> (zext (smaller load (x+c/n)))
  if (SDValue NarrowLoad = ReduceLoadWidth(N0.getNode())) {
    SDNode *oye = N0.getOperand(0).getNode();
    if (NarrowLoad.getNode() != N0.getNode()) {
      CombineTo(N0.getNode(), NarrowLoad);
      // CombineTo deleted the truncate, if needed, but not what's under it.
      AddToWorklist(oye);
    }
    return SDValue(N, 0); // Return N so it doesn't get rechecked!
  }

  EVT SrcVT = N0.getOperand(0).getValueType();
  EVT MinVT = N0.getValueType();

  // Try to mask before the extension to avoid having to generate a larger mask,
  // possibly over several sub-vectors.
  if (SrcVT.bitsLT(VT)) {
    if (!LegalOperations || (TLI.isOperationLegal(ISD::AND, SrcVT) &&
                             TLI.isOperationLegal(ISD::ZERO_EXTEND, VT))) {
      SDValue Op = N0.getOperand(0);
      Op = DAG.getZeroExtendInReg(Op, SDLoc(N), MinVT.getScalarType());
      AddToWorklist(Op.getNode());
      SDValue ZExtOrTrunc = DAG.getZExtOrTrunc(Op, SDLoc(N), VT);
      // Transfer the debug info; the new node is equivalent to N0.
      DAG.transferDbgValues(N0, ZExtOrTrunc);
      return ZExtOrTrunc;
    }
  }

  if (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT)) {
    SDValue Op = DAG.getAnyExtOrTrunc(N0.getOperand(0), SDLoc(N), VT);
    AddToWorklist(Op.getNode());
    SDValue And = DAG.getZeroExtendInReg(Op, SDLoc(N), MinVT.getScalarType());
    // We may safely transfer the debug info describing the truncate node over
    // to the equivalent and operation.
    DAG.transferDbgValues(N0, And);
    return And;
  }
}

// Fold (zext (and (trunc x), cst)) -> (and x, cst),
// if either of the casts is not free.
if (N0.getOpcode() == ISD::AND &&
    N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
    N0.getOperand(1).getOpcode() == ISD::Constant &&
    (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
                         N0.getValueType()) ||
     !TLI.isZExtFree(N0.getValueType(), VT))) {
  SDValue X = N0.getOperand(0).getOperand(0);
  X = DAG.getAnyExtOrTrunc(X, SDLoc(X), VT);
  APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
  Mask = Mask.zext(VT.getSizeInBits());
  SDLoc DL(N);
  return DAG.getNode(ISD::AND, DL, VT,
                     X, DAG.getConstant(Mask, DL, VT));
}

// fold (zext (load x)) -> (zext (truncate (zextload x)))
// Only generate vector extloads when 1) they're legal, and 2) they are
// deemed desirable by the target.
if (ISD::isNON_EXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
    ((!LegalOperations && !VT.isVector() &&
      !cast<LoadSDNode>(N0)->isVolatile()) ||
     TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, N0.getValueType()))) {
  bool DoXform = true;
  SmallVector<SDNode*, 4> SetCCs;
  if (!N0.hasOneUse())
    DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ZERO_EXTEND, SetCCs, TLI);
  if (VT.isVector())
    DoXform &= TLI.isVectorLoadExtDesirable(SDValue(N, 0));
  if (DoXform) {
    LoadSDNode *LN0 = cast<LoadSDNode>(N0);
    SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
                                     LN0->getChain(),
                                     LN0->getBasePtr(), N0.getValueType(),
                                     LN0->getMemOperand());

    ExtendSetCCUses(SetCCs, N0, ExtLoad, SDLoc(N), ISD::ZERO_EXTEND);
    // If the load value is used only by N, replace it via CombineTo N.
    bool NoReplaceTrunc = SDValue(LN0, 0).hasOneUse();
    CombineTo(N, ExtLoad);
    if (NoReplaceTrunc) {
      DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    } else {
      SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
                                  N0.getValueType(), ExtLoad);
      CombineTo(LN0, Trunc, ExtLoad.getValue(1));
    }
    return SDValue(N, 0); // Return N so it doesn't get rechecked!
  }
}

// fold (zext (load x)) to multiple smaller zextloads.
// Only on illegal but splittable vectors.
if (SDValue ExtLoad = CombineExtLoad(N))
  return ExtLoad;

// fold (zext (and/or/xor (load x), cst)) ->
//      (and/or/xor (zextload x), (zext cst))
// Unless (and (load x) cst) will match as a zextload already and has
// additional users.
if ((N0.getOpcode() == ISD::AND || N0.getOpcode() == ISD::OR ||
     N0.getOpcode() == ISD::XOR) &&
    isa<LoadSDNode>(N0.getOperand(0)) &&
    N0.getOperand(1).getOpcode() == ISD::Constant &&
    (!LegalOperations && TLI.isOperationLegal(N0.getOpcode(), VT))) {
  LoadSDNode *LN00 = cast<LoadSDNode>(N0.getOperand(0));
  EVT MemVT = LN00->getMemoryVT();
  if (TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT) &&
      LN00->getExtensionType() != ISD::SEXTLOAD && LN00->isUnindexed()) {
    bool DoXform = true;
    SmallVector<SDNode*, 4> SetCCs;
    if (!N0.hasOneUse()) {
      if (N0.getOpcode() == ISD::AND) {
        auto *AndC = cast<ConstantSDNode>(N0.getOperand(1));
        EVT LoadResultTy = AndC->getValueType(0);
        EVT ExtVT;
        if (isAndLoadExtLoad(AndC, LN00, LoadResultTy, ExtVT))
          DoXform = false;
      }
      if (DoXform)
        DoXform = ExtendUsesToFormExtLoad(N, N0.getOperand(0),
                                          ISD::ZERO_EXTEND, SetCCs, TLI);
    }
    if (DoXform) {
      SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(LN00), VT,
                                       LN00->getChain(), LN00->getBasePtr(),
                                       LN00->getMemoryVT(),
                                       LN00->getMemOperand());
      APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
      Mask = Mask.zext(VT.getSizeInBits());
      SDLoc DL(N);
      SDValue And = DAG.getNode(N0.getOpcode(), DL, VT,
                                ExtLoad, DAG.getConstant(Mask, DL, VT));
      ExtendSetCCUses(SetCCs, N0.getOperand(0), ExtLoad, DL,
                      ISD::ZERO_EXTEND);
      bool NoReplaceTruncAnd = !N0.hasOneUse();
      bool NoReplaceTrunc = SDValue(LN00, 0).hasOneUse();
      CombineTo(N, And);
      // If N0 has multiple uses, change other uses as well.
      if (NoReplaceTruncAnd) {
        SDValue TruncAnd =
            DAG.getNode(ISD::TRUNCATE, DL, N0.getValueType(), And);
        CombineTo(N0.getNode(), TruncAnd);
      }
      if (NoReplaceTrunc) {
        DAG.ReplaceAllUsesOfValueWith(SDValue(LN00, 1), ExtLoad.getValue(1));
      } else {
        SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(LN00),
                                    LN00->getValueType(0), ExtLoad);
        CombineTo(LN00, Trunc, ExtLoad.getValue(1));
      }
      return SDValue(N,0); // Return N so it doesn't get rechecked!
    }
  }
}

// fold (zext (zextload x)) -> (zext (truncate (zextload x)))
// fold (zext ( extload x)) -> (zext (truncate (zextload x)))
if ((ISD::isZEXTLoad(N0.getNode()) || ISD::isEXTLoad(N0.getNode())) &&
    ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  EVT MemVT = LN0->getMemoryVT();
  if ((!LegalOperations && !LN0->isVolatile()) ||
      TLI.isLoadExtLegal(ISD::ZEXTLOAD, VT, MemVT)) {
    SDValue ExtLoad = DAG.getExtLoad(ISD::ZEXTLOAD, SDLoc(N), VT,
                                     LN0->getChain(),
                                     LN0->getBasePtr(), MemVT,
                                     LN0->getMemOperand());
    CombineTo(N, ExtLoad);
    DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}

if (N0.getOpcode() == ISD::SETCC) {
  // Only do this before legalize for now.
  if (!LegalOperations && VT.isVector() &&
      N0.getValueType().getVectorElementType() == MVT::i1) {
    EVT N00VT = N0.getOperand(0).getValueType();
    if (getSetCCResultType(N00VT) == N0.getValueType())
      return SDValue();

    // We know that the # elements of the results is the same as the #
    // elements of the compare (and the # elements of the compare result for
    // that matter). Check to see that they are the same size. If so, we know
    // that the element size of the sext'd result matches the element size of
    // the compare operands.
    SDLoc DL(N);
    SDValue VecOnes = DAG.getConstant(1, DL, VT);
    if (VT.getSizeInBits() == N00VT.getSizeInBits()) {
      // zext(setcc) -> (and (vsetcc), (1, 1, ...) for vectors.
      SDValue VSetCC = DAG.getNode(ISD::SETCC, DL, VT, N0.getOperand(0),
                                   N0.getOperand(1), N0.getOperand(2));
      return DAG.getNode(ISD::AND, DL, VT, VSetCC, VecOnes);
    }

    // If the desired elements are smaller or larger than the source
    // elements we can use a matching integer vector type and then
    // truncate/sign extend.
    EVT MatchingVectorType = N00VT.changeVectorElementTypeToInteger();
    SDValue VsetCC =
        DAG.getNode(ISD::SETCC, DL, MatchingVectorType, N0.getOperand(0),
                    N0.getOperand(1), N0.getOperand(2));
    return DAG.getNode(ISD::AND, DL, VT, DAG.getSExtOrTrunc(VsetCC, DL, VT),
                       VecOnes);
  }

  // zext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
  SDLoc DL(N);
  if (SDValue SCC = SimplifySelectCC(
          DL, N0.getOperand(0), N0.getOperand(1), DAG.getConstant(1, DL, VT),
          DAG.getConstant(0, DL, VT),
          cast<CondCodeSDNode>(N0.getOperand(2))->get(), true))
    return SCC;
}

// (zext (shl (zext x), cst)) -> (shl (zext x), cst)
if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) &&
    isa<ConstantSDNode>(N0.getOperand(1)) &&
    N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND &&
    N0.hasOneUse()) {
  SDValue ShAmt = N0.getOperand(1);
  unsigned ShAmtVal = cast<ConstantSDNode>(ShAmt)->getZExtValue();
  if (N0.getOpcode() == ISD::SHL) {
    SDValue InnerZExt = N0.getOperand(0);
    // If the original shl may be shifting out bits, do not perform this
    // transformation.
    unsigned KnownZeroBits = InnerZExt.getValueSizeInBits() -
      InnerZExt.getOperand(0).getValueSizeInBits();
    if (ShAmtVal > KnownZeroBits)
      return SDValue();
  }

  SDLoc DL(N);

  // Ensure that the shift amount is wide enough for the shifted value.
  if (VT.getSizeInBits() >= 256)
    ShAmt = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, ShAmt);

  return DAG.getNode(N0.getOpcode(), DL, VT,
                     DAG.getNode(ISD::ZERO_EXTEND, DL, VT, N0.getOperand(0)),
                     ShAmt);
}

if (SDValue NewVSel = matchVSelectOpSizesWithSetCC(N))
  return NewVSel;

return SDValue();
8065}

8067SDValue DAGCombiner::visitANY_EXTEND(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
                                            LegalOperations))
  return SDValue(Res, 0);

// fold (aext (aext x)) -> (aext x)
// fold (aext (zext x)) -> (zext x)
// fold (aext (sext x)) -> (sext x)
if (N0.getOpcode() == ISD::ANY_EXTEND  ||
    N0.getOpcode() == ISD::ZERO_EXTEND ||
    N0.getOpcode() == ISD::SIGN_EXTEND)
  return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));

// fold (aext (truncate (load x))) -> (aext (smaller load x))
// fold (aext (truncate (srl (load x), c))) -> (aext (small load (x+c/n)))
if (N0.getOpcode() == ISD::TRUNCATE) {
  if (SDValue NarrowLoad = ReduceLoadWidth(N0.getNode())) {
    SDNode *oye = N0.getOperand(0).getNode();
    if (NarrowLoad.getNode() != N0.getNode()) {
      CombineTo(N0.getNode(), NarrowLoad);
      // CombineTo deleted the truncate, if needed, but not what's under it.
      AddToWorklist(oye);
    }
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}

// fold (aext (truncate x))
if (N0.getOpcode() == ISD::TRUNCATE)
  return DAG.getAnyExtOrTrunc(N0.getOperand(0), SDLoc(N), VT);

// Fold (aext (and (trunc x), cst)) -> (and x, cst)
// if the trunc is not free.
if (N0.getOpcode() == ISD::AND &&
    N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
    N0.getOperand(1).getOpcode() == ISD::Constant &&
    !TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
                        N0.getValueType())) {
  SDLoc DL(N);
  SDValue X = N0.getOperand(0).getOperand(0);
  X = DAG.getAnyExtOrTrunc(X, DL, VT);
  APInt Mask = cast<ConstantSDNode>(N0.getOperand(1))->getAPIntValue();
  Mask = Mask.zext(VT.getSizeInBits());
  return DAG.getNode(ISD::AND, DL, VT,
                     X, DAG.getConstant(Mask, DL, VT));
}

// fold (aext (load x)) -> (aext (truncate (extload x)))
// None of the supported targets knows how to perform load and any_ext
// on vectors in one instruction.  We only perform this transformation on
// scalars.
if (ISD::isNON_EXTLoad(N0.getNode()) && !VT.isVector() &&
    ISD::isUNINDEXEDLoad(N0.getNode()) &&
    TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
  bool DoXform = true;
  SmallVector<SDNode*, 4> SetCCs;
  if (!N0.hasOneUse())
    DoXform = ExtendUsesToFormExtLoad(N, N0, ISD::ANY_EXTEND, SetCCs, TLI);
  if (DoXform) {
    LoadSDNode *LN0 = cast<LoadSDNode>(N0);
    SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
                                     LN0->getChain(),
                                     LN0->getBasePtr(), N0.getValueType(),
                                     LN0->getMemOperand());
    ExtendSetCCUses(SetCCs, N0, ExtLoad, SDLoc(N),
                    ISD::ANY_EXTEND);
    // If the load value is used only by N, replace it via CombineTo N.
    bool NoReplaceTrunc = N0.hasOneUse();
    CombineTo(N, ExtLoad);
    if (NoReplaceTrunc) {
      DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    } else {
      SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SDLoc(N0),
                                  N0.getValueType(), ExtLoad);
      CombineTo(LN0, Trunc, ExtLoad.getValue(1));
    }
    return SDValue(N, 0); // Return N so it doesn't get rechecked!
  }
}

// fold (aext (zextload x)) -> (aext (truncate (zextload x)))
// fold (aext (sextload x)) -> (aext (truncate (sextload x)))
// fold (aext ( extload x)) -> (aext (truncate (extload  x)))
if (N0.getOpcode() == ISD::LOAD && !ISD::isNON_EXTLoad(N0.getNode()) &&
    ISD::isUNINDEXEDLoad(N0.getNode()) && N0.hasOneUse()) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  ISD::LoadExtType ExtType = LN0->getExtensionType();
  EVT MemVT = LN0->getMemoryVT();
  if (!LegalOperations || TLI.isLoadExtLegal(ExtType, VT, MemVT)) {
    SDValue ExtLoad = DAG.getExtLoad(ExtType, SDLoc(N),
                                     VT, LN0->getChain(), LN0->getBasePtr(),
                                     MemVT, LN0->getMemOperand());
    CombineTo(N, ExtLoad);
    DAG.ReplaceAllUsesOfValueWith(SDValue(LN0, 1), ExtLoad.getValue(1));
    return SDValue(N, 0);   // Return N so it doesn't get rechecked!
  }
}

if (N0.getOpcode() == ISD::SETCC) {
  // For vectors:
  // aext(setcc) -> vsetcc
  // aext(setcc) -> truncate(vsetcc)
  // aext(setcc) -> aext(vsetcc)
  // Only do this before legalize for now.
  if (VT.isVector() && !LegalOperations) {
    EVT N00VT = N0.getOperand(0).getValueType();
    if (getSetCCResultType(N00VT) == N0.getValueType())
      return SDValue();

    // We know that the # elements of the results is the same as the
    // # elements of the compare (and the # elements of the compare result
    // for that matter).  Check to see that they are the same size.  If so,
    // we know that the element size of the sext'd result matches the
    // element size of the compare operands.
    if (VT.getSizeInBits() == N00VT.getSizeInBits())
      return DAG.getSetCC(SDLoc(N), VT, N0.getOperand(0),
                           N0.getOperand(1),
                           cast<CondCodeSDNode>(N0.getOperand(2))->get());
    // If the desired elements are smaller or larger than the source
    // elements we can use a matching integer vector type and then
    // truncate/any extend
    else {
      EVT MatchingVectorType = N00VT.changeVectorElementTypeToInteger();
      SDValue VsetCC =
        DAG.getSetCC(SDLoc(N), MatchingVectorType, N0.getOperand(0),
                      N0.getOperand(1),
                      cast<CondCodeSDNode>(N0.getOperand(2))->get());
      return DAG.getAnyExtOrTrunc(VsetCC, SDLoc(N), VT);
    }
  }

  // aext(setcc x,y,cc) -> select_cc x, y, 1, 0, cc
  SDLoc DL(N);
  if (SDValue SCC = SimplifySelectCC(
          DL, N0.getOperand(0), N0.getOperand(1), DAG.getConstant(1, DL, VT),
          DAG.getConstant(0, DL, VT),
          cast<CondCodeSDNode>(N0.getOperand(2))->get(), true))
    return SCC;
}

return SDValue();
8211}

8213SDValue DAGCombiner::visitAssertExt(SDNode *N) {
unsigned Opcode = N->getOpcode();
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT AssertVT = cast<VTSDNode>(N1)->getVT();

// fold (assert?ext (assert?ext x, vt), vt) -> (assert?ext x, vt)
if (N0.getOpcode() == Opcode &&
    AssertVT == cast<VTSDNode>(N0.getOperand(1))->getVT())
  return N0;

if (N0.getOpcode() == ISD::TRUNCATE && N0.hasOneUse() &&
    N0.getOperand(0).getOpcode() == Opcode) {
  // We have an assert, truncate, assert sandwich. Make one stronger assert
  // by asserting on the smallest asserted type to the larger source type.
  // This eliminates the later assert:
  // assert (trunc (assert X, i8) to iN), i1 --> trunc (assert X, i1) to iN
  // assert (trunc (assert X, i1) to iN), i8 --> trunc (assert X, i1) to iN
  SDValue BigA = N0.getOperand(0);
  EVT BigA_AssertVT = cast<VTSDNode>(BigA.getOperand(1))->getVT();
  assert(BigA_AssertVT.bitsLE(N0.getValueType()) &&(static_cast <bool> (BigA_AssertVT.bitsLE(N0.getValueType
()) && "Asserting zero/sign-extended bits to a type larger than the "
 "truncated destination does not provide information") ? void
 (0) : __assert_fail ("BigA_AssertVT.bitsLE(N0.getValueType()) && \"Asserting zero/sign-extended bits to a type larger than the \" \"truncated destination does not provide information\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8235, __extension__ __PRETTY_FUNCTION__))
         "Asserting zero/sign-extended bits to a type larger than the "(static_cast <bool> (BigA_AssertVT.bitsLE(N0.getValueType
()) && "Asserting zero/sign-extended bits to a type larger than the "
 "truncated destination does not provide information") ? void
 (0) : __assert_fail ("BigA_AssertVT.bitsLE(N0.getValueType()) && \"Asserting zero/sign-extended bits to a type larger than the \" \"truncated destination does not provide information\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8235, __extension__ __PRETTY_FUNCTION__))
         "truncated destination does not provide information")(static_cast <bool> (BigA_AssertVT.bitsLE(N0.getValueType
()) && "Asserting zero/sign-extended bits to a type larger than the "
 "truncated destination does not provide information") ? void
 (0) : __assert_fail ("BigA_AssertVT.bitsLE(N0.getValueType()) && \"Asserting zero/sign-extended bits to a type larger than the \" \"truncated destination does not provide information\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8235, __extension__ __PRETTY_FUNCTION__));

  SDLoc DL(N);
  EVT MinAssertVT = AssertVT.bitsLT(BigA_AssertVT) ? AssertVT : BigA_AssertVT;
  SDValue MinAssertVTVal = DAG.getValueType(MinAssertVT);
  SDValue NewAssert = DAG.getNode(Opcode, DL, BigA.getValueType(),
                                  BigA.getOperand(0), MinAssertVTVal);
  return DAG.getNode(ISD::TRUNCATE, DL, N->getValueType(0), NewAssert);
}

return SDValue();
8246}

8248/// If the result of a wider load is shifted to right of N  bits and then
8249/// truncated to a narrower type and where N is a multiple of number of bits of
8250/// the narrower type, transform it to a narrower load from address + N / num of
8251/// bits of new type. Also narrow the load if the result is masked with an AND
8252/// to effectively produce a smaller type. If the result is to be extended, also
8253/// fold the extension to form a extending load.
8254SDValue DAGCombiner::ReduceLoadWidth(SDNode *N) {
unsigned Opc = N->getOpcode();

ISD::LoadExtType ExtType = ISD::NON_EXTLOAD;
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
EVT ExtVT = VT;

// This transformation isn't valid for vector loads.
if (VT.isVector())
  return SDValue();

// Special case: SIGN_EXTEND_INREG is basically truncating to ExtVT then
// extended to VT.
if (Opc == ISD::SIGN_EXTEND_INREG) {
  ExtType = ISD::SEXTLOAD;
  ExtVT = cast<VTSDNode>(N->getOperand(1))->getVT();
} else if (Opc == ISD::SRL) {
  // Another special-case: SRL is basically zero-extending a narrower value,
  // or it maybe shifting a higher subword, half or byte into the lowest
  // bits.
  ExtType = ISD::ZEXTLOAD;
  N0 = SDValue(N, 0);

  auto *LN0 = dyn_cast<LoadSDNode>(N0.getOperand(0));
  auto *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
  if (!N01 || !LN0)
    return SDValue();

  uint64_t ShiftAmt = N01->getZExtValue();
  uint64_t MemoryWidth = LN0->getMemoryVT().getSizeInBits();
  if (LN0->getExtensionType() != ISD::SEXTLOAD && MemoryWidth > ShiftAmt)
    ExtVT = EVT::getIntegerVT(*DAG.getContext(), MemoryWidth - ShiftAmt);
  else
    ExtVT = EVT::getIntegerVT(*DAG.getContext(),
                              VT.getSizeInBits() - ShiftAmt);
} else if (Opc == ISD::AND) {
  // An AND with a constant mask is the same as a truncate + zero-extend.
  auto AndC = dyn_cast<ConstantSDNode>(N->getOperand(1));
  if (!AndC || !AndC->getAPIntValue().isMask())
    return SDValue();

  unsigned ActiveBits = AndC->getAPIntValue().countTrailingOnes();
  ExtType = ISD::ZEXTLOAD;
  ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);
}

unsigned ShAmt = 0;
if (N0.getOpcode() == ISD::SRL && N0.hasOneUse()) {
  if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
    ShAmt = N01->getZExtValue();
    unsigned EVTBits = ExtVT.getSizeInBits();
    // Is the shift amount a multiple of size of VT?
    if ((ShAmt & (EVTBits-1)) == 0) {
      N0 = N0.getOperand(0);
      // Is the load width a multiple of size of VT?
      if ((N0.getValueSizeInBits() & (EVTBits-1)) != 0)
        return SDValue();
    }

    // At this point, we must have a load or else we can't do the transform.
    if (!isa<LoadSDNode>(N0)) return SDValue();

    // Because a SRL must be assumed to *need* to zero-extend the high bits
    // (as opposed to anyext the high bits), we can't combine the zextload
    // lowering of SRL and an sextload.
    if (cast<LoadSDNode>(N0)->getExtensionType() == ISD::SEXTLOAD)
      return SDValue();

    // If the shift amount is larger than the input type then we're not
    // accessing any of the loaded bytes.  If the load was a zextload/extload
    // then the result of the shift+trunc is zero/undef (handled elsewhere).
    if (ShAmt >= cast<LoadSDNode>(N0)->getMemoryVT().getSizeInBits())
      return SDValue();
  }
}

// If the load is shifted left (and the result isn't shifted back right),
// we can fold the truncate through the shift.
unsigned ShLeftAmt = 0;
if (ShAmt == 0 && N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
    ExtVT == VT && TLI.isNarrowingProfitable(N0.getValueType(), VT)) {
  if (ConstantSDNode *N01 = dyn_cast<ConstantSDNode>(N0.getOperand(1))) {
    ShLeftAmt = N01->getZExtValue();
    N0 = N0.getOperand(0);
  }
}

// If we haven't found a load, we can't narrow it.
if (!isa<LoadSDNode>(N0))
  return SDValue();

LoadSDNode *LN0 = cast<LoadSDNode>(N0);
if (!isLegalNarrowLoad(LN0, ExtType, ExtVT, ShAmt))
  return SDValue();

// For big endian targets, we need to adjust the offset to the pointer to
// load the correct bytes.
if (DAG.getDataLayout().isBigEndian()) {
  unsigned LVTStoreBits = LN0->getMemoryVT().getStoreSizeInBits();
  unsigned EVTStoreBits = ExtVT.getStoreSizeInBits();
  ShAmt = LVTStoreBits - EVTStoreBits - ShAmt;
}

EVT PtrType = N0.getOperand(1).getValueType();
uint64_t PtrOff = ShAmt / 8;
unsigned NewAlign = MinAlign(LN0->getAlignment(), PtrOff);
SDLoc DL(LN0);
// The original load itself didn't wrap, so an offset within it doesn't.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
SDValue NewPtr = DAG.getNode(ISD::ADD, DL,
                             PtrType, LN0->getBasePtr(),
                             DAG.getConstant(PtrOff, DL, PtrType),
                             Flags);
AddToWorklist(NewPtr.getNode());

SDValue Load;
if (ExtType == ISD::NON_EXTLOAD)
  Load = DAG.getLoad(VT, SDLoc(N0), LN0->getChain(), NewPtr,
                     LN0->getPointerInfo().getWithOffset(PtrOff), NewAlign,
                     LN0->getMemOperand()->getFlags(), LN0->getAAInfo());
else
  Load = DAG.getExtLoad(ExtType, SDLoc(N0), VT, LN0->getChain(), NewPtr,
                        LN0->getPointerInfo().getWithOffset(PtrOff), ExtVT,
                        NewAlign, LN0->getMemOperand()->getFlags(),
                        LN0->getAAInfo());

// Replace the old load's chain with the new load's chain.
WorklistRemover DeadNodes(*this);
DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));

// Shift the result left, if we've swallowed a left shift.
SDValue Result = Load;
if (ShLeftAmt != 0) {
  EVT ShImmTy = getShiftAmountTy(Result.getValueType());
  if (!isUIntN(ShImmTy.getSizeInBits(), ShLeftAmt))
    ShImmTy = VT;
  // If the shift amount is as large as the result size (but, presumably,
  // no larger than the source) then the useful bits of the result are
  // zero; we can't simply return the shortened shift, because the result
  // of that operation is undefined.
  SDLoc DL(N0);
  if (ShLeftAmt >= VT.getSizeInBits())
    Result = DAG.getConstant(0, DL, VT);
  else
    Result = DAG.getNode(ISD::SHL, DL, VT,
                        Result, DAG.getConstant(ShLeftAmt, DL, ShImmTy));
}

// Return the new loaded value.
return Result;
8406}

8408SDValue DAGCombiner::visitSIGN_EXTEND_INREG(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
EVT EVT = cast<VTSDNode>(N1)->getVT();
unsigned VTBits = VT.getScalarSizeInBits();
unsigned EVTBits = EVT.getScalarSizeInBits();

if (N0.isUndef())
  return DAG.getUNDEF(VT);

// fold (sext_in_reg c1) -> c1
if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
  return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT, N0, N1);

// If the input is already sign extended, just drop the extension.
if (DAG.ComputeNumSignBits(N0) >= VTBits-EVTBits+1)
  return N0;

// fold (sext_in_reg (sext_in_reg x, VT2), VT1) -> (sext_in_reg x, minVT) pt2
if (N0.getOpcode() == ISD::SIGN_EXTEND_INREG &&
    EVT.bitsLT(cast<VTSDNode>(N0.getOperand(1))->getVT()))
  return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
                     N0.getOperand(0), N1);

// fold (sext_in_reg (sext x)) -> (sext x)
// fold (sext_in_reg (aext x)) -> (sext x)
// if x is small enough.
if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
  SDValue N00 = N0.getOperand(0);
  if (N00.getScalarValueSizeInBits() <= EVTBits &&
      (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
    return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
}

// fold (sext_in_reg (*_extend_vector_inreg x)) -> (sext_vector_in_reg x)
if ((N0.getOpcode() == ISD::ANY_EXTEND_VECTOR_INREG ||
     N0.getOpcode() == ISD::SIGN_EXTEND_VECTOR_INREG ||
     N0.getOpcode() == ISD::ZERO_EXTEND_VECTOR_INREG) &&
    N0.getOperand(0).getScalarValueSizeInBits() == EVTBits) {
  if (!LegalOperations ||
      TLI.isOperationLegal(ISD::SIGN_EXTEND_VECTOR_INREG, VT))
    return DAG.getSignExtendVectorInReg(N0.getOperand(0), SDLoc(N), VT);
}

// fold (sext_in_reg (zext x)) -> (sext x)
// iff we are extending the source sign bit.
if (N0.getOpcode() == ISD::ZERO_EXTEND) {
  SDValue N00 = N0.getOperand(0);
  if (N00.getScalarValueSizeInBits() == EVTBits &&
      (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
    return DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, N00, N1);
}

// fold (sext_in_reg x) -> (zext_in_reg x) if the sign bit is known zero.
if (DAG.MaskedValueIsZero(N0, APInt::getOneBitSet(VTBits, EVTBits - 1)))
  return DAG.getZeroExtendInReg(N0, SDLoc(N), EVT.getScalarType());

// fold operands of sext_in_reg based on knowledge that the top bits are not
// demanded.
if (SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// fold (sext_in_reg (load x)) -> (smaller sextload x)
// fold (sext_in_reg (srl (load x), c)) -> (smaller sextload (x+c/evtbits))
if (SDValue NarrowLoad = ReduceLoadWidth(N))
  return NarrowLoad;

// fold (sext_in_reg (srl X, 24), i8) -> (sra X, 24)
// fold (sext_in_reg (srl X, 23), i8) -> (sra X, 23) iff possible.
// We already fold "(sext_in_reg (srl X, 25), i8) -> srl X, 25" above.
if (N0.getOpcode() == ISD::SRL) {
  if (ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(N0.getOperand(1)))
    if (ShAmt->getZExtValue()+EVTBits <= VTBits) {
      // We can turn this into an SRA iff the input to the SRL is already sign
      // extended enough.
      unsigned InSignBits = DAG.ComputeNumSignBits(N0.getOperand(0));
      if (VTBits-(ShAmt->getZExtValue()+EVTBits) < InSignBits)
        return DAG.getNode(ISD::SRA, SDLoc(N), VT,
                           N0.getOperand(0), N0.getOperand(1));
    }
}

// fold (sext_inreg (extload x)) -> (sextload x)
// If sextload is not supported by target, we can only do the combine when
// load has one use. Doing otherwise can block folding the extload with other
// extends that the target does support.
if (ISD::isEXTLoad(N0.getNode()) &&
    ISD::isUNINDEXEDLoad(N0.getNode()) &&
    EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
    ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile() &&
      N0.hasOneUse()) ||
     TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
                                   LN0->getChain(),
                                   LN0->getBasePtr(), EVT,
                                   LN0->getMemOperand());
  CombineTo(N, ExtLoad);
  CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
  AddToWorklist(ExtLoad.getNode());
  return SDValue(N, 0);   // Return N so it doesn't get rechecked!
}
// fold (sext_inreg (zextload x)) -> (sextload x) iff load has one use
if (ISD::isZEXTLoad(N0.getNode()) && ISD::isUNINDEXEDLoad(N0.getNode()) &&
    N0.hasOneUse() &&
    EVT == cast<LoadSDNode>(N0)->getMemoryVT() &&
    ((!LegalOperations && !cast<LoadSDNode>(N0)->isVolatile()) ||
     TLI.isLoadExtLegal(ISD::SEXTLOAD, VT, EVT))) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  SDValue ExtLoad = DAG.getExtLoad(ISD::SEXTLOAD, SDLoc(N), VT,
                                   LN0->getChain(),
                                   LN0->getBasePtr(), EVT,
                                   LN0->getMemOperand());
  CombineTo(N, ExtLoad);
  CombineTo(N0.getNode(), ExtLoad, ExtLoad.getValue(1));
  return SDValue(N, 0);   // Return N so it doesn't get rechecked!
}

// Form (sext_inreg (bswap >> 16)) or (sext_inreg (rotl (bswap) 16))
if (EVTBits <= 16 && N0.getOpcode() == ISD::OR) {
  if (SDValue BSwap = MatchBSwapHWordLow(N0.getNode(), N0.getOperand(0),
                                         N0.getOperand(1), false))
    return DAG.getNode(ISD::SIGN_EXTEND_INREG, SDLoc(N), VT,
                       BSwap, N1);
}

return SDValue();
8536}

8538SDValue DAGCombiner::visitSIGN_EXTEND_VECTOR_INREG(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (N0.isUndef())
  return DAG.getUNDEF(VT);

if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
                                            LegalOperations))
  return SDValue(Res, 0);

return SDValue();
8550}

8552SDValue DAGCombiner::visitZERO_EXTEND_VECTOR_INREG(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (N0.isUndef())
  return DAG.getUNDEF(VT);

if (SDNode *Res = tryToFoldExtendOfConstant(N, TLI, DAG, LegalTypes,
                                            LegalOperations))
  return SDValue(Res, 0);

return SDValue();
8564}

8566SDValue DAGCombiner::visitTRUNCATE(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
bool isLE = DAG.getDataLayout().isLittleEndian();

// noop truncate
if (N0.getValueType() == N->getValueType(0))
  return N0;

// fold (truncate (truncate x)) -> (truncate x)
if (N0.getOpcode() == ISD::TRUNCATE)
  return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));

// fold (truncate c1) -> c1
if (DAG.isConstantIntBuildVectorOrConstantInt(N0)) {
  SDValue C = DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0);
  if (C.getNode() != N)
    return C;
}

// fold (truncate (ext x)) -> (ext x) or (truncate x) or x
if (N0.getOpcode() == ISD::ZERO_EXTEND ||
    N0.getOpcode() == ISD::SIGN_EXTEND ||
    N0.getOpcode() == ISD::ANY_EXTEND) {
  // if the source is smaller than the dest, we still need an extend.
  if (N0.getOperand(0).getValueType().bitsLT(VT))
    return DAG.getNode(N0.getOpcode(), SDLoc(N), VT, N0.getOperand(0));
  // if the source is larger than the dest, than we just need the truncate.
  if (N0.getOperand(0).getValueType().bitsGT(VT))
    return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, N0.getOperand(0));
  // if the source and dest are the same type, we can drop both the extend
  // and the truncate.
  return N0.getOperand(0);
}

// If this is anyext(trunc), don't fold it, allow ourselves to be folded.
if (N->hasOneUse() && (N->use_begin()->getOpcode() == ISD::ANY_EXTEND))
  return SDValue();

// Fold extract-and-trunc into a narrow extract. For example:
//   i64 x = EXTRACT_VECTOR_ELT(v2i64 val, i32 1)
//   i32 y = TRUNCATE(i64 x)
//        -- becomes --
//   v16i8 b = BITCAST (v2i64 val)
//   i8 x = EXTRACT_VECTOR_ELT(v16i8 b, i32 8)
//
// Note: We only run this optimization after type legalization (which often
// creates this pattern) and before operation legalization after which
// we need to be more careful about the vector instructions that we generate.
if (N0.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
    LegalTypes && !LegalOperations && N0->hasOneUse() && VT != MVT::i1) {
  EVT VecTy = N0.getOperand(0).getValueType();
  EVT ExTy = N0.getValueType();
  EVT TrTy = N->getValueType(0);

  unsigned NumElem = VecTy.getVectorNumElements();
  unsigned SizeRatio = ExTy.getSizeInBits()/TrTy.getSizeInBits();

  EVT NVT = EVT::getVectorVT(*DAG.getContext(), TrTy, SizeRatio * NumElem);
  assert(NVT.getSizeInBits() == VecTy.getSizeInBits() && "Invalid Size")(static_cast <bool> (NVT.getSizeInBits() == VecTy.getSizeInBits
() && "Invalid Size") ? void (0) : __assert_fail ("NVT.getSizeInBits() == VecTy.getSizeInBits() && \"Invalid Size\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8625, __extension__ __PRETTY_FUNCTION__));

  SDValue EltNo = N0->getOperand(1);
  if (isa<ConstantSDNode>(EltNo) && isTypeLegal(NVT)) {
    int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();
    EVT IndexTy = TLI.getVectorIdxTy(DAG.getDataLayout());
    int Index = isLE ? (Elt*SizeRatio) : (Elt*SizeRatio + (SizeRatio-1));

    SDLoc DL(N);
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL, TrTy,
                       DAG.getBitcast(NVT, N0.getOperand(0)),
                       DAG.getConstant(Index, DL, IndexTy));
  }
}

// trunc (select c, a, b) -> select c, (trunc a), (trunc b)
if (N0.getOpcode() == ISD::SELECT && N0.hasOneUse()) {
  EVT SrcVT = N0.getValueType();
  if ((!LegalOperations || TLI.isOperationLegal(ISD::SELECT, SrcVT)) &&
      TLI.isTruncateFree(SrcVT, VT)) {
    SDLoc SL(N0);
    SDValue Cond = N0.getOperand(0);
    SDValue TruncOp0 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
    SDValue TruncOp1 = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(2));
    return DAG.getNode(ISD::SELECT, SDLoc(N), VT, Cond, TruncOp0, TruncOp1);
  }
}

// trunc (shl x, K) -> shl (trunc x), K => K < VT.getScalarSizeInBits()
if (N0.getOpcode() == ISD::SHL && N0.hasOneUse() &&
    (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::SHL, VT)) &&
    TLI.isTypeDesirableForOp(ISD::SHL, VT)) {
  SDValue Amt = N0.getOperand(1);
  KnownBits Known;
  DAG.computeKnownBits(Amt, Known);
  unsigned Size = VT.getScalarSizeInBits();
  if (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size)) {
    SDLoc SL(N);
    EVT AmtVT = TLI.getShiftAmountTy(VT, DAG.getDataLayout());

    SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(0));
    if (AmtVT != Amt.getValueType()) {
      Amt = DAG.getZExtOrTrunc(Amt, SL, AmtVT);
      AddToWorklist(Amt.getNode());
    }
    return DAG.getNode(ISD::SHL, SL, VT, Trunc, Amt);
  }
}

// Fold a series of buildvector, bitcast, and truncate if possible.
// For example fold
//   (2xi32 trunc (bitcast ((4xi32)buildvector x, x, y, y) 2xi64)) to
//   (2xi32 (buildvector x, y)).
if (Level == AfterLegalizeVectorOps && VT.isVector() &&
    N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
    N0.getOperand(0).getOpcode() == ISD::BUILD_VECTOR &&
    N0.getOperand(0).hasOneUse()) {
  SDValue BuildVect = N0.getOperand(0);
  EVT BuildVectEltTy = BuildVect.getValueType().getVectorElementType();
  EVT TruncVecEltTy = VT.getVectorElementType();

  // Check that the element types match.
  if (BuildVectEltTy == TruncVecEltTy) {
    // Now we only need to compute the offset of the truncated elements.
    unsigned BuildVecNumElts =  BuildVect.getNumOperands();
    unsigned TruncVecNumElts = VT.getVectorNumElements();
    unsigned TruncEltOffset = BuildVecNumElts / TruncVecNumElts;

    assert((BuildVecNumElts % TruncVecNumElts) == 0 &&(static_cast <bool> ((BuildVecNumElts % TruncVecNumElts
) == 0 && "Invalid number of elements") ? void (0) : __assert_fail
 ("(BuildVecNumElts % TruncVecNumElts) == 0 && \"Invalid number of elements\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8694, __extension__ __PRETTY_FUNCTION__))
           "Invalid number of elements")(static_cast <bool> ((BuildVecNumElts % TruncVecNumElts
) == 0 && "Invalid number of elements") ? void (0) : __assert_fail
 ("(BuildVecNumElts % TruncVecNumElts) == 0 && \"Invalid number of elements\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8694, __extension__ __PRETTY_FUNCTION__));

    SmallVector<SDValue, 8> Opnds;
    for (unsigned i = 0, e = BuildVecNumElts; i != e; i += TruncEltOffset)
      Opnds.push_back(BuildVect.getOperand(i));

    return DAG.getBuildVector(VT, SDLoc(N), Opnds);
  }
}

// See if we can simplify the input to this truncate through knowledge that
// only the low bits are being used.
// For example "trunc (or (shl x, 8), y)" // -> trunc y
// Currently we only perform this optimization on scalars because vectors
// may have different active low bits.
if (!VT.isVector()) {
  APInt Mask =
      APInt::getLowBitsSet(N0.getValueSizeInBits(), VT.getSizeInBits());
  if (SDValue Shorter = DAG.GetDemandedBits(N0, Mask))
    return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Shorter);
}

// fold (truncate (load x)) -> (smaller load x)
// fold (truncate (srl (load x), c)) -> (smaller load (x+c/evtbits))
if (!LegalTypes || TLI.isTypeDesirableForOp(N0.getOpcode(), VT)) {
  if (SDValue Reduced = ReduceLoadWidth(N))
    return Reduced;

  // Handle the case where the load remains an extending load even
  // after truncation.
  if (N0.hasOneUse() && ISD::isUNINDEXEDLoad(N0.getNode())) {
    LoadSDNode *LN0 = cast<LoadSDNode>(N0);
    if (!LN0->isVolatile() &&
        LN0->getMemoryVT().getStoreSizeInBits() < VT.getSizeInBits()) {
      SDValue NewLoad = DAG.getExtLoad(LN0->getExtensionType(), SDLoc(LN0),
                                       VT, LN0->getChain(), LN0->getBasePtr(),
                                       LN0->getMemoryVT(),
                                       LN0->getMemOperand());
      DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLoad.getValue(1));
      return NewLoad;
    }
  }
}

// fold (trunc (concat ... x ...)) -> (concat ..., (trunc x), ...)),
// where ... are all 'undef'.
if (N0.getOpcode() == ISD::CONCAT_VECTORS && !LegalTypes) {
  SmallVector<EVT, 8> VTs;
  SDValue V;
  unsigned Idx = 0;
  unsigned NumDefs = 0;

  for (unsigned i = 0, e = N0.getNumOperands(); i != e; ++i) {
    SDValue X = N0.getOperand(i);
    if (!X.isUndef()) {
      V = X;
      Idx = i;
      NumDefs++;
    }
    // Stop if more than one members are non-undef.
    if (NumDefs > 1)
      break;
    VTs.push_back(EVT::getVectorVT(*DAG.getContext(),
                                   VT.getVectorElementType(),
                                   X.getValueType().getVectorNumElements()));
  }

  if (NumDefs == 0)
    return DAG.getUNDEF(VT);

  if (NumDefs == 1) {
    assert(V.getNode() && "The single defined operand is empty!")(static_cast <bool> (V.getNode() && "The single defined operand is empty!"
) ? void (0) : __assert_fail ("V.getNode() && \"The single defined operand is empty!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8765, __extension__ __PRETTY_FUNCTION__));
    SmallVector<SDValue, 8> Opnds;
    for (unsigned i = 0, e = VTs.size(); i != e; ++i) {
      if (i != Idx) {
        Opnds.push_back(DAG.getUNDEF(VTs[i]));
        continue;
      }
      SDValue NV = DAG.getNode(ISD::TRUNCATE, SDLoc(V), VTs[i], V);
      AddToWorklist(NV.getNode());
      Opnds.push_back(NV);
    }
    return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Opnds);
  }
}

// Fold truncate of a bitcast of a vector to an extract of the low vector
// element.
//
// e.g. trunc (i64 (bitcast v2i32:x)) -> extract_vector_elt v2i32:x, idx
if (N0.getOpcode() == ISD::BITCAST && !VT.isVector()) {
  SDValue VecSrc = N0.getOperand(0);
  EVT SrcVT = VecSrc.getValueType();
  if (SrcVT.isVector() && SrcVT.getScalarType() == VT &&
      (!LegalOperations ||
       TLI.isOperationLegal(ISD::EXTRACT_VECTOR_ELT, SrcVT))) {
    SDLoc SL(N);

    EVT IdxVT = TLI.getVectorIdxTy(DAG.getDataLayout());
    unsigned Idx = isLE ? 0 : SrcVT.getVectorNumElements() - 1;
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, VT,
                       VecSrc, DAG.getConstant(Idx, SL, IdxVT));
  }
}

// Simplify the operands using demanded-bits information.
if (!VT.isVector() &&
    SimplifyDemandedBits(SDValue(N, 0)))
  return SDValue(N, 0);

// (trunc adde(X, Y, Carry)) -> (adde trunc(X), trunc(Y), Carry)
// (trunc addcarry(X, Y, Carry)) -> (addcarry trunc(X), trunc(Y), Carry)
// When the adde's carry is not used.
if ((N0.getOpcode() == ISD::ADDE || N0.getOpcode() == ISD::ADDCARRY) &&
    N0.hasOneUse() && !N0.getNode()->hasAnyUseOfValue(1) &&
    (!LegalOperations || TLI.isOperationLegal(N0.getOpcode(), VT))) {
  SDLoc SL(N);
  auto X = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(0));
  auto Y = DAG.getNode(ISD::TRUNCATE, SL, VT, N0.getOperand(1));
  auto VTs = DAG.getVTList(VT, N0->getValueType(1));
  return DAG.getNode(N0.getOpcode(), SL, VTs, X, Y, N0.getOperand(2));
}

// fold (truncate (extract_subvector(ext x))) ->
//      (extract_subvector x)
// TODO: This can be generalized to cover cases where the truncate and extract
// do not fully cancel each other out.
if (!LegalTypes && N0.getOpcode() == ISD::EXTRACT_SUBVECTOR) {
  SDValue N00 = N0.getOperand(0);
  if (N00.getOpcode() == ISD::SIGN_EXTEND ||
      N00.getOpcode() == ISD::ZERO_EXTEND ||
      N00.getOpcode() == ISD::ANY_EXTEND) {
    if (N00.getOperand(0)->getValueType(0).getVectorElementType() ==
        VT.getVectorElementType())
      return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(N0->getOperand(0)), VT,
                         N00.getOperand(0), N0.getOperand(1));
  }
}

if (SDValue NewVSel = matchVSelectOpSizesWithSetCC(N))
  return NewVSel;

return SDValue();
8837}

8839static SDNode *getBuildPairElt(SDNode *N, unsigned i) {
SDValue Elt = N->getOperand(i);
if (Elt.getOpcode() != ISD::MERGE_VALUES)
  return Elt.getNode();
return Elt.getOperand(Elt.getResNo()).getNode();
8844}

8846/// build_pair (load, load) -> load
8847/// if load locations are consecutive.
8848SDValue DAGCombiner::CombineConsecutiveLoads(SDNode *N, EVT VT) {
assert(N->getOpcode() == ISD::BUILD_PAIR)(static_cast <bool> (N->getOpcode() == ISD::BUILD_PAIR
) ? void (0) : __assert_fail ("N->getOpcode() == ISD::BUILD_PAIR"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8849, __extension__ __PRETTY_FUNCTION__));

LoadSDNode *LD1 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 0));
LoadSDNode *LD2 = dyn_cast<LoadSDNode>(getBuildPairElt(N, 1));

// A BUILD_PAIR is always having the least significant part in elt 0 and the
// most significant part in elt 1. So when combining into one large load, we
// need to consider the endianness.
if (DAG.getDataLayout().isBigEndian())
  std::swap(LD1, LD2);

if (!LD1 || !LD2 || !ISD::isNON_EXTLoad(LD1) || !LD1->hasOneUse() ||
    LD1->getAddressSpace() != LD2->getAddressSpace())
  return SDValue();
EVT LD1VT = LD1->getValueType(0);
unsigned LD1Bytes = LD1VT.getStoreSize();
if (ISD::isNON_EXTLoad(LD2) && LD2->hasOneUse() &&
    DAG.areNonVolatileConsecutiveLoads(LD2, LD1, LD1Bytes, 1)) {
  unsigned Align = LD1->getAlignment();
  unsigned NewAlign = DAG.getDataLayout().getABITypeAlignment(
      VT.getTypeForEVT(*DAG.getContext()));

  if (NewAlign <= Align &&
      (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)))
    return DAG.getLoad(VT, SDLoc(N), LD1->getChain(), LD1->getBasePtr(),
                       LD1->getPointerInfo(), Align);
}

return SDValue();
8878}

8880static unsigned getPPCf128HiElementSelector(const SelectionDAG &DAG) {
// On little-endian machines, bitcasting from ppcf128 to i128 does swap the Hi
// and Lo parts; on big-endian machines it doesn't.
return DAG.getDataLayout().isBigEndian() ? 1 : 0;
8884}

8886static SDValue foldBitcastedFPLogic(SDNode *N, SelectionDAG &DAG,
                                  const TargetLowering &TLI) {
// If this is not a bitcast to an FP type or if the target doesn't have
// IEEE754-compliant FP logic, we're done.
EVT VT = N->getValueType(0);
if (!VT.isFloatingPoint() || !TLI.hasBitPreservingFPLogic(VT))
  return SDValue();

// TODO: Use splat values for the constant-checking below and remove this
// restriction.
SDValue N0 = N->getOperand(0);
EVT SourceVT = N0.getValueType();
if (SourceVT.isVector())
  return SDValue();

unsigned FPOpcode;
APInt SignMask;
switch (N0.getOpcode()) {
case ISD::AND:
  FPOpcode = ISD::FABS;
  SignMask = ~APInt::getSignMask(SourceVT.getSizeInBits());
  break;
case ISD::XOR:
  FPOpcode = ISD::FNEG;
  SignMask = APInt::getSignMask(SourceVT.getSizeInBits());
  break;
// TODO: ISD::OR --> ISD::FNABS?
default:
  return SDValue();
}

// Fold (bitcast int (and (bitcast fp X to int), 0x7fff...) to fp) -> fabs X
// Fold (bitcast int (xor (bitcast fp X to int), 0x8000...) to fp) -> fneg X
SDValue LogicOp0 = N0.getOperand(0);
ConstantSDNode *LogicOp1 = dyn_cast<ConstantSDNode>(N0.getOperand(1));
if (LogicOp1 && LogicOp1->getAPIntValue() == SignMask &&
    LogicOp0.getOpcode() == ISD::BITCAST &&
    LogicOp0->getOperand(0).getValueType() == VT)
  return DAG.getNode(FPOpcode, SDLoc(N), VT, LogicOp0->getOperand(0));

return SDValue();
8927}

8929SDValue DAGCombiner::visitBITCAST(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (N0.isUndef())
  return DAG.getUNDEF(VT);

// If the input is a BUILD_VECTOR with all constant elements, fold this now.
// Only do this before legalize, since afterward the target may be depending
// on the bitconvert.
// First check to see if this is all constant.
if (!LegalTypes &&
    N0.getOpcode() == ISD::BUILD_VECTOR && N0.getNode()->hasOneUse() &&
    VT.isVector()) {
  bool isSimple = cast<BuildVectorSDNode>(N0)->isConstant();

  EVT DestEltVT = N->getValueType(0).getVectorElementType();
  assert(!DestEltVT.isVector() &&(static_cast <bool> (!DestEltVT.isVector() && "Element type of vector ValueType must not be vector!"
) ? void (0) : __assert_fail ("!DestEltVT.isVector() && \"Element type of vector ValueType must not be vector!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8947, __extension__ __PRETTY_FUNCTION__))
         "Element type of vector ValueType must not be vector!")(static_cast <bool> (!DestEltVT.isVector() && "Element type of vector ValueType must not be vector!"
) ? void (0) : __assert_fail ("!DestEltVT.isVector() && \"Element type of vector ValueType must not be vector!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 8947, __extension__ __PRETTY_FUNCTION__));
  if (isSimple)
    return ConstantFoldBITCASTofBUILD_VECTOR(N0.getNode(), DestEltVT);
}

// If the input is a constant, let getNode fold it.
if (isa<ConstantSDNode>(N0) || isa<ConstantFPSDNode>(N0)) {
  // If we can't allow illegal operations, we need to check that this is just
  // a fp -> int or int -> conversion and that the resulting operation will
  // be legal.
  if (!LegalOperations ||
      (isa<ConstantSDNode>(N0) && VT.isFloatingPoint() && !VT.isVector() &&
       TLI.isOperationLegal(ISD::ConstantFP, VT)) ||
      (isa<ConstantFPSDNode>(N0) && VT.isInteger() && !VT.isVector() &&
       TLI.isOperationLegal(ISD::Constant, VT)))
    return DAG.getBitcast(VT, N0);
}

// (conv (conv x, t1), t2) -> (conv x, t2)
if (N0.getOpcode() == ISD::BITCAST)
  return DAG.getBitcast(VT, N0.getOperand(0));

// fold (conv (load x)) -> (load (conv*)x)
// If the resultant load doesn't need a higher alignment than the original!
if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
    // Do not change the width of a volatile load.
    !cast<LoadSDNode>(N0)->isVolatile() &&
    // Do not remove the cast if the types differ in endian layout.
    TLI.hasBigEndianPartOrdering(N0.getValueType(), DAG.getDataLayout()) ==
        TLI.hasBigEndianPartOrdering(VT, DAG.getDataLayout()) &&
    (!LegalOperations || TLI.isOperationLegal(ISD::LOAD, VT)) &&
    TLI.isLoadBitCastBeneficial(N0.getValueType(), VT)) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  unsigned OrigAlign = LN0->getAlignment();

  bool Fast = false;
  if (TLI.allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), VT,
                             LN0->getAddressSpace(), OrigAlign, &Fast) &&
      Fast) {
    SDValue Load =
        DAG.getLoad(VT, SDLoc(N), LN0->getChain(), LN0->getBasePtr(),
                    LN0->getPointerInfo(), OrigAlign,
                    LN0->getMemOperand()->getFlags(), LN0->getAAInfo());
    DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), Load.getValue(1));
    return Load;
  }
}

if (SDValue V = foldBitcastedFPLogic(N, DAG, TLI))
  return V;

// fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
// fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
//
// For ppc_fp128:
// fold (bitcast (fneg x)) ->
//     flipbit = signbit
//     (xor (bitcast x) (build_pair flipbit, flipbit))
//
// fold (bitcast (fabs x)) ->
//     flipbit = (and (extract_element (bitcast x), 0), signbit)
//     (xor (bitcast x) (build_pair flipbit, flipbit))
// This often reduces constant pool loads.
if (((N0.getOpcode() == ISD::FNEG && !TLI.isFNegFree(N0.getValueType())) ||
     (N0.getOpcode() == ISD::FABS && !TLI.isFAbsFree(N0.getValueType()))) &&
    N0.getNode()->hasOneUse() && VT.isInteger() &&
    !VT.isVector() && !N0.getValueType().isVector()) {
  SDValue NewConv = DAG.getBitcast(VT, N0.getOperand(0));
  AddToWorklist(NewConv.getNode());

  SDLoc DL(N);
  if (N0.getValueType() == MVT::ppcf128 && !LegalTypes) {
    assert(VT.getSizeInBits() == 128)(static_cast <bool> (VT.getSizeInBits() == 128) ? void (
0) : __assert_fail ("VT.getSizeInBits() == 128", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 9019, __extension__ __PRETTY_FUNCTION__));
    SDValue SignBit = DAG.getConstant(
        APInt::getSignMask(VT.getSizeInBits() / 2), SDLoc(N0), MVT::i64);
    SDValue FlipBit;
    if (N0.getOpcode() == ISD::FNEG) {
      FlipBit = SignBit;
      AddToWorklist(FlipBit.getNode());
    } else {
      assert(N0.getOpcode() == ISD::FABS)(static_cast <bool> (N0.getOpcode() == ISD::FABS) ? void
 (0) : __assert_fail ("N0.getOpcode() == ISD::FABS", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 9027, __extension__ __PRETTY_FUNCTION__));
      SDValue Hi =
          DAG.getNode(ISD::EXTRACT_ELEMENT, SDLoc(NewConv), MVT::i64, NewConv,
                      DAG.getIntPtrConstant(getPPCf128HiElementSelector(DAG),
                                            SDLoc(NewConv)));
      AddToWorklist(Hi.getNode());
      FlipBit = DAG.getNode(ISD::AND, SDLoc(N0), MVT::i64, Hi, SignBit);
      AddToWorklist(FlipBit.getNode());
    }
    SDValue FlipBits =
        DAG.getNode(ISD::BUILD_PAIR, SDLoc(N0), VT, FlipBit, FlipBit);
    AddToWorklist(FlipBits.getNode());
    return DAG.getNode(ISD::XOR, DL, VT, NewConv, FlipBits);
  }
  APInt SignBit = APInt::getSignMask(VT.getSizeInBits());
  if (N0.getOpcode() == ISD::FNEG)
    return DAG.getNode(ISD::XOR, DL, VT,
                       NewConv, DAG.getConstant(SignBit, DL, VT));
  assert(N0.getOpcode() == ISD::FABS)(static_cast <bool> (N0.getOpcode() == ISD::FABS) ? void
 (0) : __assert_fail ("N0.getOpcode() == ISD::FABS", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 9045, __extension__ __PRETTY_FUNCTION__));
  return DAG.getNode(ISD::AND, DL, VT,
                     NewConv, DAG.getConstant(~SignBit, DL, VT));
}

// fold (bitconvert (fcopysign cst, x)) ->
//         (or (and (bitconvert x), sign), (and cst, (not sign)))
// Note that we don't handle (copysign x, cst) because this can always be
// folded to an fneg or fabs.
//
// For ppc_fp128:
// fold (bitcast (fcopysign cst, x)) ->
//     flipbit = (and (extract_element
//                     (xor (bitcast cst), (bitcast x)), 0),
//                    signbit)
//     (xor (bitcast cst) (build_pair flipbit, flipbit))
if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse() &&
    isa<ConstantFPSDNode>(N0.getOperand(0)) &&
    VT.isInteger() && !VT.isVector()) {
  unsigned OrigXWidth = N0.getOperand(1).getValueSizeInBits();
  EVT IntXVT = EVT::getIntegerVT(*DAG.getContext(), OrigXWidth);
  if (isTypeLegal(IntXVT)) {
    SDValue X = DAG.getBitcast(IntXVT, N0.getOperand(1));
    AddToWorklist(X.getNode());

    // If X has a different width than the result/lhs, sext it or truncate it.
    unsigned VTWidth = VT.getSizeInBits();
    if (OrigXWidth < VTWidth) {
      X = DAG.getNode(ISD::SIGN_EXTEND, SDLoc(N), VT, X);
      AddToWorklist(X.getNode());
    } else if (OrigXWidth > VTWidth) {
      // To get the sign bit in the right place, we have to shift it right
      // before truncating.
      SDLoc DL(X);
      X = DAG.getNode(ISD::SRL, DL,
                      X.getValueType(), X,
                      DAG.getConstant(OrigXWidth-VTWidth, DL,
                                      X.getValueType()));
      AddToWorklist(X.getNode());
      X = DAG.getNode(ISD::TRUNCATE, SDLoc(X), VT, X);
      AddToWorklist(X.getNode());
    }

    if (N0.getValueType() == MVT::ppcf128 && !LegalTypes) {
      APInt SignBit = APInt::getSignMask(VT.getSizeInBits() / 2);
      SDValue Cst = DAG.getBitcast(VT, N0.getOperand(0));
      AddToWorklist(Cst.getNode());
      SDValue X = DAG.getBitcast(VT, N0.getOperand(1));
      AddToWorklist(X.getNode());
      SDValue XorResult = DAG.getNode(ISD::XOR, SDLoc(N0), VT, Cst, X);
      AddToWorklist(XorResult.getNode());
      SDValue XorResult64 = DAG.getNode(
          ISD::EXTRACT_ELEMENT, SDLoc(XorResult), MVT::i64, XorResult,
          DAG.getIntPtrConstant(getPPCf128HiElementSelector(DAG),
                                SDLoc(XorResult)));
      AddToWorklist(XorResult64.getNode());
      SDValue FlipBit =
          DAG.getNode(ISD::AND, SDLoc(XorResult64), MVT::i64, XorResult64,
                      DAG.getConstant(SignBit, SDLoc(XorResult64), MVT::i64));
      AddToWorklist(FlipBit.getNode());
      SDValue FlipBits =
          DAG.getNode(ISD::BUILD_PAIR, SDLoc(N0), VT, FlipBit, FlipBit);
      AddToWorklist(FlipBits.getNode());
      return DAG.getNode(ISD::XOR, SDLoc(N), VT, Cst, FlipBits);
    }
    APInt SignBit = APInt::getSignMask(VT.getSizeInBits());
    X = DAG.getNode(ISD::AND, SDLoc(X), VT,
                    X, DAG.getConstant(SignBit, SDLoc(X), VT));
    AddToWorklist(X.getNode());

    SDValue Cst = DAG.getBitcast(VT, N0.getOperand(0));
    Cst = DAG.getNode(ISD::AND, SDLoc(Cst), VT,
                      Cst, DAG.getConstant(~SignBit, SDLoc(Cst), VT));
    AddToWorklist(Cst.getNode());

    return DAG.getNode(ISD::OR, SDLoc(N), VT, X, Cst);
  }
}

// bitconvert(build_pair(ld, ld)) -> ld iff load locations are consecutive.
if (N0.getOpcode() == ISD::BUILD_PAIR)
  if (SDValue CombineLD = CombineConsecutiveLoads(N0.getNode(), VT))
    return CombineLD;

// Remove double bitcasts from shuffles - this is often a legacy of
// XformToShuffleWithZero being used to combine bitmaskings (of
// float vectors bitcast to integer vectors) into shuffles.
// bitcast(shuffle(bitcast(s0),bitcast(s1))) -> shuffle(s0,s1)
if (Level < AfterLegalizeDAG && TLI.isTypeLegal(VT) && VT.isVector() &&
    N0->getOpcode() == ISD::VECTOR_SHUFFLE &&
    VT.getVectorNumElements() >= N0.getValueType().getVectorNumElements() &&
    !(VT.getVectorNumElements() % N0.getValueType().getVectorNumElements())) {
  ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N0);

  // If operands are a bitcast, peek through if it casts the original VT.
  // If operands are a constant, just bitcast back to original VT.
  auto PeekThroughBitcast = [&](SDValue Op) {
    if (Op.getOpcode() == ISD::BITCAST &&
        Op.getOperand(0).getValueType() == VT)
      return SDValue(Op.getOperand(0));
    if (Op.isUndef() || ISD::isBuildVectorOfConstantSDNodes(Op.getNode()) ||
        ISD::isBuildVectorOfConstantFPSDNodes(Op.getNode()))
      return DAG.getBitcast(VT, Op);
    return SDValue();
  };

  // FIXME: If either input vector is bitcast, try to convert the shuffle to
  // the result type of this bitcast. This would eliminate at least one
  // bitcast. See the transform in InstCombine.
  SDValue SV0 = PeekThroughBitcast(N0->getOperand(0));
  SDValue SV1 = PeekThroughBitcast(N0->getOperand(1));
  if (!(SV0 && SV1))
    return SDValue();

  int MaskScale =
      VT.getVectorNumElements() / N0.getValueType().getVectorNumElements();
  SmallVector<int, 8> NewMask;
  for (int M : SVN->getMask())
    for (int i = 0; i != MaskScale; ++i)
      NewMask.push_back(M < 0 ? -1 : M * MaskScale + i);

  bool LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
  if (!LegalMask) {
    std::swap(SV0, SV1);
    ShuffleVectorSDNode::commuteMask(NewMask);
    LegalMask = TLI.isShuffleMaskLegal(NewMask, VT);
  }

  if (LegalMask)
    return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, NewMask);
}

return SDValue();
9178}

9180SDValue DAGCombiner::visitBUILD_PAIR(SDNode *N) {
EVT VT = N->getValueType(0);
return CombineConsecutiveLoads(N, VT);
9183}

9185/// We know that BV is a build_vector node with Constant, ConstantFP or Undef
9186/// operands. DstEltVT indicates the destination element value type.
9187SDValue DAGCombiner::
9188ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
EVT SrcEltVT = BV->getValueType(0).getVectorElementType();

// If this is already the right type, we're done.
if (SrcEltVT == DstEltVT) return SDValue(BV, 0);

unsigned SrcBitSize = SrcEltVT.getSizeInBits();
unsigned DstBitSize = DstEltVT.getSizeInBits();

// If this is a conversion of N elements of one type to N elements of another
// type, convert each element.  This handles FP<->INT cases.
if (SrcBitSize == DstBitSize) {
  EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
                            BV->getValueType(0).getVectorNumElements());

  // Due to the FP element handling below calling this routine recursively,
  // we can end up with a scalar-to-vector node here.
  if (BV->getOpcode() == ISD::SCALAR_TO_VECTOR)
    return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
                       DAG.getBitcast(DstEltVT, BV->getOperand(0)));

  SmallVector<SDValue, 8> Ops;
  for (SDValue Op : BV->op_values()) {
    // If the vector element type is not legal, the BUILD_VECTOR operands
    // are promoted and implicitly truncated.  Make that explicit here.
    if (Op.getValueType() != SrcEltVT)
      Op = DAG.getNode(ISD::TRUNCATE, SDLoc(BV), SrcEltVT, Op);
    Ops.push_back(DAG.getBitcast(DstEltVT, Op));
    AddToWorklist(Ops.back().getNode());
  }
  return DAG.getBuildVector(VT, SDLoc(BV), Ops);
}

// Otherwise, we're growing or shrinking the elements.  To avoid having to
// handle annoying details of growing/shrinking FP values, we convert them to
// int first.
if (SrcEltVT.isFloatingPoint()) {
  // Convert the input float vector to a int vector where the elements are the
  // same sizes.
  EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), SrcEltVT.getSizeInBits());
  BV = ConstantFoldBITCASTofBUILD_VECTOR(BV, IntVT).getNode();
  SrcEltVT = IntVT;
}

// Now we know the input is an integer vector.  If the output is a FP type,
// convert to integer first, then to FP of the right size.
if (DstEltVT.isFloatingPoint()) {
  EVT TmpVT = EVT::getIntegerVT(*DAG.getContext(), DstEltVT.getSizeInBits());
  SDNode *Tmp = ConstantFoldBITCASTofBUILD_VECTOR(BV, TmpVT).getNode();

  // Next, convert to FP elements of the same size.
  return ConstantFoldBITCASTofBUILD_VECTOR(Tmp, DstEltVT);
}

SDLoc DL(BV);

// Okay, we know the src/dst types are both integers of differing types.
// Handling growing first.
assert(SrcEltVT.isInteger() && DstEltVT.isInteger())(static_cast <bool> (SrcEltVT.isInteger() && DstEltVT
.isInteger()) ? void (0) : __assert_fail ("SrcEltVT.isInteger() && DstEltVT.isInteger()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 9246, __extension__ __PRETTY_FUNCTION__));
if (SrcBitSize < DstBitSize) {
  unsigned NumInputsPerOutput = DstBitSize/SrcBitSize;

  SmallVector<SDValue, 8> Ops;
  for (unsigned i = 0, e = BV->getNumOperands(); i != e;
       i += NumInputsPerOutput) {
    bool isLE = DAG.getDataLayout().isLittleEndian();
    APInt NewBits = APInt(DstBitSize, 0);
    bool EltIsUndef = true;
    for (unsigned j = 0; j != NumInputsPerOutput; ++j) {
      // Shift the previously computed bits over.
      NewBits <<= SrcBitSize;
      SDValue Op = BV->getOperand(i+ (isLE ? (NumInputsPerOutput-j-1) : j));
      if (Op.isUndef()) continue;
      EltIsUndef = false;

      NewBits |= cast<ConstantSDNode>(Op)->getAPIntValue().
                 zextOrTrunc(SrcBitSize).zext(DstBitSize);
    }

    if (EltIsUndef)
      Ops.push_back(DAG.getUNDEF(DstEltVT));
    else
      Ops.push_back(DAG.getConstant(NewBits, DL, DstEltVT));
  }

  EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT, Ops.size());
  return DAG.getBuildVector(VT, DL, Ops);
}

// Finally, this must be the case where we are shrinking elements: each input
// turns into multiple outputs.
unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
                          NumOutputsPerInput*BV->getNumOperands());
SmallVector<SDValue, 8> Ops;

for (const SDValue &Op : BV->op_values()) {
  if (Op.isUndef()) {
    Ops.append(NumOutputsPerInput, DAG.getUNDEF(DstEltVT));
    continue;
  }

  APInt OpVal = cast<ConstantSDNode>(Op)->
                getAPIntValue().zextOrTrunc(SrcBitSize);

  for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
    APInt ThisVal = OpVal.trunc(DstBitSize);
    Ops.push_back(DAG.getConstant(ThisVal, DL, DstEltVT));
    OpVal.lshrInPlace(DstBitSize);
  }

  // For big endian targets, swap the order of the pieces of each element.
  if (DAG.getDataLayout().isBigEndian())
    std::reverse(Ops.end()-NumOutputsPerInput, Ops.end());
}

return DAG.getBuildVector(VT, DL, Ops);
9305}

9307static bool isContractable(SDNode *N) {
SDNodeFlags F = N->getFlags();
return F.hasAllowContract() || F.hasUnsafeAlgebra();
9310}

9312/// Try to perform FMA combining on a given FADD node.
9313SDValue DAGCombiner::visitFADDForFMACombine(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc SL(N);

const TargetOptions &Options = DAG.getTarget().Options;

// Floating-point multiply-add with intermediate rounding.
bool HasFMAD = (LegalOperations && TLI.isOperationLegal(ISD::FMAD, VT));

// Floating-point multiply-add without intermediate rounding.
bool HasFMA =
    TLI.isFMAFasterThanFMulAndFAdd(VT) &&
    (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT));

// No valid opcode, do not combine.
if (!HasFMAD && !HasFMA)
  return SDValue();

bool AllowFusionGlobally = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
                            Options.UnsafeFPMath || HasFMAD);
// If the addition is not contractable, do not combine.
if (!AllowFusionGlobally && !isContractable(N))
  return SDValue();

const SelectionDAGTargetInfo *STI = DAG.getSubtarget().getSelectionDAGInfo();
if (STI && STI->generateFMAsInMachineCombiner(OptLevel))
  return SDValue();

// Always prefer FMAD to FMA for precision.
unsigned PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
bool Aggressive = TLI.enableAggressiveFMAFusion(VT);

// Is the node an FMUL and contractable either due to global flags or
// SDNodeFlags.
auto isContractableFMUL = [AllowFusionGlobally](SDValue N) {
  if (N.getOpcode() != ISD::FMUL)
    return false;
  return AllowFusionGlobally || isContractable(N.getNode());
};
// If we have two choices trying to fold (fadd (fmul u, v), (fmul x, y)),
// prefer to fold the multiply with fewer uses.
if (Aggressive && isContractableFMUL(N0) && isContractableFMUL(N1)) {
  if (N0.getNode()->use_size() > N1.getNode()->use_size())
    std::swap(N0, N1);
}

// fold (fadd (fmul x, y), z) -> (fma x, y, z)
if (isContractableFMUL(N0) && (Aggressive || N0->hasOneUse())) {
  return DAG.getNode(PreferredFusedOpcode, SL, VT,
                     N0.getOperand(0), N0.getOperand(1), N1);
}

// fold (fadd x, (fmul y, z)) -> (fma y, z, x)
// Note: Commutes FADD operands.
if (isContractableFMUL(N1) && (Aggressive || N1->hasOneUse())) {
  return DAG.getNode(PreferredFusedOpcode, SL, VT,
                     N1.getOperand(0), N1.getOperand(1), N0);
}

// Look through FP_EXTEND nodes to do more combining.

// fold (fadd (fpext (fmul x, y)), z) -> (fma (fpext x), (fpext y), z)
if (N0.getOpcode() == ISD::FP_EXTEND) {
  SDValue N00 = N0.getOperand(0);
  if (isContractableFMUL(N00) &&
      TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N00.getValueType())) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N00.getOperand(0)),
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N00.getOperand(1)), N1);
  }
}

// fold (fadd x, (fpext (fmul y, z))) -> (fma (fpext y), (fpext z), x)
// Note: Commutes FADD operands.
if (N1.getOpcode() == ISD::FP_EXTEND) {
  SDValue N10 = N1.getOperand(0);
  if (isContractableFMUL(N10) &&
      TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N10.getValueType())) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N10.getOperand(0)),
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N10.getOperand(1)), N0);
  }
}

// More folding opportunities when target permits.
if (Aggressive) {
  // fold (fadd (fma x, y, (fmul u, v)), z) -> (fma x, y (fma u, v, z))
  // FIXME: The UnsafeAlgebra flag should be propagated to FMA/FMAD, but FMF
  // are currently only supported on binary nodes.
  if (Options.UnsafeFPMath &&
      N0.getOpcode() == PreferredFusedOpcode &&
      N0.getOperand(2).getOpcode() == ISD::FMUL &&
      N0->hasOneUse() && N0.getOperand(2)->hasOneUse()) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       N0.getOperand(0), N0.getOperand(1),
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   N0.getOperand(2).getOperand(0),
                                   N0.getOperand(2).getOperand(1),
                                   N1));
  }

  // fold (fadd x, (fma y, z, (fmul u, v)) -> (fma y, z (fma u, v, x))
  // FIXME: The UnsafeAlgebra flag should be propagated to FMA/FMAD, but FMF
  // are currently only supported on binary nodes.
  if (Options.UnsafeFPMath &&
      N1->getOpcode() == PreferredFusedOpcode &&
      N1.getOperand(2).getOpcode() == ISD::FMUL &&
      N1->hasOneUse() && N1.getOperand(2)->hasOneUse()) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       N1.getOperand(0), N1.getOperand(1),
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   N1.getOperand(2).getOperand(0),
                                   N1.getOperand(2).getOperand(1),
                                   N0));
  }


  // fold (fadd (fma x, y, (fpext (fmul u, v))), z)
  //   -> (fma x, y, (fma (fpext u), (fpext v), z))
  auto FoldFAddFMAFPExtFMul = [&] (
    SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT, X, Y,
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
                                   DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
                                   Z));
  };
  if (N0.getOpcode() == PreferredFusedOpcode) {
    SDValue N02 = N0.getOperand(2);
    if (N02.getOpcode() == ISD::FP_EXTEND) {
      SDValue N020 = N02.getOperand(0);
      if (isContractableFMUL(N020) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N020.getValueType())) {
        return FoldFAddFMAFPExtFMul(N0.getOperand(0), N0.getOperand(1),
                                    N020.getOperand(0), N020.getOperand(1),
                                    N1);
      }
    }
  }

  // fold (fadd (fpext (fma x, y, (fmul u, v))), z)
  //   -> (fma (fpext x), (fpext y), (fma (fpext u), (fpext v), z))
  // FIXME: This turns two single-precision and one double-precision
  // operation into two double-precision operations, which might not be
  // interesting for all targets, especially GPUs.
  auto FoldFAddFPExtFMAFMul = [&] (
    SDValue X, SDValue Y, SDValue U, SDValue V, SDValue Z) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FP_EXTEND, SL, VT, X),
                       DAG.getNode(ISD::FP_EXTEND, SL, VT, Y),
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   DAG.getNode(ISD::FP_EXTEND, SL, VT, U),
                                   DAG.getNode(ISD::FP_EXTEND, SL, VT, V),
                                   Z));
  };
  if (N0.getOpcode() == ISD::FP_EXTEND) {
    SDValue N00 = N0.getOperand(0);
    if (N00.getOpcode() == PreferredFusedOpcode) {
      SDValue N002 = N00.getOperand(2);
      if (isContractableFMUL(N002) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N00.getValueType())) {
        return FoldFAddFPExtFMAFMul(N00.getOperand(0), N00.getOperand(1),
                                    N002.getOperand(0), N002.getOperand(1),
                                    N1);
      }
    }
  }

  // fold (fadd x, (fma y, z, (fpext (fmul u, v)))
  //   -> (fma y, z, (fma (fpext u), (fpext v), x))
  if (N1.getOpcode() == PreferredFusedOpcode) {
    SDValue N12 = N1.getOperand(2);
    if (N12.getOpcode() == ISD::FP_EXTEND) {
      SDValue N120 = N12.getOperand(0);
      if (isContractableFMUL(N120) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N120.getValueType())) {
        return FoldFAddFMAFPExtFMul(N1.getOperand(0), N1.getOperand(1),
                                    N120.getOperand(0), N120.getOperand(1),
                                    N0);
      }
    }
  }

  // fold (fadd x, (fpext (fma y, z, (fmul u, v)))
  //   -> (fma (fpext y), (fpext z), (fma (fpext u), (fpext v), x))
  // FIXME: This turns two single-precision and one double-precision
  // operation into two double-precision operations, which might not be
  // interesting for all targets, especially GPUs.
  if (N1.getOpcode() == ISD::FP_EXTEND) {
    SDValue N10 = N1.getOperand(0);
    if (N10.getOpcode() == PreferredFusedOpcode) {
      SDValue N102 = N10.getOperand(2);
      if (isContractableFMUL(N102) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N10.getValueType())) {
        return FoldFAddFPExtFMAFMul(N10.getOperand(0), N10.getOperand(1),
                                    N102.getOperand(0), N102.getOperand(1),
                                    N0);
      }
    }
  }
}

return SDValue();
9522}

9524/// Try to perform FMA combining on a given FSUB node.
9525SDValue DAGCombiner::visitFSUBForFMACombine(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc SL(N);

const TargetOptions &Options = DAG.getTarget().Options;
// Floating-point multiply-add with intermediate rounding.
bool HasFMAD = (LegalOperations && TLI.isOperationLegal(ISD::FMAD, VT));

// Floating-point multiply-add without intermediate rounding.
bool HasFMA =
    TLI.isFMAFasterThanFMulAndFAdd(VT) &&
    (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT));

// No valid opcode, do not combine.
if (!HasFMAD && !HasFMA)
  return SDValue();

bool AllowFusionGlobally = (Options.AllowFPOpFusion == FPOpFusion::Fast ||
                            Options.UnsafeFPMath || HasFMAD);
// If the subtraction is not contractable, do not combine.
if (!AllowFusionGlobally && !isContractable(N))
  return SDValue();

const SelectionDAGTargetInfo *STI = DAG.getSubtarget().getSelectionDAGInfo();
if (STI && STI->generateFMAsInMachineCombiner(OptLevel))
  return SDValue();

// Always prefer FMAD to FMA for precision.
unsigned PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
bool Aggressive = TLI.enableAggressiveFMAFusion(VT);

// Is the node an FMUL and contractable either due to global flags or
// SDNodeFlags.
auto isContractableFMUL = [AllowFusionGlobally](SDValue N) {
  if (N.getOpcode() != ISD::FMUL)
    return false;
  return AllowFusionGlobally || isContractable(N.getNode());
};

// fold (fsub (fmul x, y), z) -> (fma x, y, (fneg z))
if (isContractableFMUL(N0) && (Aggressive || N0->hasOneUse())) {
  return DAG.getNode(PreferredFusedOpcode, SL, VT,
                     N0.getOperand(0), N0.getOperand(1),
                     DAG.getNode(ISD::FNEG, SL, VT, N1));
}

// fold (fsub x, (fmul y, z)) -> (fma (fneg y), z, x)
// Note: Commutes FSUB operands.
if (isContractableFMUL(N1) && (Aggressive || N1->hasOneUse()))
  return DAG.getNode(PreferredFusedOpcode, SL, VT,
                     DAG.getNode(ISD::FNEG, SL, VT,
                                 N1.getOperand(0)),
                     N1.getOperand(1), N0);

// fold (fsub (fneg (fmul, x, y)), z) -> (fma (fneg x), y, (fneg z))
if (N0.getOpcode() == ISD::FNEG && isContractableFMUL(N0.getOperand(0)) &&
    (Aggressive || (N0->hasOneUse() && N0.getOperand(0).hasOneUse()))) {
  SDValue N00 = N0.getOperand(0).getOperand(0);
  SDValue N01 = N0.getOperand(0).getOperand(1);
  return DAG.getNode(PreferredFusedOpcode, SL, VT,
                     DAG.getNode(ISD::FNEG, SL, VT, N00), N01,
                     DAG.getNode(ISD::FNEG, SL, VT, N1));
}

// Look through FP_EXTEND nodes to do more combining.

// fold (fsub (fpext (fmul x, y)), z)
//   -> (fma (fpext x), (fpext y), (fneg z))
if (N0.getOpcode() == ISD::FP_EXTEND) {
  SDValue N00 = N0.getOperand(0);
  if (isContractableFMUL(N00) &&
      TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N00.getValueType())) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N00.getOperand(0)),
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N00.getOperand(1)),
                       DAG.getNode(ISD::FNEG, SL, VT, N1));
  }
}

// fold (fsub x, (fpext (fmul y, z)))
//   -> (fma (fneg (fpext y)), (fpext z), x)
// Note: Commutes FSUB operands.
if (N1.getOpcode() == ISD::FP_EXTEND) {
  SDValue N10 = N1.getOperand(0);
  if (isContractableFMUL(N10) &&
      TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N10.getValueType())) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FNEG, SL, VT,
                                   DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                               N10.getOperand(0))),
                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                   N10.getOperand(1)),
                       N0);
  }
}

// fold (fsub (fpext (fneg (fmul, x, y))), z)
//   -> (fneg (fma (fpext x), (fpext y), z))
// Note: This could be removed with appropriate canonicalization of the
// input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
// orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
// from implementing the canonicalization in visitFSUB.
if (N0.getOpcode() == ISD::FP_EXTEND) {
  SDValue N00 = N0.getOperand(0);
  if (N00.getOpcode() == ISD::FNEG) {
    SDValue N000 = N00.getOperand(0);
    if (isContractableFMUL(N000) &&
        TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N00.getValueType())) {
      return DAG.getNode(ISD::FNEG, SL, VT,
                         DAG.getNode(PreferredFusedOpcode, SL, VT,
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N000.getOperand(0)),
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N000.getOperand(1)),
                                     N1));
    }
  }
}

// fold (fsub (fneg (fpext (fmul, x, y))), z)
//   -> (fneg (fma (fpext x)), (fpext y), z)
// Note: This could be removed with appropriate canonicalization of the
// input expression into (fneg (fadd (fpext (fmul, x, y)), z). However, the
// orthogonal flags -fp-contract=fast and -enable-unsafe-fp-math prevent
// from implementing the canonicalization in visitFSUB.
if (N0.getOpcode() == ISD::FNEG) {
  SDValue N00 = N0.getOperand(0);
  if (N00.getOpcode() == ISD::FP_EXTEND) {
    SDValue N000 = N00.getOperand(0);
    if (isContractableFMUL(N000) &&
        TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N000.getValueType())) {
      return DAG.getNode(ISD::FNEG, SL, VT,
                         DAG.getNode(PreferredFusedOpcode, SL, VT,
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N000.getOperand(0)),
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N000.getOperand(1)),
                                     N1));
    }
  }
}

// More folding opportunities when target permits.
if (Aggressive) {
  // fold (fsub (fma x, y, (fmul u, v)), z)
  //   -> (fma x, y (fma u, v, (fneg z)))
  // FIXME: The UnsafeAlgebra flag should be propagated to FMA/FMAD, but FMF
  // are currently only supported on binary nodes.
  if (Options.UnsafeFPMath && N0.getOpcode() == PreferredFusedOpcode &&
      isContractableFMUL(N0.getOperand(2)) && N0->hasOneUse() &&
      N0.getOperand(2)->hasOneUse()) {
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       N0.getOperand(0), N0.getOperand(1),
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   N0.getOperand(2).getOperand(0),
                                   N0.getOperand(2).getOperand(1),
                                   DAG.getNode(ISD::FNEG, SL, VT,
                                               N1)));
  }

  // fold (fsub x, (fma y, z, (fmul u, v)))
  //   -> (fma (fneg y), z, (fma (fneg u), v, x))
  // FIXME: The UnsafeAlgebra flag should be propagated to FMA/FMAD, but FMF
  // are currently only supported on binary nodes.
  if (Options.UnsafeFPMath && N1.getOpcode() == PreferredFusedOpcode &&
      isContractableFMUL(N1.getOperand(2))) {
    SDValue N20 = N1.getOperand(2).getOperand(0);
    SDValue N21 = N1.getOperand(2).getOperand(1);
    return DAG.getNode(PreferredFusedOpcode, SL, VT,
                       DAG.getNode(ISD::FNEG, SL, VT,
                                   N1.getOperand(0)),
                       N1.getOperand(1),
                       DAG.getNode(PreferredFusedOpcode, SL, VT,
                                   DAG.getNode(ISD::FNEG, SL, VT, N20),

                                   N21, N0));
  }


  // fold (fsub (fma x, y, (fpext (fmul u, v))), z)
  //   -> (fma x, y (fma (fpext u), (fpext v), (fneg z)))
  if (N0.getOpcode() == PreferredFusedOpcode) {
    SDValue N02 = N0.getOperand(2);
    if (N02.getOpcode() == ISD::FP_EXTEND) {
      SDValue N020 = N02.getOperand(0);
      if (isContractableFMUL(N020) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N020.getValueType())) {
        return DAG.getNode(PreferredFusedOpcode, SL, VT,
                           N0.getOperand(0), N0.getOperand(1),
                           DAG.getNode(PreferredFusedOpcode, SL, VT,
                                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                   N020.getOperand(0)),
                                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                   N020.getOperand(1)),
                                       DAG.getNode(ISD::FNEG, SL, VT,
                                                   N1)));
      }
    }
  }

  // fold (fsub (fpext (fma x, y, (fmul u, v))), z)
  //   -> (fma (fpext x), (fpext y),
  //           (fma (fpext u), (fpext v), (fneg z)))
  // FIXME: This turns two single-precision and one double-precision
  // operation into two double-precision operations, which might not be
  // interesting for all targets, especially GPUs.
  if (N0.getOpcode() == ISD::FP_EXTEND) {
    SDValue N00 = N0.getOperand(0);
    if (N00.getOpcode() == PreferredFusedOpcode) {
      SDValue N002 = N00.getOperand(2);
      if (isContractableFMUL(N002) &&
          TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N00.getValueType())) {
        return DAG.getNode(PreferredFusedOpcode, SL, VT,
                           DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                       N00.getOperand(0)),
                           DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                       N00.getOperand(1)),
                           DAG.getNode(PreferredFusedOpcode, SL, VT,
                                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                   N002.getOperand(0)),
                                       DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                   N002.getOperand(1)),
                                       DAG.getNode(ISD::FNEG, SL, VT,
                                                   N1)));
      }
    }
  }

  // fold (fsub x, (fma y, z, (fpext (fmul u, v))))
  //   -> (fma (fneg y), z, (fma (fneg (fpext u)), (fpext v), x))
  if (N1.getOpcode() == PreferredFusedOpcode &&
      N1.getOperand(2).getOpcode() == ISD::FP_EXTEND) {
    SDValue N120 = N1.getOperand(2).getOperand(0);
    if (isContractableFMUL(N120) &&
        TLI.isFPExtFoldable(PreferredFusedOpcode, VT, N120.getValueType())) {
      SDValue N1200 = N120.getOperand(0);
      SDValue N1201 = N120.getOperand(1);
      return DAG.getNode(PreferredFusedOpcode, SL, VT,
                         DAG.getNode(ISD::FNEG, SL, VT, N1.getOperand(0)),
                         N1.getOperand(1),
                         DAG.getNode(PreferredFusedOpcode, SL, VT,
                                     DAG.getNode(ISD::FNEG, SL, VT,
                                                 DAG.getNode(ISD::FP_EXTEND, SL,
                                                             VT, N1200)),
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N1201),
                                     N0));
    }
  }

  // fold (fsub x, (fpext (fma y, z, (fmul u, v))))
  //   -> (fma (fneg (fpext y)), (fpext z),
  //           (fma (fneg (fpext u)), (fpext v), x))
  // FIXME: This turns two single-precision and one double-precision
  // operation into two double-precision operations, which might not be
  // interesting for all targets, especially GPUs.
  if (N1.getOpcode() == ISD::FP_EXTEND &&
      N1.getOperand(0).getOpcode() == PreferredFusedOpcode) {
    SDValue CvtSrc = N1.getOperand(0);
    SDValue N100 = CvtSrc.getOperand(0);
    SDValue N101 = CvtSrc.getOperand(1);
    SDValue N102 = CvtSrc.getOperand(2);
    if (isContractableFMUL(N102) &&
        TLI.isFPExtFoldable(PreferredFusedOpcode, VT, CvtSrc.getValueType())) {
      SDValue N1020 = N102.getOperand(0);
      SDValue N1021 = N102.getOperand(1);
      return DAG.getNode(PreferredFusedOpcode, SL, VT,
                         DAG.getNode(ISD::FNEG, SL, VT,
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N100)),
                         DAG.getNode(ISD::FP_EXTEND, SL, VT, N101),
                         DAG.getNode(PreferredFusedOpcode, SL, VT,
                                     DAG.getNode(ISD::FNEG, SL, VT,
                                                 DAG.getNode(ISD::FP_EXTEND, SL,
                                                             VT, N1020)),
                                     DAG.getNode(ISD::FP_EXTEND, SL, VT,
                                                 N1021),
                                     N0));
    }
  }
}

return SDValue();
9812}

9814/// Try to perform FMA combining on a given FMUL node based on the distributive
9815/// law x * (y + 1) = x * y + x and variants thereof (commuted versions,
9816/// subtraction instead of addition).
9817SDValue DAGCombiner::visitFMULForFMADistributiveCombine(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
SDLoc SL(N);

assert(N->getOpcode() == ISD::FMUL && "Expected FMUL Operation")(static_cast <bool> (N->getOpcode() == ISD::FMUL &&
 "Expected FMUL Operation") ? void (0) : __assert_fail ("N->getOpcode() == ISD::FMUL && \"Expected FMUL Operation\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 9823, __extension__ __PRETTY_FUNCTION__));

const TargetOptions &Options = DAG.getTarget().Options;

// The transforms below are incorrect when x == 0 and y == inf, because the
// intermediate multiplication produces a nan.
if (!Options.NoInfsFPMath)
  return SDValue();

// Floating-point multiply-add without intermediate rounding.
bool HasFMA =
    (Options.AllowFPOpFusion == FPOpFusion::Fast || Options.UnsafeFPMath) &&
    TLI.isFMAFasterThanFMulAndFAdd(VT) &&
    (!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FMA, VT));

// Floating-point multiply-add with intermediate rounding. This can result
// in a less precise result due to the changed rounding order.
bool HasFMAD = Options.UnsafeFPMath &&
               (LegalOperations && TLI.isOperationLegal(ISD::FMAD, VT));

// No valid opcode, do not combine.
if (!HasFMAD && !HasFMA)
  return SDValue();

// Always prefer FMAD to FMA for precision.
unsigned PreferredFusedOpcode = HasFMAD ? ISD::FMAD : ISD::FMA;
bool Aggressive = TLI.enableAggressiveFMAFusion(VT);

// fold (fmul (fadd x, +1.0), y) -> (fma x, y, y)
// fold (fmul (fadd x, -1.0), y) -> (fma x, y, (fneg y))
auto FuseFADD = [&](SDValue X, SDValue Y) {
  if (X.getOpcode() == ISD::FADD && (Aggressive || X->hasOneUse())) {
    auto XC1 = isConstOrConstSplatFP(X.getOperand(1));
    if (XC1 && XC1->isExactlyValue(+1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT, X.getOperand(0), Y, Y);
    if (XC1 && XC1->isExactlyValue(-1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT, X.getOperand(0), Y,
                         DAG.getNode(ISD::FNEG, SL, VT, Y));
  }
  return SDValue();
};

if (SDValue FMA = FuseFADD(N0, N1))
  return FMA;
if (SDValue FMA = FuseFADD(N1, N0))
  return FMA;

// fold (fmul (fsub +1.0, x), y) -> (fma (fneg x), y, y)
// fold (fmul (fsub -1.0, x), y) -> (fma (fneg x), y, (fneg y))
// fold (fmul (fsub x, +1.0), y) -> (fma x, y, (fneg y))
// fold (fmul (fsub x, -1.0), y) -> (fma x, y, y)
auto FuseFSUB = [&](SDValue X, SDValue Y) {
  if (X.getOpcode() == ISD::FSUB && (Aggressive || X->hasOneUse())) {
    auto XC0 = isConstOrConstSplatFP(X.getOperand(0));
    if (XC0 && XC0->isExactlyValue(+1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT,
                         DAG.getNode(ISD::FNEG, SL, VT, X.getOperand(1)), Y,
                         Y);
    if (XC0 && XC0->isExactlyValue(-1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT,
                         DAG.getNode(ISD::FNEG, SL, VT, X.getOperand(1)), Y,
                         DAG.getNode(ISD::FNEG, SL, VT, Y));

    auto XC1 = isConstOrConstSplatFP(X.getOperand(1));
    if (XC1 && XC1->isExactlyValue(+1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT, X.getOperand(0), Y,
                         DAG.getNode(ISD::FNEG, SL, VT, Y));
    if (XC1 && XC1->isExactlyValue(-1.0))
      return DAG.getNode(PreferredFusedOpcode, SL, VT, X.getOperand(0), Y, Y);
  }
  return SDValue();
};

if (SDValue FMA = FuseFSUB(N0, N1))
  return FMA;
if (SDValue FMA = FuseFSUB(N1, N0))
  return FMA;

return SDValue();
9902}

9904static bool isFMulNegTwo(SDValue &N) {
if (N.getOpcode() != ISD::FMUL)
  return false;
if (ConstantFPSDNode *CFP = isConstOrConstSplatFP(N.getOperand(1)))
  return CFP->isExactlyValue(-2.0);
return false;
9910}

9912SDValue DAGCombiner::visitFADD(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
bool N0CFP = isConstantFPBuildVectorOrConstantFP(N0);
bool N1CFP = isConstantFPBuildVectorOrConstantFP(N1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

// fold (fadd c1, c2) -> c1 + c2
if (N0CFP && N1CFP)
  return DAG.getNode(ISD::FADD, DL, VT, N0, N1, Flags);

// canonicalize constant to RHS
if (N0CFP && !N1CFP)
  return DAG.getNode(ISD::FADD, DL, VT, N1, N0, Flags);

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (fadd A, (fneg B)) -> (fsub A, B)
if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
    isNegatibleForFree(N1, LegalOperations, TLI, &Options) == 2)
  return DAG.getNode(ISD::FSUB, DL, VT, N0,
                     GetNegatedExpression(N1, DAG, LegalOperations), Flags);

// fold (fadd (fneg A), B) -> (fsub B, A)
if ((!LegalOperations || TLI.isOperationLegalOrCustom(ISD::FSUB, VT)) &&
    isNegatibleForFree(N0, LegalOperations, TLI, &Options) == 2)
  return DAG.getNode(ISD::FSUB, DL, VT, N1,
                     GetNegatedExpression(N0, DAG, LegalOperations), Flags);

// fold (fadd A, (fmul B, -2.0)) -> (fsub A, (fadd B, B))
// fold (fadd (fmul B, -2.0), A) -> (fsub A, (fadd B, B))
if ((isFMulNegTwo(N0) && N0.hasOneUse()) ||
    (isFMulNegTwo(N1) && N1.hasOneUse())) {
  bool N1IsFMul = isFMulNegTwo(N1);
  SDValue AddOp = N1IsFMul ? N1.getOperand(0) : N0.getOperand(0);
  SDValue Add = DAG.getNode(ISD::FADD, DL, VT, AddOp, AddOp, Flags);
  return DAG.getNode(ISD::FSUB, DL, VT, N1IsFMul ? N0 : N1, Add, Flags);
}

// FIXME: Auto-upgrade the target/function-level option.
if (Options.NoSignedZerosFPMath || N->getFlags().hasNoSignedZeros()) {
  // fold (fadd A, 0) -> A
  if (ConstantFPSDNode *N1C = isConstOrConstSplatFP(N1))
    if (N1C->isZero())
      return N0;
}

// If 'unsafe math' is enabled, fold lots of things.
if (Options.UnsafeFPMath) {
  // No FP constant should be created after legalization as Instruction
  // Selection pass has a hard time dealing with FP constants.
  bool AllowNewConst = (Level < AfterLegalizeDAG);

  // fold (fadd (fadd x, c1), c2) -> (fadd x, (fadd c1, c2))
  if (N1CFP && N0.getOpcode() == ISD::FADD && N0.getNode()->hasOneUse() &&
      isConstantFPBuildVectorOrConstantFP(N0.getOperand(1)))
    return DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(0),
                       DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(1), N1,
                                   Flags),
                       Flags);

  // If allowed, fold (fadd (fneg x), x) -> 0.0
  if (AllowNewConst && N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1)
    return DAG.getConstantFP(0.0, DL, VT);

  // If allowed, fold (fadd x, (fneg x)) -> 0.0
  if (AllowNewConst && N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0)
    return DAG.getConstantFP(0.0, DL, VT);

  // We can fold chains of FADD's of the same value into multiplications.
  // This transform is not safe in general because we are reducing the number
  // of rounding steps.
  if (TLI.isOperationLegalOrCustom(ISD::FMUL, VT) && !N0CFP && !N1CFP) {
    if (N0.getOpcode() == ISD::FMUL) {
      bool CFP00 = isConstantFPBuildVectorOrConstantFP(N0.getOperand(0));
      bool CFP01 = isConstantFPBuildVectorOrConstantFP(N0.getOperand(1));

      // (fadd (fmul x, c), x) -> (fmul x, c+1)
      if (CFP01 && !CFP00 && N0.getOperand(0) == N1) {
        SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(1),
                                     DAG.getConstantFP(1.0, DL, VT), Flags);
        return DAG.getNode(ISD::FMUL, DL, VT, N1, NewCFP, Flags);
      }

      // (fadd (fmul x, c), (fadd x, x)) -> (fmul x, c+2)
      if (CFP01 && !CFP00 && N1.getOpcode() == ISD::FADD &&
          N1.getOperand(0) == N1.getOperand(1) &&
          N0.getOperand(0) == N1.getOperand(0)) {
        SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, N0.getOperand(1),
                                     DAG.getConstantFP(2.0, DL, VT), Flags);
        return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), NewCFP, Flags);
      }
    }

    if (N1.getOpcode() == ISD::FMUL) {
      bool CFP10 = isConstantFPBuildVectorOrConstantFP(N1.getOperand(0));
      bool CFP11 = isConstantFPBuildVectorOrConstantFP(N1.getOperand(1));

      // (fadd x, (fmul x, c)) -> (fmul x, c+1)
      if (CFP11 && !CFP10 && N1.getOperand(0) == N0) {
        SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, N1.getOperand(1),
                                     DAG.getConstantFP(1.0, DL, VT), Flags);
        return DAG.getNode(ISD::FMUL, DL, VT, N0, NewCFP, Flags);
      }

      // (fadd (fadd x, x), (fmul x, c)) -> (fmul x, c+2)
      if (CFP11 && !CFP10 && N0.getOpcode() == ISD::FADD &&
          N0.getOperand(0) == N0.getOperand(1) &&
          N1.getOperand(0) == N0.getOperand(0)) {
        SDValue NewCFP = DAG.getNode(ISD::FADD, DL, VT, N1.getOperand(1),
                                     DAG.getConstantFP(2.0, DL, VT), Flags);
        return DAG.getNode(ISD::FMUL, DL, VT, N1.getOperand(0), NewCFP, Flags);
      }
    }

    if (N0.getOpcode() == ISD::FADD && AllowNewConst) {
      bool CFP00 = isConstantFPBuildVectorOrConstantFP(N0.getOperand(0));
      // (fadd (fadd x, x), x) -> (fmul x, 3.0)
      if (!CFP00 && N0.getOperand(0) == N0.getOperand(1) &&
          (N0.getOperand(0) == N1)) {
        return DAG.getNode(ISD::FMUL, DL, VT,
                           N1, DAG.getConstantFP(3.0, DL, VT), Flags);
      }
    }

    if (N1.getOpcode() == ISD::FADD && AllowNewConst) {
      bool CFP10 = isConstantFPBuildVectorOrConstantFP(N1.getOperand(0));
      // (fadd x, (fadd x, x)) -> (fmul x, 3.0)
      if (!CFP10 && N1.getOperand(0) == N1.getOperand(1) &&
          N1.getOperand(0) == N0) {
        return DAG.getNode(ISD::FMUL, DL, VT,
                           N0, DAG.getConstantFP(3.0, DL, VT), Flags);
      }
    }

    // (fadd (fadd x, x), (fadd x, x)) -> (fmul x, 4.0)
    if (AllowNewConst &&
        N0.getOpcode() == ISD::FADD && N1.getOpcode() == ISD::FADD &&
        N0.getOperand(0) == N0.getOperand(1) &&
        N1.getOperand(0) == N1.getOperand(1) &&
        N0.getOperand(0) == N1.getOperand(0)) {
      return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0),
                         DAG.getConstantFP(4.0, DL, VT), Flags);
    }
  }
} // enable-unsafe-fp-math

// FADD -> FMA combines:
if (SDValue Fused = visitFADDForFMACombine(N)) {
  AddToWorklist(Fused.getNode());
  return Fused;
}
return SDValue();
10074}

10076SDValue DAGCombiner::visitFSUB(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

// fold (fsub c1, c2) -> c1-c2
if (N0CFP && N1CFP)
  return DAG.getNode(ISD::FSUB, DL, VT, N0, N1, Flags);

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

// fold (fsub A, (fneg B)) -> (fadd A, B)
if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
  return DAG.getNode(ISD::FADD, DL, VT, N0,
                     GetNegatedExpression(N1, DAG, LegalOperations), Flags);

// FIXME: Auto-upgrade the target/function-level option.
if (Options.NoSignedZerosFPMath  || N->getFlags().hasNoSignedZeros()) {
  // (fsub 0, B) -> -B
  if (N0CFP && N0CFP->isZero()) {
    if (isNegatibleForFree(N1, LegalOperations, TLI, &Options))
      return GetNegatedExpression(N1, DAG, LegalOperations);
    if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
      return DAG.getNode(ISD::FNEG, DL, VT, N1, Flags);
  }
}

// If 'unsafe math' is enabled, fold lots of things.
if (Options.UnsafeFPMath) {
  // (fsub A, 0) -> A
  if (N1CFP && N1CFP->isZero())
    return N0;

  // (fsub x, x) -> 0.0
  if (N0 == N1)
    return DAG.getConstantFP(0.0f, DL, VT);

  // (fsub x, (fadd x, y)) -> (fneg y)
  // (fsub x, (fadd y, x)) -> (fneg y)
  if (N1.getOpcode() == ISD::FADD) {
    SDValue N10 = N1->getOperand(0);
    SDValue N11 = N1->getOperand(1);

    if (N10 == N0 && isNegatibleForFree(N11, LegalOperations, TLI, &Options))
      return GetNegatedExpression(N11, DAG, LegalOperations);

    if (N11 == N0 && isNegatibleForFree(N10, LegalOperations, TLI, &Options))
      return GetNegatedExpression(N10, DAG, LegalOperations);
  }
}

// FSUB -> FMA combines:
if (SDValue Fused = visitFSUBForFMACombine(N)) {
  AddToWorklist(Fused.getNode());
  return Fused;
}

return SDValue();
10145}

10147SDValue DAGCombiner::visitFMUL(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
const TargetOptions &Options = DAG.getTarget().Options;
const SDNodeFlags Flags = N->getFlags();

// fold vector ops
if (VT.isVector()) {
  // This just handles C1 * C2 for vectors. Other vector folds are below.
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;
}

// fold (fmul c1, c2) -> c1*c2
if (N0CFP && N1CFP)
  return DAG.getNode(ISD::FMUL, DL, VT, N0, N1, Flags);

// canonicalize constant to RHS
if (isConstantFPBuildVectorOrConstantFP(N0) &&
   !isConstantFPBuildVectorOrConstantFP(N1))
  return DAG.getNode(ISD::FMUL, DL, VT, N1, N0, Flags);

// fold (fmul A, 1.0) -> A
if (N1CFP && N1CFP->isExactlyValue(1.0))
  return N0;

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

if (Options.UnsafeFPMath) {
  // fold (fmul A, 0) -> 0
  if (N1CFP && N1CFP->isZero())
    return N1;

  // fold (fmul (fmul x, c1), c2) -> (fmul x, (fmul c1, c2))
  if (N0.getOpcode() == ISD::FMUL) {
    // Fold scalars or any vector constants (not just splats).
    // This fold is done in general by InstCombine, but extra fmul insts
    // may have been generated during lowering.
    SDValue N00 = N0.getOperand(0);
    SDValue N01 = N0.getOperand(1);
    auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
    auto *BV00 = dyn_cast<BuildVectorSDNode>(N00);
    auto *BV01 = dyn_cast<BuildVectorSDNode>(N01);

    // Check 1: Make sure that the first operand of the inner multiply is NOT
    // a constant. Otherwise, we may induce infinite looping.
    if (!(isConstOrConstSplatFP(N00) || (BV00 && BV00->isConstant()))) {
      // Check 2: Make sure that the second operand of the inner multiply and
      // the second operand of the outer multiply are constants.
      if ((N1CFP && isConstOrConstSplatFP(N01)) ||
          (BV1 && BV01 && BV1->isConstant() && BV01->isConstant())) {
        SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, N01, N1, Flags);
        return DAG.getNode(ISD::FMUL, DL, VT, N00, MulConsts, Flags);
      }
    }
  }

  // fold (fmul (fadd x, x), c) -> (fmul x, (fmul 2.0, c))
  // Undo the fmul 2.0, x -> fadd x, x transformation, since if it occurs
  // during an early run of DAGCombiner can prevent folding with fmuls
  // inserted during lowering.
  if (N0.getOpcode() == ISD::FADD &&
      (N0.getOperand(0) == N0.getOperand(1)) &&
      N0.hasOneUse()) {
    const SDValue Two = DAG.getConstantFP(2.0, DL, VT);
    SDValue MulConsts = DAG.getNode(ISD::FMUL, DL, VT, Two, N1, Flags);
    return DAG.getNode(ISD::FMUL, DL, VT, N0.getOperand(0), MulConsts, Flags);
  }
}

// fold (fmul X, 2.0) -> (fadd X, X)
if (N1CFP && N1CFP->isExactlyValue(+2.0))
  return DAG.getNode(ISD::FADD, DL, VT, N0, N0, Flags);

// fold (fmul X, -1.0) -> (fneg X)
if (N1CFP && N1CFP->isExactlyValue(-1.0))
  if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
    return DAG.getNode(ISD::FNEG, DL, VT, N0);

// fold (fmul (fneg X), (fneg Y)) -> (fmul X, Y)
if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
  if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
    // Both can be negated for free, check to see if at least one is cheaper
    // negated.
    if (LHSNeg == 2 || RHSNeg == 2)
      return DAG.getNode(ISD::FMUL, DL, VT,
                         GetNegatedExpression(N0, DAG, LegalOperations),
                         GetNegatedExpression(N1, DAG, LegalOperations),
                         Flags);
  }
}

// fold (fmul X, (select (fcmp X > 0.0), -1.0, 1.0)) -> (fneg (fabs X))
// fold (fmul X, (select (fcmp X > 0.0), 1.0, -1.0)) -> (fabs X)
if (Flags.hasNoNaNs() && Flags.hasNoSignedZeros() &&
    (N0.getOpcode() == ISD::SELECT || N1.getOpcode() == ISD::SELECT) &&
    TLI.isOperationLegal(ISD::FABS, VT)) {
  SDValue Select = N0, X = N1;
  if (Select.getOpcode() != ISD::SELECT)
    std::swap(Select, X);

  SDValue Cond = Select.getOperand(0);
  auto TrueOpnd  = dyn_cast<ConstantFPSDNode>(Select.getOperand(1));
  auto FalseOpnd = dyn_cast<ConstantFPSDNode>(Select.getOperand(2));

  if (TrueOpnd && FalseOpnd &&
      Cond.getOpcode() == ISD::SETCC && Cond.getOperand(0) == X &&
      isa<ConstantFPSDNode>(Cond.getOperand(1)) &&
      cast<ConstantFPSDNode>(Cond.getOperand(1))->isExactlyValue(0.0)) {
    ISD::CondCode CC = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
    switch (CC) {
    default: break;
    case ISD::SETOLT:
    case ISD::SETULT:
    case ISD::SETOLE:
    case ISD::SETULE:
    case ISD::SETLT:
    case ISD::SETLE:
      std::swap(TrueOpnd, FalseOpnd);
      LLVM_FALLTHROUGH[[clang::fallthrough]];
    case ISD::SETOGT:
    case ISD::SETUGT:
    case ISD::SETOGE:
    case ISD::SETUGE:
    case ISD::SETGT:
    case ISD::SETGE:
      if (TrueOpnd->isExactlyValue(-1.0) && FalseOpnd->isExactlyValue(1.0) &&
          TLI.isOperationLegal(ISD::FNEG, VT))
        return DAG.getNode(ISD::FNEG, DL, VT,
                 DAG.getNode(ISD::FABS, DL, VT, X));
      if (TrueOpnd->isExactlyValue(1.0) && FalseOpnd->isExactlyValue(-1.0))
        return DAG.getNode(ISD::FABS, DL, VT, X);

      break;
    }
  }
}

// FMUL -> FMA combines:
if (SDValue Fused = visitFMULForFMADistributiveCombine(N)) {
  AddToWorklist(Fused.getNode());
  return Fused;
}

return SDValue();
10297}

10299SDValue DAGCombiner::visitFMA(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
const TargetOptions &Options = DAG.getTarget().Options;

// Constant fold FMA.
if (isa<ConstantFPSDNode>(N0) &&
    isa<ConstantFPSDNode>(N1) &&
    isa<ConstantFPSDNode>(N2)) {
  return DAG.getNode(ISD::FMA, DL, VT, N0, N1, N2);
}

if (Options.UnsafeFPMath) {
  if (N0CFP && N0CFP->isZero())
    return N2;
  if (N1CFP && N1CFP->isZero())
    return N2;
}
// TODO: The FMA node should have flags that propagate to these nodes.
if (N0CFP && N0CFP->isExactlyValue(1.0))
  return DAG.getNode(ISD::FADD, SDLoc(N), VT, N1, N2);
if (N1CFP && N1CFP->isExactlyValue(1.0))
  return DAG.getNode(ISD::FADD, SDLoc(N), VT, N0, N2);

// Canonicalize (fma c, x, y) -> (fma x, c, y)
if (isConstantFPBuildVectorOrConstantFP(N0) &&
   !isConstantFPBuildVectorOrConstantFP(N1))
  return DAG.getNode(ISD::FMA, SDLoc(N), VT, N1, N0, N2);

// TODO: FMA nodes should have flags that propagate to the created nodes.
// For now, create a Flags object for use with all unsafe math transforms.
SDNodeFlags Flags;
Flags.setUnsafeAlgebra(true);

if (Options.UnsafeFPMath) {
  // (fma x, c1, (fmul x, c2)) -> (fmul x, c1+c2)
  if (N2.getOpcode() == ISD::FMUL && N0 == N2.getOperand(0) &&
      isConstantFPBuildVectorOrConstantFP(N1) &&
      isConstantFPBuildVectorOrConstantFP(N2.getOperand(1))) {
    return DAG.getNode(ISD::FMUL, DL, VT, N0,
                       DAG.getNode(ISD::FADD, DL, VT, N1, N2.getOperand(1),
                                   Flags), Flags);
  }

  // (fma (fmul x, c1), c2, y) -> (fma x, c1*c2, y)
  if (N0.getOpcode() == ISD::FMUL &&
      isConstantFPBuildVectorOrConstantFP(N1) &&
      isConstantFPBuildVectorOrConstantFP(N0.getOperand(1))) {
    return DAG.getNode(ISD::FMA, DL, VT,
                       N0.getOperand(0),
                       DAG.getNode(ISD::FMUL, DL, VT, N1, N0.getOperand(1),
                                   Flags),
                       N2);
  }
}

// (fma x, 1, y) -> (fadd x, y)
// (fma x, -1, y) -> (fadd (fneg x), y)
if (N1CFP) {
  if (N1CFP->isExactlyValue(1.0))
    // TODO: The FMA node should have flags that propagate to this node.
    return DAG.getNode(ISD::FADD, DL, VT, N0, N2);

  if (N1CFP->isExactlyValue(-1.0) &&
      (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))) {
    SDValue RHSNeg = DAG.getNode(ISD::FNEG, DL, VT, N0);
    AddToWorklist(RHSNeg.getNode());
    // TODO: The FMA node should have flags that propagate to this node.
    return DAG.getNode(ISD::FADD, DL, VT, N2, RHSNeg);
  }

  // fma (fneg x), K, y -> fma x -K, y
  if (N0.getOpcode() == ISD::FNEG &&
      (TLI.isOperationLegal(ISD::ConstantFP, VT) ||
       (N1.hasOneUse() && !TLI.isFPImmLegal(N1CFP->getValueAPF(), VT)))) {
    return DAG.getNode(ISD::FMA, DL, VT, N0.getOperand(0),
                       DAG.getNode(ISD::FNEG, DL, VT, N1, Flags), N2);
  }
}

if (Options.UnsafeFPMath) {
  // (fma x, c, x) -> (fmul x, (c+1))
  if (N1CFP && N0 == N2) {
    return DAG.getNode(ISD::FMUL, DL, VT, N0,
                       DAG.getNode(ISD::FADD, DL, VT, N1,
                                   DAG.getConstantFP(1.0, DL, VT), Flags),
                       Flags);
  }

  // (fma x, c, (fneg x)) -> (fmul x, (c-1))
  if (N1CFP && N2.getOpcode() == ISD::FNEG && N2.getOperand(0) == N0) {
    return DAG.getNode(ISD::FMUL, DL, VT, N0,
                       DAG.getNode(ISD::FADD, DL, VT, N1,
                                   DAG.getConstantFP(-1.0, DL, VT), Flags),
                       Flags);
  }
}

return SDValue();
10403}

10405// Combine multiple FDIVs with the same divisor into multiple FMULs by the
10406// reciprocal.
10407// E.g., (a / D; b / D;) -> (recip = 1.0 / D; a * recip; b * recip)
10408// Notice that this is not always beneficial. One reason is different targets
10409// may have different costs for FDIV and FMUL, so sometimes the cost of two
10410// FDIVs may be lower than the cost of one FDIV and two FMULs. Another reason
10411// is the critical path is increased from "one FDIV" to "one FDIV + one FMUL".
10412SDValue DAGCombiner::combineRepeatedFPDivisors(SDNode *N) {
bool UnsafeMath = DAG.getTarget().Options.UnsafeFPMath;
const SDNodeFlags Flags = N->getFlags();
if (!UnsafeMath && !Flags.hasAllowReciprocal())
  return SDValue();

// Skip if current node is a reciprocal.
SDValue N0 = N->getOperand(0);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
if (N0CFP && N0CFP->isExactlyValue(1.0))
  return SDValue();

// Exit early if the target does not want this transform or if there can't
// possibly be enough uses of the divisor to make the transform worthwhile.
SDValue N1 = N->getOperand(1);
unsigned MinUses = TLI.combineRepeatedFPDivisors();
if (!MinUses || N1->use_size() < MinUses)
  return SDValue();

// Find all FDIV users of the same divisor.
// Use a set because duplicates may be present in the user list.
SetVector<SDNode *> Users;
for (auto *U : N1->uses()) {
  if (U->getOpcode() == ISD::FDIV && U->getOperand(1) == N1) {
    // This division is eligible for optimization only if global unsafe math
    // is enabled or if this division allows reciprocal formation.
    if (UnsafeMath || U->getFlags().hasAllowReciprocal())
      Users.insert(U);
  }
}

// Now that we have the actual number of divisor uses, make sure it meets
// the minimum threshold specified by the target.
if (Users.size() < MinUses)
  return SDValue();

EVT VT = N->getValueType(0);
SDLoc DL(N);
SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);
SDValue Reciprocal = DAG.getNode(ISD::FDIV, DL, VT, FPOne, N1, Flags);

// Dividend / Divisor -> Dividend * Reciprocal
for (auto *U : Users) {
  SDValue Dividend = U->getOperand(0);
  if (Dividend != FPOne) {
    SDValue NewNode = DAG.getNode(ISD::FMUL, SDLoc(U), VT, Dividend,
                                  Reciprocal, Flags);
    CombineTo(U, NewNode);
  } else if (U != Reciprocal.getNode()) {
    // In the absence of fast-math-flags, this user node is always the
    // same node as Reciprocal, but with FMF they may be different nodes.
    CombineTo(U, Reciprocal);
  }
}
return SDValue(N, 0);  // N was replaced.
10467}

10469SDValue DAGCombiner::visitFDIV(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);
SDLoc DL(N);
const TargetOptions &Options = DAG.getTarget().Options;
SDNodeFlags Flags = N->getFlags();

// fold vector ops
if (VT.isVector())
  if (SDValue FoldedVOp = SimplifyVBinOp(N))
    return FoldedVOp;

// fold (fdiv c1, c2) -> c1/c2
if (N0CFP && N1CFP)
  return DAG.getNode(ISD::FDIV, SDLoc(N), VT, N0, N1, Flags);

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

if (Options.UnsafeFPMath) {
  // fold (fdiv X, c2) -> fmul X, 1/c2 if losing precision is acceptable.
  if (N1CFP) {
    // Compute the reciprocal 1.0 / c2.
    const APFloat &N1APF = N1CFP->getValueAPF();
    APFloat Recip(N1APF.getSemantics(), 1); // 1.0
    APFloat::opStatus st = Recip.divide(N1APF, APFloat::rmNearestTiesToEven);
    // Only do the transform if the reciprocal is a legal fp immediate that
    // isn't too nasty (eg NaN, denormal, ...).
    if ((st == APFloat::opOK || st == APFloat::opInexact) && // Not too nasty
        (!LegalOperations ||
         // FIXME: custom lowering of ConstantFP might fail (see e.g. ARM
         // backend)... we should handle this gracefully after Legalize.
         // TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT) ||
         TLI.isOperationLegal(ISD::ConstantFP, VT) ||
         TLI.isFPImmLegal(Recip, VT)))
      return DAG.getNode(ISD::FMUL, DL, VT, N0,
                         DAG.getConstantFP(Recip, DL, VT), Flags);
  }

  // If this FDIV is part of a reciprocal square root, it may be folded
  // into a target-specific square root estimate instruction.
  if (N1.getOpcode() == ISD::FSQRT) {
    if (SDValue RV = buildRsqrtEstimate(N1.getOperand(0), Flags)) {
      return DAG.getNode(ISD::FMUL, DL, VT, N0, RV, Flags);
    }
  } else if (N1.getOpcode() == ISD::FP_EXTEND &&
             N1.getOperand(0).getOpcode() == ISD::FSQRT) {
    if (SDValue RV = buildRsqrtEstimate(N1.getOperand(0).getOperand(0),
                                        Flags)) {
      RV = DAG.getNode(ISD::FP_EXTEND, SDLoc(N1), VT, RV);
      AddToWorklist(RV.getNode());
      return DAG.getNode(ISD::FMUL, DL, VT, N0, RV, Flags);
    }
  } else if (N1.getOpcode() == ISD::FP_ROUND &&
             N1.getOperand(0).getOpcode() == ISD::FSQRT) {
    if (SDValue RV = buildRsqrtEstimate(N1.getOperand(0).getOperand(0),
                                        Flags)) {
      RV = DAG.getNode(ISD::FP_ROUND, SDLoc(N1), VT, RV, N1.getOperand(1));
      AddToWorklist(RV.getNode());
      return DAG.getNode(ISD::FMUL, DL, VT, N0, RV, Flags);
    }
  } else if (N1.getOpcode() == ISD::FMUL) {
    // Look through an FMUL. Even though this won't remove the FDIV directly,
    // it's still worthwhile to get rid of the FSQRT if possible.
    SDValue SqrtOp;
    SDValue OtherOp;
    if (N1.getOperand(0).getOpcode() == ISD::FSQRT) {
      SqrtOp = N1.getOperand(0);
      OtherOp = N1.getOperand(1);
    } else if (N1.getOperand(1).getOpcode() == ISD::FSQRT) {
      SqrtOp = N1.getOperand(1);
      OtherOp = N1.getOperand(0);
    }
    if (SqrtOp.getNode()) {
      // We found a FSQRT, so try to make this fold:
      // x / (y * sqrt(z)) -> x * (rsqrt(z) / y)
      if (SDValue RV = buildRsqrtEstimate(SqrtOp.getOperand(0), Flags)) {
        RV = DAG.getNode(ISD::FDIV, SDLoc(N1), VT, RV, OtherOp, Flags);
        AddToWorklist(RV.getNode());
        return DAG.getNode(ISD::FMUL, DL, VT, N0, RV, Flags);
      }
    }
  }

  // Fold into a reciprocal estimate and multiply instead of a real divide.
  if (SDValue RV = BuildReciprocalEstimate(N1, Flags)) {
    AddToWorklist(RV.getNode());
    return DAG.getNode(ISD::FMUL, DL, VT, N0, RV, Flags);
  }
}

// (fdiv (fneg X), (fneg Y)) -> (fdiv X, Y)
if (char LHSNeg = isNegatibleForFree(N0, LegalOperations, TLI, &Options)) {
  if (char RHSNeg = isNegatibleForFree(N1, LegalOperations, TLI, &Options)) {
    // Both can be negated for free, check to see if at least one is cheaper
    // negated.
    if (LHSNeg == 2 || RHSNeg == 2)
      return DAG.getNode(ISD::FDIV, SDLoc(N), VT,
                         GetNegatedExpression(N0, DAG, LegalOperations),
                         GetNegatedExpression(N1, DAG, LegalOperations),
                         Flags);
  }
}

if (SDValue CombineRepeatedDivisors = combineRepeatedFPDivisors(N))
  return CombineRepeatedDivisors;

return SDValue();
10580}

10582SDValue DAGCombiner::visitFREM(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);

// fold (frem c1, c2) -> fmod(c1,c2)
if (N0CFP && N1CFP)
  return DAG.getNode(ISD::FREM, SDLoc(N), VT, N0, N1, N->getFlags());

if (SDValue NewSel = foldBinOpIntoSelect(N))
  return NewSel;

return SDValue();
10597}

10599SDValue DAGCombiner::visitFSQRT(SDNode *N) {
if (!DAG.getTarget().Options.UnsafeFPMath)
  return SDValue();

SDValue N0 = N->getOperand(0);
if (TLI.isFsqrtCheap(N0, DAG))
  return SDValue();

// TODO: FSQRT nodes should have flags that propagate to the created nodes.
// For now, create a Flags object for use with all unsafe math transforms.
SDNodeFlags Flags;
Flags.setUnsafeAlgebra(true);
return buildSqrtEstimate(N0, Flags);
10612}

10614/// copysign(x, fp_extend(y)) -> copysign(x, y)
10615/// copysign(x, fp_round(y)) -> copysign(x, y)
10616static inline bool CanCombineFCOPYSIGN_EXTEND_ROUND(SDNode *N) {
SDValue N1 = N->getOperand(1);
if ((N1.getOpcode() == ISD::FP_EXTEND ||
     N1.getOpcode() == ISD::FP_ROUND)) {
  // Do not optimize out type conversion of f128 type yet.
  // For some targets like x86_64, configuration is changed to keep one f128
  // value in one SSE register, but instruction selection cannot handle
  // FCOPYSIGN on SSE registers yet.
  EVT N1VT = N1->getValueType(0);
  EVT N1Op0VT = N1->getOperand(0).getValueType();
  return (N1VT == N1Op0VT || N1Op0VT != MVT::f128);
}
return false;
10629}

10631SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1);
EVT VT = N->getValueType(0);

if (N0CFP && N1CFP) // Constant fold
  return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1);

if (N1CFP) {
  const APFloat &V = N1CFP->getValueAPF();
  // copysign(x, c1) -> fabs(x)       iff ispos(c1)
  // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1)
  if (!V.isNegative()) {
    if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT))
      return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);
  } else {
    if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT))
      return DAG.getNode(ISD::FNEG, SDLoc(N), VT,
                         DAG.getNode(ISD::FABS, SDLoc(N0), VT, N0));
  }
}

// copysign(fabs(x), y) -> copysign(x, y)
// copysign(fneg(x), y) -> copysign(x, y)
// copysign(copysign(x,z), y) -> copysign(x, y)
if (N0.getOpcode() == ISD::FABS || N0.getOpcode() == ISD::FNEG ||
    N0.getOpcode() == ISD::FCOPYSIGN)
  return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0.getOperand(0), N1);

// copysign(x, abs(y)) -> abs(x)
if (N1.getOpcode() == ISD::FABS)
  return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);

// copysign(x, copysign(y,z)) -> copysign(x, z)
if (N1.getOpcode() == ISD::FCOPYSIGN)
  return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1.getOperand(1));

// copysign(x, fp_extend(y)) -> copysign(x, y)
// copysign(x, fp_round(y)) -> copysign(x, y)
if (CanCombineFCOPYSIGN_EXTEND_ROUND(N))
  return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT, N0, N1.getOperand(0));

return SDValue();
10676}

10678SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
EVT OpVT = N0.getValueType();

// fold (sint_to_fp c1) -> c1fp
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
    // ...but only if the target supports immediate floating-point values
    (!LegalOperations ||
     TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT)))
  return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);

// If the input is a legal type, and SINT_TO_FP is not legal on this target,
// but UINT_TO_FP is legal on this target, try to convert.
if (!TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT) &&
    TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT)) {
  // If the sign bit is known to be zero, we can change this to UINT_TO_FP.
  if (DAG.SignBitIsZero(N0))
    return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);
}

// The next optimizations are desirable only if SELECT_CC can be lowered.
if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
  // fold (sint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
  if (N0.getOpcode() == ISD::SETCC && N0.getValueType() == MVT::i1 &&
      !VT.isVector() &&
      (!LegalOperations ||
       TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT))) {
    SDLoc DL(N);
    SDValue Ops[] =
      { N0.getOperand(0), N0.getOperand(1),
        DAG.getConstantFP(-1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
        N0.getOperand(2) };
    return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
  }

  // fold (sint_to_fp (zext (setcc x, y, cc))) ->
  //      (select_cc x, y, 1.0, 0.0,, cc)
  if (N0.getOpcode() == ISD::ZERO_EXTEND &&
      N0.getOperand(0).getOpcode() == ISD::SETCC &&!VT.isVector() &&
      (!LegalOperations ||
       TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT))) {
    SDLoc DL(N);
    SDValue Ops[] =
      { N0.getOperand(0).getOperand(0), N0.getOperand(0).getOperand(1),
        DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
        N0.getOperand(0).getOperand(2) };
    return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
  }
}

return SDValue();
10730}

10732SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
EVT OpVT = N0.getValueType();

// fold (uint_to_fp c1) -> c1fp
if (DAG.isConstantIntBuildVectorOrConstantInt(N0) &&
    // ...but only if the target supports immediate floating-point values
    (!LegalOperations ||
     TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT)))
  return DAG.getNode(ISD::UINT_TO_FP, SDLoc(N), VT, N0);

// If the input is a legal type, and UINT_TO_FP is not legal on this target,
// but SINT_TO_FP is legal on this target, try to convert.
if (!TLI.isOperationLegalOrCustom(ISD::UINT_TO_FP, OpVT) &&
    TLI.isOperationLegalOrCustom(ISD::SINT_TO_FP, OpVT)) {
  // If the sign bit is known to be zero, we can change this to SINT_TO_FP.
  if (DAG.SignBitIsZero(N0))
    return DAG.getNode(ISD::SINT_TO_FP, SDLoc(N), VT, N0);
}

// The next optimizations are desirable only if SELECT_CC can be lowered.
if (TLI.isOperationLegalOrCustom(ISD::SELECT_CC, VT) || !LegalOperations) {
  // fold (uint_to_fp (setcc x, y, cc)) -> (select_cc x, y, -1.0, 0.0,, cc)
  if (N0.getOpcode() == ISD::SETCC && !VT.isVector() &&
      (!LegalOperations ||
       TLI.isOperationLegalOrCustom(ISD::ConstantFP, VT))) {
    SDLoc DL(N);
    SDValue Ops[] =
      { N0.getOperand(0), N0.getOperand(1),
        DAG.getConstantFP(1.0, DL, VT), DAG.getConstantFP(0.0, DL, VT),
        N0.getOperand(2) };
    return DAG.getNode(ISD::SELECT_CC, DL, VT, Ops);
  }
}

return SDValue();
10769}

10771// Fold (fp_to_{s/u}int ({s/u}int_to_fpx)) -> zext x, sext x, trunc x, or x
10772static SDValue FoldIntToFPToInt(SDNode *N, SelectionDAG &DAG) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

if (N0.getOpcode() != ISD::UINT_TO_FP && N0.getOpcode() != ISD::SINT_TO_FP)
  return SDValue();

SDValue Src = N0.getOperand(0);
EVT SrcVT = Src.getValueType();
bool IsInputSigned = N0.getOpcode() == ISD::SINT_TO_FP;
bool IsOutputSigned = N->getOpcode() == ISD::FP_TO_SINT;

// We can safely assume the conversion won't overflow the output range,
// because (for example) (uint8_t)18293.f is undefined behavior.

// Since we can assume the conversion won't overflow, our decision as to
// whether the input will fit in the float should depend on the minimum
// of the input range and output range.

// This means this is also safe for a signed input and unsigned output, since
// a negative input would lead to undefined behavior.
unsigned InputSize = (int)SrcVT.getScalarSizeInBits() - IsInputSigned;
unsigned OutputSize = (int)VT.getScalarSizeInBits() - IsOutputSigned;
unsigned ActualSize = std::min(InputSize, OutputSize);
const fltSemantics &sem = DAG.EVTToAPFloatSemantics(N0.getValueType());

// We can only fold away the float conversion if the input range can be
// represented exactly in the float range.
if (APFloat::semanticsPrecision(sem) >= ActualSize) {
  if (VT.getScalarSizeInBits() > SrcVT.getScalarSizeInBits()) {
    unsigned ExtOp = IsInputSigned && IsOutputSigned ? ISD::SIGN_EXTEND
                                                     : ISD::ZERO_EXTEND;
    return DAG.getNode(ExtOp, SDLoc(N), VT, Src);
  }
  if (VT.getScalarSizeInBits() < SrcVT.getScalarSizeInBits())
    return DAG.getNode(ISD::TRUNCATE, SDLoc(N), VT, Src);
  return DAG.getBitcast(VT, Src);
}
return SDValue();
10811}

10813SDValue DAGCombiner::visitFP_TO_SINT(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (fp_to_sint c1fp) -> c1
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FP_TO_SINT, SDLoc(N), VT, N0);

return FoldIntToFPToInt(N, DAG);
10822}

10824SDValue DAGCombiner::visitFP_TO_UINT(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (fp_to_uint c1fp) -> c1
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FP_TO_UINT, SDLoc(N), VT, N0);

return FoldIntToFPToInt(N, DAG);
10833}

10835SDValue DAGCombiner::visitFP_ROUND(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
EVT VT = N->getValueType(0);

// fold (fp_round c1fp) -> c1fp
if (N0CFP)
  return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT, N0, N1);

// fold (fp_round (fp_extend x)) -> x
if (N0.getOpcode() == ISD::FP_EXTEND && VT == N0.getOperand(0).getValueType())
  return N0.getOperand(0);

// fold (fp_round (fp_round x)) -> (fp_round x)
if (N0.getOpcode() == ISD::FP_ROUND) {
  const bool NIsTrunc = N->getConstantOperandVal(1) == 1;
  const bool N0IsTrunc = N0.getConstantOperandVal(1) == 1;

  // Skip this folding if it results in an fp_round from f80 to f16.
  //
  // f80 to f16 always generates an expensive (and as yet, unimplemented)
  // libcall to __truncxfhf2 instead of selecting native f16 conversion
  // instructions from f32 or f64.  Moreover, the first (value-preserving)
  // fp_round from f80 to either f32 or f64 may become a NOP in platforms like
  // x86.
  if (N0.getOperand(0).getValueType() == MVT::f80 && VT == MVT::f16)
    return SDValue();

  // If the first fp_round isn't a value preserving truncation, it might
  // introduce a tie in the second fp_round, that wouldn't occur in the
  // single-step fp_round we want to fold to.
  // In other words, double rounding isn't the same as rounding.
  // Also, this is a value preserving truncation iff both fp_round's are.
  if (DAG.getTarget().Options.UnsafeFPMath || N0IsTrunc) {
    SDLoc DL(N);
    return DAG.getNode(ISD::FP_ROUND, DL, VT, N0.getOperand(0),
                       DAG.getIntPtrConstant(NIsTrunc && N0IsTrunc, DL));
  }
}

// fold (fp_round (copysign X, Y)) -> (copysign (fp_round X), Y)
if (N0.getOpcode() == ISD::FCOPYSIGN && N0.getNode()->hasOneUse()) {
  SDValue Tmp = DAG.getNode(ISD::FP_ROUND, SDLoc(N0), VT,
                            N0.getOperand(0), N1);
  AddToWorklist(Tmp.getNode());
  return DAG.getNode(ISD::FCOPYSIGN, SDLoc(N), VT,
                     Tmp, N0.getOperand(1));
}

if (SDValue NewVSel = matchVSelectOpSizesWithSetCC(N))
  return NewVSel;

return SDValue();
10889}

10891SDValue DAGCombiner::visitFP_ROUND_INREG(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);
EVT EVT = cast<VTSDNode>(N->getOperand(1))->getVT();
ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);

// fold (fp_round_inreg c1fp) -> c1fp
if (N0CFP && isTypeLegal(EVT)) {
  SDLoc DL(N);
  SDValue Round = DAG.getConstantFP(*N0CFP->getConstantFPValue(), DL, EVT);
  return DAG.getNode(ISD::FP_EXTEND, DL, VT, Round);
}

return SDValue();
10905}

10907SDValue DAGCombiner::visitFP_EXTEND(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
if (N->hasOneUse() &&
    N->use_begin()->getOpcode() == ISD::FP_ROUND)
  return SDValue();

// fold (fp_extend c1fp) -> c1fp
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, N0);

// fold (fp_extend (fp16_to_fp op)) -> (fp16_to_fp op)
if (N0.getOpcode() == ISD::FP16_TO_FP &&
    TLI.getOperationAction(ISD::FP16_TO_FP, VT) == TargetLowering::Legal)
  return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), VT, N0.getOperand(0));

// Turn fp_extend(fp_round(X, 1)) -> x since the fp_round doesn't affect the
// value of X.
if (N0.getOpcode() == ISD::FP_ROUND
    && N0.getConstantOperandVal(1) == 1) {
  SDValue In = N0.getOperand(0);
  if (In.getValueType() == VT) return In;
  if (VT.bitsLT(In.getValueType()))
    return DAG.getNode(ISD::FP_ROUND, SDLoc(N), VT,
                       In, N0.getOperand(1));
  return DAG.getNode(ISD::FP_EXTEND, SDLoc(N), VT, In);
}

// fold (fpext (load x)) -> (fpext (fptrunc (extload x)))
if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
     TLI.isLoadExtLegal(ISD::EXTLOAD, VT, N0.getValueType())) {
  LoadSDNode *LN0 = cast<LoadSDNode>(N0);
  SDValue ExtLoad = DAG.getExtLoad(ISD::EXTLOAD, SDLoc(N), VT,
                                   LN0->getChain(),
                                   LN0->getBasePtr(), N0.getValueType(),
                                   LN0->getMemOperand());
  CombineTo(N, ExtLoad);
  CombineTo(N0.getNode(),
            DAG.getNode(ISD::FP_ROUND, SDLoc(N0),
                        N0.getValueType(), ExtLoad,
                        DAG.getIntPtrConstant(1, SDLoc(N0))),
            ExtLoad.getValue(1));
  return SDValue(N, 0);   // Return N so it doesn't get rechecked!
}

if (SDValue NewVSel = matchVSelectOpSizesWithSetCC(N))
  return NewVSel;

return SDValue();
10958}

10960SDValue DAGCombiner::visitFCEIL(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (fceil c1) -> fceil(c1)
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FCEIL, SDLoc(N), VT, N0);

return SDValue();
10969}

10971SDValue DAGCombiner::visitFTRUNC(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (ftrunc c1) -> ftrunc(c1)
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0);

// fold ftrunc (known rounded int x) -> x
// ftrunc is a part of fptosi/fptoui expansion on some targets, so this is
// likely to be generated to extract integer from a rounded floating value.
switch (N0.getOpcode()) {
default: break;
case ISD::FRINT:
case ISD::FTRUNC:
case ISD::FNEARBYINT:
case ISD::FFLOOR:
case ISD::FCEIL:
  return N0;
}

return SDValue();
10993}

10995SDValue DAGCombiner::visitFFLOOR(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (ffloor c1) -> ffloor(c1)
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FFLOOR, SDLoc(N), VT, N0);

return SDValue();
11004}

11006// FIXME: FNEG and FABS have a lot in common; refactor.
11007SDValue DAGCombiner::visitFNEG(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// Constant fold FNEG.
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0);

if (isNegatibleForFree(N0, LegalOperations, DAG.getTargetLoweringInfo(),
                       &DAG.getTarget().Options))
  return GetNegatedExpression(N0, DAG, LegalOperations);

// Transform fneg(bitconvert(x)) -> bitconvert(x ^ sign) to avoid loading
// constant pool values.
if (!TLI.isFNegFree(VT) &&
    N0.getOpcode() == ISD::BITCAST &&
    N0.getNode()->hasOneUse()) {
  SDValue Int = N0.getOperand(0);
  EVT IntVT = Int.getValueType();
  if (IntVT.isInteger() && !IntVT.isVector()) {
    APInt SignMask;
    if (N0.getValueType().isVector()) {
      // For a vector, get a mask such as 0x80... per scalar element
      // and splat it.
      SignMask = APInt::getSignMask(N0.getScalarValueSizeInBits());
      SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
    } else {
      // For a scalar, just generate 0x80...
      SignMask = APInt::getSignMask(IntVT.getSizeInBits());
    }
    SDLoc DL0(N0);
    Int = DAG.getNode(ISD::XOR, DL0, IntVT, Int,
                      DAG.getConstant(SignMask, DL0, IntVT));
    AddToWorklist(Int.getNode());
    return DAG.getBitcast(VT, Int);
  }
}

// (fneg (fmul c, x)) -> (fmul -c, x)
if (N0.getOpcode() == ISD::FMUL &&
    (N0.getNode()->hasOneUse() || !TLI.isFNegFree(VT))) {
  ConstantFPSDNode *CFP1 = dyn_cast<ConstantFPSDNode>(N0.getOperand(1));
  if (CFP1) {
    APFloat CVal = CFP1->getValueAPF();
    CVal.changeSign();
    if (Level >= AfterLegalizeDAG &&
        (TLI.isFPImmLegal(CVal, VT) ||
         TLI.isOperationLegal(ISD::ConstantFP, VT)))
      return DAG.getNode(
          ISD::FMUL, SDLoc(N), VT, N0.getOperand(0),
          DAG.getNode(ISD::FNEG, SDLoc(N), VT, N0.getOperand(1)),
          N0->getFlags());
  }
}

return SDValue();
11063}

11065SDValue DAGCombiner::visitFMINNUM(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
const ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
const ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);

if (N0CFP && N1CFP) {
  const APFloat &C0 = N0CFP->getValueAPF();
  const APFloat &C1 = N1CFP->getValueAPF();
  return DAG.getConstantFP(minnum(C0, C1), SDLoc(N), VT);
}

// Canonicalize to constant on RHS.
if (isConstantFPBuildVectorOrConstantFP(N0) &&
   !isConstantFPBuildVectorOrConstantFP(N1))
  return DAG.getNode(ISD::FMINNUM, SDLoc(N), VT, N1, N0);

return SDValue();
11084}

11086SDValue DAGCombiner::visitFMAXNUM(SDNode *N) {
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
EVT VT = N->getValueType(0);
const ConstantFPSDNode *N0CFP = isConstOrConstSplatFP(N0);
const ConstantFPSDNode *N1CFP = isConstOrConstSplatFP(N1);

if (N0CFP && N1CFP) {
  const APFloat &C0 = N0CFP->getValueAPF();
  const APFloat &C1 = N1CFP->getValueAPF();
  return DAG.getConstantFP(maxnum(C0, C1), SDLoc(N), VT);
}

// Canonicalize to constant on RHS.
if (isConstantFPBuildVectorOrConstantFP(N0) &&
   !isConstantFPBuildVectorOrConstantFP(N1))
  return DAG.getNode(ISD::FMAXNUM, SDLoc(N), VT, N1, N0);

return SDValue();
11105}

11107SDValue DAGCombiner::visitFABS(SDNode *N) {
SDValue N0 = N->getOperand(0);
EVT VT = N->getValueType(0);

// fold (fabs c1) -> fabs(c1)
if (isConstantFPBuildVectorOrConstantFP(N0))
  return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0);

// fold (fabs (fabs x)) -> (fabs x)
if (N0.getOpcode() == ISD::FABS)
  return N->getOperand(0);

// fold (fabs (fneg x)) -> (fabs x)
// fold (fabs (fcopysign x, y)) -> (fabs x)
if (N0.getOpcode() == ISD::FNEG || N0.getOpcode() == ISD::FCOPYSIGN)
  return DAG.getNode(ISD::FABS, SDLoc(N), VT, N0.getOperand(0));

// Transform fabs(bitconvert(x)) -> bitconvert(x & ~sign) to avoid loading
// constant pool values.
if (!TLI.isFAbsFree(VT) &&
    N0.getOpcode() == ISD::BITCAST &&
    N0.getNode()->hasOneUse()) {
  SDValue Int = N0.getOperand(0);
  EVT IntVT = Int.getValueType();
  if (IntVT.isInteger() && !IntVT.isVector()) {
    APInt SignMask;
    if (N0.getValueType().isVector()) {
      // For a vector, get a mask such as 0x7f... per scalar element
      // and splat it.
      SignMask = ~APInt::getSignMask(N0.getScalarValueSizeInBits());
      SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask);
    } else {
      // For a scalar, just generate 0x7f...
      SignMask = ~APInt::getSignMask(IntVT.getSizeInBits());
    }
    SDLoc DL(N0);
    Int = DAG.getNode(ISD::AND, DL, IntVT, Int,
                      DAG.getConstant(SignMask, DL, IntVT));
    AddToWorklist(Int.getNode());
    return DAG.getBitcast(N->getValueType(0), Int);
  }
}

return SDValue();
11151}

11153SDValue DAGCombiner::visitBRCOND(SDNode *N) {
SDValue Chain = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);

// If N is a constant we could fold this into a fallthrough or unconditional
// branch. However that doesn't happen very often in normal code, because
// Instcombine/SimplifyCFG should have handled the available opportunities.
// If we did this folding here, it would be necessary to update the
// MachineBasicBlock CFG, which is awkward.

// fold a brcond with a setcc condition into a BR_CC node if BR_CC is legal
// on the target.
if (N1.getOpcode() == ISD::SETCC &&
    TLI.isOperationLegalOrCustom(ISD::BR_CC,
                                 N1.getOperand(0).getValueType())) {
  return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
                     Chain, N1.getOperand(2),
                     N1.getOperand(0), N1.getOperand(1), N2);
}

if ((N1.hasOneUse() && N1.getOpcode() == ISD::SRL) ||
    ((N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) &&
     (N1.getOperand(0).hasOneUse() &&
      N1.getOperand(0).getOpcode() == ISD::SRL))) {
  SDNode *Trunc = nullptr;
  if (N1.getOpcode() == ISD::TRUNCATE) {
    // Look pass the truncate.
    Trunc = N1.getNode();
    N1 = N1.getOperand(0);
  }

  // Match this pattern so that we can generate simpler code:
  //
  //   %a = ...
  //   %b = and i32 %a, 2
  //   %c = srl i32 %b, 1
  //   brcond i32 %c ...
  //
  // into
  //
  //   %a = ...
  //   %b = and i32 %a, 2
  //   %c = setcc eq %b, 0
  //   brcond %c ...
  //
  // This applies only when the AND constant value has one bit set and the
  // SRL constant is equal to the log2 of the AND constant. The back-end is
  // smart enough to convert the result into a TEST/JMP sequence.
  SDValue Op0 = N1.getOperand(0);
  SDValue Op1 = N1.getOperand(1);

  if (Op0.getOpcode() == ISD::AND &&
      Op1.getOpcode() == ISD::Constant) {
    SDValue AndOp1 = Op0.getOperand(1);

    if (AndOp1.getOpcode() == ISD::Constant) {
      const APInt &AndConst = cast<ConstantSDNode>(AndOp1)->getAPIntValue();

      if (AndConst.isPowerOf2() &&
          cast<ConstantSDNode>(Op1)->getAPIntValue()==AndConst.logBase2()) {
        SDLoc DL(N);
        SDValue SetCC =
          DAG.getSetCC(DL,
                       getSetCCResultType(Op0.getValueType()),
                       Op0, DAG.getConstant(0, DL, Op0.getValueType()),
                       ISD::SETNE);

        SDValue NewBRCond = DAG.getNode(ISD::BRCOND, DL,
                                        MVT::Other, Chain, SetCC, N2);
        // Don't add the new BRCond into the worklist or else SimplifySelectCC
        // will convert it back to (X & C1) >> C2.
        CombineTo(N, NewBRCond, false);
        // Truncate is dead.
        if (Trunc)
          deleteAndRecombine(Trunc);
        // Replace the uses of SRL with SETCC
        WorklistRemover DeadNodes(*this);
        DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
        deleteAndRecombine(N1.getNode());
        return SDValue(N, 0);   // Return N so it doesn't get rechecked!
      }
    }
  }

  if (Trunc)
    // Restore N1 if the above transformation doesn't match.
    N1 = N->getOperand(1);
}

// Transform br(xor(x, y)) -> br(x != y)
// Transform br(xor(xor(x,y), 1)) -> br (x == y)
if (N1.hasOneUse() && N1.getOpcode() == ISD::XOR) {
  SDNode *TheXor = N1.getNode();
  SDValue Op0 = TheXor->getOperand(0);
  SDValue Op1 = TheXor->getOperand(1);
  if (Op0.getOpcode() == Op1.getOpcode()) {
    // Avoid missing important xor optimizations.
    if (SDValue Tmp = visitXOR(TheXor)) {
      if (Tmp.getNode() != TheXor) {
        DEBUG(dbgs() << "\nReplacing.8 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.8 "; TheXor->
dump(&DAG); dbgs() << "\nWith: "; Tmp.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
              TheXor->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.8 "; TheXor->
dump(&DAG); dbgs() << "\nWith: "; Tmp.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
              dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.8 "; TheXor->
dump(&DAG); dbgs() << "\nWith: "; Tmp.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
              Tmp.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.8 "; TheXor->
dump(&DAG); dbgs() << "\nWith: "; Tmp.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
              dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.8 "; TheXor->
dump(&DAG); dbgs() << "\nWith: "; Tmp.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false);
        WorklistRemover DeadNodes(*this);
        DAG.ReplaceAllUsesOfValueWith(N1, Tmp);
        deleteAndRecombine(TheXor);
        return DAG.getNode(ISD::BRCOND, SDLoc(N),
                           MVT::Other, Chain, Tmp, N2);
      }

      // visitXOR has changed XOR's operands or replaced the XOR completely,
      // bail out.
      return SDValue(N, 0);
    }
  }

  if (Op0.getOpcode() != ISD::SETCC && Op1.getOpcode() != ISD::SETCC) {
    bool Equal = false;
    if (isOneConstant(Op0) && Op0.hasOneUse() &&
        Op0.getOpcode() == ISD::XOR) {
      TheXor = Op0.getNode();
      Equal = true;
    }

    EVT SetCCVT = N1.getValueType();
    if (LegalTypes)
      SetCCVT = getSetCCResultType(SetCCVT);
    SDValue SetCC = DAG.getSetCC(SDLoc(TheXor),
                                 SetCCVT,
                                 Op0, Op1,
                                 Equal ? ISD::SETEQ : ISD::SETNE);
    // Replace the uses of XOR with SETCC
    WorklistRemover DeadNodes(*this);
    DAG.ReplaceAllUsesOfValueWith(N1, SetCC);
    deleteAndRecombine(N1.getNode());
    return DAG.getNode(ISD::BRCOND, SDLoc(N),
                       MVT::Other, Chain, SetCC, N2);
  }
}

return SDValue();
11296}

11298// Operand List for BR_CC: Chain, CondCC, CondLHS, CondRHS, DestBB.
11299//
11300SDValue DAGCombiner::visitBR_CC(SDNode *N) {
CondCodeSDNode *CC = cast<CondCodeSDNode>(N->getOperand(1));
SDValue CondLHS = N->getOperand(2), CondRHS = N->getOperand(3);

// If N is a constant we could fold this into a fallthrough or unconditional
// branch. However that doesn't happen very often in normal code, because
// Instcombine/SimplifyCFG should have handled the available opportunities.
// If we did this folding here, it would be necessary to update the
// MachineBasicBlock CFG, which is awkward.

// Use SimplifySetCC to simplify SETCC's.
SDValue Simp = SimplifySetCC(getSetCCResultType(CondLHS.getValueType()),
                             CondLHS, CondRHS, CC->get(), SDLoc(N),
                             false);
if (Simp.getNode()) AddToWorklist(Simp.getNode());

// fold to a simpler setcc
if (Simp.getNode() && Simp.getOpcode() == ISD::SETCC)
  return DAG.getNode(ISD::BR_CC, SDLoc(N), MVT::Other,
                     N->getOperand(0), Simp.getOperand(2),
                     Simp.getOperand(0), Simp.getOperand(1),
                     N->getOperand(4));

return SDValue();
11324}

11326/// Return true if 'Use' is a load or a store that uses N as its base pointer
11327/// and that N may be folded in the load / store addressing mode.
11328static bool canFoldInAddressingMode(SDNode *N, SDNode *Use,
                                  SelectionDAG &DAG,
                                  const TargetLowering &TLI) {
EVT VT;
unsigned AS;

if (LoadSDNode *LD  = dyn_cast<LoadSDNode>(Use)) {
  if (LD->isIndexed() || LD->getBasePtr().getNode() != N)
    return false;
  VT = LD->getMemoryVT();
  AS = LD->getAddressSpace();
} else if (StoreSDNode *ST  = dyn_cast<StoreSDNode>(Use)) {
  if (ST->isIndexed() || ST->getBasePtr().getNode() != N)
    return false;
  VT = ST->getMemoryVT();
  AS = ST->getAddressSpace();
} else
  return false;

TargetLowering::AddrMode AM;
if (N->getOpcode() == ISD::ADD) {
  ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
  if (Offset)
    // [reg +/- imm]
    AM.BaseOffs = Offset->getSExtValue();
  else
    // [reg +/- reg]
    AM.Scale = 1;
} else if (N->getOpcode() == ISD::SUB) {
  ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
  if (Offset)
    // [reg +/- imm]
    AM.BaseOffs = -Offset->getSExtValue();
  else
    // [reg +/- reg]
    AM.Scale = 1;
} else
  return false;

return TLI.isLegalAddressingMode(DAG.getDataLayout(), AM,
                                 VT.getTypeForEVT(*DAG.getContext()), AS);
11369}

11371/// Try turning a load/store into a pre-indexed load/store when the base
11372/// pointer is an add or subtract and it has other uses besides the load/store.
11373/// After the transformation, the new indexed load/store has effectively folded
11374/// the add/subtract in and all of its other uses are redirected to the
11375/// new load/store.
11376bool DAGCombiner::CombineToPreIndexedLoadStore(SDNode *N) {
if (Level < AfterLegalizeDAG)
  return false;

bool isLoad = true;
SDValue Ptr;
EVT VT;
if (LoadSDNode *LD  = dyn_cast<LoadSDNode>(N)) {
  if (LD->isIndexed())
    return false;
  VT = LD->getMemoryVT();
  if (!TLI.isIndexedLoadLegal(ISD::PRE_INC, VT) &&
      !TLI.isIndexedLoadLegal(ISD::PRE_DEC, VT))
    return false;
  Ptr = LD->getBasePtr();
} else if (StoreSDNode *ST  = dyn_cast<StoreSDNode>(N)) {
  if (ST->isIndexed())
    return false;
  VT = ST->getMemoryVT();
  if (!TLI.isIndexedStoreLegal(ISD::PRE_INC, VT) &&
      !TLI.isIndexedStoreLegal(ISD::PRE_DEC, VT))
    return false;
  Ptr = ST->getBasePtr();
  isLoad = false;
} else {
  return false;
}

// If the pointer is not an add/sub, or if it doesn't have multiple uses, bail
// out.  There is no reason to make this a preinc/predec.
if ((Ptr.getOpcode() != ISD::ADD && Ptr.getOpcode() != ISD::SUB) ||
    Ptr.getNode()->hasOneUse())
  return false;

// Ask the target to do addressing mode selection.
SDValue BasePtr;
SDValue Offset;
ISD::MemIndexedMode AM = ISD::UNINDEXED;
if (!TLI.getPreIndexedAddressParts(N, BasePtr, Offset, AM, DAG))
  return false;

// Backends without true r+i pre-indexed forms may need to pass a
// constant base with a variable offset so that constant coercion
// will work with the patterns in canonical form.
bool Swapped = false;
if (isa<ConstantSDNode>(BasePtr)) {
  std::swap(BasePtr, Offset);
  Swapped = true;
}

// Don't create a indexed load / store with zero offset.
if (isNullConstant(Offset))
  return false;

// Try turning it into a pre-indexed load / store except when:
// 1) The new base ptr is a frame index.
// 2) If N is a store and the new base ptr is either the same as or is a
//    predecessor of the value being stored.
// 3) Another use of old base ptr is a predecessor of N. If ptr is folded
//    that would create a cycle.
// 4) All uses are load / store ops that use it as old base ptr.

// Check #1.  Preinc'ing a frame index would require copying the stack pointer
// (plus the implicit offset) to a register to preinc anyway.
if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
  return false;

// Check #2.
if (!isLoad) {
  SDValue Val = cast<StoreSDNode>(N)->getValue();
  if (Val == BasePtr || BasePtr.getNode()->isPredecessorOf(Val.getNode()))
    return false;
}

// Caches for hasPredecessorHelper.
SmallPtrSet<const SDNode *, 32> Visited;
SmallVector<const SDNode *, 16> Worklist;
Worklist.push_back(N);

// If the offset is a constant, there may be other adds of constants that
// can be folded with this one. We should do this to avoid having to keep
// a copy of the original base pointer.
SmallVector<SDNode *, 16> OtherUses;
if (isa<ConstantSDNode>(Offset))
  for (SDNode::use_iterator UI = BasePtr.getNode()->use_begin(),
                            UE = BasePtr.getNode()->use_end();
       UI != UE; ++UI) {
    SDUse &Use = UI.getUse();
    // Skip the use that is Ptr and uses of other results from BasePtr's
    // node (important for nodes that return multiple results).
    if (Use.getUser() == Ptr.getNode() || Use != BasePtr)
      continue;

    if (SDNode::hasPredecessorHelper(Use.getUser(), Visited, Worklist))
      continue;

    if (Use.getUser()->getOpcode() != ISD::ADD &&
        Use.getUser()->getOpcode() != ISD::SUB) {
      OtherUses.clear();
      break;
    }

    SDValue Op1 = Use.getUser()->getOperand((UI.getOperandNo() + 1) & 1);
    if (!isa<ConstantSDNode>(Op1)) {
      OtherUses.clear();
      break;
    }

    // FIXME: In some cases, we can be smarter about this.
    if (Op1.getValueType() != Offset.getValueType()) {
      OtherUses.clear();
      break;
    }

    OtherUses.push_back(Use.getUser());
  }

if (Swapped)
  std::swap(BasePtr, Offset);

// Now check for #3 and #4.
bool RealUse = false;

for (SDNode *Use : Ptr.getNode()->uses()) {
  if (Use == N)
    continue;
  if (SDNode::hasPredecessorHelper(Use, Visited, Worklist))
    return false;

  // If Ptr may be folded in addressing mode of other use, then it's
  // not profitable to do this transformation.
  if (!canFoldInAddressingMode(Ptr.getNode(), Use, DAG, TLI))
    RealUse = true;
}

if (!RealUse)
  return false;

SDValue Result;
if (isLoad)
  Result = DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
                              BasePtr, Offset, AM);
else
  Result = DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
                               BasePtr, Offset, AM);
++PreIndexedNodes;
++NodesCombined;
DEBUG(dbgs() << "\nReplacing.4 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.4 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.4 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.4 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      Result.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.4 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
      dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.4 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false);
WorklistRemover DeadNodes(*this);
if (isLoad) {
  DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
  DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
} else {
  DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
}

// Finally, since the node is now dead, remove it from the graph.
deleteAndRecombine(N);

if (Swapped)
  std::swap(BasePtr, Offset);

// Replace other uses of BasePtr that can be updated to use Ptr
for (unsigned i = 0, e = OtherUses.size(); i != e; ++i) {
  unsigned OffsetIdx = 1;
  if (OtherUses[i]->getOperand(OffsetIdx).getNode() == BasePtr.getNode())
    OffsetIdx = 0;
  assert(OtherUses[i]->getOperand(!OffsetIdx).getNode() ==(static_cast <bool> (OtherUses[i]->getOperand(!OffsetIdx
).getNode() == BasePtr.getNode() && "Expected BasePtr operand"
) ? void (0) : __assert_fail ("OtherUses[i]->getOperand(!OffsetIdx).getNode() == BasePtr.getNode() && \"Expected BasePtr operand\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11548, __extension__ __PRETTY_FUNCTION__))
         BasePtr.getNode() && "Expected BasePtr operand")(static_cast <bool> (OtherUses[i]->getOperand(!OffsetIdx
).getNode() == BasePtr.getNode() && "Expected BasePtr operand"
) ? void (0) : __assert_fail ("OtherUses[i]->getOperand(!OffsetIdx).getNode() == BasePtr.getNode() && \"Expected BasePtr operand\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11548, __extension__ __PRETTY_FUNCTION__));

  // We need to replace ptr0 in the following expression:
  //   x0 * offset0 + y0 * ptr0 = t0
  // knowing that
  //   x1 * offset1 + y1 * ptr0 = t1 (the indexed load/store)
  //
  // where x0, x1, y0 and y1 in {-1, 1} are given by the types of the
  // indexed load/store and the expression that needs to be re-written.
  //
  // Therefore, we have:
  //   t0 = (x0 * offset0 - x1 * y0 * y1 *offset1) + (y0 * y1) * t1

  ConstantSDNode *CN =
    cast<ConstantSDNode>(OtherUses[i]->getOperand(OffsetIdx));
  int X0, X1, Y0, Y1;
  const APInt &Offset0 = CN->getAPIntValue();
  APInt Offset1 = cast<ConstantSDNode>(Offset)->getAPIntValue();

  X0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 1) ? -1 : 1;
  Y0 = (OtherUses[i]->getOpcode() == ISD::SUB && OffsetIdx == 0) ? -1 : 1;
  X1 = (AM == ISD::PRE_DEC && !Swapped) ? -1 : 1;
  Y1 = (AM == ISD::PRE_DEC && Swapped) ? -1 : 1;

  unsigned Opcode = (Y0 * Y1 < 0) ? ISD::SUB : ISD::ADD;

  APInt CNV = Offset0;
  if (X0 < 0) CNV = -CNV;
  if (X1 * Y0 * Y1 < 0) CNV = CNV + Offset1;
  else CNV = CNV - Offset1;

  SDLoc DL(OtherUses[i]);

  // We can now generate the new expression.
  SDValue NewOp1 = DAG.getConstant(CNV, DL, CN->getValueType(0));
  SDValue NewOp2 = Result.getValue(isLoad ? 1 : 0);

  SDValue NewUse = DAG.getNode(Opcode,
                               DL,
                               OtherUses[i]->getValueType(0), NewOp1, NewOp2);
  DAG.ReplaceAllUsesOfValueWith(SDValue(OtherUses[i], 0), NewUse);
  deleteAndRecombine(OtherUses[i]);
}

// Replace the uses of Ptr with uses of the updated base value.
DAG.ReplaceAllUsesOfValueWith(Ptr, Result.getValue(isLoad ? 1 : 0));
deleteAndRecombine(Ptr.getNode());
AddToWorklist(Result.getNode());

return true;
11598}

11600/// Try to combine a load/store with a add/sub of the base pointer node into a
11601/// post-indexed load/store. The transformation folded the add/subtract into the
11602/// new indexed load/store effectively and all of its uses are redirected to the
11603/// new load/store.
11604bool DAGCombiner::CombineToPostIndexedLoadStore(SDNode *N) {
if (Level < AfterLegalizeDAG)
  return false;

bool isLoad = true;
SDValue Ptr;
EVT VT;
if (LoadSDNode *LD  = dyn_cast<LoadSDNode>(N)) {
  if (LD->isIndexed())
    return false;
  VT = LD->getMemoryVT();
  if (!TLI.isIndexedLoadLegal(ISD::POST_INC, VT) &&
      !TLI.isIndexedLoadLegal(ISD::POST_DEC, VT))
    return false;
  Ptr = LD->getBasePtr();
} else if (StoreSDNode *ST  = dyn_cast<StoreSDNode>(N)) {
  if (ST->isIndexed())
    return false;
  VT = ST->getMemoryVT();
  if (!TLI.isIndexedStoreLegal(ISD::POST_INC, VT) &&
      !TLI.isIndexedStoreLegal(ISD::POST_DEC, VT))
    return false;
  Ptr = ST->getBasePtr();
  isLoad = false;
} else {
  return false;
}

if (Ptr.getNode()->hasOneUse())
  return false;

for (SDNode *Op : Ptr.getNode()->uses()) {
  if (Op == N ||
      (Op->getOpcode() != ISD::ADD && Op->getOpcode() != ISD::SUB))
    continue;

  SDValue BasePtr;
  SDValue Offset;
  ISD::MemIndexedMode AM = ISD::UNINDEXED;
  if (TLI.getPostIndexedAddressParts(N, Op, BasePtr, Offset, AM, DAG)) {
    // Don't create a indexed load / store with zero offset.
    if (isNullConstant(Offset))
      continue;

    // Try turning it into a post-indexed load / store except when
    // 1) All uses are load / store ops that use it as base ptr (and
    //    it may be folded as addressing mmode).
    // 2) Op must be independent of N, i.e. Op is neither a predecessor
    //    nor a successor of N. Otherwise, if Op is folded that would
    //    create a cycle.

    if (isa<FrameIndexSDNode>(BasePtr) || isa<RegisterSDNode>(BasePtr))
      continue;

    // Check for #1.
    bool TryNext = false;
    for (SDNode *Use : BasePtr.getNode()->uses()) {
      if (Use == Ptr.getNode())
        continue;

      // If all the uses are load / store addresses, then don't do the
      // transformation.
      if (Use->getOpcode() == ISD::ADD || Use->getOpcode() == ISD::SUB){
        bool RealUse = false;
        for (SDNode *UseUse : Use->uses()) {
          if (!canFoldInAddressingMode(Use, UseUse, DAG, TLI))
            RealUse = true;
        }

        if (!RealUse) {
          TryNext = true;
          break;
        }
      }
    }

    if (TryNext)
      continue;

    // Check for #2
    if (!Op->isPredecessorOf(N) && !N->isPredecessorOf(Op)) {
      SDValue Result = isLoad
        ? DAG.getIndexedLoad(SDValue(N,0), SDLoc(N),
                             BasePtr, Offset, AM)
        : DAG.getIndexedStore(SDValue(N,0), SDLoc(N),
                              BasePtr, Offset, AM);
      ++PostIndexedNodes;
      ++NodesCombined;
      DEBUG(dbgs() << "\nReplacing.5 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.5 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
            N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.5 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
            dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.5 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
            Result.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.5 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false)
            dbgs() << '\n')do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.5 "; N->dump
(&DAG); dbgs() << "\nWith: "; Result.getNode()->
dump(&DAG); dbgs() << '\n'; } } while (false);
      WorklistRemover DeadNodes(*this);
      if (isLoad) {
        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(0));
        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Result.getValue(2));
      } else {
        DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Result.getValue(1));
      }

      // Finally, since the node is now dead, remove it from the graph.
      deleteAndRecombine(N);

      // Replace the uses of Use with uses of the updated base value.
      DAG.ReplaceAllUsesOfValueWith(SDValue(Op, 0),
                                    Result.getValue(isLoad ? 1 : 0));
      deleteAndRecombine(Op);
      return true;
    }
  }
}

return false;
11718}

11720/// \brief Return the base-pointer arithmetic from an indexed \p LD.
11721SDValue DAGCombiner::SplitIndexingFromLoad(LoadSDNode *LD) {
ISD::MemIndexedMode AM = LD->getAddressingMode();
assert(AM != ISD::UNINDEXED)(static_cast <bool> (AM != ISD::UNINDEXED) ? void (0) :
 __assert_fail ("AM != ISD::UNINDEXED", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11723, __extension__ __PRETTY_FUNCTION__));
SDValue BP = LD->getOperand(1);
SDValue Inc = LD->getOperand(2);

// Some backends use TargetConstants for load offsets, but don't expect
// TargetConstants in general ADD nodes. We can convert these constants into
// regular Constants (if the constant is not opaque).
assert((Inc.getOpcode() != ISD::TargetConstant ||(static_cast <bool> ((Inc.getOpcode() != ISD::TargetConstant
 || !cast<ConstantSDNode>(Inc)->isOpaque()) &&
 "Cannot split out indexing using opaque target constants") ?
 void (0) : __assert_fail ("(Inc.getOpcode() != ISD::TargetConstant || !cast<ConstantSDNode>(Inc)->isOpaque()) && \"Cannot split out indexing using opaque target constants\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11732, __extension__ __PRETTY_FUNCTION__))
        !cast<ConstantSDNode>(Inc)->isOpaque()) &&(static_cast <bool> ((Inc.getOpcode() != ISD::TargetConstant
 || !cast<ConstantSDNode>(Inc)->isOpaque()) &&
 "Cannot split out indexing using opaque target constants") ?
 void (0) : __assert_fail ("(Inc.getOpcode() != ISD::TargetConstant || !cast<ConstantSDNode>(Inc)->isOpaque()) && \"Cannot split out indexing using opaque target constants\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11732, __extension__ __PRETTY_FUNCTION__))
       "Cannot split out indexing using opaque target constants")(static_cast <bool> ((Inc.getOpcode() != ISD::TargetConstant
 || !cast<ConstantSDNode>(Inc)->isOpaque()) &&
 "Cannot split out indexing using opaque target constants") ?
 void (0) : __assert_fail ("(Inc.getOpcode() != ISD::TargetConstant || !cast<ConstantSDNode>(Inc)->isOpaque()) && \"Cannot split out indexing using opaque target constants\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11732, __extension__ __PRETTY_FUNCTION__));
if (Inc.getOpcode() == ISD::TargetConstant) {
  ConstantSDNode *ConstInc = cast<ConstantSDNode>(Inc);
  Inc = DAG.getConstant(*ConstInc->getConstantIntValue(), SDLoc(Inc),
                        ConstInc->getValueType(0));
}

unsigned Opc =
    (AM == ISD::PRE_INC || AM == ISD::POST_INC ? ISD::ADD : ISD::SUB);
return DAG.getNode(Opc, SDLoc(LD), BP.getSimpleValueType(), BP, Inc);
11742}

11744SDValue DAGCombiner::visitLOAD(SDNode *N) {
LoadSDNode *LD  = cast<LoadSDNode>(N);
SDValue Chain = LD->getChain();
SDValue Ptr   = LD->getBasePtr();

// If load is not volatile and there are no uses of the loaded value (and
// the updated indexed value in case of indexed loads), change uses of the
// chain value into uses of the chain input (i.e. delete the dead load).
if (!LD->isVolatile()) {
  if (N->getValueType(1) == MVT::Other) {
    // Unindexed loads.
    if (!N->hasAnyUseOfValue(0)) {
      // It's not safe to use the two value CombineTo variant here. e.g.
      // v1, chain2 = load chain1, loc
      // v2, chain3 = load chain2, loc
      // v3         = add v2, c
      // Now we replace use of chain2 with chain1.  This makes the second load
      // isomorphic to the one we are deleting, and thus makes this load live.
      DEBUG(dbgs() << "\nReplacing.6 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.6 "; N->dump
(&DAG); dbgs() << "\nWith chain: "; Chain.getNode()
->dump(&DAG); dbgs() << "\n"; } } while (false)
            N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.6 "; N->dump
(&DAG); dbgs() << "\nWith chain: "; Chain.getNode()
->dump(&DAG); dbgs() << "\n"; } } while (false)
            dbgs() << "\nWith chain: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.6 "; N->dump
(&DAG); dbgs() << "\nWith chain: "; Chain.getNode()
->dump(&DAG); dbgs() << "\n"; } } while (false)
            Chain.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.6 "; N->dump
(&DAG); dbgs() << "\nWith chain: "; Chain.getNode()
->dump(&DAG); dbgs() << "\n"; } } while (false)
            dbgs() << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.6 "; N->dump
(&DAG); dbgs() << "\nWith chain: "; Chain.getNode()
->dump(&DAG); dbgs() << "\n"; } } while (false);
      WorklistRemover DeadNodes(*this);
      DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
      AddUsersToWorklist(Chain.getNode());
      if (N->use_empty())
        deleteAndRecombine(N);

      return SDValue(N, 0);   // Return N so it doesn't get rechecked!
    }
  } else {
    // Indexed loads.
    assert(N->getValueType(2) == MVT::Other && "Malformed indexed loads?")(static_cast <bool> (N->getValueType(2) == MVT::Other
 && "Malformed indexed loads?") ? void (0) : __assert_fail
 ("N->getValueType(2) == MVT::Other && \"Malformed indexed loads?\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 11777, __extension__ __PRETTY_FUNCTION__));

    // If this load has an opaque TargetConstant offset, then we cannot split
    // the indexing into an add/sub directly (that TargetConstant may not be
    // valid for a different type of node, and we cannot convert an opaque
    // target constant into a regular constant).
    bool HasOTCInc = LD->getOperand(2).getOpcode() == ISD::TargetConstant &&
                     cast<ConstantSDNode>(LD->getOperand(2))->isOpaque();

    if (!N->hasAnyUseOfValue(0) &&
        ((MaySplitLoadIndex && !HasOTCInc) || !N->hasAnyUseOfValue(1))) {
      SDValue Undef = DAG.getUNDEF(N->getValueType(0));
      SDValue Index;
      if (N->hasAnyUseOfValue(1) && MaySplitLoadIndex && !HasOTCInc) {
        Index = SplitIndexingFromLoad(LD);
        // Try to fold the base pointer arithmetic into subsequent loads and
        // stores.
        AddUsersToWorklist(N);
      } else
        Index = DAG.getUNDEF(N->getValueType(1));
      DEBUG(dbgs() << "\nReplacing.7 ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.7 "; N->dump
(&DAG); dbgs() << "\nWith: "; Undef.getNode()->dump
(&DAG); dbgs() << " and 2 other values\n"; } } while
 (false)
            N->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.7 "; N->dump
(&DAG); dbgs() << "\nWith: "; Undef.getNode()->dump
(&DAG); dbgs() << " and 2 other values\n"; } } while
 (false)
            dbgs() << "\nWith: ";do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.7 "; N->dump
(&DAG); dbgs() << "\nWith: "; Undef.getNode()->dump
(&DAG); dbgs() << " and 2 other values\n"; } } while
 (false)
            Undef.getNode()->dump(&DAG);do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.7 "; N->dump
(&DAG); dbgs() << "\nWith: "; Undef.getNode()->dump
(&DAG); dbgs() << " and 2 other values\n"; } } while
 (false)
            dbgs() << " and 2 other values\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("dagcombine")) { dbgs() << "\nReplacing.7 "; N->dump
(&DAG); dbgs() << "\nWith: "; Undef.getNode()->dump
(&DAG); dbgs() << " and 2 other values\n"; } } while
 (false);
      WorklistRemover DeadNodes(*this);
      DAG.ReplaceAllUsesOfValueWith(SDValue(N, 0), Undef);
      DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Index);
      DAG.ReplaceAllUsesOfValueWith(SDValue(N, 2), Chain);
      deleteAndRecombine(N);
      return SDValue(N, 0);   // Return N so it doesn't get rechecked!
    }
  }
}

// If this load is directly stored, replace the load value with the stored
// value.
// TODO: Handle store large -> read small portion.
// TODO: Handle TRUNCSTORE/LOADEXT
if (OptLevel != CodeGenOpt::None &&
    ISD::isNormalLoad(N) && !LD->isVolatile()) {
  if (ISD::isNON_TRUNCStore(Chain.getNode())) {
    StoreSDNode *PrevST = cast<StoreSDNode>(Chain);
    if (PrevST->getBasePtr() == Ptr &&
        PrevST->getValue().getValueType() == N->getValueType(0))
      return CombineTo(N, PrevST->getOperand(1), Chain);
  }
}

// Try to infer better alignment information than the load already has.
if (OptLevel != CodeGenOpt::None && LD->isUnindexed()) {
  if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
    if (Align > LD->getMemOperand()->getBaseAlignment()) {
      SDValue NewLoad = DAG.getExtLoad(
          LD->getExtensionType(), SDLoc(N), LD->getValueType(0), Chain, Ptr,
          LD->getPointerInfo(), LD->getMemoryVT(), Align,
          LD->getMemOperand()->getFlags(), LD->getAAInfo());
      if (NewLoad.getNode() != N)
        return CombineTo(N, NewLoad, SDValue(NewLoad.getNode(), 1), true);
    }
  }
}

if (LD->isUnindexed()) {
  // Walk up chain skipping non-aliasing memory nodes.
  SDValue BetterChain = FindBetterChain(N, Chain);

  // If there is a better chain.
  if (Chain != BetterChain) {
    SDValue ReplLoad;

    // Replace the chain to void dependency.
    if (LD->getExtensionType() == ISD::NON_EXTLOAD) {
      ReplLoad = DAG.getLoad(N->getValueType(0), SDLoc(LD),
                             BetterChain, Ptr, LD->getMemOperand());
    } else {
      ReplLoad = DAG.getExtLoad(LD->getExtensionType(), SDLoc(LD),
                                LD->getValueType(0),
                                BetterChain, Ptr, LD->getMemoryVT(),
                                LD->getMemOperand());
    }

    // Create token factor to keep old chain connected.
    SDValue Token = DAG.getNode(ISD::TokenFactor, SDLoc(N),
                                MVT::Other, Chain, ReplLoad.getValue(1));

    // Replace uses with load result and token factor
    return CombineTo(N, ReplLoad.getValue(0), Token);
  }
}

// Try transforming N to an indexed load.
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
  return SDValue(N, 0);

// Try to slice up N to more direct loads if the slices are mapped to
// different register banks or pairing can take place.
if (SliceUpLoad(N))
  return SDValue(N, 0);

return SDValue();
11878}

11880namespace {

11882/// \brief Helper structure used to slice a load in smaller loads.
11883/// Basically a slice is obtained from the following sequence:
11884/// Origin = load Ty1, Base
11885/// Shift = srl Ty1 Origin, CstTy Amount
11886/// Inst = trunc Shift to Ty2
11887///
11888/// Then, it will be rewritten into:
11889/// Slice = load SliceTy, Base + SliceOffset
11890/// [Inst = zext Slice to Ty2], only if SliceTy <> Ty2
11891///
11892/// SliceTy is deduced from the number of bits that are actually used to
11893/// build Inst.
11894struct LoadedSlice {
/// \brief Helper structure used to compute the cost of a slice.
struct Cost {
  /// Are we optimizing for code size.
  bool ForCodeSize;

  /// Various cost.
  unsigned Loads = 0;
  unsigned Truncates = 0;
  unsigned CrossRegisterBanksCopies = 0;
  unsigned ZExts = 0;
  unsigned Shift = 0;

  Cost(bool ForCodeSize = false) : ForCodeSize(ForCodeSize) {}

  /// \brief Get the cost of one isolated slice.
  Cost(const LoadedSlice &LS, bool ForCodeSize = false)
      : ForCodeSize(ForCodeSize), Loads(1) {
    EVT TruncType = LS.Inst->getValueType(0);
    EVT LoadedType = LS.getLoadedType();
    if (TruncType != LoadedType &&
        !LS.DAG->getTargetLoweringInfo().isZExtFree(LoadedType, TruncType))
      ZExts = 1;
  }

  /// \brief Account for slicing gain in the current cost.
  /// Slicing provide a few gains like removing a shift or a
  /// truncate. This method allows to grow the cost of the original
  /// load with the gain from this slice.
  void addSliceGain(const LoadedSlice &LS) {
    // Each slice saves a truncate.
    const TargetLowering &TLI = LS.DAG->getTargetLoweringInfo();
    if (!TLI.isTruncateFree(LS.Inst->getOperand(0).getValueType(),
                            LS.Inst->getValueType(0)))
      ++Truncates;
    // If there is a shift amount, this slice gets rid of it.
    if (LS.Shift)
      ++Shift;
    // If this slice can merge a cross register bank copy, account for it.
    if (LS.canMergeExpensiveCrossRegisterBankCopy())
      ++CrossRegisterBanksCopies;
  }

  Cost &operator+=(const Cost &RHS) {
    Loads += RHS.Loads;
    Truncates += RHS.Truncates;
    CrossRegisterBanksCopies += RHS.CrossRegisterBanksCopies;
    ZExts += RHS.ZExts;
    Shift += RHS.Shift;
    return *this;
  }

  bool operator==(const Cost &RHS) const {
    return Loads == RHS.Loads && Truncates == RHS.Truncates &&
           CrossRegisterBanksCopies == RHS.CrossRegisterBanksCopies &&
           ZExts == RHS.ZExts && Shift == RHS.Shift;
  }

  bool operator!=(const Cost &RHS) const { return !(*this == RHS); }

  bool operator<(const Cost &RHS) const {
    // Assume cross register banks copies are as expensive as loads.
    // FIXME: Do we want some more target hooks?
    unsigned ExpensiveOpsLHS = Loads + CrossRegisterBanksCopies;
    unsigned ExpensiveOpsRHS = RHS.Loads + RHS.CrossRegisterBanksCopies;
    // Unless we are optimizing for code size, consider the
    // expensive operation first.
    if (!ForCodeSize && ExpensiveOpsLHS != ExpensiveOpsRHS)
      return ExpensiveOpsLHS < ExpensiveOpsRHS;
    return (Truncates + ZExts + Shift + ExpensiveOpsLHS) <
           (RHS.Truncates + RHS.ZExts + RHS.Shift + ExpensiveOpsRHS);
  }

  bool operator>(const Cost &RHS) const { return RHS < *this; }

  bool operator<=(const Cost &RHS) const { return !(RHS < *this); }

  bool operator>=(const Cost &RHS) const { return !(*this < RHS); }
};

// The last instruction that represent the slice. This should be a
// truncate instruction.
SDNode *Inst;

// The original load instruction.
LoadSDNode *Origin;

// The right shift amount in bits from the original load.
unsigned Shift;

// The DAG from which Origin came from.
// This is used to get some contextual information about legal types, etc.
SelectionDAG *DAG;

LoadedSlice(SDNode *Inst = nullptr, LoadSDNode *Origin = nullptr,
            unsigned Shift = 0, SelectionDAG *DAG = nullptr)
    : Inst(Inst), Origin(Origin), Shift(Shift), DAG(DAG) {}

/// \brief Get the bits used in a chunk of bits \p BitWidth large.
/// \return Result is \p BitWidth and has used bits set to 1 and
///         not used bits set to 0.
APInt getUsedBits() const {
  // Reproduce the trunc(lshr) sequence:
  // - Start from the truncated value.
  // - Zero extend to the desired bit width.
  // - Shift left.
  assert(Origin && "No original load to compare against.")(static_cast <bool> (Origin && "No original load to compare against."
) ? void (0) : __assert_fail ("Origin && \"No original load to compare against.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12000, __extension__ __PRETTY_FUNCTION__));
  unsigned BitWidth = Origin->getValueSizeInBits(0);
  assert(Inst && "This slice is not bound to an instruction")(static_cast <bool> (Inst && "This slice is not bound to an instruction"
) ? void (0) : __assert_fail ("Inst && \"This slice is not bound to an instruction\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12002, __extension__ __PRETTY_FUNCTION__));
  assert(Inst->getValueSizeInBits(0) <= BitWidth &&(static_cast <bool> (Inst->getValueSizeInBits(0) <=
 BitWidth && "Extracted slice is bigger than the whole type!"
) ? void (0) : __assert_fail ("Inst->getValueSizeInBits(0) <= BitWidth && \"Extracted slice is bigger than the whole type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12004, __extension__ __PRETTY_FUNCTION__))
         "Extracted slice is bigger than the whole type!")(static_cast <bool> (Inst->getValueSizeInBits(0) <=
 BitWidth && "Extracted slice is bigger than the whole type!"
) ? void (0) : __assert_fail ("Inst->getValueSizeInBits(0) <= BitWidth && \"Extracted slice is bigger than the whole type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12004, __extension__ __PRETTY_FUNCTION__));
  APInt UsedBits(Inst->getValueSizeInBits(0), 0);
  UsedBits.setAllBits();
  UsedBits = UsedBits.zext(BitWidth);
  UsedBits <<= Shift;
  return UsedBits;
}

/// \brief Get the size of the slice to be loaded in bytes.
unsigned getLoadedSize() const {
  unsigned SliceSize = getUsedBits().countPopulation();
  assert(!(SliceSize & 0x7) && "Size is not a multiple of a byte.")(static_cast <bool> (!(SliceSize & 0x7) && "Size is not a multiple of a byte."
) ? void (0) : __assert_fail ("!(SliceSize & 0x7) && \"Size is not a multiple of a byte.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12015, __extension__ __PRETTY_FUNCTION__));
  return SliceSize / 8;
}

/// \brief Get the type that will be loaded for this slice.
/// Note: This may not be the final type for the slice.
EVT getLoadedType() const {
  assert(DAG && "Missing context")(static_cast <bool> (DAG && "Missing context") ?
 void (0) : __assert_fail ("DAG && \"Missing context\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12022, __extension__ __PRETTY_FUNCTION__));
  LLVMContext &Ctxt = *DAG->getContext();
  return EVT::getIntegerVT(Ctxt, getLoadedSize() * 8);
}

/// \brief Get the alignment of the load used for this slice.
unsigned getAlignment() const {
  unsigned Alignment = Origin->getAlignment();
  unsigned Offset = getOffsetFromBase();
  if (Offset != 0)
    Alignment = MinAlign(Alignment, Alignment + Offset);
  return Alignment;
}

/// \brief Check if this slice can be rewritten with legal operations.
bool isLegal() const {
  // An invalid slice is not legal.
  if (!Origin || !Inst || !DAG)
    return false;

  // Offsets are for indexed load only, we do not handle that.
  if (!Origin->getOffset().isUndef())
    return false;

  const TargetLowering &TLI = DAG->getTargetLoweringInfo();

  // Check that the type is legal.
  EVT SliceType = getLoadedType();
  if (!TLI.isTypeLegal(SliceType))
    return false;

  // Check that the load is legal for this type.
  if (!TLI.isOperationLegal(ISD::LOAD, SliceType))
    return false;

  // Check that the offset can be computed.
  // 1. Check its type.
  EVT PtrType = Origin->getBasePtr().getValueType();
  if (PtrType == MVT::Untyped || PtrType.isExtended())
    return false;

  // 2. Check that it fits in the immediate.
  if (!TLI.isLegalAddImmediate(getOffsetFromBase()))
    return false;

  // 3. Check that the computation is legal.
  if (!TLI.isOperationLegal(ISD::ADD, PtrType))
    return false;

  // Check that the zext is legal if it needs one.
  EVT TruncateType = Inst->getValueType(0);
  if (TruncateType != SliceType &&
      !TLI.isOperationLegal(ISD::ZERO_EXTEND, TruncateType))
    return false;

  return true;
}

/// \brief Get the offset in bytes of this slice in the original chunk of
/// bits.
/// \pre DAG != nullptr.
uint64_t getOffsetFromBase() const {
  assert(DAG && "Missing context.")(static_cast <bool> (DAG && "Missing context.")
 ? void (0) : __assert_fail ("DAG && \"Missing context.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12084, __extension__ __PRETTY_FUNCTION__));
  bool IsBigEndian = DAG->getDataLayout().isBigEndian();
  assert(!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported.")(static_cast <bool> (!(Shift & 0x7) && "Shifts not aligned on Bytes are not supported."
) ? void (0) : __assert_fail ("!(Shift & 0x7) && \"Shifts not aligned on Bytes are not supported.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12086, __extension__ __PRETTY_FUNCTION__));
  uint64_t Offset = Shift / 8;
  unsigned TySizeInBytes = Origin->getValueSizeInBits(0) / 8;
  assert(!(Origin->getValueSizeInBits(0) & 0x7) &&(static_cast <bool> (!(Origin->getValueSizeInBits(0)
 & 0x7) && "The size of the original loaded type is not a multiple of a"
 " byte.") ? void (0) : __assert_fail ("!(Origin->getValueSizeInBits(0) & 0x7) && \"The size of the original loaded type is not a multiple of a\" \" byte.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12091, __extension__ __PRETTY_FUNCTION__))
         "The size of the original loaded type is not a multiple of a"(static_cast <bool> (!(Origin->getValueSizeInBits(0)
 & 0x7) && "The size of the original loaded type is not a multiple of a"
 " byte.") ? void (0) : __assert_fail ("!(Origin->getValueSizeInBits(0) & 0x7) && \"The size of the original loaded type is not a multiple of a\" \" byte.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12091, __extension__ __PRETTY_FUNCTION__))
         " byte.")(static_cast <bool> (!(Origin->getValueSizeInBits(0)
 & 0x7) && "The size of the original loaded type is not a multiple of a"
 " byte.") ? void (0) : __assert_fail ("!(Origin->getValueSizeInBits(0) & 0x7) && \"The size of the original loaded type is not a multiple of a\" \" byte.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12091, __extension__ __PRETTY_FUNCTION__));
  // If Offset is bigger than TySizeInBytes, it means we are loading all
  // zeros. This should have been optimized before in the process.
  assert(TySizeInBytes > Offset &&(static_cast <bool> (TySizeInBytes > Offset &&
 "Invalid shift amount for given loaded size") ? void (0) : __assert_fail
 ("TySizeInBytes > Offset && \"Invalid shift amount for given loaded size\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12095, __extension__ __PRETTY_FUNCTION__))
         "Invalid shift amount for given loaded size")(static_cast <bool> (TySizeInBytes > Offset &&
 "Invalid shift amount for given loaded size") ? void (0) : __assert_fail
 ("TySizeInBytes > Offset && \"Invalid shift amount for given loaded size\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12095, __extension__ __PRETTY_FUNCTION__));
  if (IsBigEndian)
    Offset = TySizeInBytes - Offset - getLoadedSize();
  return Offset;
}

/// \brief Generate the sequence of instructions to load the slice
/// represented by this object and redirect the uses of this slice to
/// this new sequence of instructions.
/// \pre this->Inst && this->Origin are valid Instructions and this
/// object passed the legal check: LoadedSlice::isLegal returned true.
/// \return The last instruction of the sequence used to load the slice.
SDValue loadSlice() const {
  assert(Inst && Origin && "Unable to replace a non-existing slice.")(static_cast <bool> (Inst && Origin && "Unable to replace a non-existing slice."
) ? void (0) : __assert_fail ("Inst && Origin && \"Unable to replace a non-existing slice.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12108, __extension__ __PRETTY_FUNCTION__));
  const SDValue &OldBaseAddr = Origin->getBasePtr();
  SDValue BaseAddr = OldBaseAddr;
  // Get the offset in that chunk of bytes w.r.t. the endianness.
  int64_t Offset = static_cast<int64_t>(getOffsetFromBase());
  assert(Offset >= 0 && "Offset too big to fit in int64_t!")(static_cast <bool> (Offset >= 0 && "Offset too big to fit in int64_t!"
) ? void (0) : __assert_fail ("Offset >= 0 && \"Offset too big to fit in int64_t!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12113, __extension__ __PRETTY_FUNCTION__));
  if (Offset) {
    // BaseAddr = BaseAddr + Offset.
    EVT ArithType = BaseAddr.getValueType();
    SDLoc DL(Origin);
    BaseAddr = DAG->getNode(ISD::ADD, DL, ArithType, BaseAddr,
                            DAG->getConstant(Offset, DL, ArithType));
  }

  // Create the type of the loaded slice according to its size.
  EVT SliceType = getLoadedType();

  // Create the load for the slice.
  SDValue LastInst =
      DAG->getLoad(SliceType, SDLoc(Origin), Origin->getChain(), BaseAddr,
                   Origin->getPointerInfo().getWithOffset(Offset),
                   getAlignment(), Origin->getMemOperand()->getFlags());
  // If the final type is not the same as the loaded type, this means that
  // we have to pad with zero. Create a zero extend for that.
  EVT FinalType = Inst->getValueType(0);
  if (SliceType != FinalType)
    LastInst =
        DAG->getNode(ISD::ZERO_EXTEND, SDLoc(LastInst), FinalType, LastInst);
  return LastInst;
}

/// \brief Check if this slice can be merged with an expensive cross register
/// bank copy. E.g.,
/// i = load i32
/// f = bitcast i32 i to float
bool canMergeExpensiveCrossRegisterBankCopy() const {
  if (!Inst || !Inst->hasOneUse())
    return false;
  SDNode *Use = *Inst->use_begin();
  if (Use->getOpcode() != ISD::BITCAST)
    return false;
  assert(DAG && "Missing context")(static_cast <bool> (DAG && "Missing context") ?
 void (0) : __assert_fail ("DAG && \"Missing context\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12149, __extension__ __PRETTY_FUNCTION__));
  const TargetLowering &TLI = DAG->getTargetLoweringInfo();
  EVT ResVT = Use->getValueType(0);
  const TargetRegisterClass *ResRC = TLI.getRegClassFor(ResVT.getSimpleVT());
  const TargetRegisterClass *ArgRC =
      TLI.getRegClassFor(Use->getOperand(0).getValueType().getSimpleVT());
  if (ArgRC == ResRC || !TLI.isOperationLegal(ISD::LOAD, ResVT))
    return false;

  // At this point, we know that we perform a cross-register-bank copy.
  // Check if it is expensive.
  const TargetRegisterInfo *TRI = DAG->getSubtarget().getRegisterInfo();
  // Assume bitcasts are cheap, unless both register classes do not
  // explicitly share a common sub class.
  if (!TRI || TRI->getCommonSubClass(ArgRC, ResRC))
    return false;

  // Check if it will be merged with the load.
  // 1. Check the alignment constraint.
  unsigned RequiredAlignment = DAG->getDataLayout().getABITypeAlignment(
      ResVT.getTypeForEVT(*DAG->getContext()));

  if (RequiredAlignment > getAlignment())
    return false;

  // 2. Check that the load is a legal operation for that type.
  if (!TLI.isOperationLegal(ISD::LOAD, ResVT))
    return false;

  // 3. Check that we do not have a zext in the way.
  if (Inst->getValueType(0) != getLoadedType())
    return false;

  return true;
}
12184};

12186} // end anonymous namespace

12188/// \brief Check that all bits set in \p UsedBits form a dense region, i.e.,
12189/// \p UsedBits looks like 0..0 1..1 0..0.
12190static bool areUsedBitsDense(const APInt &UsedBits) {
// If all the bits are one, this is dense!
if (UsedBits.isAllOnesValue())
  return true;

// Get rid of the unused bits on the right.
APInt NarrowedUsedBits = UsedBits.lshr(UsedBits.countTrailingZeros());
// Get rid of the unused bits on the left.
if (NarrowedUsedBits.countLeadingZeros())
  NarrowedUsedBits = NarrowedUsedBits.trunc(NarrowedUsedBits.getActiveBits());
// Check that the chunk of bits is completely used.
return NarrowedUsedBits.isAllOnesValue();
12202}

12204/// \brief Check whether or not \p First and \p Second are next to each other
12205/// in memory. This means that there is no hole between the bits loaded
12206/// by \p First and the bits loaded by \p Second.
12207static bool areSlicesNextToEachOther(const LoadedSlice &First,
                                   const LoadedSlice &Second) {
assert(First.Origin == Second.Origin && First.Origin &&(static_cast <bool> (First.Origin == Second.Origin &&
 First.Origin && "Unable to match different memory origins."
) ? void (0) : __assert_fail ("First.Origin == Second.Origin && First.Origin && \"Unable to match different memory origins.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12210, __extension__ __PRETTY_FUNCTION__))
       "Unable to match different memory origins.")(static_cast <bool> (First.Origin == Second.Origin &&
 First.Origin && "Unable to match different memory origins."
) ? void (0) : __assert_fail ("First.Origin == Second.Origin && First.Origin && \"Unable to match different memory origins.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12210, __extension__ __PRETTY_FUNCTION__));
APInt UsedBits = First.getUsedBits();
assert((UsedBits & Second.getUsedBits()) == 0 &&(static_cast <bool> ((UsedBits & Second.getUsedBits
()) == 0 && "Slices are not supposed to overlap.") ? void
 (0) : __assert_fail ("(UsedBits & Second.getUsedBits()) == 0 && \"Slices are not supposed to overlap.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12213, __extension__ __PRETTY_FUNCTION__))
       "Slices are not supposed to overlap.")(static_cast <bool> ((UsedBits & Second.getUsedBits
()) == 0 && "Slices are not supposed to overlap.") ? void
 (0) : __assert_fail ("(UsedBits & Second.getUsedBits()) == 0 && \"Slices are not supposed to overlap.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12213, __extension__ __PRETTY_FUNCTION__));
UsedBits |= Second.getUsedBits();
return areUsedBitsDense(UsedBits);
12216}

12218/// \brief Adjust the \p GlobalLSCost according to the target
12219/// paring capabilities and the layout of the slices.
12220/// \pre \p GlobalLSCost should account for at least as many loads as
12221/// there is in the slices in \p LoadedSlices.
12222static void adjustCostForPairing(SmallVectorImpl<LoadedSlice> &LoadedSlices,
                               LoadedSlice::Cost &GlobalLSCost) {
unsigned NumberOfSlices = LoadedSlices.size();
// If there is less than 2 elements, no pairing is possible.
if (NumberOfSlices < 2)
  return;

// Sort the slices so that elements that are likely to be next to each
// other in memory are next to each other in the list.
std::sort(LoadedSlices.begin(), LoadedSlices.end(),
          [](const LoadedSlice &LHS, const LoadedSlice &RHS) {
  assert(LHS.Origin == RHS.Origin && "Different bases not implemented.")(static_cast <bool> (LHS.Origin == RHS.Origin &&
 "Different bases not implemented.") ? void (0) : __assert_fail
 ("LHS.Origin == RHS.Origin && \"Different bases not implemented.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12233, __extension__ __PRETTY_FUNCTION__));
  return LHS.getOffsetFromBase() < RHS.getOffsetFromBase();
});
const TargetLowering &TLI = LoadedSlices[0].DAG->getTargetLoweringInfo();
// First (resp. Second) is the first (resp. Second) potentially candidate
// to be placed in a paired load.
const LoadedSlice *First = nullptr;
const LoadedSlice *Second = nullptr;
for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice,
              // Set the beginning of the pair.
                                                         First = Second) {
  Second = &LoadedSlices[CurrSlice];

  // If First is NULL, it means we start a new pair.
  // Get to the next slice.
  if (!First)
    continue;

  EVT LoadedType = First->getLoadedType();

  // If the types of the slices are different, we cannot pair them.
  if (LoadedType != Second->getLoadedType())
    continue;

  // Check if the target supplies paired loads for this type.
  unsigned RequiredAlignment = 0;
  if (!TLI.hasPairedLoad(LoadedType, RequiredAlignment)) {
    // move to the next pair, this type is hopeless.
    Second = nullptr;
    continue;
  }
  // Check if we meet the alignment requirement.
  if (RequiredAlignment > First->getAlignment())
    continue;

  // Check that both loads are next to each other in memory.
  if (!areSlicesNextToEachOther(*First, *Second))
    continue;

  assert(GlobalLSCost.Loads > 0 && "We save more loads than we created!")(static_cast <bool> (GlobalLSCost.Loads > 0 &&
 "We save more loads than we created!") ? void (0) : __assert_fail
 ("GlobalLSCost.Loads > 0 && \"We save more loads than we created!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12272, __extension__ __PRETTY_FUNCTION__));
  --GlobalLSCost.Loads;
  // Move to the next pair.
  Second = nullptr;
}
12277}

12279/// \brief Check the profitability of all involved LoadedSlice.
12280/// Currently, it is considered profitable if there is exactly two
12281/// involved slices (1) which are (2) next to each other in memory, and
12282/// whose cost (\see LoadedSlice::Cost) is smaller than the original load (3).
12283///
12284/// Note: The order of the elements in \p LoadedSlices may be modified, but not
12285/// the elements themselves.
12286///
12287/// FIXME: When the cost model will be mature enough, we can relax
12288/// constraints (1) and (2).
12289static bool isSlicingProfitable(SmallVectorImpl<LoadedSlice> &LoadedSlices,
                              const APInt &UsedBits, bool ForCodeSize) {
unsigned NumberOfSlices = LoadedSlices.size();
if (StressLoadSlicing)
  return NumberOfSlices > 1;

// Check (1).
if (NumberOfSlices != 2)
  return false;

// Check (2).
if (!areUsedBitsDense(UsedBits))
  return false;

// Check (3).
LoadedSlice::Cost OrigCost(ForCodeSize), GlobalSlicingCost(ForCodeSize);
// The original code has one big load.
OrigCost.Loads = 1;
for (unsigned CurrSlice = 0; CurrSlice < NumberOfSlices; ++CurrSlice) {
  const LoadedSlice &LS = LoadedSlices[CurrSlice];
  // Accumulate the cost of all the slices.
  LoadedSlice::Cost SliceCost(LS, ForCodeSize);
  GlobalSlicingCost += SliceCost;

  // Account as cost in the original configuration the gain obtained
  // with the current slices.
  OrigCost.addSliceGain(LS);
}

// If the target supports paired load, adjust the cost accordingly.
adjustCostForPairing(LoadedSlices, GlobalSlicingCost);
return OrigCost > GlobalSlicingCost;
12321}

12323/// \brief If the given load, \p LI, is used only by trunc or trunc(lshr)
12324/// operations, split it in the various pieces being extracted.
12325///
12326/// This sort of thing is introduced by SROA.
12327/// This slicing takes care not to insert overlapping loads.
12328/// \pre LI is a simple load (i.e., not an atomic or volatile load).
12329bool DAGCombiner::SliceUpLoad(SDNode *N) {
if (Level < AfterLegalizeDAG)
  return false;

LoadSDNode *LD = cast<LoadSDNode>(N);
if (LD->isVolatile() || !ISD::isNormalLoad(LD) ||
    !LD->getValueType(0).isInteger())
  return false;

// Keep track of already used bits to detect overlapping values.
// In that case, we will just abort the transformation.
APInt UsedBits(LD->getValueSizeInBits(0), 0);

SmallVector<LoadedSlice, 4> LoadedSlices;

// Check if this load is used as several smaller chunks of bits.
// Basically, look for uses in trunc or trunc(lshr) and record a new chain
// of computation for each trunc.
for (SDNode::use_iterator UI = LD->use_begin(), UIEnd = LD->use_end();
     UI != UIEnd; ++UI) {
  // Skip the uses of the chain.
  if (UI.getUse().getResNo() != 0)
    continue;

  SDNode *User = *UI;
  unsigned Shift = 0;

  // Check if this is a trunc(lshr).
  if (User->getOpcode() == ISD::SRL && User->hasOneUse() &&
      isa<ConstantSDNode>(User->getOperand(1))) {
    Shift = User->getConstantOperandVal(1);
    User = *User->use_begin();
  }

  // At this point, User is a Truncate, iff we encountered, trunc or
  // trunc(lshr).
  if (User->getOpcode() != ISD::TRUNCATE)
    return false;

  // The width of the type must be a power of 2 and greater than 8-bits.
  // Otherwise the load cannot be represented in LLVM IR.
  // Moreover, if we shifted with a non-8-bits multiple, the slice
  // will be across several bytes. We do not support that.
  unsigned Width = User->getValueSizeInBits(0);
  if (Width < 8 || !isPowerOf2_32(Width) || (Shift & 0x7))
    return false;

  // Build the slice for this chain of computations.
  LoadedSlice LS(User, LD, Shift, &DAG);
  APInt CurrentUsedBits = LS.getUsedBits();

  // Check if this slice overlaps with another.
  if ((CurrentUsedBits & UsedBits) != 0)
    return false;
  // Update the bits used globally.
  UsedBits |= CurrentUsedBits;

  // Check if the new slice would be legal.
  if (!LS.isLegal())
    return false;

  // Record the slice.
  LoadedSlices.push_back(LS);
}

// Abort slicing if it does not seem to be profitable.
if (!isSlicingProfitable(LoadedSlices, UsedBits, ForCodeSize))
  return false;

++SlicedLoads;

// Rewrite each chain to use an independent load.
// By construction, each chain can be represented by a unique load.

// Prepare the argument for the new token factor for all the slices.
SmallVector<SDValue, 8> ArgChains;
for (SmallVectorImpl<LoadedSlice>::const_iterator
         LSIt = LoadedSlices.begin(),
         LSItEnd = LoadedSlices.end();
     LSIt != LSItEnd; ++LSIt) {
  SDValue SliceInst = LSIt->loadSlice();
  CombineTo(LSIt->Inst, SliceInst, true);
  if (SliceInst.getOpcode() != ISD::LOAD)
    SliceInst = SliceInst.getOperand(0);
  assert(SliceInst->getOpcode() == ISD::LOAD &&(static_cast <bool> (SliceInst->getOpcode() == ISD::
LOAD && "It takes more than a zext to get to the loaded slice!!"
) ? void (0) : __assert_fail ("SliceInst->getOpcode() == ISD::LOAD && \"It takes more than a zext to get to the loaded slice!!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12414, __extension__ __PRETTY_FUNCTION__))
         "It takes more than a zext to get to the loaded slice!!")(static_cast <bool> (SliceInst->getOpcode() == ISD::
LOAD && "It takes more than a zext to get to the loaded slice!!"
) ? void (0) : __assert_fail ("SliceInst->getOpcode() == ISD::LOAD && \"It takes more than a zext to get to the loaded slice!!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12414, __extension__ __PRETTY_FUNCTION__));
  ArgChains.push_back(SliceInst.getValue(1));
}

SDValue Chain = DAG.getNode(ISD::TokenFactor, SDLoc(LD), MVT::Other,
                            ArgChains);
DAG.ReplaceAllUsesOfValueWith(SDValue(N, 1), Chain);
AddToWorklist(Chain.getNode());
return true;
12423}

12425/// Check to see if V is (and load (ptr), imm), where the load is having
12426/// specific bytes cleared out.  If so, return the byte size being masked out
12427/// and the shift amount.
12428static std::pair<unsigned, unsigned>
12429CheckForMaskedLoad(SDValue V, SDValue Ptr, SDValue Chain) {
std::pair<unsigned, unsigned> Result(0, 0);

// Check for the structure we're looking for.
if (V->getOpcode() != ISD::AND ||
    !isa<ConstantSDNode>(V->getOperand(1)) ||
    !ISD::isNormalLoad(V->getOperand(0).getNode()))
  return Result;

// Check the chain and pointer.
LoadSDNode *LD = cast<LoadSDNode>(V->getOperand(0));
if (LD->getBasePtr() != Ptr) return Result;  // Not from same pointer.

// The store should be chained directly to the load or be an operand of a
// tokenfactor.
if (LD == Chain.getNode())
  ; // ok.
else if (Chain->getOpcode() != ISD::TokenFactor)
  return Result; // Fail.
else {
  bool isOk = false;
  for (const SDValue &ChainOp : Chain->op_values())
    if (ChainOp.getNode() == LD) {
      isOk = true;
      break;
    }
  if (!isOk) return Result;
}

// This only handles simple types.
if (V.getValueType() != MVT::i16 &&
    V.getValueType() != MVT::i32 &&
    V.getValueType() != MVT::i64)
  return Result;

// Check the constant mask.  Invert it so that the bits being masked out are
// 0 and the bits being kept are 1.  Use getSExtValue so that leading bits
// follow the sign bit for uniformity.
uint64_t NotMask = ~cast<ConstantSDNode>(V->getOperand(1))->getSExtValue();
unsigned NotMaskLZ = countLeadingZeros(NotMask);
if (NotMaskLZ & 7) return Result;  // Must be multiple of a byte.
unsigned NotMaskTZ = countTrailingZeros(NotMask);
if (NotMaskTZ & 7) return Result;  // Must be multiple of a byte.
if (NotMaskLZ == 64) return Result;  // All zero mask.

// See if we have a continuous run of bits.  If so, we have 0*1+0*
if (countTrailingOnes(NotMask >> NotMaskTZ) + NotMaskTZ + NotMaskLZ != 64)
  return Result;

// Adjust NotMaskLZ down to be from the actual size of the int instead of i64.
if (V.getValueType() != MVT::i64 && NotMaskLZ)
  NotMaskLZ -= 64-V.getValueSizeInBits();

unsigned MaskedBytes = (V.getValueSizeInBits()-NotMaskLZ-NotMaskTZ)/8;
switch (MaskedBytes) {
case 1:
case 2:
case 4: break;
default: return Result; // All one mask, or 5-byte mask.
}

// Verify that the first bit starts at a multiple of mask so that the access
// is aligned the same as the access width.
if (NotMaskTZ && NotMaskTZ/8 % MaskedBytes) return Result;

Result.first = MaskedBytes;
Result.second = NotMaskTZ/8;
return Result;
12497}

12499/// Check to see if IVal is something that provides a value as specified by
12500/// MaskInfo. If so, replace the specified store with a narrower store of
12501/// truncated IVal.
12502static SDNode *
12503ShrinkLoadReplaceStoreWithStore(const std::pair<unsigned, unsigned> &MaskInfo,
                              SDValue IVal, StoreSDNode *St,
                              DAGCombiner *DC) {
unsigned NumBytes = MaskInfo.first;
unsigned ByteShift = MaskInfo.second;
SelectionDAG &DAG = DC->getDAG();

// Check to see if IVal is all zeros in the part being masked in by the 'or'
// that uses this.  If not, this is not a replacement.
APInt Mask = ~APInt::getBitsSet(IVal.getValueSizeInBits(),
                                ByteShift*8, (ByteShift+NumBytes)*8);
if (!DAG.MaskedValueIsZero(IVal, Mask)) return nullptr;

// Check that it is legal on the target to do this.  It is legal if the new
// VT we're shrinking to (i8/i16/i32) is legal or we're still before type
// legalization.
MVT VT = MVT::getIntegerVT(NumBytes*8);
if (!DC->isTypeLegal(VT))
  return nullptr;

// Okay, we can do this!  Replace the 'St' store with a store of IVal that is
// shifted by ByteShift and truncated down to NumBytes.
if (ByteShift) {
  SDLoc DL(IVal);
  IVal = DAG.getNode(ISD::SRL, DL, IVal.getValueType(), IVal,
                     DAG.getConstant(ByteShift*8, DL,
                                  DC->getShiftAmountTy(IVal.getValueType())));
}

// Figure out the offset for the store and the alignment of the access.
unsigned StOffset;
unsigned NewAlign = St->getAlignment();

if (DAG.getDataLayout().isLittleEndian())
  StOffset = ByteShift;
else
  StOffset = IVal.getValueType().getStoreSize() - ByteShift - NumBytes;

SDValue Ptr = St->getBasePtr();
if (StOffset) {
  SDLoc DL(IVal);
  Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(),
                    Ptr, DAG.getConstant(StOffset, DL, Ptr.getValueType()));
  NewAlign = MinAlign(NewAlign, StOffset);
}

// Truncate down to the new size.
IVal = DAG.getNode(ISD::TRUNCATE, SDLoc(IVal), VT, IVal);

++OpsNarrowed;
return DAG
    .getStore(St->getChain(), SDLoc(St), IVal, Ptr,
              St->getPointerInfo().getWithOffset(StOffset), NewAlign)
    .getNode();
12557}

12559/// Look for sequence of load / op / store where op is one of 'or', 'xor', and
12560/// 'and' of immediates. If 'op' is only touching some of the loaded bits, try
12561/// narrowing the load and store if it would end up being a win for performance
12562/// or code size.
12563SDValue DAGCombiner::ReduceLoadOpStoreWidth(SDNode *N) {
StoreSDNode *ST  = cast<StoreSDNode>(N);
if (ST->isVolatile())
  return SDValue();

SDValue Chain = ST->getChain();
SDValue Value = ST->getValue();
SDValue Ptr   = ST->getBasePtr();
EVT VT = Value.getValueType();

if (ST->isTruncatingStore() || VT.isVector() || !Value.hasOneUse())
  return SDValue();

unsigned Opc = Value.getOpcode();

// If this is "store (or X, Y), P" and X is "(and (load P), cst)", where cst
// is a byte mask indicating a consecutive number of bytes, check to see if
// Y is known to provide just those bytes.  If so, we try to replace the
// load + replace + store sequence with a single (narrower) store, which makes
// the load dead.
if (Opc == ISD::OR) {
  std::pair<unsigned, unsigned> MaskedLoad;
  MaskedLoad = CheckForMaskedLoad(Value.getOperand(0), Ptr, Chain);
  if (MaskedLoad.first)
    if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
                                                Value.getOperand(1), ST,this))
      return SDValue(NewST, 0);

  // Or is commutative, so try swapping X and Y.
  MaskedLoad = CheckForMaskedLoad(Value.getOperand(1), Ptr, Chain);
  if (MaskedLoad.first)
    if (SDNode *NewST = ShrinkLoadReplaceStoreWithStore(MaskedLoad,
                                                Value.getOperand(0), ST,this))
      return SDValue(NewST, 0);
}

if ((Opc != ISD::OR && Opc != ISD::XOR && Opc != ISD::AND) ||
    Value.getOperand(1).getOpcode() != ISD::Constant)
  return SDValue();

SDValue N0 = Value.getOperand(0);
if (ISD::isNormalLoad(N0.getNode()) && N0.hasOneUse() &&
    Chain == SDValue(N0.getNode(), 1)) {
  LoadSDNode *LD = cast<LoadSDNode>(N0);
  if (LD->getBasePtr() != Ptr ||
      LD->getPointerInfo().getAddrSpace() !=
      ST->getPointerInfo().getAddrSpace())
    return SDValue();

  // Find the type to narrow it the load / op / store to.
  SDValue N1 = Value.getOperand(1);
  unsigned BitWidth = N1.getValueSizeInBits();
  APInt Imm = cast<ConstantSDNode>(N1)->getAPIntValue();
  if (Opc == ISD::AND)
    Imm ^= APInt::getAllOnesValue(BitWidth);
  if (Imm == 0 || Imm.isAllOnesValue())
    return SDValue();
  unsigned ShAmt = Imm.countTrailingZeros();
  unsigned MSB = BitWidth - Imm.countLeadingZeros() - 1;
  unsigned NewBW = NextPowerOf2(MSB - ShAmt);
  EVT NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
  // The narrowing should be profitable, the load/store operation should be
  // legal (or custom) and the store size should be equal to the NewVT width.
  while (NewBW < BitWidth &&
         (NewVT.getStoreSizeInBits() != NewBW ||
          !TLI.isOperationLegalOrCustom(Opc, NewVT) ||
          !TLI.isNarrowingProfitable(VT, NewVT))) {
    NewBW = NextPowerOf2(NewBW);
    NewVT = EVT::getIntegerVT(*DAG.getContext(), NewBW);
  }
  if (NewBW >= BitWidth)
    return SDValue();

  // If the lsb changed does not start at the type bitwidth boundary,
  // start at the previous one.
  if (ShAmt % NewBW)
    ShAmt = (((ShAmt + NewBW - 1) / NewBW) * NewBW) - NewBW;
  APInt Mask = APInt::getBitsSet(BitWidth, ShAmt,
                                 std::min(BitWidth, ShAmt + NewBW));
  if ((Imm & Mask) == Imm) {
    APInt NewImm = (Imm & Mask).lshr(ShAmt).trunc(NewBW);
    if (Opc == ISD::AND)
      NewImm ^= APInt::getAllOnesValue(NewBW);
    uint64_t PtrOff = ShAmt / 8;
    // For big endian targets, we need to adjust the offset to the pointer to
    // load the correct bytes.
    if (DAG.getDataLayout().isBigEndian())
      PtrOff = (BitWidth + 7 - NewBW) / 8 - PtrOff;

    unsigned NewAlign = MinAlign(LD->getAlignment(), PtrOff);
    Type *NewVTTy = NewVT.getTypeForEVT(*DAG.getContext());
    if (NewAlign < DAG.getDataLayout().getABITypeAlignment(NewVTTy))
      return SDValue();

    SDValue NewPtr = DAG.getNode(ISD::ADD, SDLoc(LD),
                                 Ptr.getValueType(), Ptr,
                                 DAG.getConstant(PtrOff, SDLoc(LD),
                                                 Ptr.getValueType()));
    SDValue NewLD =
        DAG.getLoad(NewVT, SDLoc(N0), LD->getChain(), NewPtr,
                    LD->getPointerInfo().getWithOffset(PtrOff), NewAlign,
                    LD->getMemOperand()->getFlags(), LD->getAAInfo());
    SDValue NewVal = DAG.getNode(Opc, SDLoc(Value), NewVT, NewLD,
                                 DAG.getConstant(NewImm, SDLoc(Value),
                                                 NewVT));
    SDValue NewST =
        DAG.getStore(Chain, SDLoc(N), NewVal, NewPtr,
                     ST->getPointerInfo().getWithOffset(PtrOff), NewAlign);

    AddToWorklist(NewPtr.getNode());
    AddToWorklist(NewLD.getNode());
    AddToWorklist(NewVal.getNode());
    WorklistRemover DeadNodes(*this);
    DAG.ReplaceAllUsesOfValueWith(N0.getValue(1), NewLD.getValue(1));
    ++OpsNarrowed;
    return NewST;
  }
}

return SDValue();
12683}

12685/// For a given floating point load / store pair, if the load value isn't used
12686/// by any other operations, then consider transforming the pair to integer
12687/// load / store operations if the target deems the transformation profitable.
12688SDValue DAGCombiner::TransformFPLoadStorePair(SDNode *N) {
StoreSDNode *ST  = cast<StoreSDNode>(N);
SDValue Chain = ST->getChain();
SDValue Value = ST->getValue();
if (ISD::isNormalStore(ST) && ISD::isNormalLoad(Value.getNode()) &&
    Value.hasOneUse() &&
    Chain == SDValue(Value.getNode(), 1)) {
  LoadSDNode *LD = cast<LoadSDNode>(Value);
  EVT VT = LD->getMemoryVT();
  if (!VT.isFloatingPoint() ||
      VT != ST->getMemoryVT() ||
      LD->isNonTemporal() ||
      ST->isNonTemporal() ||
      LD->getPointerInfo().getAddrSpace() != 0 ||
      ST->getPointerInfo().getAddrSpace() != 0)
    return SDValue();

  EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getSizeInBits());
  if (!TLI.isOperationLegal(ISD::LOAD, IntVT) ||
      !TLI.isOperationLegal(ISD::STORE, IntVT) ||
      !TLI.isDesirableToTransformToIntegerOp(ISD::LOAD, VT) ||
      !TLI.isDesirableToTransformToIntegerOp(ISD::STORE, VT))
    return SDValue();

  unsigned LDAlign = LD->getAlignment();
  unsigned STAlign = ST->getAlignment();
  Type *IntVTTy = IntVT.getTypeForEVT(*DAG.getContext());
  unsigned ABIAlign = DAG.getDataLayout().getABITypeAlignment(IntVTTy);
  if (LDAlign < ABIAlign || STAlign < ABIAlign)
    return SDValue();

  SDValue NewLD =
      DAG.getLoad(IntVT, SDLoc(Value), LD->getChain(), LD->getBasePtr(),
                  LD->getPointerInfo(), LDAlign);

  SDValue NewST =
      DAG.getStore(NewLD.getValue(1), SDLoc(N), NewLD, ST->getBasePtr(),
                   ST->getPointerInfo(), STAlign);

  AddToWorklist(NewLD.getNode());
  AddToWorklist(NewST.getNode());
  WorklistRemover DeadNodes(*this);
  DAG.ReplaceAllUsesOfValueWith(Value.getValue(1), NewLD.getValue(1));
  ++LdStFP2Int;
  return NewST;
}

return SDValue();
12736}

12738// This is a helper function for visitMUL to check the profitability
12739// of folding (mul (add x, c1), c2) -> (add (mul x, c2), c1*c2).
12740// MulNode is the original multiply, AddNode is (add x, c1),
12741// and ConstNode is c2.
12742//
12743// If the (add x, c1) has multiple uses, we could increase
12744// the number of adds if we make this transformation.
12745// It would only be worth doing this if we can remove a
12746// multiply in the process. Check for that here.
12747// To illustrate:
12748//     (A + c1) * c3
12749//     (A + c2) * c3
12750// We're checking for cases where we have common "c3 * A" expressions.
12751bool DAGCombiner::isMulAddWithConstProfitable(SDNode *MulNode,
                                            SDValue &AddNode,
                                            SDValue &ConstNode) {
APInt Val;

// If the add only has one use, this would be OK to do.
if (AddNode.getNode()->hasOneUse())
  return true;

// Walk all the users of the constant with which we're multiplying.
for (SDNode *Use : ConstNode->uses()) {
  if (Use == MulNode) // This use is the one we're on right now. Skip it.
    continue;

  if (Use->getOpcode() == ISD::MUL) { // We have another multiply use.
    SDNode *OtherOp;
    SDNode *MulVar = AddNode.getOperand(0).getNode();

    // OtherOp is what we're multiplying against the constant.
    if (Use->getOperand(0) == ConstNode)
      OtherOp = Use->getOperand(1).getNode();
    else
      OtherOp = Use->getOperand(0).getNode();

    // Check to see if multiply is with the same operand of our "add".
    //
    //     ConstNode  = CONST
    //     Use = ConstNode * A  <-- visiting Use. OtherOp is A.
    //     ...
    //     AddNode  = (A + c1)  <-- MulVar is A.
    //         = AddNode * ConstNode   <-- current visiting instruction.
    //
    // If we make this transformation, we will have a common
    // multiply (ConstNode * A) that we can save.
    if (OtherOp == MulVar)
      return true;

    // Now check to see if a future expansion will give us a common
    // multiply.
    //
    //     ConstNode  = CONST
    //     AddNode    = (A + c1)
    //     ...   = AddNode * ConstNode <-- current visiting instruction.
    //     ...
    //     OtherOp = (A + c2)
    //     Use     = OtherOp * ConstNode <-- visiting Use.
    //
    // If we make this transformation, we will have a common
    // multiply (CONST * A) after we also do the same transformation
    // to the "t2" instruction.
    if (OtherOp->getOpcode() == ISD::ADD &&
        DAG.isConstantIntBuildVectorOrConstantInt(OtherOp->getOperand(1)) &&
        OtherOp->getOperand(0).getNode() == MulVar)
      return true;
  }
}

// Didn't find a case where this would be profitable.
return false;
12810}

12812static SDValue peekThroughBitcast(SDValue V) {
while (V.getOpcode() == ISD::BITCAST)
  V = V.getOperand(0);
return V;
12816}

12818SDValue DAGCombiner::getMergeStoreChains(SmallVectorImpl<MemOpLink> &StoreNodes,
                                       unsigned NumStores) {
SmallVector<SDValue, 8> Chains;
SmallPtrSet<const SDNode *, 8> Visited;
SDLoc StoreDL(StoreNodes[0].MemNode);

for (unsigned i = 0; i < NumStores; ++i) {
  Visited.insert(StoreNodes[i].MemNode);
}

// don't include nodes that are children
for (unsigned i = 0; i < NumStores; ++i) {
  if (Visited.count(StoreNodes[i].MemNode->getChain().getNode()) == 0)
    Chains.push_back(StoreNodes[i].MemNode->getChain());
}

assert(Chains.size() > 0 && "Chain should have generated a chain")(static_cast <bool> (Chains.size() > 0 && "Chain should have generated a chain"
) ? void (0) : __assert_fail ("Chains.size() > 0 && \"Chain should have generated a chain\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12834, __extension__ __PRETTY_FUNCTION__));
return DAG.getNode(ISD::TokenFactor, StoreDL, MVT::Other, Chains);
12836}

12838bool DAGCombiner::MergeStoresOfConstantsOrVecElts(
  SmallVectorImpl<MemOpLink> &StoreNodes, EVT MemVT, unsigned NumStores,
  bool IsConstantSrc, bool UseVector, bool UseTrunc) {
// Make sure we have something to merge.
if (NumStores < 2)
  return false;

// The latest Node in the DAG.
SDLoc DL(StoreNodes[0].MemNode);

int64_t ElementSizeBits = MemVT.getStoreSizeInBits();
unsigned SizeInBits = NumStores * ElementSizeBits;
unsigned NumMemElts = MemVT.isVector() ? MemVT.getVectorNumElements() : 1;

EVT StoreTy;
if (UseVector) {
  unsigned Elts = NumStores * NumMemElts;
  // Get the type for the merged vector store.
  StoreTy = EVT::getVectorVT(*DAG.getContext(), MemVT.getScalarType(), Elts);
} else
  StoreTy = EVT::getIntegerVT(*DAG.getContext(), SizeInBits);

SDValue StoredVal;
if (UseVector) {
  if (IsConstantSrc) {
    SmallVector<SDValue, 8> BuildVector;
    for (unsigned I = 0; I != NumStores; ++I) {
      StoreSDNode *St = cast<StoreSDNode>(StoreNodes[I].MemNode);
      SDValue Val = St->getValue();
      // If constant is of the wrong type, convert it now.
      if (MemVT != Val.getValueType()) {
        Val = peekThroughBitcast(Val);
        // Deal with constants of wrong size.
        if (ElementSizeBits != Val.getValueSizeInBits()) {
          EVT IntMemVT =
              EVT::getIntegerVT(*DAG.getContext(), MemVT.getSizeInBits());
          if (isa<ConstantFPSDNode>(Val)) {
            // Not clear how to truncate FP values.
            return false;
          } else if (auto *C = dyn_cast<ConstantSDNode>(Val))
            Val = DAG.getConstant(C->getAPIntValue()
                                      .zextOrTrunc(Val.getValueSizeInBits())
                                      .zextOrTrunc(ElementSizeBits),
                                  SDLoc(C), IntMemVT);
        }
        // Make sure correctly size type is the correct type.
        Val = DAG.getBitcast(MemVT, Val);
      }
      BuildVector.push_back(Val);
    }
    StoredVal = DAG.getNode(MemVT.isVector() ? ISD::CONCAT_VECTORS
                                             : ISD::BUILD_VECTOR,
                            DL, StoreTy, BuildVector);
  } else {
    SmallVector<SDValue, 8> Ops;
    for (unsigned i = 0; i < NumStores; ++i) {
      StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
      SDValue Val = peekThroughBitcast(St->getValue());
      // All operands of BUILD_VECTOR / CONCAT_VECTOR must be of
      // type MemVT. If the underlying value is not the correct
      // type, but it is an extraction of an appropriate vector we
      // can recast Val to be of the correct type. This may require
      // converting between EXTRACT_VECTOR_ELT and
      // EXTRACT_SUBVECTOR.
      if ((MemVT != Val.getValueType()) &&
          (Val.getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
           Val.getOpcode() == ISD::EXTRACT_SUBVECTOR)) {
        SDValue Vec = Val.getOperand(0);
        EVT MemVTScalarTy = MemVT.getScalarType();
        // We may need to add a bitcast here to get types to line up.
        if (MemVTScalarTy != Vec.getValueType()) {
          unsigned Elts = Vec.getValueType().getSizeInBits() /
                          MemVTScalarTy.getSizeInBits();
          EVT NewVecTy =
              EVT::getVectorVT(*DAG.getContext(), MemVTScalarTy, Elts);
          Vec = DAG.getBitcast(NewVecTy, Vec);
        }
        auto OpC = (MemVT.isVector()) ? ISD::EXTRACT_SUBVECTOR
                                      : ISD::EXTRACT_VECTOR_ELT;
        Val = DAG.getNode(OpC, SDLoc(Val), MemVT, Vec, Val.getOperand(1));
      }
      Ops.push_back(Val);
    }

    // Build the extracted vector elements back into a vector.
    StoredVal = DAG.getNode(MemVT.isVector() ? ISD::CONCAT_VECTORS
                                             : ISD::BUILD_VECTOR,
                            DL, StoreTy, Ops);
  }
} else {
  // We should always use a vector store when merging extracted vector
  // elements, so this path implies a store of constants.
  assert(IsConstantSrc && "Merged vector elements should use vector store")(static_cast <bool> (IsConstantSrc && "Merged vector elements should use vector store"
) ? void (0) : __assert_fail ("IsConstantSrc && \"Merged vector elements should use vector store\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12930, __extension__ __PRETTY_FUNCTION__));

  APInt StoreInt(SizeInBits, 0);

  // Construct a single integer constant which is made of the smaller
  // constant inputs.
  bool IsLE = DAG.getDataLayout().isLittleEndian();
  for (unsigned i = 0; i < NumStores; ++i) {
    unsigned Idx = IsLE ? (NumStores - 1 - i) : i;
    StoreSDNode *St  = cast<StoreSDNode>(StoreNodes[Idx].MemNode);

    SDValue Val = St->getValue();
    StoreInt <<= ElementSizeBits;
    if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val)) {
      StoreInt |= C->getAPIntValue()
                      .zextOrTrunc(ElementSizeBits)
                      .zextOrTrunc(SizeInBits);
    } else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Val)) {
      StoreInt |= C->getValueAPF()
                      .bitcastToAPInt()
                      .zextOrTrunc(ElementSizeBits)
                      .zextOrTrunc(SizeInBits);
      // If fp truncation is necessary give up for now.
      if (MemVT.getSizeInBits() != ElementSizeBits)
        return false;
    } else {
      llvm_unreachable("Invalid constant element type")::llvm::llvm_unreachable_internal("Invalid constant element type"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 12956);
    }
  }

  // Create the new Load and Store operations.
  StoredVal = DAG.getConstant(StoreInt, DL, StoreTy);
}

LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
SDValue NewChain = getMergeStoreChains(StoreNodes, NumStores);

// make sure we use trunc store if it's necessary to be legal.
SDValue NewStore;
if (!UseTrunc) {
  NewStore = DAG.getStore(NewChain, DL, StoredVal, FirstInChain->getBasePtr(),
                          FirstInChain->getPointerInfo(),
                          FirstInChain->getAlignment());
} else { // Must be realized as a trunc store
  EVT LegalizedStoredValueTy =
      TLI.getTypeToTransformTo(*DAG.getContext(), StoredVal.getValueType());
  unsigned LegalizedStoreSize = LegalizedStoredValueTy.getSizeInBits();
  ConstantSDNode *C = cast<ConstantSDNode>(StoredVal);
  SDValue ExtendedStoreVal =
      DAG.getConstant(C->getAPIntValue().zextOrTrunc(LegalizedStoreSize), DL,
                      LegalizedStoredValueTy);
  NewStore = DAG.getTruncStore(
      NewChain, DL, ExtendedStoreVal, FirstInChain->getBasePtr(),
      FirstInChain->getPointerInfo(), StoredVal.getValueType() /*TVT*/,
      FirstInChain->getAlignment(),
      FirstInChain->getMemOperand()->getFlags());
}

// Replace all merged stores with the new store.
for (unsigned i = 0; i < NumStores; ++i)
  CombineTo(StoreNodes[i].MemNode, NewStore);

AddToWorklist(NewChain.getNode());
return true;
12994}

12996void DAGCombiner::getStoreMergeCandidates(
  StoreSDNode *St, SmallVectorImpl<MemOpLink> &StoreNodes) {
// This holds the base pointer, index, and the offset in bytes from the base
// pointer.
BaseIndexOffset BasePtr = BaseIndexOffset::match(St, DAG);
EVT MemVT = St->getMemoryVT();

SDValue Val = peekThroughBitcast(St->getValue());
// We must have a base and an offset.
if (!BasePtr.getBase().getNode())
  return;

// Do not handle stores to undef base pointers.
if (BasePtr.getBase().isUndef())
  return;

bool IsConstantSrc = isa<ConstantSDNode>(Val) || isa<ConstantFPSDNode>(Val);
bool IsExtractVecSrc = (Val.getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
                        Val.getOpcode() == ISD::EXTRACT_SUBVECTOR);
bool IsLoadSrc = isa<LoadSDNode>(Val);
BaseIndexOffset LBasePtr;
// Match on loadbaseptr if relevant.
EVT LoadVT;
if (IsLoadSrc) {
  auto *Ld = cast<LoadSDNode>(Val);
  LBasePtr = BaseIndexOffset::match(Ld, DAG);
  LoadVT = Ld->getMemoryVT();
  // Load and store should be the same type.
  if (MemVT != LoadVT)
    return;
}
auto CandidateMatch = [&](StoreSDNode *Other, BaseIndexOffset &Ptr,
                          int64_t &Offset) -> bool {
  if (Other->isVolatile() || Other->isIndexed())
    return false;
  SDValue Val = peekThroughBitcast(Other->getValue());
  // Allow merging constants of different types as integers.
  bool NoTypeMatch = (MemVT.isInteger()) ? !MemVT.bitsEq(Other->getMemoryVT())
                                         : Other->getMemoryVT() != MemVT;
  if (IsLoadSrc) {
    if (NoTypeMatch)
      return false;
    // The Load's Base Ptr must also match
    if (LoadSDNode *OtherLd = dyn_cast<LoadSDNode>(Val)) {
      auto LPtr = BaseIndexOffset::match(OtherLd, DAG);
      if (LoadVT != OtherLd->getMemoryVT())
        return false;
      if (!(LBasePtr.equalBaseIndex(LPtr, DAG)))
        return false;
    } else
      return false;
  }
  if (IsConstantSrc) {
    if (NoTypeMatch)
      return false;
    if (!(isa<ConstantSDNode>(Val) || isa<ConstantFPSDNode>(Val)))
      return false;
  }
  if (IsExtractVecSrc) {
    // Do not merge truncated stores here.
    if (Other->isTruncatingStore())
      return false;
    if (!MemVT.bitsEq(Val.getValueType()))
      return false;
    if (Val.getOpcode() != ISD::EXTRACT_VECTOR_ELT &&
        Val.getOpcode() != ISD::EXTRACT_SUBVECTOR)
      return false;
  }
  Ptr = BaseIndexOffset::match(Other, DAG);
  return (BasePtr.equalBaseIndex(Ptr, DAG, Offset));
};

// We looking for a root node which is an ancestor to all mergable
// stores. We search up through a load, to our root and then down
// through all children. For instance we will find Store{1,2,3} if
// St is Store1, Store2. or Store3 where the root is not a load
// which always true for nonvolatile ops. TODO: Expand
// the search to find all valid candidates through multiple layers of loads.
//
// Root
// |-------|-------|
// Load    Load    Store3
// |       |
// Store1   Store2
//
// FIXME: We should be able to climb and
// descend TokenFactors to find candidates as well.

SDNode *RootNode = (St->getChain()).getNode();

if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(RootNode)) {
  RootNode = Ldn->getChain().getNode();
  for (auto I = RootNode->use_begin(), E = RootNode->use_end(); I != E; ++I)
    if (I.getOperandNo() == 0 && isa<LoadSDNode>(*I)) // walk down chain
      for (auto I2 = (*I)->use_begin(), E2 = (*I)->use_end(); I2 != E2; ++I2)
        if (I2.getOperandNo() == 0)
          if (StoreSDNode *OtherST = dyn_cast<StoreSDNode>(*I2)) {
            BaseIndexOffset Ptr;
            int64_t PtrDiff;
            if (CandidateMatch(OtherST, Ptr, PtrDiff))
              StoreNodes.push_back(MemOpLink(OtherST, PtrDiff));
          }
} else
  for (auto I = RootNode->use_begin(), E = RootNode->use_end(); I != E; ++I)
    if (I.getOperandNo() == 0)
      if (StoreSDNode *OtherST = dyn_cast<StoreSDNode>(*I)) {
        BaseIndexOffset Ptr;
        int64_t PtrDiff;
        if (CandidateMatch(OtherST, Ptr, PtrDiff))
          StoreNodes.push_back(MemOpLink(OtherST, PtrDiff));
      }
13107}

13109// We need to check that merging these stores does not cause a loop in
13110// the DAG. Any store candidate may depend on another candidate
13111// indirectly through its operand (we already consider dependencies
13112// through the chain). Check in parallel by searching up from
13113// non-chain operands of candidates.
13114bool DAGCombiner::checkMergeStoreCandidatesForDependencies(
  SmallVectorImpl<MemOpLink> &StoreNodes, unsigned NumStores) {
// FIXME: We should be able to truncate a full search of
// predecessors by doing a BFS and keeping tabs the originating
// stores from which worklist nodes come from in a similar way to
// TokenFactor simplfication.

SmallPtrSet<const SDNode *, 16> Visited;
SmallVector<const SDNode *, 8> Worklist;
unsigned int Max = 8192;
// Search Ops of store candidates.
for (unsigned i = 0; i < NumStores; ++i) {
  SDNode *n = StoreNodes[i].MemNode;
  // Potential loops may happen only through non-chain operands
  for (unsigned j = 1; j < n->getNumOperands(); ++j)
    Worklist.push_back(n->getOperand(j).getNode());
}
// Search through DAG. We can stop early if we find a store node.
for (unsigned i = 0; i < NumStores; ++i) {
  if (SDNode::hasPredecessorHelper(StoreNodes[i].MemNode, Visited, Worklist,
                                   Max))
    return false;
  // Check if we ended early, failing conservatively if so.
  if (Visited.size() >= Max)
    return false;
}
return true;
13141}

13143bool DAGCombiner::MergeConsecutiveStores(StoreSDNode *St) {
if (OptLevel == CodeGenOpt::None)
  return false;

EVT MemVT = St->getMemoryVT();
int64_t ElementSizeBytes = MemVT.getStoreSize();
unsigned NumMemElts = MemVT.isVector() ? MemVT.getVectorNumElements() : 1;

if (MemVT.getSizeInBits() * 2 > MaximumLegalStoreInBits)
  return false;

bool NoVectors = DAG.getMachineFunction().getFunction().hasFnAttribute(
    Attribute::NoImplicitFloat);

// This function cannot currently deal with non-byte-sized memory sizes.
if (ElementSizeBytes * 8 != MemVT.getSizeInBits())
  return false;

if (!MemVT.isSimple())
  return false;

// Perform an early exit check. Do not bother looking at stored values that
// are not constants, loads, or extracted vector elements.
SDValue StoredVal = peekThroughBitcast(St->getValue());
bool IsLoadSrc = isa<LoadSDNode>(StoredVal);
bool IsConstantSrc = isa<ConstantSDNode>(StoredVal) ||
                     isa<ConstantFPSDNode>(StoredVal);
bool IsExtractVecSrc = (StoredVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT ||
                        StoredVal.getOpcode() == ISD::EXTRACT_SUBVECTOR);

if (!IsConstantSrc && !IsLoadSrc && !IsExtractVecSrc)
  return false;

SmallVector<MemOpLink, 8> StoreNodes;
// Find potential store merge candidates by searching through chain sub-DAG
getStoreMergeCandidates(St, StoreNodes);

// Check if there is anything to merge.
if (StoreNodes.size() < 2)
  return false;

// Sort the memory operands according to their distance from the
// base pointer.
std::sort(StoreNodes.begin(), StoreNodes.end(),
          [](MemOpLink LHS, MemOpLink RHS) {
            return LHS.OffsetFromBase < RHS.OffsetFromBase;
          });

// Store Merge attempts to merge the lowest stores. This generally
// works out as if successful, as the remaining stores are checked
// after the first collection of stores is merged. However, in the
// case that a non-mergeable store is found first, e.g., {p[-2],
// p[0], p[1], p[2], p[3]}, we would fail and miss the subsequent
// mergeable cases. To prevent this, we prune such stores from the
// front of StoreNodes here.

bool RV = false;
while (StoreNodes.size() > 1) {
  unsigned StartIdx = 0;
  while ((StartIdx + 1 < StoreNodes.size()) &&
         StoreNodes[StartIdx].OffsetFromBase + ElementSizeBytes !=
             StoreNodes[StartIdx + 1].OffsetFromBase)
    ++StartIdx;

  // Bail if we don't have enough candidates to merge.
  if (StartIdx + 1 >= StoreNodes.size())
    return RV;

  if (StartIdx)
    StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + StartIdx);

  // Scan the memory operations on the chain and find the first
  // non-consecutive store memory address.
  unsigned NumConsecutiveStores = 1;
  int64_t StartAddress = StoreNodes[0].OffsetFromBase;
  // Check that the addresses are consecutive starting from the second
  // element in the list of stores.
  for (unsigned i = 1, e = StoreNodes.size(); i < e; ++i) {
    int64_t CurrAddress = StoreNodes[i].OffsetFromBase;
    if (CurrAddress - StartAddress != (ElementSizeBytes * i))
      break;
    NumConsecutiveStores = i + 1;
  }

  if (NumConsecutiveStores < 2) {
    StoreNodes.erase(StoreNodes.begin(),
                     StoreNodes.begin() + NumConsecutiveStores);
    continue;
  }

  // Check that we can merge these candidates without causing a cycle
  if (!checkMergeStoreCandidatesForDependencies(StoreNodes,
                                                NumConsecutiveStores)) {
    StoreNodes.erase(StoreNodes.begin(),
                     StoreNodes.begin() + NumConsecutiveStores);
    continue;
  }

  // The node with the lowest store address.
  LLVMContext &Context = *DAG.getContext();
  const DataLayout &DL = DAG.getDataLayout();

  // Store the constants into memory as one consecutive store.
  if (IsConstantSrc) {
    LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
    unsigned FirstStoreAS = FirstInChain->getAddressSpace();
    unsigned FirstStoreAlign = FirstInChain->getAlignment();
    unsigned LastLegalType = 1;
    unsigned LastLegalVectorType = 1;
    bool LastIntegerTrunc = false;
    bool NonZero = false;
    unsigned FirstZeroAfterNonZero = NumConsecutiveStores;
    for (unsigned i = 0; i < NumConsecutiveStores; ++i) {
      StoreSDNode *ST = cast<StoreSDNode>(StoreNodes[i].MemNode);
      SDValue StoredVal = ST->getValue();
      bool IsElementZero = false;
      if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(StoredVal))
        IsElementZero = C->isNullValue();
      else if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(StoredVal))
        IsElementZero = C->getConstantFPValue()->isNullValue();
      if (IsElementZero) {
        if (NonZero && FirstZeroAfterNonZero == NumConsecutiveStores)
          FirstZeroAfterNonZero = i;
      }
      NonZero |= !IsElementZero;

      // Find a legal type for the constant store.
      unsigned SizeInBits = (i + 1) * ElementSizeBytes * 8;
      EVT StoreTy = EVT::getIntegerVT(Context, SizeInBits);
      bool IsFast = false;
      if (TLI.isTypeLegal(StoreTy) &&
          TLI.canMergeStoresTo(FirstStoreAS, StoreTy, DAG) &&
          TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstStoreAS,
                                 FirstStoreAlign, &IsFast) &&
          IsFast) {
        LastIntegerTrunc = false;
        LastLegalType = i + 1;
        // Or check whether a truncstore is legal.
      } else if (TLI.getTypeAction(Context, StoreTy) ==
                 TargetLowering::TypePromoteInteger) {
        EVT LegalizedStoredValueTy =
            TLI.getTypeToTransformTo(Context, StoredVal.getValueType());
        if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
            TLI.canMergeStoresTo(FirstStoreAS, LegalizedStoredValueTy, DAG) &&
            TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstStoreAS,
                                   FirstStoreAlign, &IsFast) &&
            IsFast) {
          LastIntegerTrunc = true;
          LastLegalType = i + 1;
        }
      }

      // We only use vectors if the constant is known to be zero or the target
      // allows it and the function is not marked with the noimplicitfloat
      // attribute.
      if ((!NonZero ||
           TLI.storeOfVectorConstantIsCheap(MemVT, i + 1, FirstStoreAS)) &&
          !NoVectors) {
        // Find a legal type for the vector store.
        unsigned Elts = (i + 1) * NumMemElts;
        EVT Ty = EVT::getVectorVT(Context, MemVT.getScalarType(), Elts);
        if (TLI.isTypeLegal(Ty) && TLI.isTypeLegal(MemVT) &&
            TLI.canMergeStoresTo(FirstStoreAS, Ty, DAG) &&
            TLI.allowsMemoryAccess(Context, DL, Ty, FirstStoreAS,
                                   FirstStoreAlign, &IsFast) &&
            IsFast)
          LastLegalVectorType = i + 1;
      }
    }

    bool UseVector = (LastLegalVectorType > LastLegalType) && !NoVectors;
    unsigned NumElem = (UseVector) ? LastLegalVectorType : LastLegalType;

    // Check if we found a legal integer type that creates a meaningful merge.
    if (NumElem < 2) {
      // We know that candidate stores are in order and of correct
      // shape. While there is no mergeable sequence from the
      // beginning one may start later in the sequence. The only
      // reason a merge of size N could have failed where another of
      // the same size would not have, is if the alignment has
      // improved or we've dropped a non-zero value. Drop as many
      // candidates as we can here.
      unsigned NumSkip = 1;
      while (
          (NumSkip < NumConsecutiveStores) &&
          (NumSkip < FirstZeroAfterNonZero) &&
          (StoreNodes[NumSkip].MemNode->getAlignment() <= FirstStoreAlign)) {
        NumSkip++;
      }
      StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumSkip);
      continue;
    }

    bool Merged = MergeStoresOfConstantsOrVecElts(
        StoreNodes, MemVT, NumElem, true, UseVector, LastIntegerTrunc);
    RV |= Merged;

    // Remove merged stores for next iteration.
    StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumElem);
    continue;
  }

  // When extracting multiple vector elements, try to store them
  // in one vector store rather than a sequence of scalar stores.
  if (IsExtractVecSrc) {
    LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
    unsigned FirstStoreAS = FirstInChain->getAddressSpace();
    unsigned FirstStoreAlign = FirstInChain->getAlignment();
    unsigned NumStoresToMerge = 1;
    for (unsigned i = 0; i < NumConsecutiveStores; ++i) {
      StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
      SDValue StVal = peekThroughBitcast(St->getValue());
      // This restriction could be loosened.
      // Bail out if any stored values are not elements extracted from a
      // vector. It should be possible to handle mixed sources, but load
      // sources need more careful handling (see the block of code below that
      // handles consecutive loads).
      if (StVal.getOpcode() != ISD::EXTRACT_VECTOR_ELT &&
          StVal.getOpcode() != ISD::EXTRACT_SUBVECTOR)
        return RV;

      // Find a legal type for the vector store.
      unsigned Elts = (i + 1) * NumMemElts;
      EVT Ty =
          EVT::getVectorVT(*DAG.getContext(), MemVT.getScalarType(), Elts);
      bool IsFast;
      if (TLI.isTypeLegal(Ty) &&
          TLI.canMergeStoresTo(FirstStoreAS, Ty, DAG) &&
          TLI.allowsMemoryAccess(Context, DL, Ty, FirstStoreAS,
                                 FirstStoreAlign, &IsFast) &&
          IsFast)
        NumStoresToMerge = i + 1;
    }

    // Check if we found a legal integer type that creates a meaningful merge.
    if (NumStoresToMerge < 2) {
      // We know that candidate stores are in order and of correct
      // shape. While there is no mergeable sequence from the
      // beginning one may start later in the sequence. The only
      // reason a merge of size N could have failed where another of
      // the same size would not have, is if the alignment has
      // improved. Drop as many candidates as we can here.
      unsigned NumSkip = 1;
      while ((NumSkip < NumConsecutiveStores) &&
             (StoreNodes[NumSkip].MemNode->getAlignment() <= FirstStoreAlign))
        NumSkip++;

      StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumSkip);
      continue;
    }

    bool Merged = MergeStoresOfConstantsOrVecElts(
        StoreNodes, MemVT, NumStoresToMerge, false, true, false);
    if (!Merged) {
      StoreNodes.erase(StoreNodes.begin(),
                       StoreNodes.begin() + NumStoresToMerge);
      continue;
    }
    // Remove merged stores for next iteration.
    StoreNodes.erase(StoreNodes.begin(),
                     StoreNodes.begin() + NumStoresToMerge);
    RV = true;
    continue;
  }

  // Below we handle the case of multiple consecutive stores that
  // come from multiple consecutive loads. We merge them into a single
  // wide load and a single wide store.

  // Look for load nodes which are used by the stored values.
  SmallVector<MemOpLink, 8> LoadNodes;

  // Find acceptable loads. Loads need to have the same chain (token factor),
  // must not be zext, volatile, indexed, and they must be consecutive.
  BaseIndexOffset LdBasePtr;
  for (unsigned i = 0; i < NumConsecutiveStores; ++i) {
    StoreSDNode *St = cast<StoreSDNode>(StoreNodes[i].MemNode);
    SDValue Val = peekThroughBitcast(St->getValue());
    LoadSDNode *Ld = dyn_cast<LoadSDNode>(Val);
    if (!Ld)
      break;

    // Loads must only have one use.
    if (!Ld->hasNUsesOfValue(1, 0))
      break;

    // The memory operands must not be volatile.
    if (Ld->isVolatile() || Ld->isIndexed())
      break;

    // The stored memory type must be the same.
    if (Ld->getMemoryVT() != MemVT)
      break;

    BaseIndexOffset LdPtr = BaseIndexOffset::match(Ld, DAG);
    // If this is not the first ptr that we check.
    int64_t LdOffset = 0;
    if (LdBasePtr.getBase().getNode()) {
      // The base ptr must be the same.
      if (!LdBasePtr.equalBaseIndex(LdPtr, DAG, LdOffset))
        break;
    } else {
      // Check that all other base pointers are the same as this one.
      LdBasePtr = LdPtr;
    }

    // We found a potential memory operand to merge.
    LoadNodes.push_back(MemOpLink(Ld, LdOffset));
  }

  if (LoadNodes.size() < 2) {
    StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + 1);
    continue;
  }

  // If we have load/store pair instructions and we only have two values,
  // don't bother merging.
  unsigned RequiredAlignment;
  if (LoadNodes.size() == 2 && TLI.hasPairedLoad(MemVT, RequiredAlignment) &&
      StoreNodes[0].MemNode->getAlignment() >= RequiredAlignment) {
    StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + 2);
    continue;
  }
  LSBaseSDNode *FirstInChain = StoreNodes[0].MemNode;
  unsigned FirstStoreAS = FirstInChain->getAddressSpace();
  unsigned FirstStoreAlign = FirstInChain->getAlignment();
  LoadSDNode *FirstLoad = cast<LoadSDNode>(LoadNodes[0].MemNode);
  unsigned FirstLoadAS = FirstLoad->getAddressSpace();
  unsigned FirstLoadAlign = FirstLoad->getAlignment();

  // Scan the memory operations on the chain and find the first
  // non-consecutive load memory address. These variables hold the index in
  // the store node array.
  unsigned LastConsecutiveLoad = 1;
  // This variable refers to the size and not index in the array.
  unsigned LastLegalVectorType = 1;
  unsigned LastLegalIntegerType = 1;
  bool isDereferenceable = true;
  bool DoIntegerTruncate = false;
  StartAddress = LoadNodes[0].OffsetFromBase;
  SDValue FirstChain = FirstLoad->getChain();
  for (unsigned i = 1; i < LoadNodes.size(); ++i) {
    // All loads must share the same chain.
    if (LoadNodes[i].MemNode->getChain() != FirstChain)
      break;

    int64_t CurrAddress = LoadNodes[i].OffsetFromBase;
    if (CurrAddress - StartAddress != (ElementSizeBytes * i))
      break;
    LastConsecutiveLoad = i;

    if (isDereferenceable && !LoadNodes[i].MemNode->isDereferenceable())
      isDereferenceable = false;

    // Find a legal type for the vector store.
    unsigned Elts = (i + 1) * NumMemElts;
    EVT StoreTy = EVT::getVectorVT(Context, MemVT.getScalarType(), Elts);

    bool IsFastSt, IsFastLd;
    if (TLI.isTypeLegal(StoreTy) &&
        TLI.canMergeStoresTo(FirstStoreAS, StoreTy, DAG) &&
        TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstStoreAS,
                               FirstStoreAlign, &IsFastSt) &&
        IsFastSt &&
        TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstLoadAS,
                               FirstLoadAlign, &IsFastLd) &&
        IsFastLd) {
      LastLegalVectorType = i + 1;
    }

    // Find a legal type for the integer store.
    unsigned SizeInBits = (i + 1) * ElementSizeBytes * 8;
    StoreTy = EVT::getIntegerVT(Context, SizeInBits);
    if (TLI.isTypeLegal(StoreTy) &&
        TLI.canMergeStoresTo(FirstStoreAS, StoreTy, DAG) &&
        TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstStoreAS,
                               FirstStoreAlign, &IsFastSt) &&
        IsFastSt &&
        TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstLoadAS,
                               FirstLoadAlign, &IsFastLd) &&
        IsFastLd) {
      LastLegalIntegerType = i + 1;
      DoIntegerTruncate = false;
      // Or check whether a truncstore and extload is legal.
    } else if (TLI.getTypeAction(Context, StoreTy) ==
               TargetLowering::TypePromoteInteger) {
      EVT LegalizedStoredValueTy = TLI.getTypeToTransformTo(Context, StoreTy);
      if (TLI.isTruncStoreLegal(LegalizedStoredValueTy, StoreTy) &&
          TLI.canMergeStoresTo(FirstStoreAS, LegalizedStoredValueTy, DAG) &&
          TLI.isLoadExtLegal(ISD::ZEXTLOAD, LegalizedStoredValueTy,
                             StoreTy) &&
          TLI.isLoadExtLegal(ISD::SEXTLOAD, LegalizedStoredValueTy,
                             StoreTy) &&
          TLI.isLoadExtLegal(ISD::EXTLOAD, LegalizedStoredValueTy, StoreTy) &&
          TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstStoreAS,
                                 FirstStoreAlign, &IsFastSt) &&
          IsFastSt &&
          TLI.allowsMemoryAccess(Context, DL, StoreTy, FirstLoadAS,
                                 FirstLoadAlign, &IsFastLd) &&
          IsFastLd) {
        LastLegalIntegerType = i + 1;
        DoIntegerTruncate = true;
      }
    }
  }

  // Only use vector types if the vector type is larger than the integer type.
  // If they are the same, use integers.
  bool UseVectorTy = LastLegalVectorType > LastLegalIntegerType && !NoVectors;
  unsigned LastLegalType =
      std::max(LastLegalVectorType, LastLegalIntegerType);

  // We add +1 here because the LastXXX variables refer to location while
  // the NumElem refers to array/index size.
  unsigned NumElem = std::min(NumConsecutiveStores, LastConsecutiveLoad + 1);
  NumElem = std::min(LastLegalType, NumElem);

  if (NumElem < 2) {
    // We know that candidate stores are in order and of correct
    // shape. While there is no mergeable sequence from the
    // beginning one may start later in the sequence. The only
    // reason a merge of size N could have failed where another of
    // the same size would not have is if the alignment or either
    // the load or store has improved. Drop as many candidates as we
    // can here.
    unsigned NumSkip = 1;
    while ((NumSkip < LoadNodes.size()) &&
           (LoadNodes[NumSkip].MemNode->getAlignment() <= FirstLoadAlign) &&
           (StoreNodes[NumSkip].MemNode->getAlignment() <= FirstStoreAlign))
      NumSkip++;
    StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumSkip);
    continue;
  }

  // Find if it is better to use vectors or integers to load and store
  // to memory.
  EVT JointMemOpVT;
  if (UseVectorTy) {
    // Find a legal type for the vector store.
    unsigned Elts = NumElem * NumMemElts;
    JointMemOpVT = EVT::getVectorVT(Context, MemVT.getScalarType(), Elts);
  } else {
    unsigned SizeInBits = NumElem * ElementSizeBytes * 8;
    JointMemOpVT = EVT::getIntegerVT(Context, SizeInBits);
  }

  SDLoc LoadDL(LoadNodes[0].MemNode);
  SDLoc StoreDL(StoreNodes[0].MemNode);

  // The merged loads are required to have the same incoming chain, so
  // using the first's chain is acceptable.

  SDValue NewStoreChain = getMergeStoreChains(StoreNodes, NumElem);
  AddToWorklist(NewStoreChain.getNode());

  MachineMemOperand::Flags MMOFlags = isDereferenceable ?
                                        MachineMemOperand::MODereferenceable:
                                        MachineMemOperand::MONone;

  SDValue NewLoad, NewStore;
  if (UseVectorTy || !DoIntegerTruncate) {
    NewLoad = DAG.getLoad(JointMemOpVT, LoadDL, FirstLoad->getChain(),
                          FirstLoad->getBasePtr(),
                          FirstLoad->getPointerInfo(), FirstLoadAlign,
                          MMOFlags);
    NewStore = DAG.getStore(NewStoreChain, StoreDL, NewLoad,
                            FirstInChain->getBasePtr(),
                            FirstInChain->getPointerInfo(), FirstStoreAlign);
  } else { // This must be the truncstore/extload case
    EVT ExtendedTy =
        TLI.getTypeToTransformTo(*DAG.getContext(), JointMemOpVT);
    NewLoad =
        DAG.getExtLoad(ISD::EXTLOAD, LoadDL, ExtendedTy, FirstLoad->getChain(),
                       FirstLoad->getBasePtr(), FirstLoad->getPointerInfo(),
                       JointMemOpVT, FirstLoadAlign, MMOFlags);
    NewStore = DAG.getTruncStore(NewStoreChain, StoreDL, NewLoad,
                                 FirstInChain->getBasePtr(),
                                 FirstInChain->getPointerInfo(), JointMemOpVT,
                                 FirstInChain->getAlignment(),
                                 FirstInChain->getMemOperand()->getFlags());
  }

  // Transfer chain users from old loads to the new load.
  for (unsigned i = 0; i < NumElem; ++i) {
    LoadSDNode *Ld = cast<LoadSDNode>(LoadNodes[i].MemNode);
    DAG.ReplaceAllUsesOfValueWith(SDValue(Ld, 1),
                                  SDValue(NewLoad.getNode(), 1));
  }

  // Replace the all stores with the new store. Recursively remove
  // corresponding value if its no longer used.
  for (unsigned i = 0; i < NumElem; ++i) {
    SDValue Val = StoreNodes[i].MemNode->getOperand(1);
    CombineTo(StoreNodes[i].MemNode, NewStore);
    if (Val.getNode()->use_empty())
      recursivelyDeleteUnusedNodes(Val.getNode());
  }

  RV = true;
  StoreNodes.erase(StoreNodes.begin(), StoreNodes.begin() + NumElem);
}
return RV;
13645}

13647SDValue DAGCombiner::replaceStoreChain(StoreSDNode *ST, SDValue BetterChain) {
SDLoc SL(ST);
SDValue ReplStore;

// Replace the chain to avoid dependency.
if (ST->isTruncatingStore()) {
  ReplStore = DAG.getTruncStore(BetterChain, SL, ST->getValue(),
                                ST->getBasePtr(), ST->getMemoryVT(),
                                ST->getMemOperand());
} else {
  ReplStore = DAG.getStore(BetterChain, SL, ST->getValue(), ST->getBasePtr(),
                           ST->getMemOperand());
}

// Create token to keep both nodes around.
SDValue Token = DAG.getNode(ISD::TokenFactor, SL,
                            MVT::Other, ST->getChain(), ReplStore);

// Make sure the new and old chains are cleaned up.
AddToWorklist(Token.getNode());

// Don't add users to work list.
return CombineTo(ST, Token, false);
13670}

13672SDValue DAGCombiner::replaceStoreOfFPConstant(StoreSDNode *ST) {
SDValue Value = ST->getValue();
if (Value.getOpcode() == ISD::TargetConstantFP)
  return SDValue();

SDLoc DL(ST);

SDValue Chain = ST->getChain();
SDValue Ptr = ST->getBasePtr();

const ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(Value);

// NOTE: If the original store is volatile, this transform must not increase
// the number of stores.  For example, on x86-32 an f64 can be stored in one
// processor operation but an i64 (which is not legal) requires two.  So the
// transform should not be done in this case.

SDValue Tmp;
switch (CFP->getSimpleValueType(0).SimpleTy) {
default:
  llvm_unreachable("Unknown FP type")::llvm::llvm_unreachable_internal("Unknown FP type", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 13692);
case MVT::f16:    // We don't do this for these yet.
case MVT::f80:
case MVT::f128:
case MVT::ppcf128:
  return SDValue();
case MVT::f32:
  if ((isTypeLegal(MVT::i32) && !LegalOperations && !ST->isVolatile()) ||
      TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
    ;
    Tmp = DAG.getConstant((uint32_t)CFP->getValueAPF().
                          bitcastToAPInt().getZExtValue(), SDLoc(CFP),
                          MVT::i32);
    return DAG.getStore(Chain, DL, Tmp, Ptr, ST->getMemOperand());
  }

  return SDValue();
case MVT::f64:
  if ((TLI.isTypeLegal(MVT::i64) && !LegalOperations &&
       !ST->isVolatile()) ||
      TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i64)) {
    ;
    Tmp = DAG.getConstant(CFP->getValueAPF().bitcastToAPInt().
                          getZExtValue(), SDLoc(CFP), MVT::i64);
    return DAG.getStore(Chain, DL, Tmp,
                        Ptr, ST->getMemOperand());
  }

  if (!ST->isVolatile() &&
      TLI.isOperationLegalOrCustom(ISD::STORE, MVT::i32)) {
    // Many FP stores are not made apparent until after legalize, e.g. for
    // argument passing.  Since this is so common, custom legalize the
    // 64-bit integer store into two 32-bit stores.
    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
    SDValue Lo = DAG.getConstant(Val & 0xFFFFFFFF, SDLoc(CFP), MVT::i32);
    SDValue Hi = DAG.getConstant(Val >> 32, SDLoc(CFP), MVT::i32);
    if (DAG.getDataLayout().isBigEndian())
      std::swap(Lo, Hi);

    unsigned Alignment = ST->getAlignment();
    MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
    AAMDNodes AAInfo = ST->getAAInfo();

    SDValue St0 = DAG.getStore(Chain, DL, Lo, Ptr, ST->getPointerInfo(),
                               ST->getAlignment(), MMOFlags, AAInfo);
    Ptr = DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
                      DAG.getConstant(4, DL, Ptr.getValueType()));
    Alignment = MinAlign(Alignment, 4U);
    SDValue St1 = DAG.getStore(Chain, DL, Hi, Ptr,
                               ST->getPointerInfo().getWithOffset(4),
                               Alignment, MMOFlags, AAInfo);
    return DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
                       St0, St1);
  }

  return SDValue();
}
13749}

13751SDValue DAGCombiner::visitSTORE(SDNode *N) {
StoreSDNode *ST  = cast<StoreSDNode>(N);
SDValue Chain = ST->getChain();
SDValue Value = ST->getValue();
SDValue Ptr   = ST->getBasePtr();

// If this is a store of a bit convert, store the input value if the
// resultant store does not need a higher alignment than the original.
if (Value.getOpcode() == ISD::BITCAST && !ST->isTruncatingStore() &&
    ST->isUnindexed()) {
  EVT SVT = Value.getOperand(0).getValueType();
  if (((!LegalOperations && !ST->isVolatile()) ||
       TLI.isOperationLegalOrCustom(ISD::STORE, SVT)) &&
      TLI.isStoreBitCastBeneficial(Value.getValueType(), SVT)) {
    unsigned OrigAlign = ST->getAlignment();
    bool Fast = false;
    if (TLI.allowsMemoryAccess(*DAG.getContext(), DAG.getDataLayout(), SVT,
                               ST->getAddressSpace(), OrigAlign, &Fast) &&
        Fast) {
      return DAG.getStore(Chain, SDLoc(N), Value.getOperand(0), Ptr,
                          ST->getPointerInfo(), OrigAlign,
                          ST->getMemOperand()->getFlags(), ST->getAAInfo());
    }
  }
}

// Turn 'store undef, Ptr' -> nothing.
if (Value.isUndef() && ST->isUnindexed())
  return Chain;

// Try to infer better alignment information than the store already has.
if (OptLevel != CodeGenOpt::None && ST->isUnindexed()) {
  if (unsigned Align = DAG.InferPtrAlignment(Ptr)) {
    if (Align > ST->getAlignment()) {
      SDValue NewStore =
          DAG.getTruncStore(Chain, SDLoc(N), Value, Ptr, ST->getPointerInfo(),
                            ST->getMemoryVT(), Align,
                            ST->getMemOperand()->getFlags(), ST->getAAInfo());
      if (NewStore.getNode() != N)
        return CombineTo(ST, NewStore, true);
    }
  }
}

// Try transforming a pair floating point load / store ops to integer
// load / store ops.
if (SDValue NewST = TransformFPLoadStorePair(N))
  return NewST;

if (ST->isUnindexed()) {
  // Walk up chain skipping non-aliasing memory nodes, on this store and any
  // adjacent stores.
  if (findBetterNeighborChains(ST)) {
    // replaceStoreChain uses CombineTo, which handled all of the worklist
    // manipulation. Return the original node to not do anything else.
    return SDValue(ST, 0);
  }
  Chain = ST->getChain();
}

// FIXME: is there such a thing as a truncating indexed store?
if (ST->isTruncatingStore() && ST->isUnindexed() &&
    Value.getValueType().isInteger()) {
  // See if we can simplify the input to this truncstore with knowledge that
  // only the low bits are being used.  For example:
  // "truncstore (or (shl x, 8), y), i8"  -> "truncstore y, i8"
  SDValue Shorter = DAG.GetDemandedBits(
      Value, APInt::getLowBitsSet(Value.getScalarValueSizeInBits(),
                                  ST->getMemoryVT().getScalarSizeInBits()));
  AddToWorklist(Value.getNode());
  if (Shorter.getNode())
    return DAG.getTruncStore(Chain, SDLoc(N), Shorter,
                             Ptr, ST->getMemoryVT(), ST->getMemOperand());

  // Otherwise, see if we can simplify the operation with
  // SimplifyDemandedBits, which only works if the value has a single use.
  if (SimplifyDemandedBits(
          Value,
          APInt::getLowBitsSet(Value.getScalarValueSizeInBits(),
                               ST->getMemoryVT().getScalarSizeInBits()))) {
    // Re-visit the store if anything changed and the store hasn't been merged
    // with another node (N is deleted) SimplifyDemandedBits will add Value's
    // node back to the worklist if necessary, but we also need to re-visit
    // the Store node itself.
    if (N->getOpcode() != ISD::DELETED_NODE)
      AddToWorklist(N);
    return SDValue(N, 0);
  }
}

// If this is a load followed by a store to the same location, then the store
// is dead/noop.
if (LoadSDNode *Ld = dyn_cast<LoadSDNode>(Value)) {
  if (Ld->getBasePtr() == Ptr && ST->getMemoryVT() == Ld->getMemoryVT() &&
      ST->isUnindexed() && !ST->isVolatile() &&
      // There can't be any side effects between the load and store, such as
      // a call or store.
      Chain.reachesChainWithoutSideEffects(SDValue(Ld, 1))) {
    // The store is dead, remove it.
    return Chain;
  }
}

if (StoreSDNode *ST1 = dyn_cast<StoreSDNode>(Chain)) {
  if (ST->isUnindexed() && !ST->isVolatile() && ST1->isUnindexed() &&
      !ST1->isVolatile() && ST1->getBasePtr() == Ptr &&
      ST->getMemoryVT() == ST1->getMemoryVT()) {
    // If this is a store followed by a store with the same value to the same
    // location, then the store is dead/noop.
    if (ST1->getValue() == Value) {
      // The store is dead, remove it.
      return Chain;
    }

    // If this is a store who's preceeding store to the same location
    // and no one other node is chained to that store we can effectively
    // drop the store. Do not remove stores to undef as they may be used as
    // data sinks.
    if (OptLevel != CodeGenOpt::None && ST1->hasOneUse() &&
        !ST1->getBasePtr().isUndef()) {
      // ST1 is fully overwritten and can be elided. Combine with it's chain
      // value.
      CombineTo(ST1, ST1->getChain());
      return SDValue();
    }
  }
}

// If this is an FP_ROUND or TRUNC followed by a store, fold this into a
// truncating store.  We can do this even if this is already a truncstore.
if ((Value.getOpcode() == ISD::FP_ROUND || Value.getOpcode() == ISD::TRUNCATE)
    && Value.getNode()->hasOneUse() && ST->isUnindexed() &&
    TLI.isTruncStoreLegal(Value.getOperand(0).getValueType(),
                          ST->getMemoryVT())) {
  return DAG.getTruncStore(Chain, SDLoc(N), Value.getOperand(0),
                           Ptr, ST->getMemoryVT(), ST->getMemOperand());
}

// Always perform this optimization before types are legal. If the target
// prefers, also try this after legalization to catch stores that were created
// by intrinsics or other nodes.
if (!LegalTypes || (TLI.mergeStoresAfterLegalization())) {
  while (true) {
    // There can be multiple store sequences on the same chain.
    // Keep trying to merge store sequences until we are unable to do so
    // or until we merge the last store on the chain.
    bool Changed = MergeConsecutiveStores(ST);
    if (!Changed) break;
    // Return N as merge only uses CombineTo and no worklist clean
    // up is necessary.
    if (N->getOpcode() == ISD::DELETED_NODE || !isa<StoreSDNode>(N))
      return SDValue(N, 0);
  }
}

// Try transforming N to an indexed store.
if (CombineToPreIndexedLoadStore(N) || CombineToPostIndexedLoadStore(N))
  return SDValue(N, 0);

// Turn 'store float 1.0, Ptr' -> 'store int 0x12345678, Ptr'
//
// Make sure to do this only after attempting to merge stores in order to
//  avoid changing the types of some subset of stores due to visit order,
//  preventing their merging.
if (isa<ConstantFPSDNode>(ST->getValue())) {
  if (SDValue NewSt = replaceStoreOfFPConstant(ST))
    return NewSt;
}

if (SDValue NewSt = splitMergedValStore(ST))
  return NewSt;

return ReduceLoadOpStoreWidth(N);
13924}

13926/// For the instruction sequence of store below, F and I values
13927/// are bundled together as an i64 value before being stored into memory.
13928/// Sometimes it is more efficent to generate separate stores for F and I,
13929/// which can remove the bitwise instructions or sink them to colder places.
13930///
13931///   (store (or (zext (bitcast F to i32) to i64),
13932///              (shl (zext I to i64), 32)), addr)  -->
13933///   (store F, addr) and (store I, addr+4)
13934///
13935/// Similarly, splitting for other merged store can also be beneficial, like:
13936/// For pair of {i32, i32}, i64 store --> two i32 stores.
13937/// For pair of {i32, i16}, i64 store --> two i32 stores.
13938/// For pair of {i16, i16}, i32 store --> two i16 stores.
13939/// For pair of {i16, i8},  i32 store --> two i16 stores.
13940/// For pair of {i8, i8},   i16 store --> two i8 stores.
13941///
13942/// We allow each target to determine specifically which kind of splitting is
13943/// supported.
13944///
13945/// The store patterns are commonly seen from the simple code snippet below
13946/// if only std::make_pair(...) is sroa transformed before inlined into hoo.
13947///   void goo(const std::pair<int, float> &);
13948///   hoo() {
13949///     ...
13950///     goo(std::make_pair(tmp, ftmp));
13951///     ...
13952///   }
13953///
13954SDValue DAGCombiner::splitMergedValStore(StoreSDNode *ST) {
if (OptLevel == CodeGenOpt::None)
  return SDValue();

SDValue Val = ST->getValue();
SDLoc DL(ST);

// Match OR operand.
if (!Val.getValueType().isScalarInteger() || Val.getOpcode() != ISD::OR)
  return SDValue();

// Match SHL operand and get Lower and Higher parts of Val.
SDValue Op1 = Val.getOperand(0);
SDValue Op2 = Val.getOperand(1);
SDValue Lo, Hi;
if (Op1.getOpcode() != ISD::SHL) {
  std::swap(Op1, Op2);
  if (Op1.getOpcode() != ISD::SHL)
    return SDValue();
}
Lo = Op2;
Hi = Op1.getOperand(0);
if (!Op1.hasOneUse())
  return SDValue();

// Match shift amount to HalfValBitSize.
unsigned HalfValBitSize = Val.getValueSizeInBits() / 2;
ConstantSDNode *ShAmt = dyn_cast<ConstantSDNode>(Op1.getOperand(1));
if (!ShAmt || ShAmt->getAPIntValue() != HalfValBitSize)
  return SDValue();

// Lo and Hi are zero-extended from int with size less equal than 32
// to i64.
if (Lo.getOpcode() != ISD::ZERO_EXTEND || !Lo.hasOneUse() ||
    !Lo.getOperand(0).getValueType().isScalarInteger() ||
    Lo.getOperand(0).getValueSizeInBits() > HalfValBitSize ||
    Hi.getOpcode() != ISD::ZERO_EXTEND || !Hi.hasOneUse() ||
    !Hi.getOperand(0).getValueType().isScalarInteger() ||
    Hi.getOperand(0).getValueSizeInBits() > HalfValBitSize)
  return SDValue();

// Use the EVT of low and high parts before bitcast as the input
// of target query.
EVT LowTy = (Lo.getOperand(0).getOpcode() == ISD::BITCAST)
                ? Lo.getOperand(0).getValueType()
                : Lo.getValueType();
EVT HighTy = (Hi.getOperand(0).getOpcode() == ISD::BITCAST)
                 ? Hi.getOperand(0).getValueType()
                 : Hi.getValueType();
if (!TLI.isMultiStoresCheaperThanBitsMerge(LowTy, HighTy))
  return SDValue();

// Start to split store.
unsigned Alignment = ST->getAlignment();
MachineMemOperand::Flags MMOFlags = ST->getMemOperand()->getFlags();
AAMDNodes AAInfo = ST->getAAInfo();

// Change the sizes of Lo and Hi's value types to HalfValBitSize.
EVT VT = EVT::getIntegerVT(*DAG.getContext(), HalfValBitSize);
Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Lo.getOperand(0));
Hi = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Hi.getOperand(0));

SDValue Chain = ST->getChain();
SDValue Ptr = ST->getBasePtr();
// Lower value store.
SDValue St0 = DAG.getStore(Chain, DL, Lo, Ptr, ST->getPointerInfo(),
                           ST->getAlignment(), MMOFlags, AAInfo);
Ptr =
    DAG.getNode(ISD::ADD, DL, Ptr.getValueType(), Ptr,
                DAG.getConstant(HalfValBitSize / 8, DL, Ptr.getValueType()));
// Higher value store.
SDValue St1 =
    DAG.getStore(St0, DL, Hi, Ptr,
                 ST->getPointerInfo().getWithOffset(HalfValBitSize / 8),
                 Alignment / 2, MMOFlags, AAInfo);
return St1;
14030}

14032/// Convert a disguised subvector insertion into a shuffle:
14033/// insert_vector_elt V, (bitcast X from vector type), IdxC -->
14034/// bitcast(shuffle (bitcast V), (extended X), Mask)
14035/// Note: We do not use an insert_subvector node because that requires a legal
14036/// subvector type.
14037SDValue DAGCombiner::combineInsertEltToShuffle(SDNode *N, unsigned InsIndex) {
SDValue InsertVal = N->getOperand(1);
if (InsertVal.getOpcode() != ISD::BITCAST || !InsertVal.hasOneUse() ||
    !InsertVal.getOperand(0).getValueType().isVector())
  return SDValue();

SDValue SubVec = InsertVal.getOperand(0);
SDValue DestVec = N->getOperand(0);
EVT SubVecVT = SubVec.getValueType();
EVT VT = DestVec.getValueType();
unsigned NumSrcElts = SubVecVT.getVectorNumElements();
unsigned ExtendRatio = VT.getSizeInBits() / SubVecVT.getSizeInBits();
unsigned NumMaskVals = ExtendRatio * NumSrcElts;

// Step 1: Create a shuffle mask that implements this insert operation. The
// vector that we are inserting into will be operand 0 of the shuffle, so
// those elements are just 'i'. The inserted subvector is in the first
// positions of operand 1 of the shuffle. Example:
// insert v4i32 V, (v2i16 X), 2 --> shuffle v8i16 V', X', {0,1,2,3,8,9,6,7}
SmallVector<int, 16> Mask(NumMaskVals);
for (unsigned i = 0; i != NumMaskVals; ++i) {
  if (i / NumSrcElts == InsIndex)
    Mask[i] = (i % NumSrcElts) + NumMaskVals;
  else
    Mask[i] = i;
}

// Bail out if the target can not handle the shuffle we want to create.
EVT SubVecEltVT = SubVecVT.getVectorElementType();
EVT ShufVT = EVT::getVectorVT(*DAG.getContext(), SubVecEltVT, NumMaskVals);
if (!TLI.isShuffleMaskLegal(Mask, ShufVT))
  return SDValue();

// Step 2: Create a wide vector from the inserted source vector by appending
// undefined elements. This is the same size as our destination vector.
SDLoc DL(N);
SmallVector<SDValue, 8> ConcatOps(ExtendRatio, DAG.getUNDEF(SubVecVT));
ConcatOps[0] = SubVec;
SDValue PaddedSubV = DAG.getNode(ISD::CONCAT_VECTORS, DL, ShufVT, ConcatOps);

// Step 3: Shuffle in the padded subvector.
SDValue DestVecBC = DAG.getBitcast(ShufVT, DestVec);
SDValue Shuf = DAG.getVectorShuffle(ShufVT, DL, DestVecBC, PaddedSubV, Mask);
AddToWorklist(PaddedSubV.getNode());
AddToWorklist(DestVecBC.getNode());
AddToWorklist(Shuf.getNode());
return DAG.getBitcast(VT, Shuf);
14084}

14086SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) {
SDValue InVec = N->getOperand(0);
SDValue InVal = N->getOperand(1);
SDValue EltNo = N->getOperand(2);
SDLoc DL(N);

// If the inserted element is an UNDEF, just use the input vector.
if (InVal.isUndef())
  return InVec;

EVT VT = InVec.getValueType();

// Remove redundant insertions:
// (insert_vector_elt x (extract_vector_elt x idx) idx) -> x
if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT &&
    InVec == InVal.getOperand(0) && EltNo == InVal.getOperand(1))
  return InVec;

// We must know which element is being inserted for folds below here.
auto *IndexC = dyn_cast<ConstantSDNode>(EltNo);
if (!IndexC)
  return SDValue();
unsigned Elt = IndexC->getZExtValue();

if (SDValue Shuf = combineInsertEltToShuffle(N, Elt))
  return Shuf;

// Canonicalize insert_vector_elt dag nodes.
// Example:
// (insert_vector_elt (insert_vector_elt A, Idx0), Idx1)
// -> (insert_vector_elt (insert_vector_elt A, Idx1), Idx0)
//
// Do this only if the child insert_vector node has one use; also
// do this only if indices are both constants and Idx1 < Idx0.
if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT && InVec.hasOneUse()
    && isa<ConstantSDNode>(InVec.getOperand(2))) {
  unsigned OtherElt = InVec.getConstantOperandVal(2);
  if (Elt < OtherElt) {
    // Swap nodes.
    SDValue NewOp = DAG.getNode(ISD::INSERT_VECTOR_ELT, DL, VT,
                                InVec.getOperand(0), InVal, EltNo);
    AddToWorklist(NewOp.getNode());
    return DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(InVec.getNode()),
                       VT, NewOp, InVec.getOperand(1), InVec.getOperand(2));
  }
}

// If we can't generate a legal BUILD_VECTOR, exit
if (LegalOperations && !TLI.isOperationLegal(ISD::BUILD_VECTOR, VT))
  return SDValue();

// Check that the operand is a BUILD_VECTOR (or UNDEF, which can essentially
// be converted to a BUILD_VECTOR).  Fill in the Ops vector with the
// vector elements.
SmallVector<SDValue, 8> Ops;
// Do not combine these two vectors if the output vector will not replace
// the input vector.
if (InVec.getOpcode() == ISD::BUILD_VECTOR && InVec.hasOneUse()) {
  Ops.append(InVec.getNode()->op_begin(),
             InVec.getNode()->op_end());
} else if (InVec.isUndef()) {
  unsigned NElts = VT.getVectorNumElements();
  Ops.append(NElts, DAG.getUNDEF(InVal.getValueType()));
} else {
  return SDValue();
}

// Insert the element
if (Elt < Ops.size()) {
  // All the operands of BUILD_VECTOR must have the same type;
  // we enforce that here.
  EVT OpVT = Ops[0].getValueType();
  Ops[Elt] = OpVT.isInteger() ? DAG.getAnyExtOrTrunc(InVal, DL, OpVT) : InVal;
}

// Return the new vector
return DAG.getBuildVector(VT, DL, Ops);
14163}

14165SDValue DAGCombiner::ReplaceExtractVectorEltOfLoadWithNarrowedLoad(
  SDNode *EVE, EVT InVecVT, SDValue EltNo, LoadSDNode *OriginalLoad) {
assert(!OriginalLoad->isVolatile())(static_cast <bool> (!OriginalLoad->isVolatile()) ? void
 (0) : __assert_fail ("!OriginalLoad->isVolatile()", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14167, __extension__ __PRETTY_FUNCTION__));

EVT ResultVT = EVE->getValueType(0);
EVT VecEltVT = InVecVT.getVectorElementType();
unsigned Align = OriginalLoad->getAlignment();
unsigned NewAlign = DAG.getDataLayout().getABITypeAlignment(
    VecEltVT.getTypeForEVT(*DAG.getContext()));

if (NewAlign > Align || !TLI.isOperationLegalOrCustom(ISD::LOAD, VecEltVT))
  return SDValue();

ISD::LoadExtType ExtTy = ResultVT.bitsGT(VecEltVT) ?
  ISD::NON_EXTLOAD : ISD::EXTLOAD;
if (!TLI.shouldReduceLoadWidth(OriginalLoad, ExtTy, VecEltVT))
  return SDValue();

Align = NewAlign;

SDValue NewPtr = OriginalLoad->getBasePtr();
SDValue Offset;
EVT PtrType = NewPtr.getValueType();
MachinePointerInfo MPI;
SDLoc DL(EVE);
if (auto *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo)) {
  int Elt = ConstEltNo->getZExtValue();
  unsigned PtrOff = VecEltVT.getSizeInBits() * Elt / 8;
  Offset = DAG.getConstant(PtrOff, DL, PtrType);
  MPI = OriginalLoad->getPointerInfo().getWithOffset(PtrOff);
} else {
  Offset = DAG.getZExtOrTrunc(EltNo, DL, PtrType);
  Offset = DAG.getNode(
      ISD::MUL, DL, PtrType, Offset,
      DAG.getConstant(VecEltVT.getStoreSize(), DL, PtrType));
  MPI = OriginalLoad->getPointerInfo();
}
NewPtr = DAG.getNode(ISD::ADD, DL, PtrType, NewPtr, Offset);

// The replacement we need to do here is a little tricky: we need to
// replace an extractelement of a load with a load.
// Use ReplaceAllUsesOfValuesWith to do the replacement.
// Note that this replacement assumes that the extractvalue is the only
// use of the load; that's okay because we don't want to perform this
// transformation in other cases anyway.
SDValue Load;
SDValue Chain;
if (ResultVT.bitsGT(VecEltVT)) {
  // If the result type of vextract is wider than the load, then issue an
  // extending load instead.
  ISD::LoadExtType ExtType = TLI.isLoadExtLegal(ISD::ZEXTLOAD, ResultVT,
                                                VecEltVT)
                                 ? ISD::ZEXTLOAD
                                 : ISD::EXTLOAD;
  Load = DAG.getExtLoad(ExtType, SDLoc(EVE), ResultVT,
                        OriginalLoad->getChain(), NewPtr, MPI, VecEltVT,
                        Align, OriginalLoad->getMemOperand()->getFlags(),
                        OriginalLoad->getAAInfo());
  Chain = Load.getValue(1);
} else {
  Load = DAG.getLoad(VecEltVT, SDLoc(EVE), OriginalLoad->getChain(), NewPtr,
                     MPI, Align, OriginalLoad->getMemOperand()->getFlags(),
                     OriginalLoad->getAAInfo());
  Chain = Load.getValue(1);
  if (ResultVT.bitsLT(VecEltVT))
    Load = DAG.getNode(ISD::TRUNCATE, SDLoc(EVE), ResultVT, Load);
  else
    Load = DAG.getBitcast(ResultVT, Load);
}
WorklistRemover DeadNodes(*this);
SDValue From[] = { SDValue(EVE, 0), SDValue(OriginalLoad, 1) };
SDValue To[] = { Load, Chain };
DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
// Since we're explicitly calling ReplaceAllUses, add the new node to the
// worklist explicitly as well.
AddToWorklist(Load.getNode());
AddUsersToWorklist(Load.getNode()); // Add users too
// Make sure to revisit this node to clean it up; it will usually be dead.
AddToWorklist(EVE);
++OpsNarrowed;
return SDValue(EVE, 0);
14246}

14248SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) {
// (vextract (scalar_to_vector val, 0) -> val
SDValue InVec = N->getOperand(0);
EVT VT = InVec.getValueType();
EVT NVT = N->getValueType(0);

if (InVec.isUndef())
  return DAG.getUNDEF(NVT);

if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) {
  // Check if the result type doesn't match the inserted element type. A
  // SCALAR_TO_VECTOR may truncate the inserted element and the
  // EXTRACT_VECTOR_ELT may widen the extracted vector.
  SDValue InOp = InVec.getOperand(0);
  if (InOp.getValueType() != NVT) {
    assert(InOp.getValueType().isInteger() && NVT.isInteger())(static_cast <bool> (InOp.getValueType().isInteger() &&
 NVT.isInteger()) ? void (0) : __assert_fail ("InOp.getValueType().isInteger() && NVT.isInteger()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14263, __extension__ __PRETTY_FUNCTION__));
    return DAG.getSExtOrTrunc(InOp, SDLoc(InVec), NVT);
  }
  return InOp;
}

SDValue EltNo = N->getOperand(1);
ConstantSDNode *ConstEltNo = dyn_cast<ConstantSDNode>(EltNo);

// extract_vector_elt of out-of-bounds element -> UNDEF
if (ConstEltNo && ConstEltNo->getAPIntValue().uge(VT.getVectorNumElements()))
  return DAG.getUNDEF(NVT);

// extract_vector_elt (build_vector x, y), 1 -> y
if (ConstEltNo &&
    InVec.getOpcode() == ISD::BUILD_VECTOR &&
    TLI.isTypeLegal(VT) &&
    (InVec.hasOneUse() ||
     TLI.aggressivelyPreferBuildVectorSources(VT))) {
  SDValue Elt = InVec.getOperand(ConstEltNo->getZExtValue());
  EVT InEltVT = Elt.getValueType();

  // Sometimes build_vector's scalar input types do not match result type.
  if (NVT == InEltVT)
    return Elt;

  // TODO: It may be useful to truncate if free if the build_vector implicitly
  // converts.
}

// extract_vector_elt (v2i32 (bitcast i64:x)), EltTrunc -> i32 (trunc i64:x)
bool isLE = DAG.getDataLayout().isLittleEndian();
unsigned EltTrunc = isLE ? 0 : VT.getVectorNumElements() - 1;
if (ConstEltNo && InVec.getOpcode() == ISD::BITCAST && InVec.hasOneUse() &&
    ConstEltNo->getZExtValue() == EltTrunc && VT.isInteger()) {
  SDValue BCSrc = InVec.getOperand(0);
  if (BCSrc.getValueType().isScalarInteger())
    return DAG.getNode(ISD::TRUNCATE, SDLoc(N), NVT, BCSrc);
}

// extract_vector_elt (insert_vector_elt vec, val, idx), idx) -> val
//
// This only really matters if the index is non-constant since other combines
// on the constant elements already work.
if (InVec.getOpcode() == ISD::INSERT_VECTOR_ELT &&
    EltNo == InVec.getOperand(2)) {
  SDValue Elt = InVec.getOperand(1);
  return VT.isInteger() ? DAG.getAnyExtOrTrunc(Elt, SDLoc(N), NVT) : Elt;
}

// Transform: (EXTRACT_VECTOR_ELT( VECTOR_SHUFFLE )) -> EXTRACT_VECTOR_ELT.
// We only perform this optimization before the op legalization phase because
// we may introduce new vector instructions which are not backed by TD
// patterns. For example on AVX, extracting elements from a wide vector
// without using extract_subvector. However, if we can find an underlying
// scalar value, then we can always use that.
if (ConstEltNo && InVec.getOpcode() == ISD::VECTOR_SHUFFLE) {
  int NumElem = VT.getVectorNumElements();
  ShuffleVectorSDNode *SVOp = cast<ShuffleVectorSDNode>(InVec);
  // Find the new index to extract from.
  int OrigElt = SVOp->getMaskElt(ConstEltNo->getZExtValue());

  // Extracting an undef index is undef.
  if (OrigElt == -1)
    return DAG.getUNDEF(NVT);

  // Select the right vector half to extract from.
  SDValue SVInVec;
  if (OrigElt < NumElem) {
    SVInVec = InVec->getOperand(0);
  } else {
    SVInVec = InVec->getOperand(1);
    OrigElt -= NumElem;
  }

  if (SVInVec.getOpcode() == ISD::BUILD_VECTOR) {
    SDValue InOp = SVInVec.getOperand(OrigElt);
    if (InOp.getValueType() != NVT) {
      assert(InOp.getValueType().isInteger() && NVT.isInteger())(static_cast <bool> (InOp.getValueType().isInteger() &&
 NVT.isInteger()) ? void (0) : __assert_fail ("InOp.getValueType().isInteger() && NVT.isInteger()"
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14341, __extension__ __PRETTY_FUNCTION__));
      InOp = DAG.getSExtOrTrunc(InOp, SDLoc(SVInVec), NVT);
    }

    return InOp;
  }

  // FIXME: We should handle recursing on other vector shuffles and
  // scalar_to_vector here as well.

  if (!LegalOperations ||
      // FIXME: Should really be just isOperationLegalOrCustom.
      TLI.isOperationLegal(ISD::EXTRACT_VECTOR_ELT, VT) ||
      TLI.isOperationExpand(ISD::VECTOR_SHUFFLE, VT)) {
    EVT IndexTy = TLI.getVectorIdxTy(DAG.getDataLayout());
    return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SDLoc(N), NVT, SVInVec,
                       DAG.getConstant(OrigElt, SDLoc(SVOp), IndexTy));
  }
}

bool BCNumEltsChanged = false;
EVT ExtVT = VT.getVectorElementType();
EVT LVT = ExtVT;

// If the result of load has to be truncated, then it's not necessarily
// profitable.
if (NVT.bitsLT(LVT) && !TLI.isTruncateFree(LVT, NVT))
  return SDValue();

if (InVec.getOpcode() == ISD::BITCAST) {
  // Don't duplicate a load with other uses.
  if (!InVec.hasOneUse())
    return SDValue();

  EVT BCVT = InVec.getOperand(0).getValueType();
  if (!BCVT.isVector() || ExtVT.bitsGT(BCVT.getVectorElementType()))
    return SDValue();
  if (VT.getVectorNumElements() != BCVT.getVectorNumElements())
    BCNumEltsChanged = true;
  InVec = InVec.getOperand(0);
  ExtVT = BCVT.getVectorElementType();
}

// (vextract (vN[if]M load $addr), i) -> ([if]M load $addr + i * size)
if (!LegalOperations && !ConstEltNo && InVec.hasOneUse() &&
    ISD::isNormalLoad(InVec.getNode()) &&
    !N->getOperand(1)->hasPredecessor(InVec.getNode())) {
  SDValue Index = N->getOperand(1);
  if (LoadSDNode *OrigLoad = dyn_cast<LoadSDNode>(InVec)) {
    if (!OrigLoad->isVolatile()) {
      return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, Index,
                                                           OrigLoad);
    }
  }
}

// Perform only after legalization to ensure build_vector / vector_shuffle
// optimizations have already been done.
if (!LegalOperations) return SDValue();

// (vextract (v4f32 load $addr), c) -> (f32 load $addr+c*size)
// (vextract (v4f32 s2v (f32 load $addr)), c) -> (f32 load $addr+c*size)
// (vextract (v4f32 shuffle (load $addr), <1,u,u,u>), 0) -> (f32 load $addr)

if (ConstEltNo) {
  int Elt = cast<ConstantSDNode>(EltNo)->getZExtValue();

  LoadSDNode *LN0 = nullptr;
  const ShuffleVectorSDNode *SVN = nullptr;
  if (ISD::isNormalLoad(InVec.getNode())) {
    LN0 = cast<LoadSDNode>(InVec);
  } else if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR &&
             InVec.getOperand(0).getValueType() == ExtVT &&
             ISD::isNormalLoad(InVec.getOperand(0).getNode())) {
    // Don't duplicate a load with other uses.
    if (!InVec.hasOneUse())
      return SDValue();

    LN0 = cast<LoadSDNode>(InVec.getOperand(0));
  } else if ((SVN = dyn_cast<ShuffleVectorSDNode>(InVec))) {
    // (vextract (vector_shuffle (load $addr), v2, <1, u, u, u>), 1)
    // =>
    // (load $addr+1*size)

    // Don't duplicate a load with other uses.
    if (!InVec.hasOneUse())
      return SDValue();

    // If the bit convert changed the number of elements, it is unsafe
    // to examine the mask.
    if (BCNumEltsChanged)
      return SDValue();

    // Select the input vector, guarding against out of range extract vector.
    unsigned NumElems = VT.getVectorNumElements();
    int Idx = (Elt > (int)NumElems) ? -1 : SVN->getMaskElt(Elt);
    InVec = (Idx < (int)NumElems) ? InVec.getOperand(0) : InVec.getOperand(1);

    if (InVec.getOpcode() == ISD::BITCAST) {
      // Don't duplicate a load with other uses.
      if (!InVec.hasOneUse())
        return SDValue();

      InVec = InVec.getOperand(0);
    }
    if (ISD::isNormalLoad(InVec.getNode())) {
      LN0 = cast<LoadSDNode>(InVec);
      Elt = (Idx < (int)NumElems) ? Idx : Idx - (int)NumElems;
      EltNo = DAG.getConstant(Elt, SDLoc(EltNo), EltNo.getValueType());
    }
  }

  // Make sure we found a non-volatile load and the extractelement is
  // the only use.
  if (!LN0 || !LN0->hasNUsesOfValue(1,0) || LN0->isVolatile())
    return SDValue();

  // If Idx was -1 above, Elt is going to be -1, so just return undef.
  if (Elt == -1)
    return DAG.getUNDEF(LVT);

  return ReplaceExtractVectorEltOfLoadWithNarrowedLoad(N, VT, EltNo, LN0);
}

return SDValue();
14466}

14468// Simplify (build_vec (ext )) to (bitcast (build_vec ))
14469SDValue DAGCombiner::reduceBuildVecExtToExtBuildVec(SDNode *N) {
// We perform this optimization post type-legalization because
// the type-legalizer often scalarizes integer-promoted vectors.
// Performing this optimization before may create bit-casts which
// will be type-legalized to complex code sequences.
// We perform this optimization only before the operation legalizer because we
// may introduce illegal operations.
if (Level != AfterLegalizeVectorOps && Level != AfterLegalizeTypes)
  return SDValue();

unsigned NumInScalars = N->getNumOperands();
SDLoc DL(N);
EVT VT = N->getValueType(0);

// Check to see if this is a BUILD_VECTOR of a bunch of values
// which come from any_extend or zero_extend nodes. If so, we can create
// a new BUILD_VECTOR using bit-casts which may enable other BUILD_VECTOR
// optimizations. We do not handle sign-extend because we can't fill the sign
// using shuffles.
EVT SourceType = MVT::Other;
bool AllAnyExt = true;

for (unsigned i = 0; i != NumInScalars; ++i) {
  SDValue In = N->getOperand(i);
  // Ignore undef inputs.
  if (In.isUndef()) continue;

  bool AnyExt  = In.getOpcode() == ISD::ANY_EXTEND;
  bool ZeroExt = In.getOpcode() == ISD::ZERO_EXTEND;

  // Abort if the element is not an extension.
  if (!ZeroExt && !AnyExt) {
    SourceType = MVT::Other;
    break;
  }

  // The input is a ZeroExt or AnyExt. Check the original type.
  EVT InTy = In.getOperand(0).getValueType();

  // Check that all of the widened source types are the same.
  if (SourceType == MVT::Other)
    // First time.
    SourceType = InTy;
  else if (InTy != SourceType) {
    // Multiple income types. Abort.
    SourceType = MVT::Other;
    break;
  }

  // Check if all of the extends are ANY_EXTENDs.
  AllAnyExt &= AnyExt;
}

// In order to have valid types, all of the inputs must be extended from the
// same source type and all of the inputs must be any or zero extend.
// Scalar sizes must be a power of two.
EVT OutScalarTy = VT.getScalarType();
bool ValidTypes = SourceType != MVT::Other &&
               isPowerOf2_32(OutScalarTy.getSizeInBits()) &&
               isPowerOf2_32(SourceType.getSizeInBits());

// Create a new simpler BUILD_VECTOR sequence which other optimizations can
// turn into a single shuffle instruction.
if (!ValidTypes)
  return SDValue();

bool isLE = DAG.getDataLayout().isLittleEndian();
unsigned ElemRatio = OutScalarTy.getSizeInBits()/SourceType.getSizeInBits();
assert(ElemRatio > 1 && "Invalid element size ratio")(static_cast <bool> (ElemRatio > 1 && "Invalid element size ratio"
) ? void (0) : __assert_fail ("ElemRatio > 1 && \"Invalid element size ratio\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14537, __extension__ __PRETTY_FUNCTION__));
SDValue Filler = AllAnyExt ? DAG.getUNDEF(SourceType):
                             DAG.getConstant(0, DL, SourceType);

unsigned NewBVElems = ElemRatio * VT.getVectorNumElements();
SmallVector<SDValue, 8> Ops(NewBVElems, Filler);

// Populate the new build_vector
for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
  SDValue Cast = N->getOperand(i);
  assert((Cast.getOpcode() == ISD::ANY_EXTEND ||(static_cast <bool> ((Cast.getOpcode() == ISD::ANY_EXTEND
 || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) &&
 "Invalid cast opcode") ? void (0) : __assert_fail ("(Cast.getOpcode() == ISD::ANY_EXTEND || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) && \"Invalid cast opcode\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14549, __extension__ __PRETTY_FUNCTION__))
          Cast.getOpcode() == ISD::ZERO_EXTEND ||(static_cast <bool> ((Cast.getOpcode() == ISD::ANY_EXTEND
 || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) &&
 "Invalid cast opcode") ? void (0) : __assert_fail ("(Cast.getOpcode() == ISD::ANY_EXTEND || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) && \"Invalid cast opcode\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14549, __extension__ __PRETTY_FUNCTION__))
          Cast.isUndef()) && "Invalid cast opcode")(static_cast <bool> ((Cast.getOpcode() == ISD::ANY_EXTEND
 || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) &&
 "Invalid cast opcode") ? void (0) : __assert_fail ("(Cast.getOpcode() == ISD::ANY_EXTEND || Cast.getOpcode() == ISD::ZERO_EXTEND || Cast.isUndef()) && \"Invalid cast opcode\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14549, __extension__ __PRETTY_FUNCTION__));
  SDValue In;
  if (Cast.isUndef())
    In = DAG.getUNDEF(SourceType);
  else
    In = Cast->getOperand(0);
  unsigned Index = isLE ? (i * ElemRatio) :
                          (i * ElemRatio + (ElemRatio - 1));

  assert(Index < Ops.size() && "Invalid index")(static_cast <bool> (Index < Ops.size() && "Invalid index"
) ? void (0) : __assert_fail ("Index < Ops.size() && \"Invalid index\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14558, __extension__ __PRETTY_FUNCTION__));
  Ops[Index] = In;
}

// The type of the new BUILD_VECTOR node.
EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SourceType, NewBVElems);
assert(VecVT.getSizeInBits() == VT.getSizeInBits() &&(static_cast <bool> (VecVT.getSizeInBits() == VT.getSizeInBits
() && "Invalid vector size") ? void (0) : __assert_fail
 ("VecVT.getSizeInBits() == VT.getSizeInBits() && \"Invalid vector size\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14565, __extension__ __PRETTY_FUNCTION__))
       "Invalid vector size")(static_cast <bool> (VecVT.getSizeInBits() == VT.getSizeInBits
() && "Invalid vector size") ? void (0) : __assert_fail
 ("VecVT.getSizeInBits() == VT.getSizeInBits() && \"Invalid vector size\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14565, __extension__ __PRETTY_FUNCTION__));
// Check if the new vector type is legal.
if (!isTypeLegal(VecVT)) return SDValue();

// Make the new BUILD_VECTOR.
SDValue BV = DAG.getBuildVector(VecVT, DL, Ops);

// The new BUILD_VECTOR node has the potential to be further optimized.
AddToWorklist(BV.getNode());
// Bitcast to the desired type.
return DAG.getBitcast(VT, BV);
14576}

14578SDValue DAGCombiner::reduceBuildVecConvertToConvertBuildVec(SDNode *N) {
EVT VT = N->getValueType(0);

unsigned NumInScalars = N->getNumOperands();
SDLoc DL(N);

EVT SrcVT = MVT::Other;
unsigned Opcode = ISD::DELETED_NODE;
unsigned NumDefs = 0;

for (unsigned i = 0; i != NumInScalars; ++i) {
  SDValue In = N->getOperand(i);
  unsigned Opc = In.getOpcode();

  if (Opc == ISD::UNDEF)
    continue;

  // If all scalar values are floats and converted from integers.
  if (Opcode == ISD::DELETED_NODE &&
      (Opc == ISD::UINT_TO_FP || Opc == ISD::SINT_TO_FP)) {
    Opcode = Opc;
  }

  if (Opc != Opcode)
    return SDValue();

  EVT InVT = In.getOperand(0).getValueType();

  // If all scalar values are typed differently, bail out. It's chosen to
  // simplify BUILD_VECTOR of integer types.
  if (SrcVT == MVT::Other)
    SrcVT = InVT;
  if (SrcVT != InVT)
    return SDValue();
  NumDefs++;
}

// If the vector has just one element defined, it's not worth to fold it into
// a vectorized one.
if (NumDefs < 2)
  return SDValue();

assert((Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP)(static_cast <bool> ((Opcode == ISD::UINT_TO_FP || Opcode
 == ISD::SINT_TO_FP) && "Should only handle conversion from integer to float."
) ? void (0) : __assert_fail ("(Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP) && \"Should only handle conversion from integer to float.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14621, __extension__ __PRETTY_FUNCTION__))
       && "Should only handle conversion from integer to float.")(static_cast <bool> ((Opcode == ISD::UINT_TO_FP || Opcode
 == ISD::SINT_TO_FP) && "Should only handle conversion from integer to float."
) ? void (0) : __assert_fail ("(Opcode == ISD::UINT_TO_FP || Opcode == ISD::SINT_TO_FP) && \"Should only handle conversion from integer to float.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14621, __extension__ __PRETTY_FUNCTION__));
assert(SrcVT != MVT::Other && "Cannot determine source type!")(static_cast <bool> (SrcVT != MVT::Other && "Cannot determine source type!"
) ? void (0) : __assert_fail ("SrcVT != MVT::Other && \"Cannot determine source type!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14622, __extension__ __PRETTY_FUNCTION__));

EVT NVT = EVT::getVectorVT(*DAG.getContext(), SrcVT, NumInScalars);

if (!TLI.isOperationLegalOrCustom(Opcode, NVT))
  return SDValue();

// Just because the floating-point vector type is legal does not necessarily
// mean that the corresponding integer vector type is.
if (!isTypeLegal(NVT))
  return SDValue();

SmallVector<SDValue, 8> Opnds;
for (unsigned i = 0; i != NumInScalars; ++i) {
  SDValue In = N->getOperand(i);

  if (In.isUndef())
    Opnds.push_back(DAG.getUNDEF(SrcVT));
  else
    Opnds.push_back(In.getOperand(0));
}
SDValue BV = DAG.getBuildVector(NVT, DL, Opnds);
AddToWorklist(BV.getNode());

return DAG.getNode(Opcode, DL, VT, BV);
14647}

14649SDValue DAGCombiner::createBuildVecShuffle(const SDLoc &DL, SDNode *N,
                                         ArrayRef<int> VectorMask,
                                         SDValue VecIn1, SDValue VecIn2,
                                         unsigned LeftIdx) {
MVT IdxTy = TLI.getVectorIdxTy(DAG.getDataLayout());
SDValue ZeroIdx = DAG.getConstant(0, DL, IdxTy);

EVT VT = N->getValueType(0);
EVT InVT1 = VecIn1.getValueType();
EVT InVT2 = VecIn2.getNode() ? VecIn2.getValueType() : InVT1;

unsigned Vec2Offset = 0;
unsigned NumElems = VT.getVectorNumElements();
unsigned ShuffleNumElems = NumElems;

// In case both the input vectors are extracted from same base
// vector we do not need extra addend (Vec2Offset) while
// computing shuffle mask.
if (!VecIn2 || !(VecIn1.getOpcode() == ISD::EXTRACT_SUBVECTOR) ||
    !(VecIn2.getOpcode() == ISD::EXTRACT_SUBVECTOR) ||
    !(VecIn1.getOperand(0) == VecIn2.getOperand(0)))
  Vec2Offset = InVT1.getVectorNumElements();

// We can't generate a shuffle node with mismatched input and output types.
// Try to make the types match the type of the output.
if (InVT1 != VT || InVT2 != VT) {
  if ((VT.getSizeInBits() % InVT1.getSizeInBits() == 0) && InVT1 == InVT2) {
    // If the output vector length is a multiple of both input lengths,
    // we can concatenate them and pad the rest with undefs.
    unsigned NumConcats = VT.getSizeInBits() / InVT1.getSizeInBits();
    assert(NumConcats >= 2 && "Concat needs at least two inputs!")(static_cast <bool> (NumConcats >= 2 && "Concat needs at least two inputs!"
) ? void (0) : __assert_fail ("NumConcats >= 2 && \"Concat needs at least two inputs!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14679, __extension__ __PRETTY_FUNCTION__));
    SmallVector<SDValue, 2> ConcatOps(NumConcats, DAG.getUNDEF(InVT1));
    ConcatOps[0] = VecIn1;
    ConcatOps[1] = VecIn2 ? VecIn2 : DAG.getUNDEF(InVT1);
    VecIn1 = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, ConcatOps);
    VecIn2 = SDValue();
  } else if (InVT1.getSizeInBits() == VT.getSizeInBits() * 2) {
    if (!TLI.isExtractSubvectorCheap(VT, InVT1, NumElems))
      return SDValue();

    if (!VecIn2.getNode()) {
      // If we only have one input vector, and it's twice the size of the
      // output, split it in two.
      VecIn2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, VecIn1,
                           DAG.getConstant(NumElems, DL, IdxTy));
      VecIn1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, VecIn1, ZeroIdx);
      // Since we now have shorter input vectors, adjust the offset of the
      // second vector's start.
      Vec2Offset = NumElems;
    } else if (InVT2.getSizeInBits() <= InVT1.getSizeInBits()) {
      // VecIn1 is wider than the output, and we have another, possibly
      // smaller input. Pad the smaller input with undefs, shuffle at the
      // input vector width, and extract the output.
      // The shuffle type is different than VT, so check legality again.
      if (LegalOperations &&
          !TLI.isOperationLegal(ISD::VECTOR_SHUFFLE, InVT1))
        return SDValue();

      // Legalizing INSERT_SUBVECTOR is tricky - you basically have to
      // lower it back into a BUILD_VECTOR. So if the inserted type is
      // illegal, don't even try.
      if (InVT1 != InVT2) {
        if (!TLI.isTypeLegal(InVT2))
          return SDValue();
        VecIn2 = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, InVT1,
                             DAG.getUNDEF(InVT1), VecIn2, ZeroIdx);
      }
      ShuffleNumElems = NumElems * 2;
    } else {
      // Both VecIn1 and VecIn2 are wider than the output, and VecIn2 is wider
      // than VecIn1. We can't handle this for now - this case will disappear
      // when we start sorting the vectors by type.
      return SDValue();
    }
  } else if (InVT2.getSizeInBits() * 2 == VT.getSizeInBits() &&
             InVT1.getSizeInBits() == VT.getSizeInBits()) {
    SmallVector<SDValue, 2> ConcatOps(2, DAG.getUNDEF(InVT2));
    ConcatOps[0] = VecIn2;
    VecIn2 = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, ConcatOps);
  } else {
    // TODO: Support cases where the length mismatch isn't exactly by a
    // factor of 2.
    // TODO: Move this check upwards, so that if we have bad type
    // mismatches, we don't create any DAG nodes.
    return SDValue();
  }
}

// Initialize mask to undef.
SmallVector<int, 8> Mask(ShuffleNumElems, -1);

// Only need to run up to the number of elements actually used, not the
// total number of elements in the shuffle - if we are shuffling a wider
// vector, the high lanes should be set to undef.
for (unsigned i = 0; i != NumElems; ++i) {
  if (VectorMask[i] <= 0)
    continue;

  unsigned ExtIndex = N->getOperand(i).getConstantOperandVal(1);
  if (VectorMask[i] == (int)LeftIdx) {
    Mask[i] = ExtIndex;
  } else if (VectorMask[i] == (int)LeftIdx + 1) {
    Mask[i] = Vec2Offset + ExtIndex;
  }
}

// The type the input vectors may have changed above.
InVT1 = VecIn1.getValueType();

// If we already have a VecIn2, it should have the same type as VecIn1.
// If we don't, get an undef/zero vector of the appropriate type.
VecIn2 = VecIn2.getNode() ? VecIn2 : DAG.getUNDEF(InVT1);
assert(InVT1 == VecIn2.getValueType() && "Unexpected second input type.")(static_cast <bool> (InVT1 == VecIn2.getValueType() &&
 "Unexpected second input type.") ? void (0) : __assert_fail (
"InVT1 == VecIn2.getValueType() && \"Unexpected second input type.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 14761, __extension__ __PRETTY_FUNCTION__));

SDValue Shuffle = DAG.getVectorShuffle(InVT1, DL, VecIn1, VecIn2, Mask);
if (ShuffleNumElems > NumElems)
  Shuffle = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, VT, Shuffle, ZeroIdx);

return Shuffle;
14768}

14770// Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
14771// operations. If the types of the vectors we're extracting from allow it,
14772// turn this into a vector_shuffle node.
14773SDValue DAGCombiner::reduceBuildVecToShuffle(SDNode *N) {
SDLoc DL(N);
EVT VT = N->getValueType(0);

// Only type-legal BUILD_VECTOR nodes are converted to shuffle nodes.
if (!isTypeLegal(VT))
  return SDValue();

// May only combine to shuffle after legalize if shuffle is legal.
if (LegalOperations && !TLI.isOperationLegal(ISD::VECTOR_SHUFFLE, VT))
  return SDValue();

bool UsesZeroVector = false;
unsigned NumElems = N->getNumOperands();

// Record, for each element of the newly built vector, which input vector
// that element comes from. -1 stands for undef, 0 for the zero vector,
// and positive values for the input vectors.
// VectorMask maps each element to its vector number, and VecIn maps vector
// numbers to their initial SDValues.

SmallVector<int, 8> VectorMask(NumElems, -1);
SmallVector<SDValue, 8> VecIn;
VecIn.push_back(SDValue());

for (unsigned i = 0; i != NumElems; ++i) {
  SDValue Op = N->getOperand(i);

  if (Op.isUndef())
    continue;

  // See if we can use a blend with a zero vector.
  // TODO: Should we generalize this to a blend with an arbitrary constant
  // vector?
  if (isNullConstant(Op) || isNullFPConstant(Op)) {
    UsesZeroVector = true;
    VectorMask[i] = 0;
    continue;
  }

  // Not an undef or zero. If the input is something other than an
  // EXTRACT_VECTOR_ELT with an in-range constant index, bail out.
  if (Op.getOpcode() != ISD::EXTRACT_VECTOR_ELT ||
      !isa<ConstantSDNode>(Op.getOperand(1)))
    return SDValue();
  SDValue ExtractedFromVec = Op.getOperand(0);

  APInt ExtractIdx = cast<ConstantSDNode>(Op.getOperand(1))->getAPIntValue();
  if (ExtractIdx.uge(ExtractedFromVec.getValueType().getVectorNumElements()))
    return SDValue();

  // All inputs must have the same element type as the output.
  if (VT.getVectorElementType() !=
      ExtractedFromVec.getValueType().getVectorElementType())
    return SDValue();

  // Have we seen this input vector before?
  // The vectors are expected to be tiny (usually 1 or 2 elements), so using
  // a map back from SDValues to numbers isn't worth it.
  unsigned Idx = std::distance(
      VecIn.begin(), std::find(VecIn.begin(), VecIn.end(), ExtractedFromVec));
  if (Idx == VecIn.size())
    VecIn.push_back(ExtractedFromVec);

  VectorMask[i] = Idx;
}

// If we didn't find at least one input vector, bail out.
if (VecIn.size() < 2)
  return SDValue();

// If all the Operands of BUILD_VECTOR extract from same
// vector, then split the vector efficiently based on the maximum
// vector access index and adjust the VectorMask and
// VecIn accordingly.
if (VecIn.size() == 2) {
  unsigned MaxIndex = 0;
  unsigned NearestPow2 = 0;
  SDValue Vec = VecIn.back();
  EVT InVT = Vec.getValueType();
  MVT IdxTy = TLI.getVectorIdxTy(DAG.getDataLayout());
  SmallVector<unsigned, 8> IndexVec(NumElems, 0);

  for (unsigned i = 0; i < NumElems; i++) {
    if (VectorMask[i] <= 0)
      continue;
    unsigned Index = N->getOperand(i).getConstantOperandVal(1);
    IndexVec[i] = Index;
    MaxIndex = std::max(MaxIndex, Index);
  }

  NearestPow2 = PowerOf2Ceil(MaxIndex);
  if (InVT.isSimple() && NearestPow2 > 2 && MaxIndex < NearestPow2 &&
      NumElems * 2 < NearestPow2) {
    unsigned SplitSize = NearestPow2 / 2;
    EVT SplitVT = EVT::getVectorVT(*DAG.getContext(),
                                   InVT.getVectorElementType(), SplitSize);
    if (TLI.isTypeLegal(SplitVT)) {
      SDValue VecIn2 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SplitVT, Vec,
                                   DAG.getConstant(SplitSize, DL, IdxTy));
      SDValue VecIn1 = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, SplitVT, Vec,
                                   DAG.getConstant(0, DL, IdxTy));
      VecIn.pop_back();
      VecIn.push_back(VecIn1);
      VecIn.push_back(VecIn2);

      for (unsigned i = 0; i < NumElems; i++) {
        if (VectorMask[i] <= 0)
          continue;
        VectorMask[i] = (IndexVec[i] < SplitSize) ? 1 : 2;
      }
    }
  }
}

// TODO: We want to sort the vectors by descending length, so that adjacent
// pairs have similar length, and the longer vector is always first in the
// pair.

// TODO: Should this fire if some of the input vectors has illegal type (like
// it does now), or should we let legalization run its course first?

// Shuffle phase:
// Take pairs of vectors, and shuffle them so that the result has elements
// from these vectors in the correct places.
// For example, given:
// t10: i32 = extract_vector_elt t1, Constant:i64<0>
// t11: i32 = extract_vector_elt t2, Constant:i64<0>
// t12: i32 = extract_vector_elt t3, Constant:i64<0>
// t13: i32 = extract_vector_elt t1, Constant:i64<1>
// t14: v4i32 = BUILD_VECTOR t10, t11, t12, t13
// We will generate:
// t20: v4i32 = vector_shuffle<0,4,u,1> t1, t2
// t21: v4i32 = vector_shuffle<u,u,0,u> t3, undef
SmallVector<SDValue, 4> Shuffles;
for (unsigned In = 0, Len = (VecIn.size() / 2); In < Len; ++In) {
  unsigned LeftIdx = 2 * In + 1;
  SDValue VecLeft = VecIn[LeftIdx];
  SDValue VecRight =
      (LeftIdx + 1) < VecIn.size() ? VecIn[LeftIdx + 1] : SDValue();

  if (SDValue Shuffle = createBuildVecShuffle(DL, N, VectorMask, VecLeft,
                                              VecRight, LeftIdx))
    Shuffles.push_back(Shuffle);
  else
    return SDValue();
}

// If we need the zero vector as an "ingredient" in the blend tree, add it
// to the list of shuffles.
if (UsesZeroVector)
  Shuffles.push_back(VT.isInteger() ? DAG.getConstant(0, DL, VT)
                                    : DAG.getConstantFP(0.0, DL, VT));

// If we only have one shuffle, we're done.
if (Shuffles.size() == 1)
  return Shuffles[0];

// Update the vector mask to point to the post-shuffle vectors.
for (int &Vec : VectorMask)
  if (Vec == 0)
    Vec = Shuffles.size() - 1;
  else
    Vec = (Vec - 1) / 2;

// More than one shuffle. Generate a binary tree of blends, e.g. if from
// the previous step we got the set of shuffles t10, t11, t12, t13, we will
// generate:
// t10: v8i32 = vector_shuffle<0,8,u,u,u,u,u,u> t1, t2
// t11: v8i32 = vector_shuffle<u,u,0,8,u,u,u,u> t3, t4
// t12: v8i32 = vector_shuffle<u,u,u,u,0,8,u,u> t5, t6
// t13: v8i32 = vector_shuffle<u,u,u,u,u,u,0,8> t7, t8
// t20: v8i32 = vector_shuffle<0,1,10,11,u,u,u,u> t10, t11
// t21: v8i32 = vector_shuffle<u,u,u,u,4,5,14,15> t12, t13
// t30: v8i32 = vector_shuffle<0,1,2,3,12,13,14,15> t20, t21

// Make sure the initial size of the shuffle list is even.
if (Shuffles.size() % 2)
  Shuffles.push_back(DAG.getUNDEF(VT));

for (unsigned CurSize = Shuffles.size(); CurSize > 1; CurSize /= 2) {
  if (CurSize % 2) {
    Shuffles[CurSize] = DAG.getUNDEF(VT);
    CurSize++;
  }
  for (unsigned In = 0, Len = CurSize / 2; In < Len; ++In) {
    int Left = 2 * In;
    int Right = 2 * In + 1;
    SmallVector<int, 8> Mask(NumElems, -1);
    for (unsigned i = 0; i != NumElems; ++i) {
      if (VectorMask[i] == Left) {
        Mask[i] = i;
        VectorMask[i] = In;
      } else if (VectorMask[i] == Right) {
        Mask[i] = i + NumElems;
        VectorMask[i] = In;
      }
    }

    Shuffles[In] =
        DAG.getVectorShuffle(VT, DL, Shuffles[Left], Shuffles[Right], Mask);
  }
}
return Shuffles[0];
14977}

14979SDValue DAGCombiner::visitBUILD_VECTOR(SDNode *N) {
EVT VT = N->getValueType(0);

// A vector built entirely of undefs is undef.
if (ISD::allOperandsUndef(N))
  return DAG.getUNDEF(VT);

// If this is a splat of a bitcast from another vector, change to a
// concat_vector.
// For example:
//   (build_vector (i64 (bitcast (v2i32 X))), (i64 (bitcast (v2i32 X)))) ->
//     (v2i64 (bitcast (concat_vectors (v2i32 X), (v2i32 X))))
//
// If X is a build_vector itself, the concat can become a larger build_vector.
// TODO: Maybe this is useful for non-splat too?
if (!LegalOperations) {
  if (SDValue Splat = cast<BuildVectorSDNode>(N)->getSplatValue()) {
    Splat = peekThroughBitcast(Splat);
    EVT SrcVT = Splat.getValueType();
    if (SrcVT.isVector()) {
      unsigned NumElts = N->getNumOperands() * SrcVT.getVectorNumElements();
      EVT NewVT = EVT::getVectorVT(*DAG.getContext(),
                                   SrcVT.getVectorElementType(), NumElts);
      SmallVector<SDValue, 8> Ops(N->getNumOperands(), Splat);
      SDValue Concat = DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), NewVT, Ops);
      return DAG.getBitcast(VT, Concat);
    }
  }
}

// Check if we can express BUILD VECTOR via subvector extract.
if (!LegalTypes && (N->getNumOperands() > 1)) {
  SDValue Op0 = N->getOperand(0);
  auto checkElem = [&](SDValue Op) -> uint64_t {
    if ((Op.getOpcode() == ISD::EXTRACT_VECTOR_ELT) &&
        (Op0.getOperand(0) == Op.getOperand(0)))
      if (auto CNode = dyn_cast<ConstantSDNode>(Op.getOperand(1)))
        return CNode->getZExtValue();
    return -1;
  };

  int Offset = checkElem(Op0);
  for (unsigned i = 0; i < N->getNumOperands(); ++i) {
    if (Offset + i != checkElem(N->getOperand(i))) {
      Offset = -1;
      break;
    }
  }

  if ((Offset == 0) &&
      (Op0.getOperand(0).getValueType() == N->getValueType(0)))
    return Op0.getOperand(0);
  if ((Offset != -1) &&
      ((Offset % N->getValueType(0).getVectorNumElements()) ==
       0)) // IDX must be multiple of output size.
    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(N), N->getValueType(0),
                       Op0.getOperand(0), Op0.getOperand(1));
}

if (SDValue V = reduceBuildVecExtToExtBuildVec(N))
  return V;

if (SDValue V = reduceBuildVecConvertToConvertBuildVec(N))
  return V;

if (SDValue V = reduceBuildVecToShuffle(N))
  return V;

return SDValue();
15048}

15050static SDValue combineConcatVectorOfScalars(SDNode *N, SelectionDAG &DAG) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT OpVT = N->getOperand(0).getValueType();

// If the operands are legal vectors, leave them alone.
if (TLI.isTypeLegal(OpVT))
  return SDValue();

SDLoc DL(N);
EVT VT = N->getValueType(0);
SmallVector<SDValue, 8> Ops;

EVT SVT = EVT::getIntegerVT(*DAG.getContext(), OpVT.getSizeInBits());
SDValue ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);

// Keep track of what we encounter.
bool AnyInteger = false;
bool AnyFP = false;
for (const SDValue &Op : N->ops()) {
  if (ISD::BITCAST == Op.getOpcode() &&
      !Op.getOperand(0).getValueType().isVector())
    Ops.push_back(Op.getOperand(0));
  else if (ISD::UNDEF == Op.getOpcode())
    Ops.push_back(ScalarUndef);
  else
    return SDValue();

  // Note whether we encounter an integer or floating point scalar.
  // If it's neither, bail out, it could be something weird like x86mmx.
  EVT LastOpVT = Ops.back().getValueType();
  if (LastOpVT.isFloatingPoint())
    AnyFP = true;
  else if (LastOpVT.isInteger())
    AnyInteger = true;
  else
    return SDValue();
}

// If any of the operands is a floating point scalar bitcast to a vector,
// use floating point types throughout, and bitcast everything.
// Replace UNDEFs by another scalar UNDEF node, of the final desired type.
if (AnyFP) {
  SVT = EVT::getFloatingPointVT(OpVT.getSizeInBits());
  ScalarUndef = DAG.getNode(ISD::UNDEF, DL, SVT);
  if (AnyInteger) {
    for (SDValue &Op : Ops) {
      if (Op.getValueType() == SVT)
        continue;
      if (Op.isUndef())
        Op = ScalarUndef;
      else
        Op = DAG.getBitcast(SVT, Op);
    }
  }
}

EVT VecVT = EVT::getVectorVT(*DAG.getContext(), SVT,
                             VT.getSizeInBits() / SVT.getSizeInBits());
return DAG.getBitcast(VT, DAG.getBuildVector(VecVT, DL, Ops));
15109}

15111// Check to see if this is a CONCAT_VECTORS of a bunch of EXTRACT_SUBVECTOR
15112// operations. If so, and if the EXTRACT_SUBVECTOR vector inputs come from at
15113// most two distinct vectors the same size as the result, attempt to turn this
15114// into a legal shuffle.
15115static SDValue combineConcatVectorOfExtracts(SDNode *N, SelectionDAG &DAG) {
EVT VT = N->getValueType(0);
EVT OpVT = N->getOperand(0).getValueType();
int NumElts = VT.getVectorNumElements();
int NumOpElts = OpVT.getVectorNumElements();

SDValue SV0 = DAG.getUNDEF(VT), SV1 = DAG.getUNDEF(VT);
SmallVector<int, 8> Mask;

for (SDValue Op : N->ops()) {
  // Peek through any bitcast.
  Op = peekThroughBitcast(Op);

  // UNDEF nodes convert to UNDEF shuffle mask values.
  if (Op.isUndef()) {
    Mask.append((unsigned)NumOpElts, -1);
    continue;
  }

  if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
    return SDValue();

  // What vector are we extracting the subvector from and at what index?
  SDValue ExtVec = Op.getOperand(0);

  // We want the EVT of the original extraction to correctly scale the
  // extraction index.
  EVT ExtVT = ExtVec.getValueType();

  // Peek through any bitcast.
  ExtVec = peekThroughBitcast(ExtVec);

  // UNDEF nodes convert to UNDEF shuffle mask values.
  if (ExtVec.isUndef()) {
    Mask.append((unsigned)NumOpElts, -1);
    continue;
  }

  if (!isa<ConstantSDNode>(Op.getOperand(1)))
    return SDValue();
  int ExtIdx = Op.getConstantOperandVal(1);

  // Ensure that we are extracting a subvector from a vector the same
  // size as the result.
  if (ExtVT.getSizeInBits() != VT.getSizeInBits())
    return SDValue();

  // Scale the subvector index to account for any bitcast.
  int NumExtElts = ExtVT.getVectorNumElements();
  if (0 == (NumExtElts % NumElts))
    ExtIdx /= (NumExtElts / NumElts);
  else if (0 == (NumElts % NumExtElts))
    ExtIdx *= (NumElts / NumExtElts);
  else
    return SDValue();

  // At most we can reference 2 inputs in the final shuffle.
  if (SV0.isUndef() || SV0 == ExtVec) {
    SV0 = ExtVec;
    for (int i = 0; i != NumOpElts; ++i)
      Mask.push_back(i + ExtIdx);
  } else if (SV1.isUndef() || SV1 == ExtVec) {
    SV1 = ExtVec;
    for (int i = 0; i != NumOpElts; ++i)
      Mask.push_back(i + ExtIdx + NumElts);
  } else {
    return SDValue();
  }
}

if (!DAG.getTargetLoweringInfo().isShuffleMaskLegal(Mask, VT))
  return SDValue();

return DAG.getVectorShuffle(VT, SDLoc(N), DAG.getBitcast(VT, SV0),
                            DAG.getBitcast(VT, SV1), Mask);
15190}

15192SDValue DAGCombiner::visitCONCAT_VECTORS(SDNode *N) {
// If we only have one input vector, we don't need to do any concatenation.
if (N->getNumOperands() == 1)
  return N->getOperand(0);

// Check if all of the operands are undefs.
EVT VT = N->getValueType(0);
if (ISD::allOperandsUndef(N))
  return DAG.getUNDEF(VT);

// Optimize concat_vectors where all but the first of the vectors are undef.
if (std::all_of(std::next(N->op_begin()), N->op_end(), [](const SDValue &Op) {
      return Op.isUndef();
    })) {
  SDValue In = N->getOperand(0);
  assert(In.getValueType().isVector() && "Must concat vectors")(static_cast <bool> (In.getValueType().isVector() &&
 "Must concat vectors") ? void (0) : __assert_fail ("In.getValueType().isVector() && \"Must concat vectors\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15207, __extension__ __PRETTY_FUNCTION__));

  // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
  if (In->getOpcode() == ISD::BITCAST &&
      !In->getOperand(0).getValueType().isVector()) {
    SDValue Scalar = In->getOperand(0);

    // If the bitcast type isn't legal, it might be a trunc of a legal type;
    // look through the trunc so we can still do the transform:
    //   concat_vectors(trunc(scalar), undef) -> scalar_to_vector(scalar)
    if (Scalar->getOpcode() == ISD::TRUNCATE &&
        !TLI.isTypeLegal(Scalar.getValueType()) &&
        TLI.isTypeLegal(Scalar->getOperand(0).getValueType()))
      Scalar = Scalar->getOperand(0);

    EVT SclTy = Scalar->getValueType(0);

    if (!SclTy.isFloatingPoint() && !SclTy.isInteger())
      return SDValue();

    // Bail out if the vector size is not a multiple of the scalar size.
    if (VT.getSizeInBits() % SclTy.getSizeInBits())
      return SDValue();

    unsigned VNTNumElms = VT.getSizeInBits() / SclTy.getSizeInBits();
    if (VNTNumElms < 2)
      return SDValue();

    EVT NVT = EVT::getVectorVT(*DAG.getContext(), SclTy, VNTNumElms);
    if (!TLI.isTypeLegal(NVT) || !TLI.isTypeLegal(Scalar.getValueType()))
      return SDValue();

    SDValue Res = DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), NVT, Scalar);
    return DAG.getBitcast(VT, Res);
  }
}

// Fold any combination of BUILD_VECTOR or UNDEF nodes into one BUILD_VECTOR.
// We have already tested above for an UNDEF only concatenation.
// fold (concat_vectors (BUILD_VECTOR A, B, ...), (BUILD_VECTOR C, D, ...))
// -> (BUILD_VECTOR A, B, ..., C, D, ...)
auto IsBuildVectorOrUndef = [](const SDValue &Op) {
  return ISD::UNDEF == Op.getOpcode() || ISD::BUILD_VECTOR == Op.getOpcode();
};
if (llvm::all_of(N->ops(), IsBuildVectorOrUndef)) {
  SmallVector<SDValue, 8> Opnds;
  EVT SVT = VT.getScalarType();

  EVT MinVT = SVT;
  if (!SVT.isFloatingPoint()) {
    // If BUILD_VECTOR are from built from integer, they may have different
    // operand types. Get the smallest type and truncate all operands to it.
    bool FoundMinVT = false;
    for (const SDValue &Op : N->ops())
      if (ISD::BUILD_VECTOR == Op.getOpcode()) {
        EVT OpSVT = Op.getOperand(0).getValueType();
        MinVT = (!FoundMinVT || OpSVT.bitsLE(MinVT)) ? OpSVT : MinVT;
        FoundMinVT = true;
      }
    assert(FoundMinVT && "Concat vector type mismatch")(static_cast <bool> (FoundMinVT && "Concat vector type mismatch"
) ? void (0) : __assert_fail ("FoundMinVT && \"Concat vector type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15266, __extension__ __PRETTY_FUNCTION__));
  }

  for (const SDValue &Op : N->ops()) {
    EVT OpVT = Op.getValueType();
    unsigned NumElts = OpVT.getVectorNumElements();

    if (ISD::UNDEF == Op.getOpcode())
      Opnds.append(NumElts, DAG.getUNDEF(MinVT));

    if (ISD::BUILD_VECTOR == Op.getOpcode()) {
      if (SVT.isFloatingPoint()) {
        assert(SVT == OpVT.getScalarType() && "Concat vector type mismatch")(static_cast <bool> (SVT == OpVT.getScalarType() &&
 "Concat vector type mismatch") ? void (0) : __assert_fail ("SVT == OpVT.getScalarType() && \"Concat vector type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15278, __extension__ __PRETTY_FUNCTION__));
        Opnds.append(Op->op_begin(), Op->op_begin() + NumElts);
      } else {
        for (unsigned i = 0; i != NumElts; ++i)
          Opnds.push_back(
              DAG.getNode(ISD::TRUNCATE, SDLoc(N), MinVT, Op.getOperand(i)));
      }
    }
  }

  assert(VT.getVectorNumElements() == Opnds.size() &&(static_cast <bool> (VT.getVectorNumElements() == Opnds
.size() && "Concat vector type mismatch") ? void (0) :
 __assert_fail ("VT.getVectorNumElements() == Opnds.size() && \"Concat vector type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15289, __extension__ __PRETTY_FUNCTION__))
         "Concat vector type mismatch")(static_cast <bool> (VT.getVectorNumElements() == Opnds
.size() && "Concat vector type mismatch") ? void (0) :
 __assert_fail ("VT.getVectorNumElements() == Opnds.size() && \"Concat vector type mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15289, __extension__ __PRETTY_FUNCTION__));
  return DAG.getBuildVector(VT, SDLoc(N), Opnds);
}

// Fold CONCAT_VECTORS of only bitcast scalars (or undef) to BUILD_VECTOR.
if (SDValue V = combineConcatVectorOfScalars(N, DAG))
  return V;

// Fold CONCAT_VECTORS of EXTRACT_SUBVECTOR (or undef) to VECTOR_SHUFFLE.
if (Level < AfterLegalizeVectorOps && TLI.isTypeLegal(VT))
  if (SDValue V = combineConcatVectorOfExtracts(N, DAG))
    return V;

// Type legalization of vectors and DAG canonicalization of SHUFFLE_VECTOR
// nodes often generate nop CONCAT_VECTOR nodes.
// Scan the CONCAT_VECTOR operands and look for a CONCAT operations that
// place the incoming vectors at the exact same location.
SDValue SingleSource = SDValue();
unsigned PartNumElem = N->getOperand(0).getValueType().getVectorNumElements();

for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
  SDValue Op = N->getOperand(i);

  if (Op.isUndef())
    continue;

  // Check if this is the identity extract:
  if (Op.getOpcode() != ISD::EXTRACT_SUBVECTOR)
    return SDValue();

  // Find the single incoming vector for the extract_subvector.
  if (SingleSource.getNode()) {
    if (Op.getOperand(0) != SingleSource)
      return SDValue();
  } else {
    SingleSource = Op.getOperand(0);

    // Check the source type is the same as the type of the result.
    // If not, this concat may extend the vector, so we can not
    // optimize it away.
    if (SingleSource.getValueType() != N->getValueType(0))
      return SDValue();
  }

  unsigned IdentityIndex = i * PartNumElem;
  ConstantSDNode *CS = dyn_cast<ConstantSDNode>(Op.getOperand(1));
  // The extract index must be constant.
  if (!CS)
    return SDValue();

  // Check that we are reading from the identity index.
  if (CS->getZExtValue() != IdentityIndex)
    return SDValue();
}

if (SingleSource.getNode())
  return SingleSource;

return SDValue();
15348}

15350/// If we are extracting a subvector produced by a wide binary operator with at
15351/// at least one operand that was the result of a vector concatenation, then try
15352/// to use the narrow vector operands directly to avoid the concatenation and
15353/// extraction.
15354static SDValue narrowExtractedVectorBinOp(SDNode *Extract, SelectionDAG &DAG) {
// TODO: Refactor with the caller (visitEXTRACT_SUBVECTOR), so we can share
// some of these bailouts with other transforms.

// The extract index must be a constant, so we can map it to a concat operand.
auto *ExtractIndex = dyn_cast<ConstantSDNode>(Extract->getOperand(1));
if (!ExtractIndex)
  return SDValue();

// Only handle the case where we are doubling and then halving. A larger ratio
// may require more than two narrow binops to replace the wide binop.
EVT VT = Extract->getValueType(0);
unsigned NumElems = VT.getVectorNumElements();
assert((ExtractIndex->getZExtValue() % NumElems) == 0 &&(static_cast <bool> ((ExtractIndex->getZExtValue() %
 NumElems) == 0 && "Extract index is not a multiple of the vector length."
) ? void (0) : __assert_fail ("(ExtractIndex->getZExtValue() % NumElems) == 0 && \"Extract index is not a multiple of the vector length.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15368, __extension__ __PRETTY_FUNCTION__))
       "Extract index is not a multiple of the vector length.")(static_cast <bool> ((ExtractIndex->getZExtValue() %
 NumElems) == 0 && "Extract index is not a multiple of the vector length."
) ? void (0) : __assert_fail ("(ExtractIndex->getZExtValue() % NumElems) == 0 && \"Extract index is not a multiple of the vector length.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15368, __extension__ __PRETTY_FUNCTION__));
if (Extract->getOperand(0).getValueSizeInBits() != VT.getSizeInBits() * 2)
  return SDValue();

// We are looking for an optionally bitcasted wide vector binary operator
// feeding an extract subvector.
SDValue BinOp = peekThroughBitcast(Extract->getOperand(0));

// TODO: The motivating case for this transform is an x86 AVX1 target. That
// target has temptingly almost legal versions of bitwise logic ops in 256-bit
// flavors, but no other 256-bit integer support. This could be extended to
// handle any binop, but that may require fixing/adding other folds to avoid
// codegen regressions.
unsigned BOpcode = BinOp.getOpcode();
if (BOpcode != ISD::AND && BOpcode != ISD::OR && BOpcode != ISD::XOR)
  return SDValue();

// The binop must be a vector type, so we can chop it in half.
EVT WideBVT = BinOp.getValueType();
if (!WideBVT.isVector())
  return SDValue();

// Bail out if the target does not support a narrower version of the binop.
EVT NarrowBVT = EVT::getVectorVT(*DAG.getContext(), WideBVT.getScalarType(),
                                 WideBVT.getVectorNumElements() / 2);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (!TLI.isOperationLegalOrCustomOrPromote(BOpcode, NarrowBVT))
  return SDValue();

// Peek through bitcasts of the binary operator operands if needed.
SDValue LHS = peekThroughBitcast(BinOp.getOperand(0));
SDValue RHS = peekThroughBitcast(BinOp.getOperand(1));

// We need at least one concatenation operation of a binop operand to make
// this transform worthwhile. The concat must double the input vector sizes.
// TODO: Should we also handle INSERT_SUBVECTOR patterns?
bool ConcatL =
    LHS.getOpcode() == ISD::CONCAT_VECTORS && LHS.getNumOperands() == 2;
bool ConcatR =
    RHS.getOpcode() == ISD::CONCAT_VECTORS && RHS.getNumOperands() == 2;
if (!ConcatL && !ConcatR)
  return SDValue();

// If one of the binop operands was not the result of a concat, we must
// extract a half-sized operand for our new narrow binop. We can't just reuse
// the original extract index operand because we may have bitcasted.
unsigned ConcatOpNum = ExtractIndex->getZExtValue() / NumElems;
unsigned ExtBOIdx = ConcatOpNum * NarrowBVT.getVectorNumElements();
EVT ExtBOIdxVT = Extract->getOperand(1).getValueType();
SDLoc DL(Extract);

// extract (binop (concat X1, X2), (concat Y1, Y2)), N --> binop XN, YN
// extract (binop (concat X1, X2), Y), N --> binop XN, (extract Y, N)
// extract (binop X, (concat Y1, Y2)), N --> binop (extract X, N), YN
SDValue X = ConcatL ? DAG.getBitcast(NarrowBVT, LHS.getOperand(ConcatOpNum))
                    : DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, NarrowBVT,
                                  BinOp.getOperand(0),
                                  DAG.getConstant(ExtBOIdx, DL, ExtBOIdxVT));

SDValue Y = ConcatR ? DAG.getBitcast(NarrowBVT, RHS.getOperand(ConcatOpNum))
                    : DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, NarrowBVT,
                                  BinOp.getOperand(1),
                                  DAG.getConstant(ExtBOIdx, DL, ExtBOIdxVT));

SDValue NarrowBinOp = DAG.getNode(BOpcode, DL, NarrowBVT, X, Y);
return DAG.getBitcast(VT, NarrowBinOp);
15434}

15436/// If we are extracting a subvector from a wide vector load, convert to a
15437/// narrow load to eliminate the extraction:
15438/// (extract_subvector (load wide vector)) --> (load narrow vector)
15439static SDValue narrowExtractedVectorLoad(SDNode *Extract, SelectionDAG &DAG) {
// TODO: Add support for big-endian. The offset calculation must be adjusted.
if (DAG.getDataLayout().isBigEndian())
  return SDValue();

// TODO: The one-use check is overly conservative. Check the cost of the
// extract instead or remove that condition entirely.
auto *Ld = dyn_cast<LoadSDNode>(Extract->getOperand(0));
auto *ExtIdx = dyn_cast<ConstantSDNode>(Extract->getOperand(1));
if (!Ld || !Ld->hasOneUse() || Ld->getExtensionType() || Ld->isVolatile() ||
    !ExtIdx)
  return SDValue();

// The narrow load will be offset from the base address of the old load if
// we are extracting from something besides index 0 (little-endian).
EVT VT = Extract->getValueType(0);
SDLoc DL(Extract);
SDValue BaseAddr = Ld->getOperand(1);
unsigned Offset = ExtIdx->getZExtValue() * VT.getScalarType().getStoreSize();

// TODO: Use "BaseIndexOffset" to make this more effective.
SDValue NewAddr = DAG.getMemBasePlusOffset(BaseAddr, Offset, DL);
MachineFunction &MF = DAG.getMachineFunction();
MachineMemOperand *MMO = MF.getMachineMemOperand(Ld->getMemOperand(), Offset,
                                                 VT.getStoreSize());
SDValue NewLd = DAG.getLoad(VT, DL, Ld->getChain(), NewAddr, MMO);
DAG.makeEquivalentMemoryOrdering(Ld, NewLd);
return NewLd;
15467}

15469SDValue DAGCombiner::visitEXTRACT_SUBVECTOR(SDNode* N) {
EVT NVT = N->getValueType(0);
SDValue V = N->getOperand(0);

// Extract from UNDEF is UNDEF.
if (V.isUndef())
  return DAG.getUNDEF(NVT);

if (TLI.isOperationLegalOrCustomOrPromote(ISD::LOAD, NVT))
  if (SDValue NarrowLoad = narrowExtractedVectorLoad(N, DAG))
    return NarrowLoad;

// Combine:
//    (extract_subvec (concat V1, V2, ...), i)
// Into:
//    Vi if possible
// Only operand 0 is checked as 'concat' assumes all inputs of the same
// type.
if (V->getOpcode() == ISD::CONCAT_VECTORS &&
    isa<ConstantSDNode>(N->getOperand(1)) &&
    V->getOperand(0).getValueType() == NVT) {
  unsigned Idx = N->getConstantOperandVal(1);
  unsigned NumElems = NVT.getVectorNumElements();
  assert((Idx % NumElems) == 0 &&(static_cast <bool> ((Idx % NumElems) == 0 && "IDX in concat is not a multiple of the result vector length."
) ? void (0) : __assert_fail ("(Idx % NumElems) == 0 && \"IDX in concat is not a multiple of the result vector length.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15493, __extension__ __PRETTY_FUNCTION__))
         "IDX in concat is not a multiple of the result vector length.")(static_cast <bool> ((Idx % NumElems) == 0 && "IDX in concat is not a multiple of the result vector length."
) ? void (0) : __assert_fail ("(Idx % NumElems) == 0 && \"IDX in concat is not a multiple of the result vector length.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15493, __extension__ __PRETTY_FUNCTION__));
  return V->getOperand(Idx / NumElems);
}

// Skip bitcasting
V = peekThroughBitcast(V);

// If the input is a build vector. Try to make a smaller build vector.
if (V->getOpcode() == ISD::BUILD_VECTOR) {
  if (auto *Idx = dyn_cast<ConstantSDNode>(N->getOperand(1))) {
    EVT InVT = V->getValueType(0);
    unsigned ExtractSize = NVT.getSizeInBits();
    unsigned EltSize = InVT.getScalarSizeInBits();
    // Only do this if we won't split any elements.
    if (ExtractSize % EltSize == 0) {
      unsigned NumElems = ExtractSize / EltSize;
      EVT ExtractVT = EVT::getVectorVT(*DAG.getContext(),
                                       InVT.getVectorElementType(), NumElems);
      if ((!LegalOperations ||
           TLI.isOperationLegal(ISD::BUILD_VECTOR, ExtractVT)) &&
          (!LegalTypes || TLI.isTypeLegal(ExtractVT))) {
        unsigned IdxVal = (Idx->getZExtValue() * NVT.getScalarSizeInBits()) /
                          EltSize;

        // Extract the pieces from the original build_vector.
        SDValue BuildVec = DAG.getBuildVector(ExtractVT, SDLoc(N),
                                          makeArrayRef(V->op_begin() + IdxVal,
                                                       NumElems));
        return DAG.getBitcast(NVT, BuildVec);
      }
    }
  }
}

if (V->getOpcode() == ISD::INSERT_SUBVECTOR) {
  // Handle only simple case where vector being inserted and vector
  // being extracted are of same size.
  EVT SmallVT = V->getOperand(1).getValueType();
  if (!NVT.bitsEq(SmallVT))
    return SDValue();

  // Only handle cases where both indexes are constants.
  ConstantSDNode *ExtIdx = dyn_cast<ConstantSDNode>(N->getOperand(1));
  ConstantSDNode *InsIdx = dyn_cast<ConstantSDNode>(V->getOperand(2));

  if (InsIdx && ExtIdx) {
    // Combine:
    //    (extract_subvec (insert_subvec V1, V2, InsIdx), ExtIdx)
    // Into:
    //    indices are equal or bit offsets are equal => V1
    //    otherwise => (extract_subvec V1, ExtIdx)
    if (InsIdx->getZExtValue() * SmallVT.getScalarSizeInBits() ==
        ExtIdx->getZExtValue() * NVT.getScalarSizeInBits())
      return DAG.getBitcast(NVT, V->getOperand(1));
    return DAG.getNode(
        ISD::EXTRACT_SUBVECTOR, SDLoc(N), NVT,
        DAG.getBitcast(N->getOperand(0).getValueType(), V->getOperand(0)),
        N->getOperand(1));
  }
}

if (SDValue NarrowBOp = narrowExtractedVectorBinOp(N, DAG))
  return NarrowBOp;

return SDValue();
15558}

15560static SDValue simplifyShuffleOperandRecursively(SmallBitVector &UsedElements,
                                               SDValue V, SelectionDAG &DAG) {
SDLoc DL(V);
EVT VT = V.getValueType();

switch (V.getOpcode()) {
default:
  return V;

case ISD::CONCAT_VECTORS: {
  EVT OpVT = V->getOperand(0).getValueType();
  int OpSize = OpVT.getVectorNumElements();
  SmallBitVector OpUsedElements(OpSize, false);
  bool FoundSimplification = false;
  SmallVector<SDValue, 4> NewOps;
  NewOps.reserve(V->getNumOperands());
  for (int i = 0, NumOps = V->getNumOperands(); i < NumOps; ++i) {
    SDValue Op = V->getOperand(i);
    bool OpUsed = false;
    for (int j = 0; j < OpSize; ++j)
      if (UsedElements[i * OpSize + j]) {
        OpUsedElements[j] = true;
        OpUsed = true;
      }
    NewOps.push_back(
        OpUsed ? simplifyShuffleOperandRecursively(OpUsedElements, Op, DAG)
               : DAG.getUNDEF(OpVT));
    FoundSimplification |= Op == NewOps.back();
    OpUsedElements.reset();
  }
  if (FoundSimplification)
    V = DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, NewOps);
  return V;
}

case ISD::INSERT_SUBVECTOR: {
  SDValue BaseV = V->getOperand(0);
  SDValue SubV = V->getOperand(1);
  auto *IdxN = dyn_cast<ConstantSDNode>(V->getOperand(2));
  if (!IdxN)
    return V;

  int SubSize = SubV.getValueType().getVectorNumElements();
  int Idx = IdxN->getZExtValue();
  bool SubVectorUsed = false;
  SmallBitVector SubUsedElements(SubSize, false);
  for (int i = 0; i < SubSize; ++i)
    if (UsedElements[i + Idx]) {
      SubVectorUsed = true;
      SubUsedElements[i] = true;
      UsedElements[i + Idx] = false;
    }

  // Now recurse on both the base and sub vectors.
  SDValue SimplifiedSubV =
      SubVectorUsed
          ? simplifyShuffleOperandRecursively(SubUsedElements, SubV, DAG)
          : DAG.getUNDEF(SubV.getValueType());
  SDValue SimplifiedBaseV = simplifyShuffleOperandRecursively(UsedElements, BaseV, DAG);
  if (SimplifiedSubV != SubV || SimplifiedBaseV != BaseV)
    V = DAG.getNode(ISD::INSERT_SUBVECTOR, DL, VT,
                    SimplifiedBaseV, SimplifiedSubV, V->getOperand(2));
  return V;
}
}
15625}

15627static SDValue simplifyShuffleOperands(ShuffleVectorSDNode *SVN, SDValue N0,
                                     SDValue N1, SelectionDAG &DAG) {
EVT VT = SVN->getValueType(0);
int NumElts = VT.getVectorNumElements();
SmallBitVector N0UsedElements(NumElts, false), N1UsedElements(NumElts, false);
9
←
Calling constructor for 'SmallBitVector'→
13
←
Returning from constructor for 'SmallBitVector'→
for (int M : SVN->getMask())
14
←
Assuming '__begin' is equal to '__end'→
  if (M >= 0 && M < NumElts)
    N0UsedElements[M] = true;
  else if (M >= NumElts)
    N1UsedElements[M - NumElts] = true;

SDValue S0 = simplifyShuffleOperandRecursively(N0UsedElements, N0, DAG);
SDValue S1 = simplifyShuffleOperandRecursively(N1UsedElements, N1, DAG);
if (S0 == N0 && S1 == N1)
15
←
Taking true branch→
  return SDValue();

return DAG.getVectorShuffle(VT, SDLoc(SVN), S0, S1, SVN->getMask());
15644}
16
←
Potential leak of memory pointed to by 'N0UsedElements.X'

15646static SDValue simplifyShuffleMask(ShuffleVectorSDNode *SVN, SDValue N0,
                                 SDValue N1, SelectionDAG &DAG) {
auto isUndefElt = [](SDValue V, int Idx) {
  // TODO - handle more cases as required.
  if (V.getOpcode() == ISD::BUILD_VECTOR)
    return V.getOperand(Idx).isUndef();
  if (V.getOpcode() == ISD::SCALAR_TO_VECTOR)
    return (Idx != 0) || V.getOperand(0).isUndef();
  return false;
};

EVT VT = SVN->getValueType(0);
unsigned NumElts = VT.getVectorNumElements();

bool Changed = false;
SmallVector<int, 8> NewMask;
for (unsigned i = 0; i != NumElts; ++i) {
  int Idx = SVN->getMaskElt(i);
  if ((0 <= Idx && Idx < (int)NumElts && isUndefElt(N0, Idx)) ||
      ((int)NumElts < Idx && isUndefElt(N1, Idx - NumElts))) {
    Changed = true;
    Idx = -1;
  }
  NewMask.push_back(Idx);
}
if (Changed)
  return DAG.getVectorShuffle(VT, SDLoc(SVN), N0, N1, NewMask);

return SDValue();
15675}

15677// Tries to turn a shuffle of two CONCAT_VECTORS into a single concat,
15678// or turn a shuffle of a single concat into simpler shuffle then concat.
15679static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) {
EVT VT = N->getValueType(0);
unsigned NumElts = VT.getVectorNumElements();

SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);

SmallVector<SDValue, 4> Ops;
EVT ConcatVT = N0.getOperand(0).getValueType();
unsigned NumElemsPerConcat = ConcatVT.getVectorNumElements();
unsigned NumConcats = NumElts / NumElemsPerConcat;

// Special case: shuffle(concat(A,B)) can be more efficiently represented
// as concat(shuffle(A,B),UNDEF) if the shuffle doesn't set any of the high
// half vector elements.
if (NumElemsPerConcat * 2 == NumElts && N1.isUndef() &&
    std::all_of(SVN->getMask().begin() + NumElemsPerConcat,
                SVN->getMask().end(), [](int i) { return i == -1; })) {
  N0 = DAG.getVectorShuffle(ConcatVT, SDLoc(N), N0.getOperand(0), N0.getOperand(1),
                            makeArrayRef(SVN->getMask().begin(), NumElemsPerConcat));
  N1 = DAG.getUNDEF(ConcatVT);
  return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, N0, N1);
}

// Look at every vector that's inserted. We're looking for exact
// subvector-sized copies from a concatenated vector
for (unsigned I = 0; I != NumConcats; ++I) {
  // Make sure we're dealing with a copy.
  unsigned Begin = I * NumElemsPerConcat;
  bool AllUndef = true, NoUndef = true;
  for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) {
    if (SVN->getMaskElt(J) >= 0)
      AllUndef = false;
    else
      NoUndef = false;
  }

  if (NoUndef) {
    if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0)
      return SDValue();

    for (unsigned J = 1; J != NumElemsPerConcat; ++J)
      if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J))
        return SDValue();

    unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat;
    if (FirstElt < N0.getNumOperands())
      Ops.push_back(N0.getOperand(FirstElt));
    else
      Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands()));

  } else if (AllUndef) {
    Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType()));
  } else { // Mixed with general masks and undefs, can't do optimization.
    return SDValue();
  }
}

return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops);
15739}

15741// Attempt to combine a shuffle of 2 inputs of 'scalar sources' -
15742// BUILD_VECTOR or SCALAR_TO_VECTOR into a single BUILD_VECTOR.
15743//
15744// SHUFFLE(BUILD_VECTOR(), BUILD_VECTOR()) -> BUILD_VECTOR() is always
15745// a simplification in some sense, but it isn't appropriate in general: some
15746// BUILD_VECTORs are substantially cheaper than others. The general case
15747// of a BUILD_VECTOR requires inserting each element individually (or
15748// performing the equivalent in a temporary stack variable). A BUILD_VECTOR of
15749// all constants is a single constant pool load.  A BUILD_VECTOR where each
15750// element is identical is a splat.  A BUILD_VECTOR where most of the operands
15751// are undef lowers to a small number of element insertions.
15752//
15753// To deal with this, we currently use a bunch of mostly arbitrary heuristics.
15754// We don't fold shuffles where one side is a non-zero constant, and we don't
15755// fold shuffles if the resulting (non-splat) BUILD_VECTOR would have duplicate
15756// non-constant operands. This seems to work out reasonably well in practice.
15757static SDValue combineShuffleOfScalars(ShuffleVectorSDNode *SVN,
                                     SelectionDAG &DAG,
                                     const TargetLowering &TLI) {
EVT VT = SVN->getValueType(0);
unsigned NumElts = VT.getVectorNumElements();
SDValue N0 = SVN->getOperand(0);
SDValue N1 = SVN->getOperand(1);

if (!N0->hasOneUse() || !N1->hasOneUse())
  return SDValue();

// If only one of N1,N2 is constant, bail out if it is not ALL_ZEROS as
// discussed above.
if (!N1.isUndef()) {
  bool N0AnyConst = isAnyConstantBuildVector(N0.getNode());
  bool N1AnyConst = isAnyConstantBuildVector(N1.getNode());
  if (N0AnyConst && !N1AnyConst && !ISD::isBuildVectorAllZeros(N0.getNode()))
    return SDValue();
  if (!N0AnyConst && N1AnyConst && !ISD::isBuildVectorAllZeros(N1.getNode()))
    return SDValue();
}

// If both inputs are splats of the same value then we can safely merge this
// to a single BUILD_VECTOR with undef elements based on the shuffle mask.
bool IsSplat = false;
auto *BV0 = dyn_cast<BuildVectorSDNode>(N0);
auto *BV1 = dyn_cast<BuildVectorSDNode>(N1);
if (BV0 && BV1)
  if (SDValue Splat0 = BV0->getSplatValue())
    IsSplat = (Splat0 == BV1->getSplatValue());

SmallVector<SDValue, 8> Ops;
SmallSet<SDValue, 16> DuplicateOps;
for (int M : SVN->getMask()) {
  SDValue Op = DAG.getUNDEF(VT.getScalarType());
  if (M >= 0) {
    int Idx = M < (int)NumElts ? M : M - NumElts;
    SDValue &S = (M < (int)NumElts ? N0 : N1);
    if (S.getOpcode() == ISD::BUILD_VECTOR) {
      Op = S.getOperand(Idx);
    } else if (S.getOpcode() == ISD::SCALAR_TO_VECTOR) {
      assert(Idx == 0 && "Unexpected SCALAR_TO_VECTOR operand index.")(static_cast <bool> (Idx == 0 && "Unexpected SCALAR_TO_VECTOR operand index."
) ? void (0) : __assert_fail ("Idx == 0 && \"Unexpected SCALAR_TO_VECTOR operand index.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15798, __extension__ __PRETTY_FUNCTION__));
      Op = S.getOperand(0);
    } else {
      // Operand can't be combined - bail out.
      return SDValue();
    }
  }

  // Don't duplicate a non-constant BUILD_VECTOR operand unless we're
  // generating a splat; semantically, this is fine, but it's likely to
  // generate low-quality code if the target can't reconstruct an appropriate
  // shuffle.
  if (!Op.isUndef() && !isa<ConstantSDNode>(Op) && !isa<ConstantFPSDNode>(Op))
    if (!IsSplat && !DuplicateOps.insert(Op).second)
      return SDValue();

  Ops.push_back(Op);
}

// BUILD_VECTOR requires all inputs to be of the same type, find the
// maximum type and extend them all.
EVT SVT = VT.getScalarType();
if (SVT.isInteger())
  for (SDValue &Op : Ops)
    SVT = (SVT.bitsLT(Op.getValueType()) ? Op.getValueType() : SVT);
if (SVT != VT.getScalarType())
  for (SDValue &Op : Ops)
    Op = TLI.isZExtFree(Op.getValueType(), SVT)
             ? DAG.getZExtOrTrunc(Op, SDLoc(SVN), SVT)
             : DAG.getSExtOrTrunc(Op, SDLoc(SVN), SVT);
return DAG.getBuildVector(VT, SDLoc(SVN), Ops);
15829}

15831// Match shuffles that can be converted to any_vector_extend_in_reg.
15832// This is often generated during legalization.
15833// e.g. v4i32 <0,u,1,u> -> (v2i64 any_vector_extend_in_reg(v4i32 src))
15834// TODO Add support for ZERO_EXTEND_VECTOR_INREG when we have a test case.
15835static SDValue combineShuffleToVectorExtend(ShuffleVectorSDNode *SVN,
                                          SelectionDAG &DAG,
                                          const TargetLowering &TLI,
                                          bool LegalOperations,
                                          bool LegalTypes) {
EVT VT = SVN->getValueType(0);
bool IsBigEndian = DAG.getDataLayout().isBigEndian();

// TODO Add support for big-endian when we have a test case.
if (!VT.isInteger() || IsBigEndian)
  return SDValue();

unsigned NumElts = VT.getVectorNumElements();
unsigned EltSizeInBits = VT.getScalarSizeInBits();
ArrayRef<int> Mask = SVN->getMask();
SDValue N0 = SVN->getOperand(0);

// shuffle<0,-1,1,-1> == (v2i64 anyextend_vector_inreg(v4i32))
auto isAnyExtend = [&Mask, &NumElts](unsigned Scale) {
  for (unsigned i = 0; i != NumElts; ++i) {
    if (Mask[i] < 0)
      continue;
    if ((i % Scale) == 0 && Mask[i] == (int)(i / Scale))
      continue;
    return false;
  }
  return true;
};

// Attempt to match a '*_extend_vector_inreg' shuffle, we just search for
// power-of-2 extensions as they are the most likely.
for (unsigned Scale = 2; Scale < NumElts; Scale *= 2) {
  // Check for non power of 2 vector sizes
  if (NumElts % Scale != 0)
    continue;
  if (!isAnyExtend(Scale))
    continue;

  EVT OutSVT = EVT::getIntegerVT(*DAG.getContext(), EltSizeInBits * Scale);
  EVT OutVT = EVT::getVectorVT(*DAG.getContext(), OutSVT, NumElts / Scale);
  if (!LegalTypes || TLI.isTypeLegal(OutVT))
    if (!LegalOperations ||
        TLI.isOperationLegalOrCustom(ISD::ANY_EXTEND_VECTOR_INREG, OutVT))
      return DAG.getBitcast(VT,
                          DAG.getAnyExtendVectorInReg(N0, SDLoc(SVN), OutVT));
}

return SDValue();
15883}

15885// Detect 'truncate_vector_inreg' style shuffles that pack the lower parts of
15886// each source element of a large type into the lowest elements of a smaller
15887// destination type. This is often generated during legalization.
15888// If the source node itself was a '*_extend_vector_inreg' node then we should
15889// then be able to remove it.
15890static SDValue combineTruncationShuffle(ShuffleVectorSDNode *SVN,
                                      SelectionDAG &DAG) {
EVT VT = SVN->getValueType(0);
bool IsBigEndian = DAG.getDataLayout().isBigEndian();

// TODO Add support for big-endian when we have a test case.
if (!VT.isInteger() || IsBigEndian)
  return SDValue();

SDValue N0 = peekThroughBitcast(SVN->getOperand(0));

unsigned Opcode = N0.getOpcode();
if (Opcode != ISD::ANY_EXTEND_VECTOR_INREG &&
    Opcode != ISD::SIGN_EXTEND_VECTOR_INREG &&
    Opcode != ISD::ZERO_EXTEND_VECTOR_INREG)
  return SDValue();

SDValue N00 = N0.getOperand(0);
ArrayRef<int> Mask = SVN->getMask();
unsigned NumElts = VT.getVectorNumElements();
unsigned EltSizeInBits = VT.getScalarSizeInBits();
unsigned ExtSrcSizeInBits = N00.getScalarValueSizeInBits();
unsigned ExtDstSizeInBits = N0.getScalarValueSizeInBits();

if (ExtDstSizeInBits % ExtSrcSizeInBits != 0)
  return SDValue();
unsigned ExtScale = ExtDstSizeInBits / ExtSrcSizeInBits;

// (v4i32 truncate_vector_inreg(v2i64)) == shuffle<0,2-1,-1>
// (v8i16 truncate_vector_inreg(v4i32)) == shuffle<0,2,4,6,-1,-1,-1,-1>
// (v8i16 truncate_vector_inreg(v2i64)) == shuffle<0,4,-1,-1,-1,-1,-1,-1>
auto isTruncate = [&Mask, &NumElts](unsigned Scale) {
  for (unsigned i = 0; i != NumElts; ++i) {
    if (Mask[i] < 0)
      continue;
    if ((i * Scale) < NumElts && Mask[i] == (int)(i * Scale))
      continue;
    return false;
  }
  return true;
};

// At the moment we just handle the case where we've truncated back to the
// same size as before the extension.
// TODO: handle more extension/truncation cases as cases arise.
if (EltSizeInBits != ExtSrcSizeInBits)
  return SDValue();

// We can remove *extend_vector_inreg only if the truncation happens at
// the same scale as the extension.
if (isTruncate(ExtScale))
  return DAG.getBitcast(VT, N00);

return SDValue();
15944}

15946// Combine shuffles of splat-shuffles of the form:
15947// shuffle (shuffle V, undef, splat-mask), undef, M
15948// If splat-mask contains undef elements, we need to be careful about
15949// introducing undef's in the folded mask which are not the result of composing
15950// the masks of the shuffles.
15951static SDValue combineShuffleOfSplat(ArrayRef<int> UserMask,
                                   ShuffleVectorSDNode *Splat,
                                   SelectionDAG &DAG) {
ArrayRef<int> SplatMask = Splat->getMask();
assert(UserMask.size() == SplatMask.size() && "Mask length mismatch")(static_cast <bool> (UserMask.size() == SplatMask.size(
) && "Mask length mismatch") ? void (0) : __assert_fail
 ("UserMask.size() == SplatMask.size() && \"Mask length mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 15955, __extension__ __PRETTY_FUNCTION__));

// Prefer simplifying to the splat-shuffle, if possible. This is legal if
// every undef mask element in the splat-shuffle has a corresponding undef
// element in the user-shuffle's mask or if the composition of mask elements
// would result in undef.
// Examples for (shuffle (shuffle v, undef, SplatMask), undef, UserMask):
// * UserMask=[0,2,u,u], SplatMask=[2,u,2,u] -> [2,2,u,u]
//   In this case it is not legal to simplify to the splat-shuffle because we
//   may be exposing the users of the shuffle an undef element at index 1
//   which was not there before the combine.
// * UserMask=[0,u,2,u], SplatMask=[2,u,2,u] -> [2,u,2,u]
//   In this case the composition of masks yields SplatMask, so it's ok to
//   simplify to the splat-shuffle.
// * UserMask=[3,u,2,u], SplatMask=[2,u,2,u] -> [u,u,2,u]
//   In this case the composed mask includes all undef elements of SplatMask
//   and in addition sets element zero to undef. It is safe to simplify to
//   the splat-shuffle.
auto CanSimplifyToExistingSplat = [](ArrayRef<int> UserMask,
                                     ArrayRef<int> SplatMask) {
  for (unsigned i = 0, e = UserMask.size(); i != e; ++i)
    if (UserMask[i] != -1 && SplatMask[i] == -1 &&
        SplatMask[UserMask[i]] != -1)
      return false;
  return true;
};
if (CanSimplifyToExistingSplat(UserMask, SplatMask))
  return SDValue(Splat, 0);

// Create a new shuffle with a mask that is composed of the two shuffles'
// masks.
SmallVector<int, 32> NewMask;
for (int Idx : UserMask)
  NewMask.push_back(Idx == -1 ? -1 : SplatMask[Idx]);

return DAG.getVectorShuffle(Splat->getValueType(0), SDLoc(Splat),
                            Splat->getOperand(0), Splat->getOperand(1),
                            NewMask);
15993}

15995/// If the shuffle mask is taking exactly one element from the first vector
15996/// operand and passing through all other elements from the second vector
15997/// operand, return the index of the mask element that is choosing an element
15998/// from the first operand. Otherwise, return -1.
15999static int getShuffleMaskIndexOfOneElementFromOp0IntoOp1(ArrayRef<int> Mask) {
int MaskSize = Mask.size();
int EltFromOp0 = -1;
// TODO: This does not match if there are undef elements in the shuffle mask.
// Should we ignore undefs in the shuffle mask instead? The trade-off is
// removing an instruction (a shuffle), but losing the knowledge that some
// vector lanes are not needed.
for (int i = 0; i != MaskSize; ++i) {
  if (Mask[i] >= 0 && Mask[i] < MaskSize) {
    // We're looking for a shuffle of exactly one element from operand 0.
    if (EltFromOp0 != -1)
      return -1;
    EltFromOp0 = i;
  } else if (Mask[i] != i + MaskSize) {
    // Nothing from operand 1 can change lanes.
    return -1;
  }
}
return EltFromOp0;
16018}

16020/// If a shuffle inserts exactly one element from a source vector operand into
16021/// another vector operand and we can access the specified element as a scalar,
16022/// then we can eliminate the shuffle.
16023static SDValue replaceShuffleOfInsert(ShuffleVectorSDNode *Shuf,
                                    SelectionDAG &DAG) {
// First, check if we are taking one element of a vector and shuffling that
// element into another vector.
ArrayRef<int> Mask = Shuf->getMask();
SmallVector<int, 16> CommutedMask(Mask.begin(), Mask.end());
SDValue Op0 = Shuf->getOperand(0);
SDValue Op1 = Shuf->getOperand(1);
int ShufOp0Index = getShuffleMaskIndexOfOneElementFromOp0IntoOp1(Mask);
if (ShufOp0Index == -1) {
  // Commute mask and check again.
  ShuffleVectorSDNode::commuteMask(CommutedMask);
  ShufOp0Index = getShuffleMaskIndexOfOneElementFromOp0IntoOp1(CommutedMask);
  if (ShufOp0Index == -1)
    return SDValue();
  // Commute operands to match the commuted shuffle mask.
  std::swap(Op0, Op1);
  Mask = CommutedMask;
}

// The shuffle inserts exactly one element from operand 0 into operand 1.
// Now see if we can access that element as a scalar via a real insert element
// instruction.
// TODO: We can try harder to locate the element as a scalar. Examples: it
// could be an operand of SCALAR_TO_VECTOR, BUILD_VECTOR, or a constant.
assert(Mask[ShufOp0Index] >= 0 && Mask[ShufOp0Index] < (int)Mask.size() &&(static_cast <bool> (Mask[ShufOp0Index] >= 0 &&
 Mask[ShufOp0Index] < (int)Mask.size() && "Shuffle mask value must be from operand 0"
) ? void (0) : __assert_fail ("Mask[ShufOp0Index] >= 0 && Mask[ShufOp0Index] < (int)Mask.size() && \"Shuffle mask value must be from operand 0\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16049, __extension__ __PRETTY_FUNCTION__))
       "Shuffle mask value must be from operand 0")(static_cast <bool> (Mask[ShufOp0Index] >= 0 &&
 Mask[ShufOp0Index] < (int)Mask.size() && "Shuffle mask value must be from operand 0"
) ? void (0) : __assert_fail ("Mask[ShufOp0Index] >= 0 && Mask[ShufOp0Index] < (int)Mask.size() && \"Shuffle mask value must be from operand 0\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16049, __extension__ __PRETTY_FUNCTION__));
if (Op0.getOpcode() != ISD::INSERT_VECTOR_ELT)
  return SDValue();

auto *InsIndexC = dyn_cast<ConstantSDNode>(Op0.getOperand(2));
if (!InsIndexC || InsIndexC->getSExtValue() != Mask[ShufOp0Index])
  return SDValue();

// There's an existing insertelement with constant insertion index, so we
// don't need to check the legality/profitability of a replacement operation
// that differs at most in the constant value. The target should be able to
// lower any of those in a similar way. If not, legalization will expand this
// to a scalar-to-vector plus shuffle.
//
// Note that the shuffle may move the scalar from the position that the insert
// element used. Therefore, our new insert element occurs at the shuffle's
// mask index value, not the insert's index value.
// shuffle (insertelt v1, x, C), v2, mask --> insertelt v2, x, C'
SDValue NewInsIndex = DAG.getConstant(ShufOp0Index, SDLoc(Shuf),
                                      Op0.getOperand(2).getValueType());
return DAG.getNode(ISD::INSERT_VECTOR_ELT, SDLoc(Shuf), Op0.getValueType(),
                   Op1, Op0.getOperand(1), NewInsIndex);
16071}

16073SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
EVT VT = N->getValueType(0);
unsigned NumElts = VT.getVectorNumElements();

SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);

assert(N0.getValueType() == VT && "Vector shuffle must be normalized in DAG")(static_cast <bool> (N0.getValueType() == VT &&
 "Vector shuffle must be normalized in DAG") ? void (0) : __assert_fail
 ("N0.getValueType() == VT && \"Vector shuffle must be normalized in DAG\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16080, __extension__ __PRETTY_FUNCTION__));

// Canonicalize shuffle undef, undef -> undef
if (N0.isUndef() && N1.isUndef())
  return DAG.getUNDEF(VT);

ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);

// Canonicalize shuffle v, v -> v, undef
if (N0 == N1) {
1
Taking false branch→
  SmallVector<int, 8> NewMask;
  for (unsigned i = 0; i != NumElts; ++i) {
    int Idx = SVN->getMaskElt(i);
    if (Idx >= (int)NumElts) Idx -= NumElts;
    NewMask.push_back(Idx);
  }
  return DAG.getVectorShuffle(VT, SDLoc(N), N0, DAG.getUNDEF(VT), NewMask);
}

// Canonicalize shuffle undef, v -> v, undef.  Commute the shuffle mask.
if (N0.isUndef())
2
←
Taking false branch→
  return DAG.getCommutedVectorShuffle(*SVN);

// Remove references to rhs if it is undef
if (N1.isUndef()) {
3
←
Taking false branch→
  bool Changed = false;
  SmallVector<int, 8> NewMask;
  for (unsigned i = 0; i != NumElts; ++i) {
    int Idx = SVN->getMaskElt(i);
    if (Idx >= (int)NumElts) {
      Idx = -1;
      Changed = true;
    }
    NewMask.push_back(Idx);
  }
  if (Changed)
    return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, NewMask);
}

// Simplify shuffle mask if a referenced element is UNDEF.
if (SDValue V = simplifyShuffleMask(SVN, N0, N1, DAG))
4
←
Taking false branch→
  return V;

if (SDValue InsElt = replaceShuffleOfInsert(SVN, DAG))
5
←
Taking false branch→
  return InsElt;

// A shuffle of a single vector that is a splat can always be folded.
if (auto *N0Shuf = dyn_cast<ShuffleVectorSDNode>(N0))
6
←
Taking false branch→
  if (N1->isUndef() && N0Shuf->isSplat())
    return combineShuffleOfSplat(SVN->getMask(), N0Shuf, DAG);

// If it is a splat, check if the argument vector is another splat or a
// build_vector.
if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
7
←
Assuming the condition is false→
  SDNode *V = N0.getNode();

  // If this is a bit convert that changes the element type of the vector but
  // not the number of vector elements, look through it.  Be careful not to
  // look though conversions that change things like v4f32 to v2f64.
  if (V->getOpcode() == ISD::BITCAST) {
    SDValue ConvInput = V->getOperand(0);
    if (ConvInput.getValueType().isVector() &&
        ConvInput.getValueType().getVectorNumElements() == NumElts)
      V = ConvInput.getNode();
  }

  if (V->getOpcode() == ISD::BUILD_VECTOR) {
    assert(V->getNumOperands() == NumElts &&(static_cast <bool> (V->getNumOperands() == NumElts &&
 "BUILD_VECTOR has wrong number of operands") ? void (0) : __assert_fail
 ("V->getNumOperands() == NumElts && \"BUILD_VECTOR has wrong number of operands\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16148, __extension__ __PRETTY_FUNCTION__))
           "BUILD_VECTOR has wrong number of operands")(static_cast <bool> (V->getNumOperands() == NumElts &&
 "BUILD_VECTOR has wrong number of operands") ? void (0) : __assert_fail
 ("V->getNumOperands() == NumElts && \"BUILD_VECTOR has wrong number of operands\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16148, __extension__ __PRETTY_FUNCTION__));
    SDValue Base;
    bool AllSame = true;
    for (unsigned i = 0; i != NumElts; ++i) {
      if (!V->getOperand(i).isUndef()) {
        Base = V->getOperand(i);
        break;
      }
    }
    // Splat of <u, u, u, u>, return <u, u, u, u>
    if (!Base.getNode())
      return N0;
    for (unsigned i = 0; i != NumElts; ++i) {
      if (V->getOperand(i) != Base) {
        AllSame = false;
        break;
      }
    }
    // Splat of <x, x, x, x>, return <x, x, x, x>
    if (AllSame)
      return N0;

    // Canonicalize any other splat as a build_vector.
    const SDValue &Splatted = V->getOperand(SVN->getSplatIndex());
    SmallVector<SDValue, 8> Ops(NumElts, Splatted);
    SDValue NewBV = DAG.getBuildVector(V->getValueType(0), SDLoc(N), Ops);

    // We may have jumped through bitcasts, so the type of the
    // BUILD_VECTOR may not match the type of the shuffle.
    if (V->getValueType(0) != VT)
      NewBV = DAG.getBitcast(VT, NewBV);
    return NewBV;
  }
}

// There are various patterns used to build up a vector from smaller vectors,
// subvectors, or elements. Scan chains of these and replace unused insertions
// or components with undef.
if (SDValue S = simplifyShuffleOperands(SVN, N0, N1, DAG))
8
←
Calling 'simplifyShuffleOperands'→
  return S;

// Match shuffles that can be converted to any_vector_extend_in_reg.
if (SDValue V = combineShuffleToVectorExtend(SVN, DAG, TLI, LegalOperations, LegalTypes))
  return V;

// Combine "truncate_vector_in_reg" style shuffles.
if (SDValue V = combineTruncationShuffle(SVN, DAG))
  return V;

if (N0.getOpcode() == ISD::CONCAT_VECTORS &&
    Level < AfterLegalizeVectorOps &&
    (N1.isUndef() ||
    (N1.getOpcode() == ISD::CONCAT_VECTORS &&
     N0.getOperand(0).getValueType() == N1.getOperand(0).getValueType()))) {
  if (SDValue V = partitionShuffleOfConcats(N, DAG))
    return V;
}

// Attempt to combine a shuffle of 2 inputs of 'scalar sources' -
// BUILD_VECTOR or SCALAR_TO_VECTOR into a single BUILD_VECTOR.
if (Level < AfterLegalizeVectorOps && TLI.isTypeLegal(VT))
  if (SDValue Res = combineShuffleOfScalars(SVN, DAG, TLI))
    return Res;

// If this shuffle only has a single input that is a bitcasted shuffle,
// attempt to merge the 2 shuffles and suitably bitcast the inputs/output
// back to their original types.
if (N0.getOpcode() == ISD::BITCAST && N0.hasOneUse() &&
    N1.isUndef() && Level < AfterLegalizeVectorOps &&
    TLI.isTypeLegal(VT)) {

  // Peek through the bitcast only if there is one user.
  SDValue BC0 = N0;
  while (BC0.getOpcode() == ISD::BITCAST) {
    if (!BC0.hasOneUse())
      break;
    BC0 = BC0.getOperand(0);
  }

  auto ScaleShuffleMask = [](ArrayRef<int> Mask, int Scale) {
    if (Scale == 1)
      return SmallVector<int, 8>(Mask.begin(), Mask.end());

    SmallVector<int, 8> NewMask;
    for (int M : Mask)
      for (int s = 0; s != Scale; ++s)
        NewMask.push_back(M < 0 ? -1 : Scale * M + s);
    return NewMask;
  };

  if (BC0.getOpcode() == ISD::VECTOR_SHUFFLE && BC0.hasOneUse()) {
    EVT SVT = VT.getScalarType();
    EVT InnerVT = BC0->getValueType(0);
    EVT InnerSVT = InnerVT.getScalarType();

    // Determine which shuffle works with the smaller scalar type.
    EVT ScaleVT = SVT.bitsLT(InnerSVT) ? VT : InnerVT;
    EVT ScaleSVT = ScaleVT.getScalarType();

    if (TLI.isTypeLegal(ScaleVT) &&
        0 == (InnerSVT.getSizeInBits() % ScaleSVT.getSizeInBits()) &&
        0 == (SVT.getSizeInBits() % ScaleSVT.getSizeInBits())) {
      int InnerScale = InnerSVT.getSizeInBits() / ScaleSVT.getSizeInBits();
      int OuterScale = SVT.getSizeInBits() / ScaleSVT.getSizeInBits();

      // Scale the shuffle masks to the smaller scalar type.
      ShuffleVectorSDNode *InnerSVN = cast<ShuffleVectorSDNode>(BC0);
      SmallVector<int, 8> InnerMask =
          ScaleShuffleMask(InnerSVN->getMask(), InnerScale);
      SmallVector<int, 8> OuterMask =
          ScaleShuffleMask(SVN->getMask(), OuterScale);

      // Merge the shuffle masks.
      SmallVector<int, 8> NewMask;
      for (int M : OuterMask)
        NewMask.push_back(M < 0 ? -1 : InnerMask[M]);

      // Test for shuffle mask legality over both commutations.
      SDValue SV0 = BC0->getOperand(0);
      SDValue SV1 = BC0->getOperand(1);
      bool LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
      if (!LegalMask) {
        std::swap(SV0, SV1);
        ShuffleVectorSDNode::commuteMask(NewMask);
        LegalMask = TLI.isShuffleMaskLegal(NewMask, ScaleVT);
      }

      if (LegalMask) {
        SV0 = DAG.getBitcast(ScaleVT, SV0);
        SV1 = DAG.getBitcast(ScaleVT, SV1);
        return DAG.getBitcast(
            VT, DAG.getVectorShuffle(ScaleVT, SDLoc(N), SV0, SV1, NewMask));
      }
    }
  }
}

// Canonicalize shuffles according to rules:
//  shuffle(A, shuffle(A, B)) -> shuffle(shuffle(A,B), A)
//  shuffle(B, shuffle(A, B)) -> shuffle(shuffle(A,B), B)
//  shuffle(B, shuffle(A, Undef)) -> shuffle(shuffle(A, Undef), B)
if (N1.getOpcode() == ISD::VECTOR_SHUFFLE &&
    N0.getOpcode() != ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG &&
    TLI.isTypeLegal(VT)) {
  // The incoming shuffle must be of the same type as the result of the
  // current shuffle.
  assert(N1->getOperand(0).getValueType() == VT &&(static_cast <bool> (N1->getOperand(0).getValueType(
) == VT && "Shuffle types don't match") ? void (0) : __assert_fail
 ("N1->getOperand(0).getValueType() == VT && \"Shuffle types don't match\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16295, __extension__ __PRETTY_FUNCTION__))
         "Shuffle types don't match")(static_cast <bool> (N1->getOperand(0).getValueType(
) == VT && "Shuffle types don't match") ? void (0) : __assert_fail
 ("N1->getOperand(0).getValueType() == VT && \"Shuffle types don't match\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16295, __extension__ __PRETTY_FUNCTION__));

  SDValue SV0 = N1->getOperand(0);
  SDValue SV1 = N1->getOperand(1);
  bool HasSameOp0 = N0 == SV0;
  bool IsSV1Undef = SV1.isUndef();
  if (HasSameOp0 || IsSV1Undef || N0 == SV1)
    // Commute the operands of this shuffle so that next rule
    // will trigger.
    return DAG.getCommutedVectorShuffle(*SVN);
}

// Try to fold according to rules:
//   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
//   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
//   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
// Don't try to fold shuffles with illegal type.
// Only fold if this shuffle is the only user of the other shuffle.
if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && N->isOnlyUserOf(N0.getNode()) &&
    Level < AfterLegalizeDAG && TLI.isTypeLegal(VT)) {
  ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0);

  // Don't try to fold splats; they're likely to simplify somehow, or they
  // might be free.
  if (OtherSV->isSplat())
    return SDValue();

  // The incoming shuffle must be of the same type as the result of the
  // current shuffle.
  assert(OtherSV->getOperand(0).getValueType() == VT &&(static_cast <bool> (OtherSV->getOperand(0).getValueType
() == VT && "Shuffle types don't match") ? void (0) :
 __assert_fail ("OtherSV->getOperand(0).getValueType() == VT && \"Shuffle types don't match\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16325, __extension__ __PRETTY_FUNCTION__))
         "Shuffle types don't match")(static_cast <bool> (OtherSV->getOperand(0).getValueType
() == VT && "Shuffle types don't match") ? void (0) :
 __assert_fail ("OtherSV->getOperand(0).getValueType() == VT && \"Shuffle types don't match\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16325, __extension__ __PRETTY_FUNCTION__));

  SDValue SV0, SV1;
  SmallVector<int, 4> Mask;
  // Compute the combined shuffle mask for a shuffle with SV0 as the first
  // operand, and SV1 as the second operand.
  for (unsigned i = 0; i != NumElts; ++i) {
    int Idx = SVN->getMaskElt(i);
    if (Idx < 0) {
      // Propagate Undef.
      Mask.push_back(Idx);
      continue;
    }

    SDValue CurrentVec;
    if (Idx < (int)NumElts) {
      // This shuffle index refers to the inner shuffle N0. Lookup the inner
      // shuffle mask to identify which vector is actually referenced.
      Idx = OtherSV->getMaskElt(Idx);
      if (Idx < 0) {
        // Propagate Undef.
        Mask.push_back(Idx);
        continue;
      }

      CurrentVec = (Idx < (int) NumElts) ? OtherSV->getOperand(0)
                                         : OtherSV->getOperand(1);
    } else {
      // This shuffle index references an element within N1.
      CurrentVec = N1;
    }

    // Simple case where 'CurrentVec' is UNDEF.
    if (CurrentVec.isUndef()) {
      Mask.push_back(-1);
      continue;
    }

    // Canonicalize the shuffle index. We don't know yet if CurrentVec
    // will be the first or second operand of the combined shuffle.
    Idx = Idx % NumElts;
    if (!SV0.getNode() || SV0 == CurrentVec) {
      // Ok. CurrentVec is the left hand side.
      // Update the mask accordingly.
      SV0 = CurrentVec;
      Mask.push_back(Idx);
      continue;
    }

    // Bail out if we cannot convert the shuffle pair into a single shuffle.
    if (SV1.getNode() && SV1 != CurrentVec)
      return SDValue();

    // Ok. CurrentVec is the right hand side.
    // Update the mask accordingly.
    SV1 = CurrentVec;
    Mask.push_back(Idx + NumElts);
  }

  // Check if all indices in Mask are Undef. In case, propagate Undef.
  bool isUndefMask = true;
  for (unsigned i = 0; i != NumElts && isUndefMask; ++i)
    isUndefMask &= Mask[i] < 0;

  if (isUndefMask)
    return DAG.getUNDEF(VT);

  if (!SV0.getNode())
    SV0 = DAG.getUNDEF(VT);
  if (!SV1.getNode())
    SV1 = DAG.getUNDEF(VT);

  // Avoid introducing shuffles with illegal mask.
  if (!TLI.isShuffleMaskLegal(Mask, VT)) {
    ShuffleVectorSDNode::commuteMask(Mask);

    if (!TLI.isShuffleMaskLegal(Mask, VT))
      return SDValue();

    //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, A, M2)
    //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, A, M2)
    //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(C, B, M2)
    std::swap(SV0, SV1);
  }

  //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, B, M2)
  //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2)
  //   shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2)
  return DAG.getVectorShuffle(VT, SDLoc(N), SV0, SV1, Mask);
}

return SDValue();
16417}

16419SDValue DAGCombiner::visitSCALAR_TO_VECTOR(SDNode *N) {
SDValue InVal = N->getOperand(0);
EVT VT = N->getValueType(0);

// Replace a SCALAR_TO_VECTOR(EXTRACT_VECTOR_ELT(V,C0)) pattern
// with a VECTOR_SHUFFLE and possible truncate.
if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT) {
  SDValue InVec = InVal->getOperand(0);
  SDValue EltNo = InVal->getOperand(1);
  auto InVecT = InVec.getValueType();
  if (ConstantSDNode *C0 = dyn_cast<ConstantSDNode>(EltNo)) {
    SmallVector<int, 8> NewMask(InVecT.getVectorNumElements(), -1);
    int Elt = C0->getZExtValue();
    NewMask[0] = Elt;
    SDValue Val;
    // If we have an implict truncate do truncate here as long as it's legal.
    // if it's not legal, this should
    if (VT.getScalarType() != InVal.getValueType() &&
        InVal.getValueType().isScalarInteger() &&
        isTypeLegal(VT.getScalarType())) {
      Val =
          DAG.getNode(ISD::TRUNCATE, SDLoc(InVal), VT.getScalarType(), InVal);
      return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(N), VT, Val);
    }
    if (VT.getScalarType() == InVecT.getScalarType() &&
        VT.getVectorNumElements() <= InVecT.getVectorNumElements() &&
        TLI.isShuffleMaskLegal(NewMask, VT)) {
      Val = DAG.getVectorShuffle(InVecT, SDLoc(N), InVec,
                                 DAG.getUNDEF(InVecT), NewMask);
      // If the initial vector is the correct size this shuffle is a
      // valid result.
      if (VT == InVecT)
        return Val;
      // If not we must truncate the vector.
      if (VT.getVectorNumElements() != InVecT.getVectorNumElements()) {
        MVT IdxTy = TLI.getVectorIdxTy(DAG.getDataLayout());
        SDValue ZeroIdx = DAG.getConstant(0, SDLoc(N), IdxTy);
        EVT SubVT =
            EVT::getVectorVT(*DAG.getContext(), InVecT.getVectorElementType(),
                             VT.getVectorNumElements());
        Val = DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(N), SubVT, Val,
                          ZeroIdx);
        return Val;
      }
    }
  }
}

return SDValue();
16468}

16470SDValue DAGCombiner::visitINSERT_SUBVECTOR(SDNode *N) {
EVT VT = N->getValueType(0);
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue N2 = N->getOperand(2);

// If inserting an UNDEF, just return the original vector.
if (N1.isUndef())
  return N0;

// For nested INSERT_SUBVECTORs, attempt to combine inner node first to allow
// us to pull BITCASTs from input to output.
if (N0.hasOneUse() && N0->getOpcode() == ISD::INSERT_SUBVECTOR)
  if (SDValue NN0 = visitINSERT_SUBVECTOR(N0.getNode()))
    return DAG.getNode(ISD::INSERT_SUBVECTOR, SDLoc(N), VT, NN0, N1, N2);

// If this is an insert of an extracted vector into an undef vector, we can
// just use the input to the extract.
if (N0.isUndef() && N1.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
    N1.getOperand(1) == N2 && N1.getOperand(0).getValueType() == VT)
  return N1.getOperand(0);

// If we are inserting a bitcast value into an undef, with the same
// number of elements, just use the bitcast input of the extract.
// i.e. INSERT_SUBVECTOR UNDEF (BITCAST N1) N2 ->
//        BITCAST (INSERT_SUBVECTOR UNDEF N1 N2)
if (N0.isUndef() && N1.getOpcode() == ISD::BITCAST &&
    N1.getOperand(0).getOpcode() == ISD::EXTRACT_SUBVECTOR &&
    N1.getOperand(0).getOperand(1) == N2 &&
    N1.getOperand(0).getOperand(0).getValueType().getVectorNumElements() ==
        VT.getVectorNumElements() &&
    N1.getOperand(0).getOperand(0).getValueType().getSizeInBits() ==
        VT.getSizeInBits()) {
  return DAG.getBitcast(VT, N1.getOperand(0).getOperand(0));
}

// If both N1 and N2 are bitcast values on which insert_subvector
// would makes sense, pull the bitcast through.
// i.e. INSERT_SUBVECTOR (BITCAST N0) (BITCAST N1) N2 ->
//        BITCAST (INSERT_SUBVECTOR N0 N1 N2)
if (N0.getOpcode() == ISD::BITCAST && N1.getOpcode() == ISD::BITCAST) {
  SDValue CN0 = N0.getOperand(0);
  SDValue CN1 = N1.getOperand(0);
  if (CN0.getValueType().getVectorElementType() ==
          CN1.getValueType().getVectorElementType() &&
      CN0.getValueType().getVectorNumElements() ==
          VT.getVectorNumElements()) {
    SDValue NewINSERT = DAG.getNode(ISD::INSERT_SUBVECTOR, SDLoc(N),
                                    CN0.getValueType(), CN0, CN1, N2);
    return DAG.getBitcast(VT, NewINSERT);
  }
}

// Combine INSERT_SUBVECTORs where we are inserting to the same index.
// INSERT_SUBVECTOR( INSERT_SUBVECTOR( Vec, SubOld, Idx ), SubNew, Idx )
// --> INSERT_SUBVECTOR( Vec, SubNew, Idx )
if (N0.getOpcode() == ISD::INSERT_SUBVECTOR &&
    N0.getOperand(1).getValueType() == N1.getValueType() &&
    N0.getOperand(2) == N2)
  return DAG.getNode(ISD::INSERT_SUBVECTOR, SDLoc(N), VT, N0.getOperand(0),
                     N1, N2);

if (!isa<ConstantSDNode>(N2))
  return SDValue();

unsigned InsIdx = cast<ConstantSDNode>(N2)->getZExtValue();

// Canonicalize insert_subvector dag nodes.
// Example:
// (insert_subvector (insert_subvector A, Idx0), Idx1)
// -> (insert_subvector (insert_subvector A, Idx1), Idx0)
if (N0.getOpcode() == ISD::INSERT_SUBVECTOR && N0.hasOneUse() &&
    N1.getValueType() == N0.getOperand(1).getValueType() &&
    isa<ConstantSDNode>(N0.getOperand(2))) {
  unsigned OtherIdx = N0.getConstantOperandVal(2);
  if (InsIdx < OtherIdx) {
    // Swap nodes.
    SDValue NewOp = DAG.getNode(ISD::INSERT_SUBVECTOR, SDLoc(N), VT,
                                N0.getOperand(0), N1, N2);
    AddToWorklist(NewOp.getNode());
    return DAG.getNode(ISD::INSERT_SUBVECTOR, SDLoc(N0.getNode()),
                       VT, NewOp, N0.getOperand(1), N0.getOperand(2));
  }
}

// If the input vector is a concatenation, and the insert replaces
// one of the pieces, we can optimize into a single concat_vectors.
if (N0.getOpcode() == ISD::CONCAT_VECTORS && N0.hasOneUse() &&
    N0.getOperand(0).getValueType() == N1.getValueType()) {
  unsigned Factor = N1.getValueType().getVectorNumElements();

  SmallVector<SDValue, 8> Ops(N0->op_begin(), N0->op_end());
  Ops[cast<ConstantSDNode>(N2)->getZExtValue() / Factor] = N1;

  return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(N), VT, Ops);
}

return SDValue();
16568}

16570SDValue DAGCombiner::visitFP_TO_FP16(SDNode *N) {
SDValue N0 = N->getOperand(0);

// fold (fp_to_fp16 (fp16_to_fp op)) -> op
if (N0->getOpcode() == ISD::FP16_TO_FP)
  return N0->getOperand(0);

return SDValue();
16578}

16580SDValue DAGCombiner::visitFP16_TO_FP(SDNode *N) {
SDValue N0 = N->getOperand(0);

// fold fp16_to_fp(op & 0xffff) -> fp16_to_fp(op)
if (N0->getOpcode() == ISD::AND) {
  ConstantSDNode *AndConst = getAsNonOpaqueConstant(N0.getOperand(1));
  if (AndConst && AndConst->getAPIntValue() == 0xffff) {
    return DAG.getNode(ISD::FP16_TO_FP, SDLoc(N), N->getValueType(0),
                       N0.getOperand(0));
  }
}

return SDValue();
16593}

16595/// Returns a vector_shuffle if it able to transform an AND to a vector_shuffle
16596/// with the destination vector and a zero vector.
16597/// e.g. AND V, <0xffffffff, 0, 0xffffffff, 0>. ==>
16598///      vector_shuffle V, Zero, <0, 4, 2, 4>
16599SDValue DAGCombiner::XformToShuffleWithZero(SDNode *N) {
assert(N->getOpcode() == ISD::AND && "Unexpected opcode!")(static_cast <bool> (N->getOpcode() == ISD::AND &&
 "Unexpected opcode!") ? void (0) : __assert_fail ("N->getOpcode() == ISD::AND && \"Unexpected opcode!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16600, __extension__ __PRETTY_FUNCTION__));

EVT VT = N->getValueType(0);
SDValue LHS = N->getOperand(0);
SDValue RHS = peekThroughBitcast(N->getOperand(1));
SDLoc DL(N);

// Make sure we're not running after operation legalization where it
// may have custom lowered the vector shuffles.
if (LegalOperations)
  return SDValue();

if (RHS.getOpcode() != ISD::BUILD_VECTOR)
  return SDValue();

EVT RVT = RHS.getValueType();
unsigned NumElts = RHS.getNumOperands();

// Attempt to create a valid clear mask, splitting the mask into
// sub elements and checking to see if each is
// all zeros or all ones - suitable for shuffle masking.
auto BuildClearMask = [&](int Split) {
  int NumSubElts = NumElts * Split;
  int NumSubBits = RVT.getScalarSizeInBits() / Split;

  SmallVector<int, 8> Indices;
  for (int i = 0; i != NumSubElts; ++i) {
    int EltIdx = i / Split;
    int SubIdx = i % Split;
    SDValue Elt = RHS.getOperand(EltIdx);
    if (Elt.isUndef()) {
      Indices.push_back(-1);
      continue;
    }

    APInt Bits;
    if (isa<ConstantSDNode>(Elt))
      Bits = cast<ConstantSDNode>(Elt)->getAPIntValue();
    else if (isa<ConstantFPSDNode>(Elt))
      Bits = cast<ConstantFPSDNode>(Elt)->getValueAPF().bitcastToAPInt();
    else
      return SDValue();

    // Extract the sub element from the constant bit mask.
    if (DAG.getDataLayout().isBigEndian()) {
      Bits.lshrInPlace((Split - SubIdx - 1) * NumSubBits);
    } else {
      Bits.lshrInPlace(SubIdx * NumSubBits);
    }

    if (Split > 1)
      Bits = Bits.trunc(NumSubBits);

    if (Bits.isAllOnesValue())
      Indices.push_back(i);
    else if (Bits == 0)
      Indices.push_back(i + NumSubElts);
    else
      return SDValue();
  }

  // Let's see if the target supports this vector_shuffle.
  EVT ClearSVT = EVT::getIntegerVT(*DAG.getContext(), NumSubBits);
  EVT ClearVT = EVT::getVectorVT(*DAG.getContext(), ClearSVT, NumSubElts);
  if (!TLI.isVectorClearMaskLegal(Indices, ClearVT))
    return SDValue();

  SDValue Zero = DAG.getConstant(0, DL, ClearVT);
  return DAG.getBitcast(VT, DAG.getVectorShuffle(ClearVT, DL,
                                                 DAG.getBitcast(ClearVT, LHS),
                                                 Zero, Indices));
};

// Determine maximum split level (byte level masking).
int MaxSplit = 1;
if (RVT.getScalarSizeInBits() % 8 == 0)
  MaxSplit = RVT.getScalarSizeInBits() / 8;

for (int Split = 1; Split <= MaxSplit; ++Split)
  if (RVT.getScalarSizeInBits() % Split == 0)
    if (SDValue S = BuildClearMask(Split))
      return S;

return SDValue();
16684}

16686/// Visit a binary vector operation, like ADD.
16687SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) {
assert(N->getValueType(0).isVector() &&(static_cast <bool> (N->getValueType(0).isVector() &&
 "SimplifyVBinOp only works on vectors!") ? void (0) : __assert_fail
 ("N->getValueType(0).isVector() && \"SimplifyVBinOp only works on vectors!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16689, __extension__ __PRETTY_FUNCTION__))
       "SimplifyVBinOp only works on vectors!")(static_cast <bool> (N->getValueType(0).isVector() &&
 "SimplifyVBinOp only works on vectors!") ? void (0) : __assert_fail
 ("N->getValueType(0).isVector() && \"SimplifyVBinOp only works on vectors!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16689, __extension__ __PRETTY_FUNCTION__));

SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
SDValue Ops[] = {LHS, RHS};

// See if we can constant fold the vector operation.
if (SDValue Fold = DAG.FoldConstantVectorArithmetic(
        N->getOpcode(), SDLoc(LHS), LHS.getValueType(), Ops, N->getFlags()))
  return Fold;

// Type legalization might introduce new shuffles in the DAG.
// Fold (VBinOp (shuffle (A, Undef, Mask)), (shuffle (B, Undef, Mask)))
//   -> (shuffle (VBinOp (A, B)), Undef, Mask).
if (LegalTypes && isa<ShuffleVectorSDNode>(LHS) &&
    isa<ShuffleVectorSDNode>(RHS) && LHS.hasOneUse() && RHS.hasOneUse() &&
    LHS.getOperand(1).isUndef() &&
    RHS.getOperand(1).isUndef()) {
  ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(LHS);
  ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(RHS);

  if (SVN0->getMask().equals(SVN1->getMask())) {
    EVT VT = N->getValueType(0);
    SDValue UndefVector = LHS.getOperand(1);
    SDValue NewBinOp = DAG.getNode(N->getOpcode(), SDLoc(N), VT,
                                   LHS.getOperand(0), RHS.getOperand(0),
                                   N->getFlags());
    AddUsersToWorklist(N);
    return DAG.getVectorShuffle(VT, SDLoc(N), NewBinOp, UndefVector,
                                SVN0->getMask());
  }
}

return SDValue();
16723}

16725SDValue DAGCombiner::SimplifySelect(const SDLoc &DL, SDValue N0, SDValue N1,
                                  SDValue N2) {
assert(N0.getOpcode() ==ISD::SETCC && "First argument must be a SetCC node!")(static_cast <bool> (N0.getOpcode() ==ISD::SETCC &&
 "First argument must be a SetCC node!") ? void (0) : __assert_fail
 ("N0.getOpcode() ==ISD::SETCC && \"First argument must be a SetCC node!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 16727, __extension__ __PRETTY_FUNCTION__));

SDValue SCC = SimplifySelectCC(DL, N0.getOperand(0), N0.getOperand(1), N1, N2,
                               cast<CondCodeSDNode>(N0.getOperand(2))->get());

// If we got a simplified select_cc node back from SimplifySelectCC, then
// break it down into a new SETCC node, and a new SELECT node, and then return
// the SELECT node, since we were called with a SELECT node.
if (SCC.getNode()) {
  // Check to see if we got a select_cc back (to turn into setcc/select).
  // Otherwise, just return whatever node we got back, like fabs.
  if (SCC.getOpcode() == ISD::SELECT_CC) {
    SDValue SETCC = DAG.getNode(ISD::SETCC, SDLoc(N0),
                                N0.getValueType(),
                                SCC.getOperand(0), SCC.getOperand(1),
                                SCC.getOperand(4));
    AddToWorklist(SETCC.getNode());
    return DAG.getSelect(SDLoc(SCC), SCC.getValueType(), SETCC,
                         SCC.getOperand(2), SCC.getOperand(3));
  }

  return SCC;
}
return SDValue();
16751}

16753/// Given a SELECT or a SELECT_CC node, where LHS and RHS are the two values
16754/// being selected between, see if we can simplify the select.  Callers of this
16755/// should assume that TheSelect is deleted if this returns true.  As such, they
16756/// should return the appropriate thing (e.g. the node) back to the top-level of
16757/// the DAG combiner loop to avoid it being looked at.
16758bool DAGCombiner::SimplifySelectOps(SDNode *TheSelect, SDValue LHS,
                                  SDValue RHS) {
// fold (select (setcc x, [+-]0.0, *lt), NaN, (fsqrt x))
// The select + setcc is redundant, because fsqrt returns NaN for X < 0.
if (const ConstantFPSDNode *NaN = isConstOrConstSplatFP(LHS)) {
  if (NaN->isNaN() && RHS.getOpcode() == ISD::FSQRT) {
    // We have: (select (setcc ?, ?, ?), NaN, (fsqrt ?))
    SDValue Sqrt = RHS;
    ISD::CondCode CC;
    SDValue CmpLHS;
    const ConstantFPSDNode *Zero = nullptr;

    if (TheSelect->getOpcode() == ISD::SELECT_CC) {
      CC = dyn_cast<CondCodeSDNode>(TheSelect->getOperand(4))->get();
      CmpLHS = TheSelect->getOperand(0);
      Zero = isConstOrConstSplatFP(TheSelect->getOperand(1));
    } else {
      // SELECT or VSELECT
      SDValue Cmp = TheSelect->getOperand(0);
      if (Cmp.getOpcode() == ISD::SETCC) {
        CC = dyn_cast<CondCodeSDNode>(Cmp.getOperand(2))->get();
        CmpLHS = Cmp.getOperand(0);
        Zero = isConstOrConstSplatFP(Cmp.getOperand(1));
      }
    }
    if (Zero && Zero->isZero() &&
        Sqrt.getOperand(0) == CmpLHS && (CC == ISD::SETOLT ||
        CC == ISD::SETULT || CC == ISD::SETLT)) {
      // We have: (select (setcc x, [+-]0.0, *lt), NaN, (fsqrt x))
      CombineTo(TheSelect, Sqrt);
      return true;
    }
  }
}
// Cannot simplify select with vector condition
if (TheSelect->getOperand(0).getValueType().isVector()) return false;

// If this is a select from two identical things, try to pull the operation
// through the select.
if (LHS.getOpcode() != RHS.getOpcode() ||
    !LHS.hasOneUse() || !RHS.hasOneUse())
  return false;

// If this is a load and the token chain is identical, replace the select
// of two loads with a load through a select of the address to load from.
// This triggers in things like "select bool X, 10.0, 123.0" after the FP
// constants have been dropped into the constant pool.
if (LHS.getOpcode() == ISD::LOAD) {
  LoadSDNode *LLD = cast<LoadSDNode>(LHS);
  LoadSDNode *RLD = cast<LoadSDNode>(RHS);

  // Token chains must be identical.
  if (LHS.getOperand(0) != RHS.getOperand(0) ||
      // Do not let this transformation reduce the number of volatile loads.
      LLD->isVolatile() || RLD->isVolatile() ||
      // FIXME: If either is a pre/post inc/dec load,
      // we'd need to split out the address adjustment.
      LLD->isIndexed() || RLD->isIndexed() ||
      // If this is an EXTLOAD, the VT's must match.
      LLD->getMemoryVT() != RLD->getMemoryVT() ||
      // If this is an EXTLOAD, the kind of extension must match.
      (LLD->getExtensionType() != RLD->getExtensionType() &&
       // The only exception is if one of the extensions is anyext.
       LLD->getExtensionType() != ISD::EXTLOAD &&
       RLD->getExtensionType() != ISD::EXTLOAD) ||
      // FIXME: this discards src value information.  This is
      // over-conservative. It would be beneficial to be able to remember
      // both potential memory locations.  Since we are discarding
      // src value info, don't do the transformation if the memory
      // locations are not in the default address space.
      LLD->getPointerInfo().getAddrSpace() != 0 ||
      RLD->getPointerInfo().getAddrSpace() != 0 ||
      !TLI.isOperationLegalOrCustom(TheSelect->getOpcode(),
                                    LLD->getBasePtr().getValueType()))
    return false;

  // Check that the select condition doesn't reach either load.  If so,
  // folding this will induce a cycle into the DAG.  If not, this is safe to
  // xform, so create a select of the addresses.
  SDValue Addr;
  if (TheSelect->getOpcode() == ISD::SELECT) {
    SDNode *CondNode = TheSelect->getOperand(0).getNode();
    if ((LLD->hasAnyUseOfValue(1) && LLD->isPredecessorOf(CondNode)) ||
        (RLD->hasAnyUseOfValue(1) && RLD->isPredecessorOf(CondNode)))
      return false;
    // The loads must not depend on one another.
    if (LLD->isPredecessorOf(RLD) ||
        RLD->isPredecessorOf(LLD))
      return false;
    Addr = DAG.getSelect(SDLoc(TheSelect),
                         LLD->getBasePtr().getValueType(),
                         TheSelect->getOperand(0), LLD->getBasePtr(),
                         RLD->getBasePtr());
  } else {  // Otherwise SELECT_CC
    SDNode *CondLHS = TheSelect->getOperand(0).getNode();
    SDNode *CondRHS = TheSelect->getOperand(1).getNode();

    if ((LLD->hasAnyUseOfValue(1) &&
         (LLD->isPredecessorOf(CondLHS) || LLD->isPredecessorOf(CondRHS))) ||
        (RLD->hasAnyUseOfValue(1) &&
         (RLD->isPredecessorOf(CondLHS) || RLD->isPredecessorOf(CondRHS))))
      return false;

    Addr = DAG.getNode(ISD::SELECT_CC, SDLoc(TheSelect),
                       LLD->getBasePtr().getValueType(),
                       TheSelect->getOperand(0),
                       TheSelect->getOperand(1),
                       LLD->getBasePtr(), RLD->getBasePtr(),
                       TheSelect->getOperand(4));
  }

  SDValue Load;
  // It is safe to replace the two loads if they have different alignments,
  // but the new load must be the minimum (most restrictive) alignment of the
  // inputs.
  unsigned Alignment = std::min(LLD->getAlignment(), RLD->getAlignment());
  MachineMemOperand::Flags MMOFlags = LLD->getMemOperand()->getFlags();
  if (!RLD->isInvariant())
    MMOFlags &= ~MachineMemOperand::MOInvariant;
  if (!RLD->isDereferenceable())
    MMOFlags &= ~MachineMemOperand::MODereferenceable;
  if (LLD->getExtensionType() == ISD::NON_EXTLOAD) {
    // FIXME: Discards pointer and AA info.
    Load = DAG.getLoad(TheSelect->getValueType(0), SDLoc(TheSelect),
                       LLD->getChain(), Addr, MachinePointerInfo(), Alignment,
                       MMOFlags);
  } else {
    // FIXME: Discards pointer and AA info.
    Load = DAG.getExtLoad(
        LLD->getExtensionType() == ISD::EXTLOAD ? RLD->getExtensionType()
                                                : LLD->getExtensionType(),
        SDLoc(TheSelect), TheSelect->getValueType(0), LLD->getChain(), Addr,
        MachinePointerInfo(), LLD->getMemoryVT(), Alignment, MMOFlags);
  }

  // Users of the select now use the result of the load.
  CombineTo(TheSelect, Load);

  // Users of the old loads now use the new load's chain.  We know the
  // old-load value is dead now.
  CombineTo(LHS.getNode(), Load.getValue(0), Load.getValue(1));
  CombineTo(RHS.getNode(), Load.getValue(0), Load.getValue(1));
  return true;
}

return false;
16904}

16906/// Try to fold an expression of the form (N0 cond N1) ? N2 : N3 to a shift and
16907/// bitwise 'and'.
16908SDValue DAGCombiner::foldSelectCCToShiftAnd(const SDLoc &DL, SDValue N0,
                                          SDValue N1, SDValue N2, SDValue N3,
                                          ISD::CondCode CC) {
// If this is a select where the false operand is zero and the compare is a
// check of the sign bit, see if we can perform the "gzip trick":
// select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A
// select_cc setgt X, 0, A, 0 -> and (not (sra X, size(X)-1)), A
EVT XType = N0.getValueType();
EVT AType = N2.getValueType();
if (!isNullConstant(N3) || !XType.bitsGE(AType))
  return SDValue();

// If the comparison is testing for a positive value, we have to invert
// the sign bit mask, so only do that transform if the target has a bitwise
// 'and not' instruction (the invert is free).
if (CC == ISD::SETGT && TLI.hasAndNot(N2)) {
  // (X > -1) ? A : 0
  // (X >  0) ? X : 0 <-- This is canonical signed max.
  if (!(isAllOnesConstant(N1) || (isNullConstant(N1) && N0 == N2)))
    return SDValue();
} else if (CC == ISD::SETLT) {
  // (X <  0) ? A : 0
  // (X <  1) ? X : 0 <-- This is un-canonicalized signed min.
  if (!(isNullConstant(N1) || (isOneConstant(N1) && N0 == N2)))
    return SDValue();
} else {
  return SDValue();
}

// and (sra X, size(X)-1), A -> "and (srl X, C2), A" iff A is a single-bit
// constant.
EVT ShiftAmtTy = getShiftAmountTy(N0.getValueType());
auto *N2C = dyn_cast<ConstantSDNode>(N2.getNode());
if (N2C && ((N2C->getAPIntValue() & (N2C->getAPIntValue() - 1)) == 0)) {
  unsigned ShCt = XType.getSizeInBits() - N2C->getAPIntValue().logBase2() - 1;
  SDValue ShiftAmt = DAG.getConstant(ShCt, DL, ShiftAmtTy);
  SDValue Shift = DAG.getNode(ISD::SRL, DL, XType, N0, ShiftAmt);
  AddToWorklist(Shift.getNode());

  if (XType.bitsGT(AType)) {
    Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
    AddToWorklist(Shift.getNode());
  }

  if (CC == ISD::SETGT)
    Shift = DAG.getNOT(DL, Shift, AType);

  return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
}

SDValue ShiftAmt = DAG.getConstant(XType.getSizeInBits() - 1, DL, ShiftAmtTy);
SDValue Shift = DAG.getNode(ISD::SRA, DL, XType, N0, ShiftAmt);
AddToWorklist(Shift.getNode());

if (XType.bitsGT(AType)) {
  Shift = DAG.getNode(ISD::TRUNCATE, DL, AType, Shift);
  AddToWorklist(Shift.getNode());
}

if (CC == ISD::SETGT)
  Shift = DAG.getNOT(DL, Shift, AType);

return DAG.getNode(ISD::AND, DL, AType, Shift, N2);
16971}

16973/// Simplify an expression of the form (N0 cond N1) ? N2 : N3
16974/// where 'cond' is the comparison specified by CC.
16975SDValue DAGCombiner::SimplifySelectCC(const SDLoc &DL, SDValue N0, SDValue N1,
                                    SDValue N2, SDValue N3, ISD::CondCode CC,
                                    bool NotExtCompare) {
// (x ? y : y) -> y.
if (N2 == N3) return N2;

EVT VT = N2.getValueType();
ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getNode());
ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.getNode());

// Determine if the condition we're dealing with is constant
SDValue SCC = SimplifySetCC(getSetCCResultType(N0.getValueType()),
                            N0, N1, CC, DL, false);
if (SCC.getNode()) AddToWorklist(SCC.getNode());

if (ConstantSDNode *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
  // fold select_cc true, x, y -> x
  // fold select_cc false, x, y -> y
  return !SCCC->isNullValue() ? N2 : N3;
}

// Check to see if we can simplify the select into an fabs node
if (ConstantFPSDNode *CFP = dyn_cast<ConstantFPSDNode>(N1)) {
  // Allow either -0.0 or 0.0
  if (CFP->isZero()) {
    // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs
    if ((CC == ISD::SETGE || CC == ISD::SETGT) &&
        N0 == N2 && N3.getOpcode() == ISD::FNEG &&
        N2 == N3.getOperand(0))
      return DAG.getNode(ISD::FABS, DL, VT, N0);

    // select (setl[te] X, +/-0.0), fneg(X), X -> fabs
    if ((CC == ISD::SETLT || CC == ISD::SETLE) &&
        N0 == N3 && N2.getOpcode() == ISD::FNEG &&
        N2.getOperand(0) == N3)
      return DAG.getNode(ISD::FABS, DL, VT, N3);
  }
}

// Turn "(a cond b) ? 1.0f : 2.0f" into "load (tmp + ((a cond b) ? 0 : 4)"
// where "tmp" is a constant pool entry containing an array with 1.0 and 2.0
// in it.  This is a win when the constant is not otherwise available because
// it replaces two constant pool loads with one.  We only do this if the FP
// type is known to be legal, because if it isn't, then we are before legalize
// types an we want the other legalization to happen first (e.g. to avoid
// messing with soft float) and if the ConstantFP is not legal, because if
// it is legal, we may not need to store the FP constant in a constant pool.
if (ConstantFPSDNode *TV = dyn_cast<ConstantFPSDNode>(N2))
  if (ConstantFPSDNode *FV = dyn_cast<ConstantFPSDNode>(N3)) {
    if (TLI.isTypeLegal(N2.getValueType()) &&
        (TLI.getOperationAction(ISD::ConstantFP, N2.getValueType()) !=
             TargetLowering::Legal &&
         !TLI.isFPImmLegal(TV->getValueAPF(), TV->getValueType(0)) &&
         !TLI.isFPImmLegal(FV->getValueAPF(), FV->getValueType(0))) &&
        // If both constants have multiple uses, then we won't need to do an
        // extra load, they are likely around in registers for other users.
        (TV->hasOneUse() || FV->hasOneUse())) {
      Constant *Elts[] = {
        const_cast<ConstantFP*>(FV->getConstantFPValue()),
        const_cast<ConstantFP*>(TV->getConstantFPValue())
      };
      Type *FPTy = Elts[0]->getType();
      const DataLayout &TD = DAG.getDataLayout();

      // Create a ConstantArray of the two constants.
      Constant *CA = ConstantArray::get(ArrayType::get(FPTy, 2), Elts);
      SDValue CPIdx =
          DAG.getConstantPool(CA, TLI.getPointerTy(DAG.getDataLayout()),
                              TD.getPrefTypeAlignment(FPTy));
      unsigned Alignment = cast<ConstantPoolSDNode>(CPIdx)->getAlignment();

      // Get the offsets to the 0 and 1 element of the array so that we can
      // select between them.
      SDValue Zero = DAG.getIntPtrConstant(0, DL);
      unsigned EltSize = (unsigned)TD.getTypeAllocSize(Elts[0]->getType());
      SDValue One = DAG.getIntPtrConstant(EltSize, SDLoc(FV));

      SDValue Cond = DAG.getSetCC(DL,
                                  getSetCCResultType(N0.getValueType()),
                                  N0, N1, CC);
      AddToWorklist(Cond.getNode());
      SDValue CstOffset = DAG.getSelect(DL, Zero.getValueType(),
                                        Cond, One, Zero);
      AddToWorklist(CstOffset.getNode());
      CPIdx = DAG.getNode(ISD::ADD, DL, CPIdx.getValueType(), CPIdx,
                          CstOffset);
      AddToWorklist(CPIdx.getNode());
      return DAG.getLoad(
          TV->getValueType(0), DL, DAG.getEntryNode(), CPIdx,
          MachinePointerInfo::getConstantPool(DAG.getMachineFunction()),
          Alignment);
    }
  }

if (SDValue V = foldSelectCCToShiftAnd(DL, N0, N1, N2, N3, CC))
  return V;

// fold (select_cc seteq (and x, y), 0, 0, A) -> (and (shr (shl x)) A)
// where y is has a single bit set.
// A plaintext description would be, we can turn the SELECT_CC into an AND
// when the condition can be materialized as an all-ones register.  Any
// single bit-test can be materialized as an all-ones register with
// shift-left and shift-right-arith.
if (CC == ISD::SETEQ && N0->getOpcode() == ISD::AND &&
    N0->getValueType(0) == VT && isNullConstant(N1) && isNullConstant(N2)) {
  SDValue AndLHS = N0->getOperand(0);
  ConstantSDNode *ConstAndRHS = dyn_cast<ConstantSDNode>(N0->getOperand(1));
  if (ConstAndRHS && ConstAndRHS->getAPIntValue().countPopulation() == 1) {
    // Shift the tested bit over the sign bit.
    const APInt &AndMask = ConstAndRHS->getAPIntValue();
    SDValue ShlAmt =
      DAG.getConstant(AndMask.countLeadingZeros(), SDLoc(AndLHS),
                      getShiftAmountTy(AndLHS.getValueType()));
    SDValue Shl = DAG.getNode(ISD::SHL, SDLoc(N0), VT, AndLHS, ShlAmt);

    // Now arithmetic right shift it all the way over, so the result is either
    // all-ones, or zero.
    SDValue ShrAmt =
      DAG.getConstant(AndMask.getBitWidth() - 1, SDLoc(Shl),
                      getShiftAmountTy(Shl.getValueType()));
    SDValue Shr = DAG.getNode(ISD::SRA, SDLoc(N0), VT, Shl, ShrAmt);

    return DAG.getNode(ISD::AND, DL, VT, Shr, N3);
  }
}

// fold select C, 16, 0 -> shl C, 4
if (N2C && isNullConstant(N3) && N2C->getAPIntValue().isPowerOf2() &&
    TLI.getBooleanContents(N0.getValueType()) ==
        TargetLowering::ZeroOrOneBooleanContent) {

  // If the caller doesn't want us to simplify this into a zext of a compare,
  // don't do it.
  if (NotExtCompare && N2C->isOne())
    return SDValue();

  // Get a SetCC of the condition
  // NOTE: Don't create a SETCC if it's not legal on this target.
  if (!LegalOperations ||
      TLI.isOperationLegal(ISD::SETCC, N0.getValueType())) {
    SDValue Temp, SCC;
    // cast from setcc result type to select result type
    if (LegalTypes) {
      SCC  = DAG.getSetCC(DL, getSetCCResultType(N0.getValueType()),
                          N0, N1, CC);
      if (N2.getValueType().bitsLT(SCC.getValueType()))
        Temp = DAG.getZeroExtendInReg(SCC, SDLoc(N2),
                                      N2.getValueType());
      else
        Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
                           N2.getValueType(), SCC);
    } else {
      SCC  = DAG.getSetCC(SDLoc(N0), MVT::i1, N0, N1, CC);
      Temp = DAG.getNode(ISD::ZERO_EXTEND, SDLoc(N2),
                         N2.getValueType(), SCC);
    }

    AddToWorklist(SCC.getNode());
    AddToWorklist(Temp.getNode());

    if (N2C->isOne())
      return Temp;

    // shl setcc result by log2 n2c
    return DAG.getNode(
        ISD::SHL, DL, N2.getValueType(), Temp,
        DAG.getConstant(N2C->getAPIntValue().logBase2(), SDLoc(Temp),
                        getShiftAmountTy(Temp.getValueType())));
  }
}

// Check to see if this is an integer abs.
// select_cc setg[te] X,  0,  X, -X ->
// select_cc setgt    X, -1,  X, -X ->
// select_cc setl[te] X,  0, -X,  X ->
// select_cc setlt    X,  1, -X,  X ->
// Y = sra (X, size(X)-1); xor (add (X, Y), Y)
if (N1C) {
  ConstantSDNode *SubC = nullptr;
  if (((N1C->isNullValue() && (CC == ISD::SETGT || CC == ISD::SETGE)) ||
       (N1C->isAllOnesValue() && CC == ISD::SETGT)) &&
      N0 == N2 && N3.getOpcode() == ISD::SUB && N0 == N3.getOperand(1))
    SubC = dyn_cast<ConstantSDNode>(N3.getOperand(0));
  else if (((N1C->isNullValue() && (CC == ISD::SETLT || CC == ISD::SETLE)) ||
            (N1C->isOne() && CC == ISD::SETLT)) &&
           N0 == N3 && N2.getOpcode() == ISD::SUB && N0 == N2.getOperand(1))
    SubC = dyn_cast<ConstantSDNode>(N2.getOperand(0));

  EVT XType = N0.getValueType();
  if (SubC && SubC->isNullValue() && XType.isInteger()) {
    SDLoc DL(N0);
    SDValue Shift = DAG.getNode(ISD::SRA, DL, XType,
                                N0,
                                DAG.getConstant(XType.getSizeInBits() - 1, DL,
                                       getShiftAmountTy(N0.getValueType())));
    SDValue Add = DAG.getNode(ISD::ADD, DL,
                              XType, N0, Shift);
    AddToWorklist(Shift.getNode());
    AddToWorklist(Add.getNode());
    return DAG.getNode(ISD::XOR, DL, XType, Add, Shift);
  }
}

// select_cc seteq X, 0, sizeof(X), ctlz(X) -> ctlz(X)
// select_cc seteq X, 0, sizeof(X), ctlz_zero_undef(X) -> ctlz(X)
// select_cc seteq X, 0, sizeof(X), cttz(X) -> cttz(X)
// select_cc seteq X, 0, sizeof(X), cttz_zero_undef(X) -> cttz(X)
// select_cc setne X, 0, ctlz(X), sizeof(X) -> ctlz(X)
// select_cc setne X, 0, ctlz_zero_undef(X), sizeof(X) -> ctlz(X)
// select_cc setne X, 0, cttz(X), sizeof(X) -> cttz(X)
// select_cc setne X, 0, cttz_zero_undef(X), sizeof(X) -> cttz(X)
if (N1C && N1C->isNullValue() && (CC == ISD::SETEQ || CC == ISD::SETNE)) {
  SDValue ValueOnZero = N2;
  SDValue Count = N3;
  // If the condition is NE instead of E, swap the operands.
  if (CC == ISD::SETNE)
    std::swap(ValueOnZero, Count);
  // Check if the value on zero is a constant equal to the bits in the type.
  if (auto *ValueOnZeroC = dyn_cast<ConstantSDNode>(ValueOnZero)) {
    if (ValueOnZeroC->getAPIntValue() == VT.getSizeInBits()) {
      // If the other operand is cttz/cttz_zero_undef of N0, and cttz is
      // legal, combine to just cttz.
      if ((Count.getOpcode() == ISD::CTTZ ||
           Count.getOpcode() == ISD::CTTZ_ZERO_UNDEF) &&
          N0 == Count.getOperand(0) &&
          (!LegalOperations || TLI.isOperationLegal(ISD::CTTZ, VT)))
        return DAG.getNode(ISD::CTTZ, DL, VT, N0);
      // If the other operand is ctlz/ctlz_zero_undef of N0, and ctlz is
      // legal, combine to just ctlz.
      if ((Count.getOpcode() == ISD::CTLZ ||
           Count.getOpcode() == ISD::CTLZ_ZERO_UNDEF) &&
          N0 == Count.getOperand(0) &&
          (!LegalOperations || TLI.isOperationLegal(ISD::CTLZ, VT)))
        return DAG.getNode(ISD::CTLZ, DL, VT, N0);
    }
  }
}

return SDValue();
17214}

17216/// This is a stub for TargetLowering::SimplifySetCC.
17217SDValue DAGCombiner::SimplifySetCC(EVT VT, SDValue N0, SDValue N1,
                                 ISD::CondCode Cond, const SDLoc &DL,
                                 bool foldBooleans) {
TargetLowering::DAGCombinerInfo
  DagCombineInfo(DAG, Level, false, this);
return TLI.SimplifySetCC(VT, N0, N1, Cond, foldBooleans, DagCombineInfo, DL);
17223}

17225/// Given an ISD::SDIV node expressing a divide by constant, return
17226/// a DAG expression to select that will generate the same value by multiplying
17227/// by a magic number.
17228/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
17229SDValue DAGCombiner::BuildSDIV(SDNode *N) {
// when optimising for minimum size, we don't want to expand a div to a mul
// and a shift.
if (DAG.getMachineFunction().getFunction().optForMinSize())
  return SDValue();

ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
  return SDValue();

// Avoid division by zero.
if (C->isNullValue())
  return SDValue();

std::vector<SDNode *> Built;
SDValue S =
    TLI.BuildSDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);

for (SDNode *N : Built)
  AddToWorklist(N);
return S;
17250}

17252/// Given an ISD::SDIV node expressing a divide by constant power of 2, return a
17253/// DAG expression that will generate the same value by right shifting.
17254SDValue DAGCombiner::BuildSDIVPow2(SDNode *N) {
ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
  return SDValue();

// Avoid division by zero.
if (C->isNullValue())
  return SDValue();

std::vector<SDNode *> Built;
SDValue S = TLI.BuildSDIVPow2(N, C->getAPIntValue(), DAG, &Built);

for (SDNode *N : Built)
  AddToWorklist(N);
return S;
17269}

17271/// Given an ISD::UDIV node expressing a divide by constant, return a DAG
17272/// expression that will generate the same value by multiplying by a magic
17273/// number.
17274/// Ref: "Hacker's Delight" or "The PowerPC Compiler Writer's Guide".
17275SDValue DAGCombiner::BuildUDIV(SDNode *N) {
// when optimising for minimum size, we don't want to expand a div to a mul
// and a shift.
if (DAG.getMachineFunction().getFunction().optForMinSize())
  return SDValue();

ConstantSDNode *C = isConstOrConstSplat(N->getOperand(1));
if (!C)
  return SDValue();

// Avoid division by zero.
if (C->isNullValue())
  return SDValue();

std::vector<SDNode *> Built;
SDValue S =
    TLI.BuildUDIV(N, C->getAPIntValue(), DAG, LegalOperations, &Built);

for (SDNode *N : Built)
  AddToWorklist(N);
return S;
17296}

17298/// Determines the LogBase2 value for a non-null input value using the
17299/// transform: LogBase2(V) = (EltBits - 1) - ctlz(V).
17300SDValue DAGCombiner::BuildLogBase2(SDValue V, const SDLoc &DL) {
EVT VT = V.getValueType();
unsigned EltBits = VT.getScalarSizeInBits();
SDValue Ctlz = DAG.getNode(ISD::CTLZ, DL, VT, V);
SDValue Base = DAG.getConstant(EltBits - 1, DL, VT);
SDValue LogBase2 = DAG.getNode(ISD::SUB, DL, VT, Base, Ctlz);
return LogBase2;
17307}

17309/// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
17310/// For the reciprocal, we need to find the zero of the function:
17311///   F(X) = A X - 1 [which has a zero at X = 1/A]
17312///     =>
17313///   X_{i+1} = X_i (2 - A X_i) = X_i + X_i (1 - A X_i) [this second form
17314///     does not require additional intermediate precision]
17315SDValue DAGCombiner::BuildReciprocalEstimate(SDValue Op, SDNodeFlags Flags) {
if (Level >= AfterLegalizeDAG)
  return SDValue();

// TODO: Handle half and/or extended types?
EVT VT = Op.getValueType();
if (VT.getScalarType() != MVT::f32 && VT.getScalarType() != MVT::f64)
  return SDValue();

// If estimates are explicitly disabled for this function, we're done.
MachineFunction &MF = DAG.getMachineFunction();
int Enabled = TLI.getRecipEstimateDivEnabled(VT, MF);
if (Enabled == TLI.ReciprocalEstimate::Disabled)
  return SDValue();

// Estimates may be explicitly enabled for this type with a custom number of
// refinement steps.
int Iterations = TLI.getDivRefinementSteps(VT, MF);
if (SDValue Est = TLI.getRecipEstimate(Op, DAG, Enabled, Iterations)) {
  AddToWorklist(Est.getNode());

  if (Iterations) {
    EVT VT = Op.getValueType();
    SDLoc DL(Op);
    SDValue FPOne = DAG.getConstantFP(1.0, DL, VT);

    // Newton iterations: Est = Est + Est (1 - Arg * Est)
    for (int i = 0; i < Iterations; ++i) {
      SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Op, Est, Flags);
      AddToWorklist(NewEst.getNode());

      NewEst = DAG.getNode(ISD::FSUB, DL, VT, FPOne, NewEst, Flags);
      AddToWorklist(NewEst.getNode());

      NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst, Flags);
      AddToWorklist(NewEst.getNode());

      Est = DAG.getNode(ISD::FADD, DL, VT, Est, NewEst, Flags);
      AddToWorklist(Est.getNode());
    }
  }
  return Est;
}

return SDValue();
17360}

17362/// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
17363/// For the reciprocal sqrt, we need to find the zero of the function:
17364///   F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
17365///     =>
17366///   X_{i+1} = X_i (1.5 - A X_i^2 / 2)
17367/// As a result, we precompute A/2 prior to the iteration loop.
17368SDValue DAGCombiner::buildSqrtNROneConst(SDValue Arg, SDValue Est,
                                       unsigned Iterations,
                                       SDNodeFlags Flags, bool Reciprocal) {
EVT VT = Arg.getValueType();
SDLoc DL(Arg);
SDValue ThreeHalves = DAG.getConstantFP(1.5, DL, VT);

// We now need 0.5 * Arg which we can write as (1.5 * Arg - Arg) so that
// this entire sequence requires only one FP constant.
SDValue HalfArg = DAG.getNode(ISD::FMUL, DL, VT, ThreeHalves, Arg, Flags);
AddToWorklist(HalfArg.getNode());

HalfArg = DAG.getNode(ISD::FSUB, DL, VT, HalfArg, Arg, Flags);
AddToWorklist(HalfArg.getNode());

// Newton iterations: Est = Est * (1.5 - HalfArg * Est * Est)
for (unsigned i = 0; i < Iterations; ++i) {
  SDValue NewEst = DAG.getNode(ISD::FMUL, DL, VT, Est, Est, Flags);
  AddToWorklist(NewEst.getNode());

  NewEst = DAG.getNode(ISD::FMUL, DL, VT, HalfArg, NewEst, Flags);
  AddToWorklist(NewEst.getNode());

  NewEst = DAG.getNode(ISD::FSUB, DL, VT, ThreeHalves, NewEst, Flags);
  AddToWorklist(NewEst.getNode());

  Est = DAG.getNode(ISD::FMUL, DL, VT, Est, NewEst, Flags);
  AddToWorklist(Est.getNode());
}

// If non-reciprocal square root is requested, multiply the result by Arg.
if (!Reciprocal) {
  Est = DAG.getNode(ISD::FMUL, DL, VT, Est, Arg, Flags);
  AddToWorklist(Est.getNode());
}

return Est;
17405}

17407/// Newton iteration for a function: F(X) is X_{i+1} = X_i - F(X_i)/F'(X_i)
17408/// For the reciprocal sqrt, we need to find the zero of the function:
17409///   F(X) = 1/X^2 - A [which has a zero at X = 1/sqrt(A)]
17410///     =>
17411///   X_{i+1} = (-0.5 * X_i) * (A * X_i * X_i + (-3.0))
17412SDValue DAGCombiner::buildSqrtNRTwoConst(SDValue Arg, SDValue Est,
                                       unsigned Iterations,
                                       SDNodeFlags Flags, bool Reciprocal) {
EVT VT = Arg.getValueType();
SDLoc DL(Arg);
SDValue MinusThree = DAG.getConstantFP(-3.0, DL, VT);
SDValue MinusHalf = DAG.getConstantFP(-0.5, DL, VT);

// This routine must enter the loop below to work correctly
// when (Reciprocal == false).
assert(Iterations > 0)(static_cast <bool> (Iterations > 0) ? void (0) : __assert_fail
 ("Iterations > 0", "/build/llvm-toolchain-snapshot-7~svn325118/lib/CodeGen/SelectionDAG/DAGCombiner.cpp"
, 17422, __extension__ __PRETTY_FUNCTION__));

// Newton iterations for reciprocal square root:
// E = (E * -0.5) * ((A * E) * E + -3.0)
for (unsigned i = 0; i < Iterations; ++i) {
  SDValue AE = DAG.getNode(ISD::FMUL, DL, VT, Arg, Est, Flags);
  AddToWorklist(AE.getNode());

  SDValue AEE = DAG.getNode(ISD::FMUL, DL, VT, AE, Est, Flags);
  AddToWorklist(AEE.getNode());

  SDValue RHS = DAG.getNode(ISD::FADD, DL, VT, AEE, MinusThree, Flags);
  AddToWorklist(RHS.getNode());

  // When calculating a square root at the last iteration build:
  // S = ((A * E) * -0.5) * ((A * E) * E + -3.0)
  // (notice a common subexpression)
  SDValue LHS;
  if (Reciprocal || (i + 1) < Iterations) {
    // RSQRT: LHS = (E * -0.5)
    LHS = DAG.getNode(ISD::FMUL, DL, VT, Est, MinusHalf, Flags);
  } else {
    // SQRT: LHS = (A * E) * -0.5
    LHS = DAG.getNode(ISD::FMUL, DL, VT, AE, MinusHalf, Flags);
  }
  AddToWorklist(LHS.getNode());

  Est = DAG.getNode(ISD::FMUL, DL, VT, LHS, RHS, Flags);
  AddToWorklist(Est.getNode());
}

return Est;
17454}

17456/// Build code to calculate either rsqrt(Op) or sqrt(Op). In the latter case
17457/// Op*rsqrt(Op) is actually computed, so additional postprocessing is needed if
17458/// Op can be zero.
17459SDValue DAGCombiner::buildSqrtEstimateImpl(SDValue Op, SDNodeFlags Flags,
                                         bool Reciprocal) {
if (Level >= AfterLegalizeDAG)
  return SDValue();

// TODO: Handle half and/or extended types?
EVT VT = Op.getValueType();
if (VT.getScalarType() != MVT::f32 && VT.getScalarType() != MVT::f64)
  return SDValue();

// If estimates are explicitly disabled for this function, we're done.
MachineFunction &MF = DAG.getMachineFunction();
int Enabled = TLI.getRecipEstimateSqrtEnabled(VT, MF);
if (Enabled == TLI.ReciprocalEstimate::Disabled)
  return SDValue();

// Estimates may be explicitly enabled for this type with a custom number of
// refinement steps.
int Iterations = TLI.getSqrtRefinementSteps(VT, MF);

bool UseOneConstNR = false;
if (SDValue Est =
    TLI.getSqrtEstimate(Op, DAG, Enabled, Iterations, UseOneConstNR,
                        Reciprocal)) {
  AddToWorklist(Est.getNode());

  if (Iterations) {
    Est = UseOneConstNR
          ? buildSqrtNROneConst(Op, Est, Iterations, Flags, Reciprocal)
          : buildSqrtNRTwoConst(Op, Est, Iterations, Flags, Reciprocal);

    if (!Reciprocal) {
      // The estimate is now completely wrong if the input was exactly 0.0 or
      // possibly a denormal. Force the answer to 0.0 for those cases.
      EVT VT = Op.getValueType();
      SDLoc DL(Op);
      EVT CCVT = getSetCCResultType(VT);
      ISD::NodeType SelOpcode = VT.isVector() ? ISD::VSELECT : ISD::SELECT;
      const Function &F = DAG.getMachineFunction().getFunction();
      Attribute Denorms = F.getFnAttribute("denormal-fp-math");
      if (Denorms.getValueAsString().equals("ieee")) {
        // fabs(X) < SmallestNormal ? 0.0 : Est
        const fltSemantics &FltSem = DAG.EVTToAPFloatSemantics(VT);
        APFloat SmallestNorm = APFloat::getSmallestNormalized(FltSem);
        SDValue NormC = DAG.getConstantFP(SmallestNorm, DL, VT);
        SDValue FPZero = DAG.getConstantFP(0.0, DL, VT);
        SDValue Fabs = DAG.getNode(ISD::FABS, DL, VT, Op);
        SDValue IsDenorm = DAG.getSetCC(DL, CCVT, Fabs, NormC, ISD::SETLT);
        Est = DAG.getNode(SelOpcode, DL, VT, IsDenorm, FPZero, Est);
        AddToWorklist(Fabs.getNode());
        AddToWorklist(IsDenorm.getNode());
        AddToWorklist(Est.getNode());
      } else {
        // X == 0.0 ? 0.0 : Est
        SDValue FPZero = DAG.getConstantFP(0.0, DL, VT);
        SDValue IsZero = DAG.getSetCC(DL, CCVT, Op, FPZero, ISD::SETEQ);
        Est = DAG.getNode(SelOpcode, DL, VT, IsZero, FPZero, Est);
        AddToWorklist(IsZero.getNode());
        AddToWorklist(Est.getNode());
      }
    }
  }
  return Est;
}

return SDValue();
17525}

17527SDValue DAGCombiner::buildRsqrtEstimate(SDValue Op, SDNodeFlags Flags) {
return buildSqrtEstimateImpl(Op, Flags, true);
17529}

17531SDValue DAGCombiner::buildSqrtEstimate(SDValue Op, SDNodeFlags Flags) {
return buildSqrtEstimateImpl(Op, Flags, false);
17533}

17535/// Return true if there is any possibility that the two addresses overlap.
17536bool DAGCombiner::isAlias(LSBaseSDNode *Op0, LSBaseSDNode *Op1) const {
// If they are the same then they must be aliases.
if (Op0->getBasePtr() == Op1->getBasePtr()) return true;

// If they are both volatile then they cannot be reordered.
if (Op0->isVolatile() && Op1->isVolatile()) return true;

// If one operation reads from invariant memory, and the other may store, they
// cannot alias. These should really be checking the equivalent of mayWrite,
// but it only matters for memory nodes other than load /store.
if (Op0->isInvariant() && Op1->writeMem())
  return false;

if (Op1->isInvariant() && Op0->writeMem())
  return false;

unsigned NumBytes0 = Op0->getMemoryVT().getStoreSize();
unsigned NumBytes1 = Op1->getMemoryVT().getStoreSize();

// Check for BaseIndexOffset matching.
BaseIndexOffset BasePtr0 = BaseIndexOffset::match(Op0, DAG);
BaseIndexOffset BasePtr1 = BaseIndexOffset::match(Op1, DAG);
int64_t PtrDiff;
if (BasePtr0.getBase().getNode() && BasePtr1.getBase().getNode()) {
  if (BasePtr0.equalBaseIndex(BasePtr1, DAG, PtrDiff))
    return !((NumBytes0 <= PtrDiff) || (PtrDiff + NumBytes1 <= 0));

  // If both BasePtr0 and BasePtr1 are FrameIndexes, we will not be
  // able to calculate their relative offset if at least one arises
  // from an alloca. However, these allocas cannot overlap and we
  // can infer there is no alias.
  if (auto *A = dyn_cast<FrameIndexSDNode>(BasePtr0.getBase()))
    if (auto *B = dyn_cast<FrameIndexSDNode>(BasePtr1.getBase())) {
      MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
      // If the base are the same frame index but the we couldn't find a
      // constant offset, (indices are different) be conservative.
      if (A != B && (!MFI.isFixedObjectIndex(A->getIndex()) ||
                     !MFI.isFixedObjectIndex(B->getIndex())))
        return false;
    }

  bool IsFI0 = isa<FrameIndexSDNode>(BasePtr0.getBase());
  bool IsFI1 = isa<FrameIndexSDNode>(BasePtr1.getBase());
  bool IsGV0 = isa<GlobalAddressSDNode>(BasePtr0.getBase());
  bool IsGV1 = isa<GlobalAddressSDNode>(BasePtr1.getBase());
  bool IsCV0 = isa<ConstantPoolSDNode>(BasePtr0.getBase());
  bool IsCV1 = isa<ConstantPoolSDNode>(BasePtr1.getBase());

  // If of mismatched base types or checkable indices we can check
  // they do not alias.
  if ((BasePtr0.getIndex() == BasePtr1.getIndex() || (IsFI0 != IsFI1) ||
       (IsGV0 != IsGV1) || (IsCV0 != IsCV1)) &&
      (IsFI0 || IsGV0 || IsCV0) && (IsFI1 || IsGV1 || IsCV1))
    return false;
}

// If we know required SrcValue1 and SrcValue2 have relatively large
// alignment compared to the size and offset of the access, we may be able
// to prove they do not alias. This check is conservative for now to catch
// cases created by splitting vector types.
int64_t SrcValOffset0 = Op0->getSrcValueOffset();
int64_t SrcValOffset1 = Op1->getSrcValueOffset();
unsigned OrigAlignment0 = Op0->getOriginalAlignment();
unsigned OrigAlignment1 = Op1->getOriginalAlignment();
if (OrigAlignment0 == OrigAlignment1 && SrcValOffset0 != SrcValOffset1 &&
    NumBytes0 == NumBytes1 && OrigAlignment0 > NumBytes0) {
  int64_t OffAlign0 = SrcValOffset0 % OrigAlignment0;
  int64_t OffAlign1 = SrcValOffset1 % OrigAlignment1;

  // There is no overlap between these relatively aligned accesses of
  // similar size. Return no alias.
  if ((OffAlign0 + NumBytes0) <= OffAlign1 ||
      (OffAlign1 + NumBytes1) <= OffAlign0)
    return false;
}

bool UseAA = CombinerGlobalAA.getNumOccurrences() > 0
                 ? CombinerGlobalAA
                 : DAG.getSubtarget().useAA();
17615#ifndef NDEBUG
if (CombinerAAOnlyFunc.getNumOccurrences() &&
    CombinerAAOnlyFunc != DAG.getMachineFunction().getName())
  UseAA = false;
17619#endif

if (UseAA && AA &&
    Op0->getMemOperand()->getValue() && Op1->getMemOperand()->getValue()) {
  // Use alias analysis information.
  int64_t MinOffset = std::min(SrcValOffset0, SrcValOffset1);
  int64_t Overlap0 = NumBytes0 + SrcValOffset0 - MinOffset;
  int64_t Overlap1 = NumBytes1 + SrcValOffset1 - MinOffset;
  AliasResult AAResult =
      AA->alias(MemoryLocation(Op0->getMemOperand()->getValue(), Overlap0,
                               UseTBAA ? Op0->getAAInfo() : AAMDNodes()),
                MemoryLocation(Op1->getMemOperand()->getValue(), Overlap1,
                               UseTBAA ? Op1->getAAInfo() : AAMDNodes()) );
  if (AAResult == NoAlias)
    return false;
}

// Otherwise we have to assume they alias.
return true;
17638}

17640/// Walk up chain skipping non-aliasing memory nodes,
17641/// looking for aliasing nodes and adding them to the Aliases vector.
17642void DAGCombiner::GatherAllAliases(SDNode *N, SDValue OriginalChain,
                                 SmallVectorImpl<SDValue> &Aliases) {
SmallVector<SDValue, 8> Chains;     // List of chains to visit.
SmallPtrSet<SDNode *, 16> Visited;  // Visited node set.

// Get alias information for node.
bool IsLoad = isa<LoadSDNode>(N) && !cast<LSBaseSDNode>(N)->isVolatile();

// Starting off.
Chains.push_back(OriginalChain);
unsigned Depth = 0;

// Look at each chain and determine if it is an alias.  If so, add it to the
// aliases list.  If not, then continue up the chain looking for the next
// candidate.
while (!Chains.empty()) {
  SDValue Chain = Chains.pop_back_val();

  // For TokenFactor nodes, look at each operand and only continue up the
  // chain until we reach the depth limit.
  //
  // FIXME: The depth check could be made to return the last non-aliasing
  // chain we found before we hit a tokenfactor rather than the original
  // chain.
  if (Depth > TLI.getGatherAllAliasesMaxDepth()) {
    Aliases.clear();
    Aliases.push_back(OriginalChain);
    return;
  }

  // Don't bother if we've been before.
  if (!Visited.insert(Chain.getNode()).second)
    continue;

  switch (Chain.getOpcode()) {
  case ISD::EntryToken:
    // Entry token is ideal chain operand, but handled in FindBetterChain.
    break;

  case ISD::LOAD:
  case ISD::STORE: {
    // Get alias information for Chain.
    bool IsOpLoad = isa<LoadSDNode>(Chain.getNode()) &&
        !cast<LSBaseSDNode>(Chain.getNode())->isVolatile();

    // If chain is alias then stop here.
    if (!(IsLoad && IsOpLoad) &&
        isAlias(cast<LSBaseSDNode>(N), cast<LSBaseSDNode>(Chain.getNode()))) {
      Aliases.push_back(Chain);
    } else {
      // Look further up the chain.
      Chains.push_back(Chain.getOperand(0));
      ++Depth;
    }
    break;
  }

  case ISD::TokenFactor:
    // We have to check each of the operands of the token factor for "small"
    // token factors, so we queue them up.  Adding the operands to the queue
    // (stack) in reverse order maintains the original order and increases the
    // likelihood that getNode will find a matching token factor (CSE.)
    if (Chain.getNumOperands() > 16) {
      Aliases.push_back(Chain);
      break;
    }
    for (unsigned n = Chain.getNumOperands(); n;)
      Chains.push_back(Chain.getOperand(--n));
    ++Depth;
    break;

  case ISD::CopyFromReg:
    // Forward past CopyFromReg.
    Chains.push_back(Chain.getOperand(0));
    ++Depth;
    break;

  default:
    // For all other instructions we will just have to take what we can get.
    Aliases.push_back(Chain);
    break;
  }
}
17725}

17727/// Walk up chain skipping non-aliasing memory nodes, looking for a better chain
17728/// (aliasing node.)
17729SDValue DAGCombiner::FindBetterChain(SDNode *N, SDValue OldChain) {
if (OptLevel == CodeGenOpt::None)
  return OldChain;

// Ops for replacing token factor.
SmallVector<SDValue, 8> Aliases;

// Accumulate all the aliases to this node.
GatherAllAliases(N, OldChain, Aliases);

// If no operands then chain to entry token.
if (Aliases.size() == 0)
  return DAG.getEntryNode();

// If a single operand then chain to it.  We don't need to revisit it.
if (Aliases.size() == 1)
  return Aliases[0];

// Construct a custom tailored token factor.
return DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Aliases);
17749}

17751// This function tries to collect a bunch of potentially interesting
17752// nodes to improve the chains of, all at once. This might seem
17753// redundant, as this function gets called when visiting every store
17754// node, so why not let the work be done on each store as it's visited?
17755//
17756// I believe this is mainly important because MergeConsecutiveStores
17757// is unable to deal with merging stores of different sizes, so unless
17758// we improve the chains of all the potential candidates up-front
17759// before running MergeConsecutiveStores, it might only see some of
17760// the nodes that will eventually be candidates, and then not be able
17761// to go from a partially-merged state to the desired final
17762// fully-merged state.
17763bool DAGCombiner::findBetterNeighborChains(StoreSDNode *St) {
if (OptLevel == CodeGenOpt::None)
  return false;

// This holds the base pointer, index, and the offset in bytes from the base
// pointer.
BaseIndexOffset BasePtr = BaseIndexOffset::match(St, DAG);

// We must have a base and an offset.
if (!BasePtr.getBase().getNode())
  return false;

// Do not handle stores to undef base pointers.
if (BasePtr.getBase().isUndef())
  return false;

SmallVector<StoreSDNode *, 8> ChainedStores;
ChainedStores.push_back(St);

// Walk up the chain and look for nodes with offsets from the same
// base pointer. Stop when reaching an instruction with a different kind
// or instruction which has a different base pointer.
StoreSDNode *Index = St;
while (Index) {
  // If the chain has more than one use, then we can't reorder the mem ops.
  if (Index != St && !SDValue(Index, 0)->hasOneUse())
    break;

  if (Index->isVolatile() || Index->isIndexed())
    break;

  // Find the base pointer and offset for this memory node.
  BaseIndexOffset Ptr = BaseIndexOffset::match(Index, DAG);

  // Check that the base pointer is the same as the original one.
  if (!BasePtr.equalBaseIndex(Ptr, DAG))
    break;

  // Walk up the chain to find the next store node, ignoring any
  // intermediate loads. Any other kind of node will halt the loop.
  SDNode *NextInChain = Index->getChain().getNode();
  while (true) {
    if (StoreSDNode *STn = dyn_cast<StoreSDNode>(NextInChain)) {
      // We found a store node. Use it for the next iteration.
      if (STn->isVolatile() || STn->isIndexed()) {
        Index = nullptr;
        break;
      }
      ChainedStores.push_back(STn);
      Index = STn;
      break;
    } else if (LoadSDNode *Ldn = dyn_cast<LoadSDNode>(NextInChain)) {
      NextInChain = Ldn->getChain().getNode();
      continue;
    } else {
      Index = nullptr;
      break;
    }
  } // end while
}

// At this point, ChainedStores lists all of the Store nodes
// reachable by iterating up through chain nodes matching the above
// conditions.  For each such store identified, try to find an
// earlier chain to attach the store to which won't violate the
// required ordering.
bool MadeChangeToSt = false;
SmallVector<std::pair<StoreSDNode *, SDValue>, 8> BetterChains;

for (StoreSDNode *ChainedStore : ChainedStores) {
  SDValue Chain = ChainedStore->getChain();
  SDValue BetterChain = FindBetterChain(ChainedStore, Chain);

  if (Chain != BetterChain) {
    if (ChainedStore == St)
      MadeChangeToSt = true;
    BetterChains.push_back(std::make_pair(ChainedStore, BetterChain));
  }
}

// Do all replacements after finding the replacements to make to avoid making
// the chains more complicated by introducing new TokenFactors.
for (auto Replacement : BetterChains)
  replaceStoreChain(Replacement.first, Replacement.second);

return MadeChangeToSt;
17849}

17851/// This is the entry point for the file.
17852void SelectionDAG::Combine(CombineLevel Level, AliasAnalysis *AA,
                         CodeGenOpt::Level OptLevel) {
/// This is the main entry point to this class.
DAGCombiner(*this, AA, OptLevel).Run(Level);
17856}

←

/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h

1//===- llvm/ADT/SmallBitVector.h - 'Normally small' bit vectors -*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the SmallBitVector class.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_ADT_SMALLBITVECTOR_H
15#define LLVM_ADT_SMALLBITVECTOR_H

17#include "llvm/ADT/BitVector.h"
18#include "llvm/ADT/iterator_range.h"
19#include "llvm/Support/MathExtras.h"
20#include <algorithm>
21#include <cassert>
22#include <climits>
23#include <cstddef>
24#include <cstdint>
25#include <limits>
26#include <utility>

28namespace llvm {

30/// This is a 'bitvector' (really, a variable-sized bit array), optimized for
31/// the case when the array is small. It contains one pointer-sized field, which
32/// is directly used as a plain collection of bits when possible, or as a
33/// pointer to a larger heap-allocated array when necessary. This allows normal
34/// "small" cases to be fast without losing generality for large inputs.
35class SmallBitVector {
// TODO: In "large" mode, a pointer to a BitVector is used, leading to an
// unnecessary level of indirection. It would be more efficient to use a
// pointer to memory containing size, allocation size, and the array of bits.
uintptr_t X = 1;

enum {
  // The number of bits in this class.
  NumBaseBits = sizeof(uintptr_t) * CHAR_BIT8,

  // One bit is used to discriminate between small and large mode. The
  // remaining bits are used for the small-mode representation.
  SmallNumRawBits = NumBaseBits - 1,

  // A few more bits are used to store the size of the bit set in small mode.
  // Theoretically this is a ceil-log2. These bits are encoded in the most
  // significant bits of the raw bits.
  SmallNumSizeBits = (NumBaseBits == 32 ? 5 :
                      NumBaseBits == 64 ? 6 :
                      SmallNumRawBits),

  // The remaining bits are used to store the actual set in small mode.
  SmallNumDataBits = SmallNumRawBits - SmallNumSizeBits
};

static_assert(NumBaseBits == 64 || NumBaseBits == 32,
              "Unsupported word size");

63public:
using size_type = unsigned;

// Encapsulation of a single bit.
class reference {
  SmallBitVector &TheVector;
  unsigned BitPos;

public:
  reference(SmallBitVector &b, unsigned Idx) : TheVector(b), BitPos(Idx) {}

  reference(const reference&) = default;

  reference& operator=(reference t) {
    *this = bool(t);
    return *this;
  }

  reference& operator=(bool t) {
    if (t)
      TheVector.set(BitPos);
    else
      TheVector.reset(BitPos);
    return *this;
  }

  operator bool() const {
    return const_cast<const SmallBitVector &>(TheVector).operator[](BitPos);
  }
};

94private:
bool isSmall() const {
  return X & uintptr_t(1);
}

BitVector *getPointer() const {
  assert(!isSmall())(static_cast <bool> (!isSmall()) ? void (0) : __assert_fail
 ("!isSmall()", "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 100, __extension__ __PRETTY_FUNCTION__));
  return reinterpret_cast<BitVector *>(X);
}

void switchToSmall(uintptr_t NewSmallBits, size_t NewSize) {
  X = 1;
  setSmallSize(NewSize);
  setSmallBits(NewSmallBits);
}

void switchToLarge(BitVector *BV) {
  X = reinterpret_cast<uintptr_t>(BV);
  assert(!isSmall() && "Tried to use an unaligned pointer")(static_cast <bool> (!isSmall() && "Tried to use an unaligned pointer"
) ? void (0) : __assert_fail ("!isSmall() && \"Tried to use an unaligned pointer\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 112, __extension__ __PRETTY_FUNCTION__));
}

// Return all the bits used for the "small" representation; this includes
// bits for the size as well as the element bits.
uintptr_t getSmallRawBits() const {
  assert(isSmall())(static_cast <bool> (isSmall()) ? void (0) : __assert_fail
 ("isSmall()", "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 118, __extension__ __PRETTY_FUNCTION__));
  return X >> 1;
}

void setSmallRawBits(uintptr_t NewRawBits) {
  assert(isSmall())(static_cast <bool> (isSmall()) ? void (0) : __assert_fail
 ("isSmall()", "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 123, __extension__ __PRETTY_FUNCTION__));
  X = (NewRawBits << 1) | uintptr_t(1);
}

// Return the size.
size_t getSmallSize() const { return getSmallRawBits() >> SmallNumDataBits; }

void setSmallSize(size_t Size) {
  setSmallRawBits(getSmallBits() | (Size << SmallNumDataBits));
}

// Return the element bits.
uintptr_t getSmallBits() const {
  return getSmallRawBits() & ~(~uintptr_t(0) << getSmallSize());
}

void setSmallBits(uintptr_t NewBits) {
  setSmallRawBits((NewBits & ~(~uintptr_t(0) << getSmallSize())) |
                  (getSmallSize() << SmallNumDataBits));
}

144public:
/// Creates an empty bitvector.
SmallBitVector() = default;

/// Creates a bitvector of specified number of bits. All bits are initialized
/// to the specified value.
explicit SmallBitVector(unsigned s, bool t = false) {
  if (s <= SmallNumDataBits)
10
←
Assuming 's' is > SmallNumDataBits→
11
←
Taking false branch→
    switchToSmall(t ? ~uintptr_t(0) : 0, s);
  else
    switchToLarge(new BitVector(s, t));
12
←
Memory is allocated→
}

/// SmallBitVector copy ctor.
SmallBitVector(const SmallBitVector &RHS) {
  if (RHS.isSmall())
    X = RHS.X;
  else
    switchToLarge(new BitVector(*RHS.getPointer()));
}

SmallBitVector(SmallBitVector &&RHS) : X(RHS.X) {
  RHS.X = 1;
}

~SmallBitVector() {
  if (!isSmall())
    delete getPointer();
}

using const_set_bits_iterator = const_set_bits_iterator_impl<SmallBitVector>;
using set_iterator = const_set_bits_iterator;

const_set_bits_iterator set_bits_begin() const {
  return const_set_bits_iterator(*this);
}

const_set_bits_iterator set_bits_end() const {
  return const_set_bits_iterator(*this, -1);
}

iterator_range<const_set_bits_iterator> set_bits() const {
  return make_range(set_bits_begin(), set_bits_end());
}

/// Tests whether there are no bits in this bitvector.
bool empty() const {
  return isSmall() ? getSmallSize() == 0 : getPointer()->empty();
}

/// Returns the number of bits in this bitvector.
size_t size() const {
  return isSmall() ? getSmallSize() : getPointer()->size();
}

/// Returns the number of bits which are set.
size_type count() const {
  if (isSmall()) {
    uintptr_t Bits = getSmallBits();
    return countPopulation(Bits);
  }
  return getPointer()->count();
}

/// Returns true if any bit is set.
bool any() const {
  if (isSmall())
    return getSmallBits() != 0;
  return getPointer()->any();
}

/// Returns true if all bits are set.
bool all() const {
  if (isSmall())
    return getSmallBits() == (uintptr_t(1) << getSmallSize()) - 1;
  return getPointer()->all();
}

/// Returns true if none of the bits are set.
bool none() const {
  if (isSmall())
    return getSmallBits() == 0;
  return getPointer()->none();
}

/// Returns the index of the first set bit, -1 if none of the bits are set.
int find_first() const {
  if (isSmall()) {
    uintptr_t Bits = getSmallBits();
    if (Bits == 0)
      return -1;
    return countTrailingZeros(Bits);
  }
  return getPointer()->find_first();
}

int find_last() const {
  if (isSmall()) {
    uintptr_t Bits = getSmallBits();
    if (Bits == 0)
      return -1;
    return NumBaseBits - countLeadingZeros(Bits);
  }
  return getPointer()->find_last();
}

/// Returns the index of the first unset bit, -1 if all of the bits are set.
int find_first_unset() const {
  if (isSmall()) {
    if (count() == getSmallSize())
      return -1;

    uintptr_t Bits = getSmallBits();
    return countTrailingOnes(Bits);
  }
  return getPointer()->find_first_unset();
}

int find_last_unset() const {
  if (isSmall()) {
    if (count() == getSmallSize())
      return -1;

    uintptr_t Bits = getSmallBits();
    return NumBaseBits - countLeadingOnes(Bits);
  }
  return getPointer()->find_last_unset();
}

/// Returns the index of the next set bit following the "Prev" bit.
/// Returns -1 if the next set bit is not found.
int find_next(unsigned Prev) const {
  if (isSmall()) {
    uintptr_t Bits = getSmallBits();
    // Mask off previous bits.
    Bits &= ~uintptr_t(0) << (Prev + 1);
    if (Bits == 0 || Prev + 1 >= getSmallSize())
      return -1;
    return countTrailingZeros(Bits);
  }
  return getPointer()->find_next(Prev);
}

/// Returns the index of the next unset bit following the "Prev" bit.
/// Returns -1 if the next unset bit is not found.
int find_next_unset(unsigned Prev) const {
  if (isSmall()) {
    ++Prev;
    uintptr_t Bits = getSmallBits();
    // Mask in previous bits.
    uintptr_t Mask = (1 << Prev) - 1;
    Bits |= Mask;

    if (Bits == ~uintptr_t(0) || Prev + 1 >= getSmallSize())
      return -1;
    return countTrailingOnes(Bits);
  }
  return getPointer()->find_next_unset(Prev);
}

/// find_prev - Returns the index of the first set bit that precedes the
/// the bit at \p PriorTo.  Returns -1 if all previous bits are unset.
int find_prev(unsigned PriorTo) const {
  if (isSmall()) {
    if (PriorTo == 0)
      return -1;

    --PriorTo;
    uintptr_t Bits = getSmallBits();
    Bits &= maskTrailingOnes<uintptr_t>(PriorTo + 1);
    if (Bits == 0)
      return -1;

    return NumBaseBits - countLeadingZeros(Bits) - 1;
  }
  return getPointer()->find_prev(PriorTo);
}

/// Clear all bits.
void clear() {
  if (!isSmall())
    delete getPointer();
  switchToSmall(0, 0);
}

/// Grow or shrink the bitvector.
void resize(unsigned N, bool t = false) {
  if (!isSmall()) {
    getPointer()->resize(N, t);
  } else if (SmallNumDataBits >= N) {
    uintptr_t NewBits = t ? ~uintptr_t(0) << getSmallSize() : 0;
    setSmallSize(N);
    setSmallBits(NewBits | getSmallBits());
  } else {
    BitVector *BV = new BitVector(N, t);
    uintptr_t OldBits = getSmallBits();
    for (size_t i = 0, e = getSmallSize(); i != e; ++i)
      (*BV)[i] = (OldBits >> i) & 1;
    switchToLarge(BV);
  }
}

void reserve(unsigned N) {
  if (isSmall()) {
    if (N > SmallNumDataBits) {
      uintptr_t OldBits = getSmallRawBits();
      size_t SmallSize = getSmallSize();
      BitVector *BV = new BitVector(SmallSize);
      for (size_t i = 0; i < SmallSize; ++i)
        if ((OldBits >> i) & 1)
          BV->set(i);
      BV->reserve(N);
      switchToLarge(BV);
    }
  } else {
    getPointer()->reserve(N);
  }
}

// Set, reset, flip
SmallBitVector &set() {
  if (isSmall())
    setSmallBits(~uintptr_t(0));
  else
    getPointer()->set();
  return *this;
}

SmallBitVector &set(unsigned Idx) {
  if (isSmall()) {
    assert(Idx <= static_cast<unsigned>((static_cast <bool> (Idx <= static_cast<unsigned>
( std::numeric_limits<uintptr_t>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("Idx <= static_cast<unsigned>( std::numeric_limits<uintptr_t>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 376, __extension__ __PRETTY_FUNCTION__))
                      std::numeric_limits<uintptr_t>::digits) &&(static_cast <bool> (Idx <= static_cast<unsigned>
( std::numeric_limits<uintptr_t>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("Idx <= static_cast<unsigned>( std::numeric_limits<uintptr_t>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 376, __extension__ __PRETTY_FUNCTION__))
           "undefined behavior")(static_cast <bool> (Idx <= static_cast<unsigned>
( std::numeric_limits<uintptr_t>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("Idx <= static_cast<unsigned>( std::numeric_limits<uintptr_t>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 376, __extension__ __PRETTY_FUNCTION__));
    setSmallBits(getSmallBits() | (uintptr_t(1) << Idx));
  }
  else
    getPointer()->set(Idx);
  return *this;
}

/// Efficiently set a range of bits in [I, E)
SmallBitVector &set(unsigned I, unsigned E) {
  assert(I <= E && "Attempted to set backwards range!")(static_cast <bool> (I <= E && "Attempted to set backwards range!"
) ? void (0) : __assert_fail ("I <= E && \"Attempted to set backwards range!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 386, __extension__ __PRETTY_FUNCTION__));
  assert(E <= size() && "Attempted to set out-of-bounds range!")(static_cast <bool> (E <= size() && "Attempted to set out-of-bounds range!"
) ? void (0) : __assert_fail ("E <= size() && \"Attempted to set out-of-bounds range!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 387, __extension__ __PRETTY_FUNCTION__));
  if (I == E) return *this;
  if (isSmall()) {
    uintptr_t EMask = ((uintptr_t)1) << E;
    uintptr_t IMask = ((uintptr_t)1) << I;
    uintptr_t Mask = EMask - IMask;
    setSmallBits(getSmallBits() | Mask);
  } else
    getPointer()->set(I, E);
  return *this;
}

SmallBitVector &reset() {
  if (isSmall())
    setSmallBits(0);
  else
    getPointer()->reset();
  return *this;
}

SmallBitVector &reset(unsigned Idx) {
  if (isSmall())
    setSmallBits(getSmallBits() & ~(uintptr_t(1) << Idx));
  else
    getPointer()->reset(Idx);
  return *this;
}

/// Efficiently reset a range of bits in [I, E)
SmallBitVector &reset(unsigned I, unsigned E) {
  assert(I <= E && "Attempted to reset backwards range!")(static_cast <bool> (I <= E && "Attempted to reset backwards range!"
) ? void (0) : __assert_fail ("I <= E && \"Attempted to reset backwards range!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 417, __extension__ __PRETTY_FUNCTION__));
  assert(E <= size() && "Attempted to reset out-of-bounds range!")(static_cast <bool> (E <= size() && "Attempted to reset out-of-bounds range!"
) ? void (0) : __assert_fail ("E <= size() && \"Attempted to reset out-of-bounds range!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 418, __extension__ __PRETTY_FUNCTION__));
  if (I == E) return *this;
  if (isSmall()) {
    uintptr_t EMask = ((uintptr_t)1) << E;
    uintptr_t IMask = ((uintptr_t)1) << I;
    uintptr_t Mask = EMask - IMask;
    setSmallBits(getSmallBits() & ~Mask);
  } else
    getPointer()->reset(I, E);
  return *this;
}

SmallBitVector &flip() {
  if (isSmall())
    setSmallBits(~getSmallBits());
  else
    getPointer()->flip();
  return *this;
}

SmallBitVector &flip(unsigned Idx) {
  if (isSmall())
    setSmallBits(getSmallBits() ^ (uintptr_t(1) << Idx));
  else
    getPointer()->flip(Idx);
  return *this;
}

// No argument flip.
SmallBitVector operator~() const {
  return SmallBitVector(*this).flip();
}

// Indexing.
reference operator[](unsigned Idx) {
  assert(Idx < size() && "Out-of-bounds Bit access.")(static_cast <bool> (Idx < size() && "Out-of-bounds Bit access."
) ? void (0) : __assert_fail ("Idx < size() && \"Out-of-bounds Bit access.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 453, __extension__ __PRETTY_FUNCTION__));
  return reference(*this, Idx);
}

bool operator[](unsigned Idx) const {
  assert(Idx < size() && "Out-of-bounds Bit access.")(static_cast <bool> (Idx < size() && "Out-of-bounds Bit access."
) ? void (0) : __assert_fail ("Idx < size() && \"Out-of-bounds Bit access.\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 458, __extension__ __PRETTY_FUNCTION__));
  if (isSmall())
    return ((getSmallBits() >> Idx) & 1) != 0;
  return getPointer()->operator[](Idx);
}

bool test(unsigned Idx) const {
  return (*this)[Idx];
}

/// Test if any common bits are set.
bool anyCommon(const SmallBitVector &RHS) const {
  if (isSmall() && RHS.isSmall())
    return (getSmallBits() & RHS.getSmallBits()) != 0;
  if (!isSmall() && !RHS.isSmall())
    return getPointer()->anyCommon(*RHS.getPointer());

  for (unsigned i = 0, e = std::min(size(), RHS.size()); i != e; ++i)
    if (test(i) && RHS.test(i))
      return true;
  return false;
}

// Comparison operators.
bool operator==(const SmallBitVector &RHS) const {
  if (size() != RHS.size())
    return false;
  if (isSmall())
    return getSmallBits() == RHS.getSmallBits();
  else
    return *getPointer() == *RHS.getPointer();
}

bool operator!=(const SmallBitVector &RHS) const {
  return !(*this == RHS);
}

// Intersection, union, disjoint union.
SmallBitVector &operator&=(const SmallBitVector &RHS) {
  resize(std::max(size(), RHS.size()));
  if (isSmall())
    setSmallBits(getSmallBits() & RHS.getSmallBits());
  else if (!RHS.isSmall())
    getPointer()->operator&=(*RHS.getPointer());
  else {
    SmallBitVector Copy = RHS;
    Copy.resize(size());
    getPointer()->operator&=(*Copy.getPointer());
  }
  return *this;
}

/// Reset bits that are set in RHS. Same as *this &= ~RHS.
SmallBitVector &reset(const SmallBitVector &RHS) {
  if (isSmall() && RHS.isSmall())
    setSmallBits(getSmallBits() & ~RHS.getSmallBits());
  else if (!isSmall() && !RHS.isSmall())
    getPointer()->reset(*RHS.getPointer());
  else
    for (unsigned i = 0, e = std::min(size(), RHS.size()); i != e; ++i)
      if (RHS.test(i))
        reset(i);

  return *this;
}

/// Check if (This - RHS) is zero. This is the same as reset(RHS) and any().
bool test(const SmallBitVector &RHS) const {
  if (isSmall() && RHS.isSmall())
    return (getSmallBits() & ~RHS.getSmallBits()) != 0;
  if (!isSmall() && !RHS.isSmall())
    return getPointer()->test(*RHS.getPointer());

  unsigned i, e;
  for (i = 0, e = std::min(size(), RHS.size()); i != e; ++i)
    if (test(i) && !RHS.test(i))
      return true;

  for (e = size(); i != e; ++i)
    if (test(i))
      return true;

  return false;
}

SmallBitVector &operator|=(const SmallBitVector &RHS) {
  resize(std::max(size(), RHS.size()));
  if (isSmall())
    setSmallBits(getSmallBits() | RHS.getSmallBits());
  else if (!RHS.isSmall())
    getPointer()->operator|=(*RHS.getPointer());
  else {
    SmallBitVector Copy = RHS;
    Copy.resize(size());
    getPointer()->operator|=(*Copy.getPointer());
  }
  return *this;
}

SmallBitVector &operator^=(const SmallBitVector &RHS) {
  resize(std::max(size(), RHS.size()));
  if (isSmall())
    setSmallBits(getSmallBits() ^ RHS.getSmallBits());
  else if (!RHS.isSmall())
    getPointer()->operator^=(*RHS.getPointer());
  else {
    SmallBitVector Copy = RHS;
    Copy.resize(size());
    getPointer()->operator^=(*Copy.getPointer());
  }
  return *this;
}

SmallBitVector &operator<<=(unsigned N) {
  if (isSmall())
    setSmallBits(getSmallBits() << N);
  else
    getPointer()->operator<<=(N);
  return *this;
}

SmallBitVector &operator>>=(unsigned N) {
  if (isSmall())
    setSmallBits(getSmallBits() >> N);
  else
    getPointer()->operator>>=(N);
  return *this;
}

// Assignment operator.
const SmallBitVector &operator=(const SmallBitVector &RHS) {
  if (isSmall()) {
    if (RHS.isSmall())
      X = RHS.X;
    else
      switchToLarge(new BitVector(*RHS.getPointer()));
  } else {
    if (!RHS.isSmall())
      *getPointer() = *RHS.getPointer();
    else {
      delete getPointer();
      X = RHS.X;
    }
  }
  return *this;
}

const SmallBitVector &operator=(SmallBitVector &&RHS) {
  if (this != &RHS) {
    clear();
    swap(RHS);
  }
  return *this;
}

void swap(SmallBitVector &RHS) {
  std::swap(X, RHS.X);
}

/// Add '1' bits from Mask to this vector. Don't resize.
/// This computes "*this |= Mask".
void setBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
  if (isSmall())
    applyMask<true, false>(Mask, MaskWords);
  else
    getPointer()->setBitsInMask(Mask, MaskWords);
}

/// Clear any bits in this vector that are set in Mask. Don't resize.
/// This computes "*this &= ~Mask".
void clearBitsInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
  if (isSmall())
    applyMask<false, false>(Mask, MaskWords);
  else
    getPointer()->clearBitsInMask(Mask, MaskWords);
}

/// Add a bit to this vector for every '0' bit in Mask. Don't resize.
/// This computes "*this |= ~Mask".
void setBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
  if (isSmall())
    applyMask<true, true>(Mask, MaskWords);
  else
    getPointer()->setBitsNotInMask(Mask, MaskWords);
}

/// Clear a bit in this vector for every '0' bit in Mask. Don't resize.
/// This computes "*this &= Mask".
void clearBitsNotInMask(const uint32_t *Mask, unsigned MaskWords = ~0u) {
  if (isSmall())
    applyMask<false, true>(Mask, MaskWords);
  else
    getPointer()->clearBitsNotInMask(Mask, MaskWords);
}

653private:
template <bool AddBits, bool InvertMask>
void applyMask(const uint32_t *Mask, unsigned MaskWords) {
  assert(MaskWords <= sizeof(uintptr_t) && "Mask is larger than base!")(static_cast <bool> (MaskWords <= sizeof(uintptr_t) &&
 "Mask is larger than base!") ? void (0) : __assert_fail ("MaskWords <= sizeof(uintptr_t) && \"Mask is larger than base!\""
, "/build/llvm-toolchain-snapshot-7~svn325118/include/llvm/ADT/SmallBitVector.h"
, 656, __extension__ __PRETTY_FUNCTION__));
  uintptr_t M = Mask[0];
  if (NumBaseBits == 64)
    M |= uint64_t(Mask[1]) << 32;
  if (InvertMask)
    M = ~M;
  if (AddBits)
    setSmallBits(getSmallBits() | M);
  else
    setSmallBits(getSmallBits() & ~M);
}
667};

669inline SmallBitVector
670operator&(const SmallBitVector &LHS, const SmallBitVector &RHS) {
SmallBitVector Result(LHS);
Result &= RHS;
return Result;
674}

676inline SmallBitVector
677operator|(const SmallBitVector &LHS, const SmallBitVector &RHS) {
SmallBitVector Result(LHS);
Result |= RHS;
return Result;
681}

683inline SmallBitVector
684operator^(const SmallBitVector &LHS, const SmallBitVector &RHS) {
SmallBitVector Result(LHS);
Result ^= RHS;
return Result;
688}

690} // end namespace llvm

692namespace std {

694/// Implement std::swap in terms of BitVector swap.
695inline void
696swap(llvm::SmallBitVector &LHS, llvm::SmallBitVector &RHS) {
LHS.swap(RHS);
698}

700} // end namespace std

702#endif // LLVM_ADT_SMALLBITVECTOR_H