/build/source/llvm/lib/Analysis/ConstantFolding.cpp

Bug Summary

File:	build/source/llvm/lib/Analysis/ConstantFolding.cpp
Warning:	line 1102, column 9 Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

Show analyzer invocation

clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name ConstantFolding.cpp -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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/source/build-llvm -resource-dir /usr/lib/llvm-17/lib/clang/17 -I lib/Analysis -I /build/source/llvm/lib/Analysis -I include -I /build/source/llvm/include -D _DEBUG -D _GLIBCXX_ASSERTIONS -D _GNU_SOURCE -D _LIBCPP_ENABLE_ASSERTIONS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-17/lib/clang/17/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/source/build-llvm=build-llvm -fmacro-prefix-map=/build/source/= -fcoverage-prefix-map=/build/source/build-llvm=build-llvm -fcoverage-prefix-map=/build/source/= -source-date-epoch 1677881322 -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -Wno-misleading-indentation -std=c++17 -fdeprecated-macro -fdebug-compilation-dir=/build/source/build-llvm -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -fdebug-prefix-map=/build/source/build-llvm=build-llvm -fdebug-prefix-map=/build/source/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2023-03-04-000721-16503-1 -x c++ /build/source/llvm/lib/Analysis/ConstantFolding.cpp

/build/source/llvm/lib/Analysis/ConstantFolding.cpp

→

1//===-- ConstantFolding.cpp - Fold instructions into constants ------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines routines for folding instructions into constants.
10//
11// Also, to supplement the basic IR ConstantExpr simplifications,
12// this file defines some additional folding routines that can make use of
13// DataLayout information. These functions cannot go in IR due to library
14// dependency issues.
15//
16//===----------------------------------------------------------------------===//

18#include "llvm/Analysis/ConstantFolding.h"
19#include "llvm/ADT/APFloat.h"
20#include "llvm/ADT/APInt.h"
21#include "llvm/ADT/APSInt.h"
22#include "llvm/ADT/ArrayRef.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/ADT/SmallVector.h"
26#include "llvm/ADT/StringRef.h"
27#include "llvm/Analysis/TargetFolder.h"
28#include "llvm/Analysis/TargetLibraryInfo.h"
29#include "llvm/Analysis/ValueTracking.h"
30#include "llvm/Analysis/VectorUtils.h"
31#include "llvm/Config/config.h"
32#include "llvm/IR/Constant.h"
33#include "llvm/IR/ConstantFold.h"
34#include "llvm/IR/Constants.h"
35#include "llvm/IR/DataLayout.h"
36#include "llvm/IR/DerivedTypes.h"
37#include "llvm/IR/Function.h"
38#include "llvm/IR/GlobalValue.h"
39#include "llvm/IR/GlobalVariable.h"
40#include "llvm/IR/InstrTypes.h"
41#include "llvm/IR/Instruction.h"
42#include "llvm/IR/Instructions.h"
43#include "llvm/IR/IntrinsicInst.h"
44#include "llvm/IR/Intrinsics.h"
45#include "llvm/IR/IntrinsicsAArch64.h"
46#include "llvm/IR/IntrinsicsAMDGPU.h"
47#include "llvm/IR/IntrinsicsARM.h"
48#include "llvm/IR/IntrinsicsWebAssembly.h"
49#include "llvm/IR/IntrinsicsX86.h"
50#include "llvm/IR/Operator.h"
51#include "llvm/IR/Type.h"
52#include "llvm/IR/Value.h"
53#include "llvm/Support/Casting.h"
54#include "llvm/Support/ErrorHandling.h"
55#include "llvm/Support/KnownBits.h"
56#include "llvm/Support/MathExtras.h"
57#include <cassert>
58#include <cerrno>
59#include <cfenv>
60#include <cmath>
61#include <cstdint>

63using namespace llvm;

65namespace {

67//===----------------------------------------------------------------------===//
68// Constant Folding internal helper functions
69//===----------------------------------------------------------------------===//

71static Constant *foldConstVectorToAPInt(APInt &Result, Type *DestTy,
                                      Constant *C, Type *SrcEltTy,
                                      unsigned NumSrcElts,
                                      const DataLayout &DL) {
// Now that we know that the input value is a vector of integers, just shift
// and insert them into our result.
unsigned BitShift = DL.getTypeSizeInBits(SrcEltTy);
for (unsigned i = 0; i != NumSrcElts; ++i) {
  Constant *Element;
  if (DL.isLittleEndian())
    Element = C->getAggregateElement(NumSrcElts - i - 1);
  else
    Element = C->getAggregateElement(i);

  if (Element && isa<UndefValue>(Element)) {
    Result <<= BitShift;
    continue;
  }

  auto *ElementCI = dyn_cast_or_null<ConstantInt>(Element);
  if (!ElementCI)
    return ConstantExpr::getBitCast(C, DestTy);

  Result <<= BitShift;
  Result |= ElementCI->getValue().zext(Result.getBitWidth());
}

return nullptr;
99}

101/// Constant fold bitcast, symbolically evaluating it with DataLayout.
102/// This always returns a non-null constant, but it may be a
103/// ConstantExpr if unfoldable.
104Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) {
assert(CastInst::castIsValid(Instruction::BitCast, C, DestTy) &&(static_cast <bool> (CastInst::castIsValid(Instruction::
BitCast, C, DestTy) && "Invalid constantexpr bitcast!"
) ? void (0) : __assert_fail ("CastInst::castIsValid(Instruction::BitCast, C, DestTy) && \"Invalid constantexpr bitcast!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 106, __extension__
 __PRETTY_FUNCTION__))
       "Invalid constantexpr bitcast!")(static_cast <bool> (CastInst::castIsValid(Instruction::
BitCast, C, DestTy) && "Invalid constantexpr bitcast!"
) ? void (0) : __assert_fail ("CastInst::castIsValid(Instruction::BitCast, C, DestTy) && \"Invalid constantexpr bitcast!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 106, __extension__
 __PRETTY_FUNCTION__));

// Catch the obvious splat cases.
if (Constant *Res = ConstantFoldLoadFromUniformValue(C, DestTy))
  return Res;

if (auto *VTy = dyn_cast<VectorType>(C->getType())) {
  // Handle a vector->scalar integer/fp cast.
  if (isa<IntegerType>(DestTy) || DestTy->isFloatingPointTy()) {
    unsigned NumSrcElts = cast<FixedVectorType>(VTy)->getNumElements();
    Type *SrcEltTy = VTy->getElementType();

    // If the vector is a vector of floating point, convert it to vector of int
    // to simplify things.
    if (SrcEltTy->isFloatingPointTy()) {
      unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
      auto *SrcIVTy = FixedVectorType::get(
          IntegerType::get(C->getContext(), FPWidth), NumSrcElts);
      // Ask IR to do the conversion now that #elts line up.
      C = ConstantExpr::getBitCast(C, SrcIVTy);
    }

    APInt Result(DL.getTypeSizeInBits(DestTy), 0);
    if (Constant *CE = foldConstVectorToAPInt(Result, DestTy, C,
                                              SrcEltTy, NumSrcElts, DL))
      return CE;

    if (isa<IntegerType>(DestTy))
      return ConstantInt::get(DestTy, Result);

    APFloat FP(DestTy->getFltSemantics(), Result);
    return ConstantFP::get(DestTy->getContext(), FP);
  }
}

// The code below only handles casts to vectors currently.
auto *DestVTy = dyn_cast<VectorType>(DestTy);
if (!DestVTy)
  return ConstantExpr::getBitCast(C, DestTy);

// If this is a scalar -> vector cast, convert the input into a <1 x scalar>
// vector so the code below can handle it uniformly.
if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) {
  Constant *Ops = C; // don't take the address of C!
  return FoldBitCast(ConstantVector::get(Ops), DestTy, DL);
}

// If this is a bitcast from constant vector -> vector, fold it.
if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C))
  return ConstantExpr::getBitCast(C, DestTy);

// If the element types match, IR can fold it.
unsigned NumDstElt = cast<FixedVectorType>(DestVTy)->getNumElements();
unsigned NumSrcElt = cast<FixedVectorType>(C->getType())->getNumElements();
if (NumDstElt == NumSrcElt)
  return ConstantExpr::getBitCast(C, DestTy);

Type *SrcEltTy = cast<VectorType>(C->getType())->getElementType();
Type *DstEltTy = DestVTy->getElementType();

// Otherwise, we're changing the number of elements in a vector, which
// requires endianness information to do the right thing.  For example,
//    bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
// folds to (little endian):
//    <4 x i32> <i32 0, i32 0, i32 1, i32 0>
// and to (big endian):
//    <4 x i32> <i32 0, i32 0, i32 0, i32 1>

// First thing is first.  We only want to think about integer here, so if
// we have something in FP form, recast it as integer.
if (DstEltTy->isFloatingPointTy()) {
  // Fold to an vector of integers with same size as our FP type.
  unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits();
  auto *DestIVTy = FixedVectorType::get(
      IntegerType::get(C->getContext(), FPWidth), NumDstElt);
  // Recursively handle this integer conversion, if possible.
  C = FoldBitCast(C, DestIVTy, DL);

  // Finally, IR can handle this now that #elts line up.
  return ConstantExpr::getBitCast(C, DestTy);
}

// Okay, we know the destination is integer, if the input is FP, convert
// it to integer first.
if (SrcEltTy->isFloatingPointTy()) {
  unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits();
  auto *SrcIVTy = FixedVectorType::get(
      IntegerType::get(C->getContext(), FPWidth), NumSrcElt);
  // Ask IR to do the conversion now that #elts line up.
  C = ConstantExpr::getBitCast(C, SrcIVTy);
  // If IR wasn't able to fold it, bail out.
  if (!isa<ConstantVector>(C) &&  // FIXME: Remove ConstantVector.
      !isa<ConstantDataVector>(C))
    return C;
}

// Now we know that the input and output vectors are both integer vectors
// of the same size, and that their #elements is not the same.  Do the
// conversion here, which depends on whether the input or output has
// more elements.
bool isLittleEndian = DL.isLittleEndian();

SmallVector<Constant*, 32> Result;
if (NumDstElt < NumSrcElt) {
  // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>)
  Constant *Zero = Constant::getNullValue(DstEltTy);
  unsigned Ratio = NumSrcElt/NumDstElt;
  unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits();
  unsigned SrcElt = 0;
  for (unsigned i = 0; i != NumDstElt; ++i) {
    // Build each element of the result.
    Constant *Elt = Zero;
    unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1);
    for (unsigned j = 0; j != Ratio; ++j) {
      Constant *Src = C->getAggregateElement(SrcElt++);
      if (Src && isa<UndefValue>(Src))
        Src = Constant::getNullValue(
            cast<VectorType>(C->getType())->getElementType());
      else
        Src = dyn_cast_or_null<ConstantInt>(Src);
      if (!Src)  // Reject constantexpr elements.
        return ConstantExpr::getBitCast(C, DestTy);

      // Zero extend the element to the right size.
      Src = ConstantExpr::getZExt(Src, Elt->getType());

      // Shift it to the right place, depending on endianness.
      Src = ConstantExpr::getShl(Src,
                                 ConstantInt::get(Src->getType(), ShiftAmt));
      ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize;

      // Mix it in.
      Elt = ConstantExpr::getOr(Elt, Src);
    }
    Result.push_back(Elt);
  }
  return ConstantVector::get(Result);
}

// Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
unsigned Ratio = NumDstElt/NumSrcElt;
unsigned DstBitSize = DL.getTypeSizeInBits(DstEltTy);

// Loop over each source value, expanding into multiple results.
for (unsigned i = 0; i != NumSrcElt; ++i) {
  auto *Element = C->getAggregateElement(i);

  if (!Element) // Reject constantexpr elements.
    return ConstantExpr::getBitCast(C, DestTy);

  if (isa<UndefValue>(Element)) {
    // Correctly Propagate undef values.
    Result.append(Ratio, UndefValue::get(DstEltTy));
    continue;
  }

  auto *Src = dyn_cast<ConstantInt>(Element);
  if (!Src)
    return ConstantExpr::getBitCast(C, DestTy);

  unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1);
  for (unsigned j = 0; j != Ratio; ++j) {
    // Shift the piece of the value into the right place, depending on
    // endianness.
    Constant *Elt = ConstantExpr::getLShr(Src,
                                ConstantInt::get(Src->getType(), ShiftAmt));
    ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;

    // Truncate the element to an integer with the same pointer size and
    // convert the element back to a pointer using a inttoptr.
    if (DstEltTy->isPointerTy()) {
      IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize);
      Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy);
      Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy));
      continue;
    }

    // Truncate and remember this piece.
    Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
  }
}

return ConstantVector::get(Result);
289}

291} // end anonymous namespace

293/// If this constant is a constant offset from a global, return the global and
294/// the constant. Because of constantexprs, this function is recursive.
295bool llvm::IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV,
                                    APInt &Offset, const DataLayout &DL,
                                    DSOLocalEquivalent **DSOEquiv) {
if (DSOEquiv)
  *DSOEquiv = nullptr;

// Trivial case, constant is the global.
if ((GV = dyn_cast<GlobalValue>(C))) {
  unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType());
  Offset = APInt(BitWidth, 0);
  return true;
}

if (auto *FoundDSOEquiv = dyn_cast<DSOLocalEquivalent>(C)) {
  if (DSOEquiv)
    *DSOEquiv = FoundDSOEquiv;
  GV = FoundDSOEquiv->getGlobalValue();
  unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType());
  Offset = APInt(BitWidth, 0);
  return true;
}

// Otherwise, if this isn't a constant expr, bail out.
auto *CE = dyn_cast<ConstantExpr>(C);
if (!CE) return false;

// Look through ptr->int and ptr->ptr casts.
if (CE->getOpcode() == Instruction::PtrToInt ||
    CE->getOpcode() == Instruction::BitCast)
  return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL,
                                    DSOEquiv);

// i32* getelementptr ([5 x i32]* @a, i32 0, i32 5)
auto *GEP = dyn_cast<GEPOperator>(CE);
if (!GEP)
  return false;

unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType());
APInt TmpOffset(BitWidth, 0);

// If the base isn't a global+constant, we aren't either.
if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, DL,
                                DSOEquiv))
  return false;

// Otherwise, add any offset that our operands provide.
if (!GEP->accumulateConstantOffset(DL, TmpOffset))
  return false;

Offset = TmpOffset;
return true;
346}

348Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy,
                                       const DataLayout &DL) {
do {
  Type *SrcTy = C->getType();
  if (SrcTy == DestTy)
    return C;

  TypeSize DestSize = DL.getTypeSizeInBits(DestTy);
  TypeSize SrcSize = DL.getTypeSizeInBits(SrcTy);
  if (!TypeSize::isKnownGE(SrcSize, DestSize))
    return nullptr;

  // Catch the obvious splat cases (since all-zeros can coerce non-integral
  // pointers legally).
  if (Constant *Res = ConstantFoldLoadFromUniformValue(C, DestTy))
    return Res;

  // If the type sizes are the same and a cast is legal, just directly
  // cast the constant.
  // But be careful not to coerce non-integral pointers illegally.
  if (SrcSize == DestSize &&
      DL.isNonIntegralPointerType(SrcTy->getScalarType()) ==
          DL.isNonIntegralPointerType(DestTy->getScalarType())) {
    Instruction::CastOps Cast = Instruction::BitCast;
    // If we are going from a pointer to int or vice versa, we spell the cast
    // differently.
    if (SrcTy->isIntegerTy() && DestTy->isPointerTy())
      Cast = Instruction::IntToPtr;
    else if (SrcTy->isPointerTy() && DestTy->isIntegerTy())
      Cast = Instruction::PtrToInt;

    if (CastInst::castIsValid(Cast, C, DestTy))
      return ConstantExpr::getCast(Cast, C, DestTy);
  }

  // If this isn't an aggregate type, there is nothing we can do to drill down
  // and find a bitcastable constant.
  if (!SrcTy->isAggregateType() && !SrcTy->isVectorTy())
    return nullptr;

  // We're simulating a load through a pointer that was bitcast to point to
  // a different type, so we can try to walk down through the initial
  // elements of an aggregate to see if some part of the aggregate is
  // castable to implement the "load" semantic model.
  if (SrcTy->isStructTy()) {
    // Struct types might have leading zero-length elements like [0 x i32],
    // which are certainly not what we are looking for, so skip them.
    unsigned Elem = 0;
    Constant *ElemC;
    do {
      ElemC = C->getAggregateElement(Elem++);
    } while (ElemC && DL.getTypeSizeInBits(ElemC->getType()).isZero());
    C = ElemC;
  } else {
    // For non-byte-sized vector elements, the first element is not
    // necessarily located at the vector base address.
    if (auto *VT = dyn_cast<VectorType>(SrcTy))
      if (!DL.typeSizeEqualsStoreSize(VT->getElementType()))
        return nullptr;

    C = C->getAggregateElement(0u);
  }
} while (C);

return nullptr;
413}

415namespace {

417/// Recursive helper to read bits out of global. C is the constant being copied
418/// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy
419/// results into and BytesLeft is the number of bytes left in
420/// the CurPtr buffer. DL is the DataLayout.
421bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr,
                      unsigned BytesLeft, const DataLayout &DL) {
assert(ByteOffset <= DL.getTypeAllocSize(C->getType()) &&(static_cast <bool> (ByteOffset <= DL.getTypeAllocSize
(C->getType()) && "Out of range access") ? void (0
) : __assert_fail ("ByteOffset <= DL.getTypeAllocSize(C->getType()) && \"Out of range access\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 424, __extension__
 __PRETTY_FUNCTION__))
       "Out of range access")(static_cast <bool> (ByteOffset <= DL.getTypeAllocSize
(C->getType()) && "Out of range access") ? void (0
) : __assert_fail ("ByteOffset <= DL.getTypeAllocSize(C->getType()) && \"Out of range access\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 424, __extension__
 __PRETTY_FUNCTION__));

// If this element is zero or undefined, we can just return since *CurPtr is
// zero initialized.
if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C))
  return true;

if (auto *CI = dyn_cast<ConstantInt>(C)) {
  if (CI->getBitWidth() > 64 ||
      (CI->getBitWidth() & 7) != 0)
    return false;

  uint64_t Val = CI->getZExtValue();
  unsigned IntBytes = unsigned(CI->getBitWidth()/8);

  for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) {
    int n = ByteOffset;
    if (!DL.isLittleEndian())
      n = IntBytes - n - 1;
    CurPtr[i] = (unsigned char)(Val >> (n * 8));
    ++ByteOffset;
  }
  return true;
}

if (auto *CFP = dyn_cast<ConstantFP>(C)) {
  if (CFP->getType()->isDoubleTy()) {
    C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), DL);
    return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
  }
  if (CFP->getType()->isFloatTy()){
    C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), DL);
    return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
  }
  if (CFP->getType()->isHalfTy()){
    C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), DL);
    return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL);
  }
  return false;
}

if (auto *CS = dyn_cast<ConstantStruct>(C)) {
  const StructLayout *SL = DL.getStructLayout(CS->getType());
  unsigned Index = SL->getElementContainingOffset(ByteOffset);
  uint64_t CurEltOffset = SL->getElementOffset(Index);
  ByteOffset -= CurEltOffset;

  while (true) {
    // If the element access is to the element itself and not to tail padding,
    // read the bytes from the element.
    uint64_t EltSize = DL.getTypeAllocSize(CS->getOperand(Index)->getType());

    if (ByteOffset < EltSize &&
        !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr,
                            BytesLeft, DL))
      return false;

    ++Index;

    // Check to see if we read from the last struct element, if so we're done.
    if (Index == CS->getType()->getNumElements())
      return true;

    // If we read all of the bytes we needed from this element we're done.
    uint64_t NextEltOffset = SL->getElementOffset(Index);

    if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset)
      return true;

    // Move to the next element of the struct.
    CurPtr += NextEltOffset - CurEltOffset - ByteOffset;
    BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset;
    ByteOffset = 0;
    CurEltOffset = NextEltOffset;
  }
  // not reached.
}

if (isa<ConstantArray>(C) || isa<ConstantVector>(C) ||
    isa<ConstantDataSequential>(C)) {
  uint64_t NumElts;
  Type *EltTy;
  if (auto *AT = dyn_cast<ArrayType>(C->getType())) {
    NumElts = AT->getNumElements();
    EltTy = AT->getElementType();
  } else {
    NumElts = cast<FixedVectorType>(C->getType())->getNumElements();
    EltTy = cast<FixedVectorType>(C->getType())->getElementType();
  }
  uint64_t EltSize = DL.getTypeAllocSize(EltTy);
  uint64_t Index = ByteOffset / EltSize;
  uint64_t Offset = ByteOffset - Index * EltSize;

  for (; Index != NumElts; ++Index) {
    if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr,
                            BytesLeft, DL))
      return false;

    uint64_t BytesWritten = EltSize - Offset;
    assert(BytesWritten <= EltSize && "Not indexing into this element?")(static_cast <bool> (BytesWritten <= EltSize &&
 "Not indexing into this element?") ? void (0) : __assert_fail
 ("BytesWritten <= EltSize && \"Not indexing into this element?\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 523, __extension__
 __PRETTY_FUNCTION__));
    if (BytesWritten >= BytesLeft)
      return true;

    Offset = 0;
    BytesLeft -= BytesWritten;
    CurPtr += BytesWritten;
  }
  return true;
}

if (auto *CE = dyn_cast<ConstantExpr>(C)) {
  if (CE->getOpcode() == Instruction::IntToPtr &&
      CE->getOperand(0)->getType() == DL.getIntPtrType(CE->getType())) {
    return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr,
                              BytesLeft, DL);
  }
}

// Otherwise, unknown initializer type.
return false;
544}

546Constant *FoldReinterpretLoadFromConst(Constant *C, Type *LoadTy,
                                     int64_t Offset, const DataLayout &DL) {
// Bail out early. Not expect to load from scalable global variable.
if (isa<ScalableVectorType>(LoadTy))
  return nullptr;

auto *IntType = dyn_cast<IntegerType>(LoadTy);

// If this isn't an integer load we can't fold it directly.
if (!IntType) {
  // If this is a non-integer load, we can try folding it as an int load and
  // then bitcast the result.  This can be useful for union cases.  Note
  // that address spaces don't matter here since we're not going to result in
  // an actual new load.
  if (!LoadTy->isFloatingPointTy() && !LoadTy->isPointerTy() &&
      !LoadTy->isVectorTy())
    return nullptr;

  Type *MapTy = Type::getIntNTy(C->getContext(),
                                DL.getTypeSizeInBits(LoadTy).getFixedValue());
  if (Constant *Res = FoldReinterpretLoadFromConst(C, MapTy, Offset, DL)) {
    if (Res->isNullValue() && !LoadTy->isX86_MMXTy() &&
        !LoadTy->isX86_AMXTy())
      // Materializing a zero can be done trivially without a bitcast
      return Constant::getNullValue(LoadTy);
    Type *CastTy = LoadTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(LoadTy) : LoadTy;
    Res = FoldBitCast(Res, CastTy, DL);
    if (LoadTy->isPtrOrPtrVectorTy()) {
      // For vector of pointer, we needed to first convert to a vector of integer, then do vector inttoptr
      if (Res->isNullValue() && !LoadTy->isX86_MMXTy() &&
          !LoadTy->isX86_AMXTy())
        return Constant::getNullValue(LoadTy);
      if (DL.isNonIntegralPointerType(LoadTy->getScalarType()))
        // Be careful not to replace a load of an addrspace value with an inttoptr here
        return nullptr;
      Res = ConstantExpr::getCast(Instruction::IntToPtr, Res, LoadTy);
    }
    return Res;
  }
  return nullptr;
}

unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8;
if (BytesLoaded > 32 || BytesLoaded == 0)
  return nullptr;

// If we're not accessing anything in this constant, the result is undefined.
if (Offset <= -1 * static_cast<int64_t>(BytesLoaded))
  return PoisonValue::get(IntType);

// TODO: We should be able to support scalable types.
TypeSize InitializerSize = DL.getTypeAllocSize(C->getType());
if (InitializerSize.isScalable())
  return nullptr;

// If we're not accessing anything in this constant, the result is undefined.
if (Offset >= (int64_t)InitializerSize.getFixedValue())
  return PoisonValue::get(IntType);

unsigned char RawBytes[32] = {0};
unsigned char *CurPtr = RawBytes;
unsigned BytesLeft = BytesLoaded;

// If we're loading off the beginning of the global, some bytes may be valid.
if (Offset < 0) {
  CurPtr += -Offset;
  BytesLeft += Offset;
  Offset = 0;
}

if (!ReadDataFromGlobal(C, Offset, CurPtr, BytesLeft, DL))
  return nullptr;

APInt ResultVal = APInt(IntType->getBitWidth(), 0);
if (DL.isLittleEndian()) {
  ResultVal = RawBytes[BytesLoaded - 1];
  for (unsigned i = 1; i != BytesLoaded; ++i) {
    ResultVal <<= 8;
    ResultVal |= RawBytes[BytesLoaded - 1 - i];
  }
} else {
  ResultVal = RawBytes[0];
  for (unsigned i = 1; i != BytesLoaded; ++i) {
    ResultVal <<= 8;
    ResultVal |= RawBytes[i];
  }
}

return ConstantInt::get(IntType->getContext(), ResultVal);
635}

637} // anonymous namespace

639// If GV is a constant with an initializer read its representation starting
640// at Offset and return it as a constant array of unsigned char.  Otherwise
641// return null.
642Constant *llvm::ReadByteArrayFromGlobal(const GlobalVariable *GV,
                                      uint64_t Offset) {
if (!GV->isConstant() || !GV->hasDefinitiveInitializer())
  return nullptr;

const DataLayout &DL = GV->getParent()->getDataLayout();
Constant *Init = const_cast<Constant *>(GV->getInitializer());
TypeSize InitSize = DL.getTypeAllocSize(Init->getType());
if (InitSize < Offset)
  return nullptr;

uint64_t NBytes = InitSize - Offset;
if (NBytes > UINT16_MAX(65535))
  // Bail for large initializers in excess of 64K to avoid allocating
  // too much memory.
  // Offset is assumed to be less than or equal than InitSize (this
  // is enforced in ReadDataFromGlobal).
  return nullptr;

SmallVector<unsigned char, 256> RawBytes(static_cast<size_t>(NBytes));
unsigned char *CurPtr = RawBytes.data();

if (!ReadDataFromGlobal(Init, Offset, CurPtr, NBytes, DL))
  return nullptr;

return ConstantDataArray::get(GV->getContext(), RawBytes);
668}

670/// If this Offset points exactly to the start of an aggregate element, return
671/// that element, otherwise return nullptr.
672Constant *getConstantAtOffset(Constant *Base, APInt Offset,
                            const DataLayout &DL) {
if (Offset.isZero())
  return Base;

if (!isa<ConstantAggregate>(Base) && !isa<ConstantDataSequential>(Base))
  return nullptr;

Type *ElemTy = Base->getType();
SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset);
if (!Offset.isZero() || !Indices[0].isZero())
  return nullptr;

Constant *C = Base;
for (const APInt &Index : drop_begin(Indices)) {
  if (Index.isNegative() || Index.getActiveBits() >= 32)
    return nullptr;

  C = C->getAggregateElement(Index.getZExtValue());
  if (!C)
    return nullptr;
}

return C;
696}

698Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,
                                        const APInt &Offset,
                                        const DataLayout &DL) {
if (Constant *AtOffset = getConstantAtOffset(C, Offset, DL))
  if (Constant *Result = ConstantFoldLoadThroughBitcast(AtOffset, Ty, DL))
    return Result;

// Explicitly check for out-of-bounds access, so we return poison even if the
// constant is a uniform value.
TypeSize Size = DL.getTypeAllocSize(C->getType());
if (!Size.isScalable() && Offset.sge(Size.getFixedValue()))
  return PoisonValue::get(Ty);

// Try an offset-independent fold of a uniform value.
if (Constant *Result = ConstantFoldLoadFromUniformValue(C, Ty))
  return Result;

// Try hard to fold loads from bitcasted strange and non-type-safe things.
if (Offset.getSignificantBits() <= 64)
  if (Constant *Result =
          FoldReinterpretLoadFromConst(C, Ty, Offset.getSExtValue(), DL))
    return Result;

return nullptr;
722}

724Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty,
                                        const DataLayout &DL) {
return ConstantFoldLoadFromConst(C, Ty, APInt(64, 0), DL);
727}

729Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty,
                                           APInt Offset,
                                           const DataLayout &DL) {
// We can only fold loads from constant globals with a definitive initializer.
// Check this upfront, to skip expensive offset calculations.
auto *GV = dyn_cast<GlobalVariable>(getUnderlyingObject(C));
if (!GV || !GV->isConstant() || !GV->hasDefinitiveInitializer())
  return nullptr;

C = cast<Constant>(C->stripAndAccumulateConstantOffsets(
        DL, Offset, /* AllowNonInbounds */ true));

if (C == GV)
  if (Constant *Result = ConstantFoldLoadFromConst(GV->getInitializer(), Ty,
                                                   Offset, DL))
    return Result;

// If this load comes from anywhere in a uniform constant global, the value
// is always the same, regardless of the loaded offset.
return ConstantFoldLoadFromUniformValue(GV->getInitializer(), Ty);
749}

751Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty,
                                           const DataLayout &DL) {
APInt Offset(DL.getIndexTypeSizeInBits(C->getType()), 0);
return ConstantFoldLoadFromConstPtr(C, Ty, Offset, DL);
755}

757Constant *llvm::ConstantFoldLoadFromUniformValue(Constant *C, Type *Ty) {
if (isa<PoisonValue>(C))
  return PoisonValue::get(Ty);
if (isa<UndefValue>(C))
  return UndefValue::get(Ty);
if (C->isNullValue() && !Ty->isX86_MMXTy() && !Ty->isX86_AMXTy())
  return Constant::getNullValue(Ty);
if (C->isAllOnesValue() &&
    (Ty->isIntOrIntVectorTy() || Ty->isFPOrFPVectorTy()))
  return Constant::getAllOnesValue(Ty);
return nullptr;
768}

770namespace {

772/// One of Op0/Op1 is a constant expression.
773/// Attempt to symbolically evaluate the result of a binary operator merging
774/// these together.  If target data info is available, it is provided as DL,
775/// otherwise DL is null.
776Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, Constant *Op1,
                                  const DataLayout &DL) {
// SROA

// Fold (and 0xffffffff00000000, (shl x, 32)) -> shl.
// Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute
// bits.

if (Opc == Instruction::And) {
  KnownBits Known0 = computeKnownBits(Op0, DL);
  KnownBits Known1 = computeKnownBits(Op1, DL);
  if ((Known1.One | Known0.Zero).isAllOnes()) {
    // All the bits of Op0 that the 'and' could be masking are already zero.
    return Op0;
  }
  if ((Known0.One | Known1.Zero).isAllOnes()) {
    // All the bits of Op1 that the 'and' could be masking are already zero.
    return Op1;
  }

  Known0 &= Known1;
  if (Known0.isConstant())
    return ConstantInt::get(Op0->getType(), Known0.getConstant());
}

// If the constant expr is something like &A[123] - &A[4].f, fold this into a
// constant.  This happens frequently when iterating over a global array.
if (Opc == Instruction::Sub) {
  GlobalValue *GV1, *GV2;
  APInt Offs1, Offs2;

  if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, DL))
    if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, DL) && GV1 == GV2) {
      unsigned OpSize = DL.getTypeSizeInBits(Op0->getType());

      // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow.
      // PtrToInt may change the bitwidth so we have convert to the right size
      // first.
      return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) -
                                              Offs2.zextOrTrunc(OpSize));
    }
}

return nullptr;
820}

822/// If array indices are not pointer-sized integers, explicitly cast them so
823/// that they aren't implicitly casted by the getelementptr.
824Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops,
                       Type *ResultTy, std::optional<unsigned> InRangeIndex,
                       const DataLayout &DL, const TargetLibraryInfo *TLI) {
Type *IntIdxTy = DL.getIndexType(ResultTy);
Type *IntIdxScalarTy = IntIdxTy->getScalarType();

bool Any = false;
SmallVector<Constant*, 32> NewIdxs;
for (unsigned i = 1, e = Ops.size(); i != e; ++i) {
  if ((i == 1 ||
       !isa<StructType>(GetElementPtrInst::getIndexedType(
           SrcElemTy, Ops.slice(1, i - 1)))) &&
      Ops[i]->getType()->getScalarType() != IntIdxScalarTy) {
    Any = true;
    Type *NewType = Ops[i]->getType()->isVectorTy()
                        ? IntIdxTy
                        : IntIdxScalarTy;
    NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i],
                                                                    true,
                                                                    NewType,
                                                                    true),
                                            Ops[i], NewType));
  } else
    NewIdxs.push_back(Ops[i]);
}

if (!Any)
  return nullptr;

Constant *C = ConstantExpr::getGetElementPtr(
    SrcElemTy, Ops[0], NewIdxs, /*InBounds=*/false, InRangeIndex);
return ConstantFoldConstant(C, DL, TLI);
856}

858/// Strip the pointer casts, but preserve the address space information.
859Constant *StripPtrCastKeepAS(Constant *Ptr) {
assert(Ptr->getType()->isPointerTy() && "Not a pointer type")(static_cast <bool> (Ptr->getType()->isPointerTy(
) && "Not a pointer type") ? void (0) : __assert_fail
 ("Ptr->getType()->isPointerTy() && \"Not a pointer type\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 860, __extension__
 __PRETTY_FUNCTION__));
auto *OldPtrTy = cast<PointerType>(Ptr->getType());
Ptr = cast<Constant>(Ptr->stripPointerCasts());
auto *NewPtrTy = cast<PointerType>(Ptr->getType());

// Preserve the address space number of the pointer.
if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) {
  Ptr = ConstantExpr::getPointerCast(
      Ptr, PointerType::getWithSamePointeeType(NewPtrTy,
                                               OldPtrTy->getAddressSpace()));
}
return Ptr;
872}

874/// If we can symbolically evaluate the GEP constant expression, do so.
875Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP,
                                ArrayRef<Constant *> Ops,
                                const DataLayout &DL,
                                const TargetLibraryInfo *TLI) {
const GEPOperator *InnermostGEP = GEP;
bool InBounds = GEP->isInBounds();

Type *SrcElemTy = GEP->getSourceElementType();
Type *ResElemTy = GEP->getResultElementType();
Type *ResTy = GEP->getType();
if (!SrcElemTy->isSized() || isa<ScalableVectorType>(SrcElemTy))
  return nullptr;

if (Constant *C = CastGEPIndices(SrcElemTy, Ops, ResTy,
                                 GEP->getInRangeIndex(), DL, TLI))
  return C;

Constant *Ptr = Ops[0];
if (!Ptr->getType()->isPointerTy())
  return nullptr;

Type *IntIdxTy = DL.getIndexType(Ptr->getType());

for (unsigned i = 1, e = Ops.size(); i != e; ++i)
  if (!isa<ConstantInt>(Ops[i]))
    return nullptr;

unsigned BitWidth = DL.getTypeSizeInBits(IntIdxTy);
APInt Offset = APInt(
    BitWidth,
    DL.getIndexedOffsetInType(
        SrcElemTy, ArrayRef((Value *const *)Ops.data() + 1, Ops.size() - 1)));
Ptr = StripPtrCastKeepAS(Ptr);

// If this is a GEP of a GEP, fold it all into a single GEP.
while (auto *GEP = dyn_cast<GEPOperator>(Ptr)) {
  InnermostGEP = GEP;
  InBounds &= GEP->isInBounds();

  SmallVector<Value *, 4> NestedOps(llvm::drop_begin(GEP->operands()));

  // Do not try the incorporate the sub-GEP if some index is not a number.
  bool AllConstantInt = true;
  for (Value *NestedOp : NestedOps)
    if (!isa<ConstantInt>(NestedOp)) {
      AllConstantInt = false;
      break;
    }
  if (!AllConstantInt)
    break;

  Ptr = cast<Constant>(GEP->getOperand(0));
  SrcElemTy = GEP->getSourceElementType();
  Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps));
  Ptr = StripPtrCastKeepAS(Ptr);
}

// If the base value for this address is a literal integer value, fold the
// getelementptr to the resulting integer value casted to the pointer type.
APInt BasePtr(BitWidth, 0);
if (auto *CE = dyn_cast<ConstantExpr>(Ptr)) {
  if (CE->getOpcode() == Instruction::IntToPtr) {
    if (auto *Base = dyn_cast<ConstantInt>(CE->getOperand(0)))
      BasePtr = Base->getValue().zextOrTrunc(BitWidth);
  }
}

auto *PTy = cast<PointerType>(Ptr->getType());
if ((Ptr->isNullValue() || BasePtr != 0) &&
    !DL.isNonIntegralPointerType(PTy)) {
  Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr);
  return ConstantExpr::getIntToPtr(C, ResTy);
}

// Otherwise form a regular getelementptr. Recompute the indices so that
// we eliminate over-indexing of the notional static type array bounds.
// This makes it easy to determine if the getelementptr is "inbounds".
// Also, this helps GlobalOpt do SROA on GlobalVariables.

// For GEPs of GlobalValues, use the value type even for opaque pointers.
// Otherwise use an i8 GEP.
if (auto *GV = dyn_cast<GlobalValue>(Ptr))
  SrcElemTy = GV->getValueType();
else if (!PTy->isOpaque())
  SrcElemTy = PTy->getNonOpaquePointerElementType();
else
  SrcElemTy = Type::getInt8Ty(Ptr->getContext());

if (!SrcElemTy->isSized())
  return nullptr;

Type *ElemTy = SrcElemTy;
SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset);
if (Offset != 0)
  return nullptr;

// Try to add additional zero indices to reach the desired result element
// type.
// TODO: Should we avoid extra zero indices if ResElemTy can't be reached and
// we'll have to insert a bitcast anyway?
while (ElemTy != ResElemTy) {
  Type *NextTy = GetElementPtrInst::getTypeAtIndex(ElemTy, (uint64_t)0);
  if (!NextTy)
    break;

  Indices.push_back(APInt::getZero(isa<StructType>(ElemTy) ? 32 : BitWidth));
  ElemTy = NextTy;
}

SmallVector<Constant *, 32> NewIdxs;
for (const APInt &Index : Indices)
  NewIdxs.push_back(ConstantInt::get(
      Type::getIntNTy(Ptr->getContext(), Index.getBitWidth()), Index));

// Preserve the inrange index from the innermost GEP if possible. We must
// have calculated the same indices up to and including the inrange index.
std::optional<unsigned> InRangeIndex;
if (std::optional<unsigned> LastIRIndex = InnermostGEP->getInRangeIndex())
  if (SrcElemTy == InnermostGEP->getSourceElementType() &&
      NewIdxs.size() > *LastIRIndex) {
    InRangeIndex = LastIRIndex;
    for (unsigned I = 0; I <= *LastIRIndex; ++I)
      if (NewIdxs[I] != InnermostGEP->getOperand(I + 1))
        return nullptr;
  }

// Create a GEP.
Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ptr, NewIdxs,
                                             InBounds, InRangeIndex);
assert((static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1006, __extension__
 __PRETTY_FUNCTION__))
    cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) &&(static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1006, __extension__
 __PRETTY_FUNCTION__))
    "Computed GetElementPtr has unexpected type!")(static_cast <bool> (cast<PointerType>(C->getType
())->isOpaqueOrPointeeTypeMatches(ElemTy) && "Computed GetElementPtr has unexpected type!"
) ? void (0) : __assert_fail ("cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && \"Computed GetElementPtr has unexpected type!\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1006, __extension__
 __PRETTY_FUNCTION__));

// If we ended up indexing a member with a type that doesn't match
// the type of what the original indices indexed, add a cast.
if (C->getType() != ResTy)
  C = FoldBitCast(C, ResTy, DL);

return C;
1014}

1016/// Attempt to constant fold an instruction with the
1017/// specified opcode and operands.  If successful, the constant result is
1018/// returned, if not, null is returned.  Note that this function can fail when
1019/// attempting to fold instructions like loads and stores, which have no
1020/// constant expression form.
1021Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode,
                                     ArrayRef<Constant *> Ops,
                                     const DataLayout &DL,
                                     const TargetLibraryInfo *TLI) {
Type *DestTy = InstOrCE->getType();

if (Instruction::isUnaryOp(Opcode))
9
←
Calling 'Instruction::isUnaryOp'→
12
←
Returning from 'Instruction::isUnaryOp'→
13
←
Taking false branch→
  return ConstantFoldUnaryOpOperand(Opcode, Ops[0], DL);

if (Instruction::isBinaryOp(Opcode)) {
14
←
Calling 'Instruction::isBinaryOp'→
16
←
Returning from 'Instruction::isBinaryOp'→
17
←
Taking false branch→
  switch (Opcode) {
  default:
    break;
  case Instruction::FAdd:
  case Instruction::FSub:
  case Instruction::FMul:
  case Instruction::FDiv:
  case Instruction::FRem:
    // Handle floating point instructions separately to account for denormals
    // TODO: If a constant expression is being folded rather than an
    // instruction, denormals will not be flushed/treated as zero
    if (const auto *I = dyn_cast<Instruction>(InstOrCE)) {
      return ConstantFoldFPInstOperands(Opcode, Ops[0], Ops[1], DL, I);
    }
  }
  return ConstantFoldBinaryOpOperands(Opcode, Ops[0], Ops[1], DL);
}

if (Instruction::isCast(Opcode))
18
←
Calling 'Instruction::isCast'→
20
←
Returning from 'Instruction::isCast'→
21
←
Taking false branch→
  return ConstantFoldCastOperand(Opcode, Ops[0], DestTy, DL);

if (auto *GEP22.1
'GEP' is null
1
'GEP' is null
 = dyn_cast<GEPOperator>(InstOrCE)) {
22
←
Assuming 'InstOrCE' is not a 'CastReturnType'→
23
←
Taking false branch→
  if (Constant *C = SymbolicallyEvaluateGEP(GEP, Ops, DL, TLI))
    return C;

  return ConstantExpr::getGetElementPtr(GEP->getSourceElementType(), Ops[0],
                                        Ops.slice(1), GEP->isInBounds(),
                                        GEP->getInRangeIndex());
}

if (auto *CE24.1
'CE' is null
1
'CE' is null
 = dyn_cast<ConstantExpr>(InstOrCE)) {
24
←
Assuming 'InstOrCE' is not a 'CastReturnType'→
25
←
Taking false branch→
  if (CE->isCompare())
    return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1],
                                           DL, TLI);
  return CE->getWithOperands(Ops);
}

switch (Opcode) {
26
←
Control jumps to 'case Load:'  at line 1100→
default: return nullptr;
case Instruction::ICmp:
case Instruction::FCmp: {
  auto *C = cast<CmpInst>(InstOrCE);
  return ConstantFoldCompareInstOperands(C->getPredicate(), Ops[0], Ops[1],
                                         DL, TLI, C);
}
case Instruction::Freeze:
  return isGuaranteedNotToBeUndefOrPoison(Ops[0]) ? Ops[0] : nullptr;
case Instruction::Call:
  if (auto *F = dyn_cast<Function>(Ops.back())) {
    const auto *Call = cast<CallBase>(InstOrCE);
    if (canConstantFoldCallTo(Call, F))
      return ConstantFoldCall(Call, F, Ops.slice(0, Ops.size() - 1), TLI);
  }
  return nullptr;
case Instruction::Select:
  return ConstantFoldSelectInstruction(Ops[0], Ops[1], Ops[2]);
case Instruction::ExtractElement:
  return ConstantExpr::getExtractElement(Ops[0], Ops[1]);
case Instruction::ExtractValue:
  return ConstantFoldExtractValueInstruction(
      Ops[0], cast<ExtractValueInst>(InstOrCE)->getIndices());
case Instruction::InsertElement:
  return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]);
case Instruction::InsertValue:
  return ConstantFoldInsertValueInstruction(
      Ops[0], Ops[1], cast<InsertValueInst>(InstOrCE)->getIndices());
case Instruction::ShuffleVector:
  return ConstantExpr::getShuffleVector(
      Ops[0], Ops[1], cast<ShuffleVectorInst>(InstOrCE)->getShuffleMask());
case Instruction::Load: {
  const auto *LI = dyn_cast<LoadInst>(InstOrCE);
27
←
Assuming 'InstOrCE' is not a 'CastReturnType'→
28
←
'LI' initialized to a null pointer value→
  if (LI->isVolatile())
29
←
Called C++ object pointer is null
    return nullptr;
  return ConstantFoldLoadFromConstPtr(Ops[0], LI->getType(), DL);
}
}
1107}

1109} // end anonymous namespace

1111//===----------------------------------------------------------------------===//
1112// Constant Folding public APIs
1113//===----------------------------------------------------------------------===//

1115namespace {

1117Constant *
1118ConstantFoldConstantImpl(const Constant *C, const DataLayout &DL,
                       const TargetLibraryInfo *TLI,
                       SmallDenseMap<Constant *, Constant *> &FoldedOps) {
if (!isa<ConstantVector>(C) && !isa<ConstantExpr>(C))
2
←
Assuming 'C' is not a 'ConstantVector'→
3
←
Assuming 'C' is a 'class llvm::ConstantExpr &'→
4
←
Taking false branch→
  return const_cast<Constant *>(C);

SmallVector<Constant *, 8> Ops;
for (const Use &OldU : C->operands()) {
5
←
Assuming '__begin1' is equal to '__end1'→
  Constant *OldC = cast<Constant>(&OldU);
  Constant *NewC = OldC;
  // Recursively fold the ConstantExpr's operands. If we have already folded
  // a ConstantExpr, we don't have to process it again.
  if (isa<ConstantVector>(OldC) || isa<ConstantExpr>(OldC)) {
    auto It = FoldedOps.find(OldC);
    if (It == FoldedOps.end()) {
      NewC = ConstantFoldConstantImpl(OldC, DL, TLI, FoldedOps);
      FoldedOps.insert({OldC, NewC});
    } else {
      NewC = It->second;
    }
  }
  Ops.push_back(NewC);
}

if (auto *CE6.1
'CE' is non-null
1
'CE' is non-null
 = dyn_cast<ConstantExpr>(C)) {
6
←
'C' is a 'ConstantExpr'→
7
←
Taking true branch→
  if (Constant *Res =
          ConstantFoldInstOperandsImpl(CE, CE->getOpcode(), Ops, DL, TLI))
8
←
Calling 'ConstantFoldInstOperandsImpl'→
    return Res;
  return const_cast<Constant *>(C);
}

assert(isa<ConstantVector>(C))(static_cast <bool> (isa<ConstantVector>(C)) ? void
 (0) : __assert_fail ("isa<ConstantVector>(C)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1149, __extension__ __PRETTY_FUNCTION__));
return ConstantVector::get(Ops);
1151}

1153} // end anonymous namespace

1155Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL,
                                      const TargetLibraryInfo *TLI) {
// Handle PHI nodes quickly here...
if (auto *PN = dyn_cast<PHINode>(I)) {
  Constant *CommonValue = nullptr;

  SmallDenseMap<Constant *, Constant *> FoldedOps;
  for (Value *Incoming : PN->incoming_values()) {
    // If the incoming value is undef then skip it.  Note that while we could
    // skip the value if it is equal to the phi node itself we choose not to
    // because that would break the rule that constant folding only applies if
    // all operands are constants.
    if (isa<UndefValue>(Incoming))
      continue;
    // If the incoming value is not a constant, then give up.
    auto *C = dyn_cast<Constant>(Incoming);
    if (!C)
      return nullptr;
    // Fold the PHI's operands.
    C = ConstantFoldConstantImpl(C, DL, TLI, FoldedOps);
    // If the incoming value is a different constant to
    // the one we saw previously, then give up.
    if (CommonValue && C != CommonValue)
      return nullptr;
    CommonValue = C;
  }

  // If we reach here, all incoming values are the same constant or undef.
  return CommonValue ? CommonValue : UndefValue::get(PN->getType());
}

// Scan the operand list, checking to see if they are all constants, if so,
// hand off to ConstantFoldInstOperandsImpl.
if (!all_of(I->operands(), [](Use &U) { return isa<Constant>(U); }))
  return nullptr;

SmallDenseMap<Constant *, Constant *> FoldedOps;
SmallVector<Constant *, 8> Ops;
for (const Use &OpU : I->operands()) {
  auto *Op = cast<Constant>(&OpU);
  // Fold the Instruction's operands.
  Op = ConstantFoldConstantImpl(Op, DL, TLI, FoldedOps);
  Ops.push_back(Op);
}

return ConstantFoldInstOperands(I, Ops, DL, TLI);
1201}

1203Constant *llvm::ConstantFoldConstant(const Constant *C, const DataLayout &DL,
                                   const TargetLibraryInfo *TLI) {
SmallDenseMap<Constant *, Constant *> FoldedOps;
return ConstantFoldConstantImpl(C, DL, TLI, FoldedOps);
1
Calling 'ConstantFoldConstantImpl'→
1207}

1209Constant *llvm::ConstantFoldInstOperands(Instruction *I,
                                       ArrayRef<Constant *> Ops,
                                       const DataLayout &DL,
                                       const TargetLibraryInfo *TLI) {
return ConstantFoldInstOperandsImpl(I, I->getOpcode(), Ops, DL, TLI);
1214}

1216Constant *llvm::ConstantFoldCompareInstOperands(
  unsigned IntPredicate, Constant *Ops0, Constant *Ops1, const DataLayout &DL,
  const TargetLibraryInfo *TLI, const Instruction *I) {
CmpInst::Predicate Predicate = (CmpInst::Predicate)IntPredicate;
// fold: icmp (inttoptr x), null         -> icmp x, 0
// fold: icmp null, (inttoptr x)         -> icmp 0, x
// fold: icmp (ptrtoint x), 0            -> icmp x, null
// fold: icmp 0, (ptrtoint x)            -> icmp null, x
// fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y
// fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y
//
// FIXME: The following comment is out of data and the DataLayout is here now.
// ConstantExpr::getCompare cannot do this, because it doesn't have DL
// around to know if bit truncation is happening.
if (auto *CE0 = dyn_cast<ConstantExpr>(Ops0)) {
  if (Ops1->isNullValue()) {
    if (CE0->getOpcode() == Instruction::IntToPtr) {
      Type *IntPtrTy = DL.getIntPtrType(CE0->getType());
      // Convert the integer value to the right size to ensure we get the
      // proper extension or truncation.
      Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0),
                                                 IntPtrTy, false);
      Constant *Null = Constant::getNullValue(C->getType());
      return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
    }

    // Only do this transformation if the int is intptrty in size, otherwise
    // there is a truncation or extension that we aren't modeling.
    if (CE0->getOpcode() == Instruction::PtrToInt) {
      Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
      if (CE0->getType() == IntPtrTy) {
        Constant *C = CE0->getOperand(0);
        Constant *Null = Constant::getNullValue(C->getType());
        return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI);
      }
    }
  }

  if (auto *CE1 = dyn_cast<ConstantExpr>(Ops1)) {
    if (CE0->getOpcode() == CE1->getOpcode()) {
      if (CE0->getOpcode() == Instruction::IntToPtr) {
        Type *IntPtrTy = DL.getIntPtrType(CE0->getType());

        // Convert the integer value to the right size to ensure we get the
        // proper extension or truncation.
        Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0),
                                                    IntPtrTy, false);
        Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0),
                                                    IntPtrTy, false);
        return ConstantFoldCompareInstOperands(Predicate, C0, C1, DL, TLI);
      }

      // Only do this transformation if the int is intptrty in size, otherwise
      // there is a truncation or extension that we aren't modeling.
      if (CE0->getOpcode() == Instruction::PtrToInt) {
        Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType());
        if (CE0->getType() == IntPtrTy &&
            CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) {
          return ConstantFoldCompareInstOperands(
              Predicate, CE0->getOperand(0), CE1->getOperand(0), DL, TLI);
        }
      }
    }
  }

  // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0)
  // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0)
  if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) &&
      CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) {
    Constant *LHS = ConstantFoldCompareInstOperands(
        Predicate, CE0->getOperand(0), Ops1, DL, TLI);
    Constant *RHS = ConstantFoldCompareInstOperands(
        Predicate, CE0->getOperand(1), Ops1, DL, TLI);
    unsigned OpC =
      Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or;
    return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL);
  }

  // Convert pointer comparison (base+offset1) pred (base+offset2) into
  // offset1 pred offset2, for the case where the offset is inbounds. This
  // only works for equality and unsigned comparison, as inbounds permits
  // crossing the sign boundary. However, the offset comparison itself is
  // signed.
  if (Ops0->getType()->isPointerTy() && !ICmpInst::isSigned(Predicate)) {
    unsigned IndexWidth = DL.getIndexTypeSizeInBits(Ops0->getType());
    APInt Offset0(IndexWidth, 0);
    Value *Stripped0 =
        Ops0->stripAndAccumulateInBoundsConstantOffsets(DL, Offset0);
    APInt Offset1(IndexWidth, 0);
    Value *Stripped1 =
        Ops1->stripAndAccumulateInBoundsConstantOffsets(DL, Offset1);
    if (Stripped0 == Stripped1)
      return ConstantExpr::getCompare(
          ICmpInst::getSignedPredicate(Predicate),
          ConstantInt::get(CE0->getContext(), Offset0),
          ConstantInt::get(CE0->getContext(), Offset1));
  }
} else if (isa<ConstantExpr>(Ops1)) {
  // If RHS is a constant expression, but the left side isn't, swap the
  // operands and try again.
  Predicate = ICmpInst::getSwappedPredicate(Predicate);
  return ConstantFoldCompareInstOperands(Predicate, Ops1, Ops0, DL, TLI);
}

// Flush any denormal constant float input according to denormal handling
// mode.
Ops0 = FlushFPConstant(Ops0, I, /* IsOutput */ false);
Ops1 = FlushFPConstant(Ops1, I, /* IsOutput */ false);

return ConstantExpr::getCompare(Predicate, Ops0, Ops1);
1326}

1328Constant *llvm::ConstantFoldUnaryOpOperand(unsigned Opcode, Constant *Op,
                                         const DataLayout &DL) {
assert(Instruction::isUnaryOp(Opcode))(static_cast <bool> (Instruction::isUnaryOp(Opcode)) ? void
 (0) : __assert_fail ("Instruction::isUnaryOp(Opcode)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1330, __extension__ __PRETTY_FUNCTION__));

return ConstantFoldUnaryInstruction(Opcode, Op);
1333}

1335Constant *llvm::ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS,
                                           Constant *RHS,
                                           const DataLayout &DL) {
assert(Instruction::isBinaryOp(Opcode))(static_cast <bool> (Instruction::isBinaryOp(Opcode)) ?
 void (0) : __assert_fail ("Instruction::isBinaryOp(Opcode)",
 "llvm/lib/Analysis/ConstantFolding.cpp", 1338, __extension__
 __PRETTY_FUNCTION__));
if (isa<ConstantExpr>(LHS) || isa<ConstantExpr>(RHS))
  if (Constant *C = SymbolicallyEvaluateBinop(Opcode, LHS, RHS, DL))
    return C;

if (ConstantExpr::isDesirableBinOp(Opcode))
  return ConstantExpr::get(Opcode, LHS, RHS);
return ConstantFoldBinaryInstruction(Opcode, LHS, RHS);
1346}

1348Constant *llvm::FlushFPConstant(Constant *Operand, const Instruction *I,
                              bool IsOutput) {
if (!I || !I->getParent() || !I->getFunction())
  return Operand;

ConstantFP *CFP = dyn_cast<ConstantFP>(Operand);
if (!CFP)
  return Operand;

const APFloat &APF = CFP->getValueAPF();
Type *Ty = CFP->getType();
DenormalMode DenormMode =
    I->getFunction()->getDenormalMode(Ty->getFltSemantics());
DenormalMode::DenormalModeKind Mode =
    IsOutput ? DenormMode.Output : DenormMode.Input;
switch (Mode) {
default:
  llvm_unreachable("unknown denormal mode")::llvm::llvm_unreachable_internal("unknown denormal mode", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1365);
  return Operand;
case DenormalMode::IEEE:
  return Operand;
case DenormalMode::PreserveSign:
  if (APF.isDenormal()) {
    return ConstantFP::get(
        Ty->getContext(),
        APFloat::getZero(Ty->getFltSemantics(), APF.isNegative()));
  }
  return Operand;
case DenormalMode::PositiveZero:
  if (APF.isDenormal()) {
    return ConstantFP::get(Ty->getContext(),
                           APFloat::getZero(Ty->getFltSemantics(), false));
  }
  return Operand;
}
return Operand;
1384}

1386Constant *llvm::ConstantFoldFPInstOperands(unsigned Opcode, Constant *LHS,
                                         Constant *RHS, const DataLayout &DL,
                                         const Instruction *I) {
if (Instruction::isBinaryOp(Opcode)) {
  // Flush denormal inputs if needed.
  Constant *Op0 = FlushFPConstant(LHS, I, /* IsOutput */ false);
  Constant *Op1 = FlushFPConstant(RHS, I, /* IsOutput */ false);

  // Calculate constant result.
  Constant *C = ConstantFoldBinaryOpOperands(Opcode, Op0, Op1, DL);
  if (!C)
    return nullptr;

  // Flush denormal output if needed.
  return FlushFPConstant(C, I, /* IsOutput */ true);
}
// If instruction lacks a parent/function and the denormal mode cannot be
// determined, use the default (IEEE).
return ConstantFoldBinaryOpOperands(Opcode, LHS, RHS, DL);
1405}

1407Constant *llvm::ConstantFoldCastOperand(unsigned Opcode, Constant *C,
                                      Type *DestTy, const DataLayout &DL) {
assert(Instruction::isCast(Opcode))(static_cast <bool> (Instruction::isCast(Opcode)) ? void
 (0) : __assert_fail ("Instruction::isCast(Opcode)", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1409, __extension__ __PRETTY_FUNCTION__));
switch (Opcode) {
default:
  llvm_unreachable("Missing case")::llvm::llvm_unreachable_internal("Missing case", "llvm/lib/Analysis/ConstantFolding.cpp"
, 1412);
case Instruction::PtrToInt:
  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
    Constant *FoldedValue = nullptr;
    // If the input is a inttoptr, eliminate the pair.  This requires knowing
    // the width of a pointer, so it can't be done in ConstantExpr::getCast.
    if (CE->getOpcode() == Instruction::IntToPtr) {
      // zext/trunc the inttoptr to pointer size.
      FoldedValue = ConstantExpr::getIntegerCast(
          CE->getOperand(0), DL.getIntPtrType(CE->getType()),
          /*IsSigned=*/false);
    } else if (auto *GEP = dyn_cast<GEPOperator>(CE)) {
      // If we have GEP, we can perform the following folds:
      // (ptrtoint (gep null, x)) -> x
      // (ptrtoint (gep (gep null, x), y) -> x + y, etc.
      unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType());
      APInt BaseOffset(BitWidth, 0);
      auto *Base = cast<Constant>(GEP->stripAndAccumulateConstantOffsets(
          DL, BaseOffset, /*AllowNonInbounds=*/true));
      if (Base->isNullValue()) {
        FoldedValue = ConstantInt::get(CE->getContext(), BaseOffset);
      } else {
        // ptrtoint (gep i8, Ptr, (sub 0, V)) -> sub (ptrtoint Ptr), V
        if (GEP->getNumIndices() == 1 &&
            GEP->getSourceElementType()->isIntegerTy(8)) {
          auto *Ptr = cast<Constant>(GEP->getPointerOperand());
          auto *Sub = dyn_cast<ConstantExpr>(GEP->getOperand(1));
          Type *IntIdxTy = DL.getIndexType(Ptr->getType());
          if (Sub && Sub->getType() == IntIdxTy &&
              Sub->getOpcode() == Instruction::Sub &&
              Sub->getOperand(0)->isNullValue())
            FoldedValue = ConstantExpr::getSub(
                ConstantExpr::getPtrToInt(Ptr, IntIdxTy), Sub->getOperand(1));
        }
      }
    }
    if (FoldedValue) {
      // Do a zext or trunc to get to the ptrtoint dest size.
      return ConstantExpr::getIntegerCast(FoldedValue, DestTy,
                                          /*IsSigned=*/false);
    }
  }
  return ConstantExpr::getCast(Opcode, C, DestTy);
case Instruction::IntToPtr:
  // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if
  // the int size is >= the ptr size and the address spaces are the same.
  // This requires knowing the width of a pointer, so it can't be done in
  // ConstantExpr::getCast.
  if (auto *CE = dyn_cast<ConstantExpr>(C)) {
    if (CE->getOpcode() == Instruction::PtrToInt) {
      Constant *SrcPtr = CE->getOperand(0);
      unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType());
      unsigned MidIntSize = CE->getType()->getScalarSizeInBits();

      if (MidIntSize >= SrcPtrSize) {
        unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace();
        if (SrcAS == DestTy->getPointerAddressSpace())
          return FoldBitCast(CE->getOperand(0), DestTy, DL);
      }
    }
  }

  return ConstantExpr::getCast(Opcode, C, DestTy);
case Instruction::Trunc:
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPTrunc:
case Instruction::FPExt:
case Instruction::UIToFP:
case Instruction::SIToFP:
case Instruction::FPToUI:
case Instruction::FPToSI:
case Instruction::AddrSpaceCast:
    return ConstantExpr::getCast(Opcode, C, DestTy);
case Instruction::BitCast:
  return FoldBitCast(C, DestTy, DL);
}
1489}

1491//===----------------------------------------------------------------------===//
1492//  Constant Folding for Calls
1493//

1495bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
if (Call->isNoBuiltin())
  return false;
if (Call->getFunctionType() != F->getFunctionType())
  return false;
switch (F->getIntrinsicID()) {
// Operations that do not operate floating-point numbers and do not depend on
// FP environment can be folded even in strictfp functions.
case Intrinsic::bswap:
case Intrinsic::ctpop:
case Intrinsic::ctlz:
case Intrinsic::cttz:
case Intrinsic::fshl:
case Intrinsic::fshr:
case Intrinsic::launder_invariant_group:
case Intrinsic::strip_invariant_group:
case Intrinsic::masked_load:
case Intrinsic::get_active_lane_mask:
case Intrinsic::abs:
case Intrinsic::smax:
case Intrinsic::smin:
case Intrinsic::umax:
case Intrinsic::umin:
case Intrinsic::sadd_with_overflow:
case Intrinsic::uadd_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::usub_with_overflow:
case Intrinsic::smul_with_overflow:
case Intrinsic::umul_with_overflow:
case Intrinsic::sadd_sat:
case Intrinsic::uadd_sat:
case Intrinsic::ssub_sat:
case Intrinsic::usub_sat:
case Intrinsic::smul_fix:
case Intrinsic::smul_fix_sat:
case Intrinsic::bitreverse:
case Intrinsic::is_constant:
case Intrinsic::vector_reduce_add:
case Intrinsic::vector_reduce_mul:
case Intrinsic::vector_reduce_and:
case Intrinsic::vector_reduce_or:
case Intrinsic::vector_reduce_xor:
case Intrinsic::vector_reduce_smin:
case Intrinsic::vector_reduce_smax:
case Intrinsic::vector_reduce_umin:
case Intrinsic::vector_reduce_umax:
// Target intrinsics
case Intrinsic::amdgcn_perm:
case Intrinsic::arm_mve_vctp8:
case Intrinsic::arm_mve_vctp16:
case Intrinsic::arm_mve_vctp32:
case Intrinsic::arm_mve_vctp64:
case Intrinsic::aarch64_sve_convert_from_svbool:
// WebAssembly float semantics are always known
case Intrinsic::wasm_trunc_signed:
case Intrinsic::wasm_trunc_unsigned:
  return true;

// Floating point operations cannot be folded in strictfp functions in
// general case. They can be folded if FP environment is known to compiler.
case Intrinsic::minnum:
case Intrinsic::maxnum:
case Intrinsic::minimum:
case Intrinsic::maximum:
case Intrinsic::log:
case Intrinsic::log2:
case Intrinsic::log10:
case Intrinsic::exp:
case Intrinsic::exp2:
case Intrinsic::sqrt:
case Intrinsic::sin:
case Intrinsic::cos:
case Intrinsic::pow:
case Intrinsic::powi:
case Intrinsic::fma:
case Intrinsic::fmuladd:
case Intrinsic::fptoui_sat:
case Intrinsic::fptosi_sat:
case Intrinsic::convert_from_fp16:
case Intrinsic::convert_to_fp16:
case Intrinsic::amdgcn_cos:
case Intrinsic::amdgcn_cubeid:
case Intrinsic::amdgcn_cubema:
case Intrinsic::amdgcn_cubesc:
case Intrinsic::amdgcn_cubetc:
case Intrinsic::amdgcn_fmul_legacy:
case Intrinsic::amdgcn_fma_legacy:
case Intrinsic::amdgcn_fract:
case Intrinsic::amdgcn_ldexp:
case Intrinsic::amdgcn_sin:
// The intrinsics below depend on rounding mode in MXCSR.
case Intrinsic::x86_sse_cvtss2si:
case Intrinsic::x86_sse_cvtss2si64:
case Intrinsic::x86_sse_cvttss2si:
case Intrinsic::x86_sse_cvttss2si64:
case Intrinsic::x86_sse2_cvtsd2si:
case Intrinsic::x86_sse2_cvtsd2si64:
case Intrinsic::x86_sse2_cvttsd2si:
case Intrinsic::x86_sse2_cvttsd2si64:
case Intrinsic::x86_avx512_vcvtss2si32:
case Intrinsic::x86_avx512_vcvtss2si64:
case Intrinsic::x86_avx512_cvttss2si:
case Intrinsic::x86_avx512_cvttss2si64:
case Intrinsic::x86_avx512_vcvtsd2si32:
case Intrinsic::x86_avx512_vcvtsd2si64:
case Intrinsic::x86_avx512_cvttsd2si:
case Intrinsic::x86_avx512_cvttsd2si64:
case Intrinsic::x86_avx512_vcvtss2usi32:
case Intrinsic::x86_avx512_vcvtss2usi64:
case Intrinsic::x86_avx512_cvttss2usi:
case Intrinsic::x86_avx512_cvttss2usi64:
case Intrinsic::x86_avx512_vcvtsd2usi32:
case Intrinsic::x86_avx512_vcvtsd2usi64:
case Intrinsic::x86_avx512_cvttsd2usi:
case Intrinsic::x86_avx512_cvttsd2usi64:
  return !Call->isStrictFP();

// Sign operations are actually bitwise operations, they do not raise
// exceptions even for SNANs.
case Intrinsic::fabs:
case Intrinsic::copysign:
case Intrinsic::is_fpclass:
// Non-constrained variants of rounding operations means default FP
// environment, they can be folded in any case.
case Intrinsic::ceil:
case Intrinsic::floor:
case Intrinsic::round:
case Intrinsic::roundeven:
case Intrinsic::trunc:
case Intrinsic::nearbyint:
case Intrinsic::rint:
case Intrinsic::canonicalize:
// Constrained intrinsics can be folded if FP environment is known
// to compiler.
case Intrinsic::experimental_constrained_fma:
case Intrinsic::experimental_constrained_fmuladd:
case Intrinsic::experimental_constrained_fadd:
case Intrinsic::experimental_constrained_fsub:
case Intrinsic::experimental_constrained_fmul:
case Intrinsic::experimental_constrained_fdiv:
case Intrinsic::experimental_constrained_frem:
case Intrinsic::experimental_constrained_ceil:
case Intrinsic::experimental_constrained_floor:
case Intrinsic::experimental_constrained_round:
case Intrinsic::experimental_constrained_roundeven:
case Intrinsic::experimental_constrained_trunc:
case Intrinsic::experimental_constrained_nearbyint:
case Intrinsic::experimental_constrained_rint:
case Intrinsic::experimental_constrained_fcmp:
case Intrinsic::experimental_constrained_fcmps:
  return true;
default:
  return false;
case Intrinsic::not_intrinsic: break;
}

if (!F->hasName() || Call->isStrictFP())
  return false;

// In these cases, the check of the length is required.  We don't want to
// return true for a name like "cos\0blah" which strcmp would return equal to
// "cos", but has length 8.
StringRef Name = F->getName();
switch (Name[0]) {
default:
  return false;
case 'a':
  return Name == "acos" || Name == "acosf" ||
         Name == "asin" || Name == "asinf" ||
         Name == "atan" || Name == "atanf" ||
         Name == "atan2" || Name == "atan2f";
case 'c':
  return Name == "ceil" || Name == "ceilf" ||
         Name == "cos" || Name == "cosf" ||
         Name == "cosh" || Name == "coshf";
case 'e':
  return Name == "exp" || Name == "expf" ||
         Name == "exp2" || Name == "exp2f";
case 'f':
  return Name == "fabs" || Name == "fabsf" ||
         Name == "floor" || Name == "floorf" ||
         Name == "fmod" || Name == "fmodf";
case 'l':
  return Name == "log" || Name == "logf" ||
         Name == "log2" || Name == "log2f" ||
         Name == "log10" || Name == "log10f";
case 'n':
  return Name == "nearbyint" || Name == "nearbyintf";
case 'p':
  return Name == "pow" || Name == "powf";
case 'r':
  return Name == "remainder" || Name == "remainderf" ||
         Name == "rint" || Name == "rintf" ||
         Name == "round" || Name == "roundf";
case 's':
  return Name == "sin" || Name == "sinf" ||
         Name == "sinh" || Name == "sinhf" ||
         Name == "sqrt" || Name == "sqrtf";
case 't':
  return Name == "tan" || Name == "tanf" ||
         Name == "tanh" || Name == "tanhf" ||
         Name == "trunc" || Name == "truncf";
case '_':
  // Check for various function names that get used for the math functions
  // when the header files are preprocessed with the macro
  // __FINITE_MATH_ONLY__ enabled.
  // The '12' here is the length of the shortest name that can match.
  // We need to check the size before looking at Name[1] and Name[2]
  // so we may as well check a limit that will eliminate mismatches.
  if (Name.size() < 12 || Name[1] != '_')
    return false;
  switch (Name[2]) {
  default:
    return false;
  case 'a':
    return Name == "__acos_finite" || Name == "__acosf_finite" ||
           Name == "__asin_finite" || Name == "__asinf_finite" ||
           Name == "__atan2_finite" || Name == "__atan2f_finite";
  case 'c':
    return Name == "__cosh_finite" || Name == "__coshf_finite";
  case 'e':
    return Name == "__exp_finite" || Name == "__expf_finite" ||
           Name == "__exp2_finite" || Name == "__exp2f_finite";
  case 'l':
    return Name == "__log_finite" || Name == "__logf_finite" ||
           Name == "__log10_finite" || Name == "__log10f_finite";
  case 'p':
    return Name == "__pow_finite" || Name == "__powf_finite";
  case 's':
    return Name == "__sinh_finite" || Name == "__sinhf_finite";
  }
}
1727}

1729namespace {

1731Constant *GetConstantFoldFPValue(double V, Type *Ty) {
if (Ty->isHalfTy() || Ty->isFloatTy()) {
  APFloat APF(V);
  bool unused;
  APF.convert(Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &unused);
  return ConstantFP::get(Ty->getContext(), APF);
}
if (Ty->isDoubleTy())
  return ConstantFP::get(Ty->getContext(), APFloat(V));
llvm_unreachable("Can only constant fold half/float/double")::llvm::llvm_unreachable_internal("Can only constant fold half/float/double"
, "llvm/lib/Analysis/ConstantFolding.cpp", 1740);
1741}

1743/// Clear the floating-point exception state.
1744inline void llvm_fenv_clearexcept() {
1745#if defined(HAVE_FENV_H1) && HAVE_DECL_FE_ALL_EXCEPT1
feclearexcept(FE_ALL_EXCEPT(0x20 | 0x04 | 0x10 | 0x08 | 0x01));
1747#endif
errno(*__errno_location ()) = 0;
1749}

1751/// Test if a floating-point exception was raised.
1752inline bool llvm_fenv_testexcept() {
int errno_val = errno(*__errno_location ());
if (errno_val == ERANGE34 || errno_val == EDOM33)
  return true;
1756#if defined(HAVE_FENV_H1) && HAVE_DECL_FE_ALL_EXCEPT1 && HAVE_DECL_FE_INEXACT1
if (fetestexcept(FE_ALL_EXCEPT(0x20 | 0x04 | 0x10 | 0x08 | 0x01) & ~FE_INEXACT0x20))
  return true;
1759#endif
return false;
1761}

1763Constant *ConstantFoldFP(double (*NativeFP)(double), const APFloat &V,
                       Type *Ty) {
llvm_fenv_clearexcept();
double Result = NativeFP(V.convertToDouble());
if (llvm_fenv_testexcept()) {
  llvm_fenv_clearexcept();
  return nullptr;
}

return GetConstantFoldFPValue(Result, Ty);
1773}

1775Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double),
                             const APFloat &V, const APFloat &W, Type *Ty) {
llvm_fenv_clearexcept();
double Result = NativeFP(V.convertToDouble(), W.convertToDouble());
if (llvm_fenv_testexcept()) {
  llvm_fenv_clearexcept();
  return nullptr;
}

return GetConstantFoldFPValue(Result, Ty);
1785}

1787Constant *constantFoldVectorReduce(Intrinsic::ID IID, Constant *Op) {
FixedVectorType *VT = dyn_cast<FixedVectorType>(Op->getType());
if (!VT)
  return nullptr;

// This isn't strictly necessary, but handle the special/common case of zero:
// all integer reductions of a zero input produce zero.
if (isa<ConstantAggregateZero>(Op))
  return ConstantInt::get(VT->getElementType(), 0);

// This is the same as the underlying binops - poison propagates.
if (isa<PoisonValue>(Op) || Op->containsPoisonElement())
  return PoisonValue::get(VT->getElementType());

// TODO: Handle undef.
if (!isa<ConstantVector>(Op) && !isa<ConstantDataVector>(Op))
  return nullptr;

auto *EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(0U));
if (!EltC)
  return nullptr;

APInt Acc = EltC->getValue();
for (unsigned I = 1, E = VT->getNumElements(); I != E; I++) {
  if (!(EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(I))))
    return nullptr;
  const APInt &X = EltC->getValue();
  switch (IID) {
  case Intrinsic::vector_reduce_add:
    Acc = Acc + X;
    break;
  case Intrinsic::vector_reduce_mul:
    Acc = Acc * X;
    break;
  case Intrinsic::vector_reduce_and:
    Acc = Acc & X;
    break;
  case Intrinsic::vector_reduce_or:
    Acc = Acc | X;
    break;
  case Intrinsic::vector_reduce_xor:
    Acc = Acc ^ X;
    break;
  case Intrinsic::vector_reduce_smin:
    Acc = APIntOps::smin(Acc, X);
    break;
  case Intrinsic::vector_reduce_smax:
    Acc = APIntOps::smax(Acc, X);
    break;
  case Intrinsic::vector_reduce_umin:
    Acc = APIntOps::umin(Acc, X);
    break;
  case Intrinsic::vector_reduce_umax:
    Acc = APIntOps::umax(Acc, X);
    break;
  }
}

return ConstantInt::get(Op->getContext(), Acc);
1846}

1848/// Attempt to fold an SSE floating point to integer conversion of a constant
1849/// floating point. If roundTowardZero is false, the default IEEE rounding is
1850/// used (toward nearest, ties to even). This matches the behavior of the
1851/// non-truncating SSE instructions in the default rounding mode. The desired
1852/// integer type Ty is used to select how many bits are available for the
1853/// result. Returns null if the conversion cannot be performed, otherwise
1854/// returns the Constant value resulting from the conversion.
1855Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero,
                                    Type *Ty, bool IsSigned) {
// All of these conversion intrinsics form an integer of at most 64bits.
unsigned ResultWidth = Ty->getIntegerBitWidth();
assert(ResultWidth <= 64 &&(static_cast <bool> (ResultWidth <= 64 && "Can only constant fold conversions to 64 and 32 bit ints"
) ? void (0) : __assert_fail ("ResultWidth <= 64 && \"Can only constant fold conversions to 64 and 32 bit ints\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1860, __extension__
 __PRETTY_FUNCTION__))
       "Can only constant fold conversions to 64 and 32 bit ints")(static_cast <bool> (ResultWidth <= 64 && "Can only constant fold conversions to 64 and 32 bit ints"
) ? void (0) : __assert_fail ("ResultWidth <= 64 && \"Can only constant fold conversions to 64 and 32 bit ints\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1860, __extension__
 __PRETTY_FUNCTION__));

uint64_t UIntVal;
bool isExact = false;
APFloat::roundingMode mode = roundTowardZero? APFloat::rmTowardZero
                                            : APFloat::rmNearestTiesToEven;
APFloat::opStatus status =
    Val.convertToInteger(MutableArrayRef(UIntVal), ResultWidth,
                         IsSigned, mode, &isExact);
if (status != APFloat::opOK &&
    (!roundTowardZero || status != APFloat::opInexact))
  return nullptr;
return ConstantInt::get(Ty, UIntVal, IsSigned);
1873}

1875double getValueAsDouble(ConstantFP *Op) {
Type *Ty = Op->getType();

if (Ty->isBFloatTy() || Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy())
  return Op->getValueAPF().convertToDouble();

bool unused;
APFloat APF = Op->getValueAPF();
APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &unused);
return APF.convertToDouble();
1885}

1887static bool getConstIntOrUndef(Value *Op, const APInt *&C) {
if (auto *CI = dyn_cast<ConstantInt>(Op)) {
  C = &CI->getValue();
  return true;
}
if (isa<UndefValue>(Op)) {
  C = nullptr;
  return true;
}
return false;
1897}

1899/// Checks if the given intrinsic call, which evaluates to constant, is allowed
1900/// to be folded.
1901///
1902/// \param CI Constrained intrinsic call.
1903/// \param St Exception flags raised during constant evaluation.
1904static bool mayFoldConstrained(ConstrainedFPIntrinsic *CI,
                             APFloat::opStatus St) {
std::optional<RoundingMode> ORM = CI->getRoundingMode();
std::optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();

// If the operation does not change exception status flags, it is safe
// to fold.
if (St == APFloat::opStatus::opOK)
  return true;

// If evaluation raised FP exception, the result can depend on rounding
// mode. If the latter is unknown, folding is not possible.
if (ORM && *ORM == RoundingMode::Dynamic)
  return false;

// If FP exceptions are ignored, fold the call, even if such exception is
// raised.
if (EB && *EB != fp::ExceptionBehavior::ebStrict)
  return true;

// Leave the calculation for runtime so that exception flags be correctly set
// in hardware.
return false;
1927}

1929/// Returns the rounding mode that should be used for constant evaluation.
1930static RoundingMode
1931getEvaluationRoundingMode(const ConstrainedFPIntrinsic *CI) {
std::optional<RoundingMode> ORM = CI->getRoundingMode();
if (!ORM || *ORM == RoundingMode::Dynamic)
  // Even if the rounding mode is unknown, try evaluating the operation.
  // If it does not raise inexact exception, rounding was not applied,
  // so the result is exact and does not depend on rounding mode. Whether
  // other FP exceptions are raised, it does not depend on rounding mode.
  return RoundingMode::NearestTiesToEven;
return *ORM;
1940}

1942/// Try to constant fold llvm.canonicalize for the given caller and value.
1943static Constant *constantFoldCanonicalize(const Type *Ty, const CallBase *CI,
                                        const APFloat &Src) {
// Zero, positive and negative, is always OK to fold.
if (Src.isZero()) {
  // Get a fresh 0, since ppc_fp128 does have non-canonical zeros.
  return ConstantFP::get(
      CI->getContext(),
      APFloat::getZero(Src.getSemantics(), Src.isNegative()));
}

if (!Ty->isIEEELikeFPTy())
  return nullptr;

// Zero is always canonical and the sign must be preserved.
//
// Denorms and nans may have special encodings, but it should be OK to fold a
// totally average number.
if (Src.isNormal() || Src.isInfinity())
  return ConstantFP::get(CI->getContext(), Src);

if (Src.isDenormal() && CI->getParent() && CI->getFunction()) {
  DenormalMode DenormMode =
      CI->getFunction()->getDenormalMode(Src.getSemantics());
  if (DenormMode == DenormalMode::getIEEE())
    return nullptr;

  bool IsPositive =
      (!Src.isNegative() || DenormMode.Input == DenormalMode::PositiveZero ||
       (DenormMode.Output == DenormalMode::PositiveZero &&
        DenormMode.Input == DenormalMode::IEEE));
  return ConstantFP::get(CI->getContext(),
                         APFloat::getZero(Src.getSemantics(), !IsPositive));
}

return nullptr;
1978}

1980static Constant *ConstantFoldScalarCall1(StringRef Name,
                                       Intrinsic::ID IntrinsicID,
                                       Type *Ty,
                                       ArrayRef<Constant *> Operands,
                                       const TargetLibraryInfo *TLI,
                                       const CallBase *Call) {
assert(Operands.size() == 1 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 1 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 1 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 1986, __extension__
 __PRETTY_FUNCTION__));

if (IntrinsicID == Intrinsic::is_constant) {
  // We know we have a "Constant" argument. But we want to only
  // return true for manifest constants, not those that depend on
  // constants with unknowable values, e.g. GlobalValue or BlockAddress.
  if (Operands[0]->isManifestConstant())
    return ConstantInt::getTrue(Ty->getContext());
  return nullptr;
}

if (isa<PoisonValue>(Operands[0])) {
  // TODO: All of these operations should probably propagate poison.
  if (IntrinsicID == Intrinsic::canonicalize)
    return PoisonValue::get(Ty);
}

if (isa<UndefValue>(Operands[0])) {
  // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN.
  // ctpop() is between 0 and bitwidth, pick 0 for undef.
  // fptoui.sat and fptosi.sat can always fold to zero (for a zero input).
  if (IntrinsicID == Intrinsic::cos ||
      IntrinsicID == Intrinsic::ctpop ||
      IntrinsicID == Intrinsic::fptoui_sat ||
      IntrinsicID == Intrinsic::fptosi_sat ||
      IntrinsicID == Intrinsic::canonicalize)
    return Constant::getNullValue(Ty);
  if (IntrinsicID == Intrinsic::bswap ||
      IntrinsicID == Intrinsic::bitreverse ||
      IntrinsicID == Intrinsic::launder_invariant_group ||
      IntrinsicID == Intrinsic::strip_invariant_group)
    return Operands[0];
}

if (isa<ConstantPointerNull>(Operands[0])) {
  // launder(null) == null == strip(null) iff in addrspace 0
  if (IntrinsicID == Intrinsic::launder_invariant_group ||
      IntrinsicID == Intrinsic::strip_invariant_group) {
    // If instruction is not yet put in a basic block (e.g. when cloning
    // a function during inlining), Call's caller may not be available.
    // So check Call's BB first before querying Call->getCaller.
    const Function *Caller =
        Call->getParent() ? Call->getCaller() : nullptr;
    if (Caller &&
        !NullPointerIsDefined(
            Caller, Operands[0]->getType()->getPointerAddressSpace())) {
      return Operands[0];
    }
    return nullptr;
  }
}

if (auto *Op = dyn_cast<ConstantFP>(Operands[0])) {
  if (IntrinsicID == Intrinsic::convert_to_fp16) {
    APFloat Val(Op->getValueAPF());

    bool lost = false;
    Val.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &lost);

    return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt());
  }

  APFloat U = Op->getValueAPF();

  if (IntrinsicID == Intrinsic::wasm_trunc_signed ||
      IntrinsicID == Intrinsic::wasm_trunc_unsigned) {
    bool Signed = IntrinsicID == Intrinsic::wasm_trunc_signed;

    if (U.isNaN())
      return nullptr;

    unsigned Width = Ty->getIntegerBitWidth();
    APSInt Int(Width, !Signed);
    bool IsExact = false;
    APFloat::opStatus Status =
        U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact);

    if (Status == APFloat::opOK || Status == APFloat::opInexact)
      return ConstantInt::get(Ty, Int);

    return nullptr;
  }

  if (IntrinsicID == Intrinsic::fptoui_sat ||
      IntrinsicID == Intrinsic::fptosi_sat) {
    // convertToInteger() already has the desired saturation semantics.
    APSInt Int(Ty->getIntegerBitWidth(),
               IntrinsicID == Intrinsic::fptoui_sat);
    bool IsExact;
    U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact);
    return ConstantInt::get(Ty, Int);
  }

  if (IntrinsicID == Intrinsic::canonicalize)
    return constantFoldCanonicalize(Ty, Call, U);

  if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
    return nullptr;

  // Use internal versions of these intrinsics.

  if (IntrinsicID == Intrinsic::nearbyint || IntrinsicID == Intrinsic::rint) {
    U.roundToIntegral(APFloat::rmNearestTiesToEven);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::round) {
    U.roundToIntegral(APFloat::rmNearestTiesToAway);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::roundeven) {
    U.roundToIntegral(APFloat::rmNearestTiesToEven);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::ceil) {
    U.roundToIntegral(APFloat::rmTowardPositive);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::floor) {
    U.roundToIntegral(APFloat::rmTowardNegative);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::trunc) {
    U.roundToIntegral(APFloat::rmTowardZero);
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::fabs) {
    U.clearSign();
    return ConstantFP::get(Ty->getContext(), U);
  }

  if (IntrinsicID == Intrinsic::amdgcn_fract) {
    // The v_fract instruction behaves like the OpenCL spec, which defines
    // fract(x) as fmin(x - floor(x), 0x1.fffffep-1f): "The min() operator is
    //   there to prevent fract(-small) from returning 1.0. It returns the
    //   largest positive floating-point number less than 1.0."
    APFloat FloorU(U);
    FloorU.roundToIntegral(APFloat::rmTowardNegative);
    APFloat FractU(U - FloorU);
    APFloat AlmostOne(U.getSemantics(), 1);
    AlmostOne.next(/*nextDown*/ true);
    return ConstantFP::get(Ty->getContext(), minimum(FractU, AlmostOne));
  }

  // Rounding operations (floor, trunc, ceil, round and nearbyint) do not
  // raise FP exceptions, unless the argument is signaling NaN.

  std::optional<APFloat::roundingMode> RM;
  switch (IntrinsicID) {
  default:
    break;
  case Intrinsic::experimental_constrained_nearbyint:
  case Intrinsic::experimental_constrained_rint: {
    auto CI = cast<ConstrainedFPIntrinsic>(Call);
    RM = CI->getRoundingMode();
    if (!RM || *RM == RoundingMode::Dynamic)
      return nullptr;
    break;
  }
  case Intrinsic::experimental_constrained_round:
    RM = APFloat::rmNearestTiesToAway;
    break;
  case Intrinsic::experimental_constrained_ceil:
    RM = APFloat::rmTowardPositive;
    break;
  case Intrinsic::experimental_constrained_floor:
    RM = APFloat::rmTowardNegative;
    break;
  case Intrinsic::experimental_constrained_trunc:
    RM = APFloat::rmTowardZero;
    break;
  }
  if (RM) {
    auto CI = cast<ConstrainedFPIntrinsic>(Call);
    if (U.isFinite()) {
      APFloat::opStatus St = U.roundToIntegral(*RM);
      if (IntrinsicID == Intrinsic::experimental_constrained_rint &&
          St == APFloat::opInexact) {
        std::optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();
        if (EB && *EB == fp::ebStrict)
          return nullptr;
      }
    } else if (U.isSignaling()) {
      std::optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior();
      if (EB && *EB != fp::ebIgnore)
        return nullptr;
      U = APFloat::getQNaN(U.getSemantics());
    }
    return ConstantFP::get(Ty->getContext(), U);
  }

  /// We only fold functions with finite arguments. Folding NaN and inf is
  /// likely to be aborted with an exception anyway, and some host libms
  /// have known errors raising exceptions.
  if (!U.isFinite())
    return nullptr;

  /// Currently APFloat versions of these functions do not exist, so we use
  /// the host native double versions.  Float versions are not called
  /// directly but for all these it is true (float)(f((double)arg)) ==
  /// f(arg).  Long double not supported yet.
  const APFloat &APF = Op->getValueAPF();

  switch (IntrinsicID) {
    default: break;
    case Intrinsic::log:
      return ConstantFoldFP(log, APF, Ty);
    case Intrinsic::log2:
      // TODO: What about hosts that lack a C99 library?
      return ConstantFoldFP(log2, APF, Ty);
    case Intrinsic::log10:
      // TODO: What about hosts that lack a C99 library?
      return ConstantFoldFP(log10, APF, Ty);
    case Intrinsic::exp:
      return ConstantFoldFP(exp, APF, Ty);
    case Intrinsic::exp2:
      // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library.
      return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty);
    case Intrinsic::sin:
      return ConstantFoldFP(sin, APF, Ty);
    case Intrinsic::cos:
      return ConstantFoldFP(cos, APF, Ty);
    case Intrinsic::sqrt:
      return ConstantFoldFP(sqrt, APF, Ty);
    case Intrinsic::amdgcn_cos:
    case Intrinsic::amdgcn_sin: {
      double V = getValueAsDouble(Op);
      if (V < -256.0 || V > 256.0)
        // The gfx8 and gfx9 architectures handle arguments outside the range
        // [-256, 256] differently. This should be a rare case so bail out
        // rather than trying to handle the difference.
        return nullptr;
      bool IsCos = IntrinsicID == Intrinsic::amdgcn_cos;
      double V4 = V * 4.0;
      if (V4 == floor(V4)) {
        // Force exact results for quarter-integer inputs.
        const double SinVals[4] = { 0.0, 1.0, 0.0, -1.0 };
        V = SinVals[((int)V4 + (IsCos ? 1 : 0)) & 3];
      } else {
        if (IsCos)
          V = cos(V * 2.0 * numbers::pi);
        else
          V = sin(V * 2.0 * numbers::pi);
      }
      return GetConstantFoldFPValue(V, Ty);
    }
  }

  if (!TLI)
    return nullptr;

  LibFunc Func = NotLibFunc;
  if (!TLI->getLibFunc(Name, Func))
    return nullptr;

  switch (Func) {
  default:
    break;
  case LibFunc_acos:
  case LibFunc_acosf:
  case LibFunc_acos_finite:
  case LibFunc_acosf_finite:
    if (TLI->has(Func))
      return ConstantFoldFP(acos, APF, Ty);
    break;
  case LibFunc_asin:
  case LibFunc_asinf:
  case LibFunc_asin_finite:
  case LibFunc_asinf_finite:
    if (TLI->has(Func))
      return ConstantFoldFP(asin, APF, Ty);
    break;
  case LibFunc_atan:
  case LibFunc_atanf:
    if (TLI->has(Func))
      return ConstantFoldFP(atan, APF, Ty);
    break;
  case LibFunc_ceil:
  case LibFunc_ceilf:
    if (TLI->has(Func)) {
      U.roundToIntegral(APFloat::rmTowardPositive);
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  case LibFunc_cos:
  case LibFunc_cosf:
    if (TLI->has(Func))
      return ConstantFoldFP(cos, APF, Ty);
    break;
  case LibFunc_cosh:
  case LibFunc_coshf:
  case LibFunc_cosh_finite:
  case LibFunc_coshf_finite:
    if (TLI->has(Func))
      return ConstantFoldFP(cosh, APF, Ty);
    break;
  case LibFunc_exp:
  case LibFunc_expf:
  case LibFunc_exp_finite:
  case LibFunc_expf_finite:
    if (TLI->has(Func))
      return ConstantFoldFP(exp, APF, Ty);
    break;
  case LibFunc_exp2:
  case LibFunc_exp2f:
  case LibFunc_exp2_finite:
  case LibFunc_exp2f_finite:
    if (TLI->has(Func))
      // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library.
      return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty);
    break;
  case LibFunc_fabs:
  case LibFunc_fabsf:
    if (TLI->has(Func)) {
      U.clearSign();
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  case LibFunc_floor:
  case LibFunc_floorf:
    if (TLI->has(Func)) {
      U.roundToIntegral(APFloat::rmTowardNegative);
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  case LibFunc_log:
  case LibFunc_logf:
  case LibFunc_log_finite:
  case LibFunc_logf_finite:
    if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
      return ConstantFoldFP(log, APF, Ty);
    break;
  case LibFunc_log2:
  case LibFunc_log2f:
  case LibFunc_log2_finite:
  case LibFunc_log2f_finite:
    if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
      // TODO: What about hosts that lack a C99 library?
      return ConstantFoldFP(log2, APF, Ty);
    break;
  case LibFunc_log10:
  case LibFunc_log10f:
  case LibFunc_log10_finite:
  case LibFunc_log10f_finite:
    if (!APF.isNegative() && !APF.isZero() && TLI->has(Func))
      // TODO: What about hosts that lack a C99 library?
      return ConstantFoldFP(log10, APF, Ty);
    break;
  case LibFunc_nearbyint:
  case LibFunc_nearbyintf:
  case LibFunc_rint:
  case LibFunc_rintf:
    if (TLI->has(Func)) {
      U.roundToIntegral(APFloat::rmNearestTiesToEven);
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  case LibFunc_round:
  case LibFunc_roundf:
    if (TLI->has(Func)) {
      U.roundToIntegral(APFloat::rmNearestTiesToAway);
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  case LibFunc_sin:
  case LibFunc_sinf:
    if (TLI->has(Func))
      return ConstantFoldFP(sin, APF, Ty);
    break;
  case LibFunc_sinh:
  case LibFunc_sinhf:
  case LibFunc_sinh_finite:
  case LibFunc_sinhf_finite:
    if (TLI->has(Func))
      return ConstantFoldFP(sinh, APF, Ty);
    break;
  case LibFunc_sqrt:
  case LibFunc_sqrtf:
    if (!APF.isNegative() && TLI->has(Func))
      return ConstantFoldFP(sqrt, APF, Ty);
    break;
  case LibFunc_tan:
  case LibFunc_tanf:
    if (TLI->has(Func))
      return ConstantFoldFP(tan, APF, Ty);
    break;
  case LibFunc_tanh:
  case LibFunc_tanhf:
    if (TLI->has(Func))
      return ConstantFoldFP(tanh, APF, Ty);
    break;
  case LibFunc_trunc:
  case LibFunc_truncf:
    if (TLI->has(Func)) {
      U.roundToIntegral(APFloat::rmTowardZero);
      return ConstantFP::get(Ty->getContext(), U);
    }
    break;
  }
  return nullptr;
}

if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
  switch (IntrinsicID) {
  case Intrinsic::bswap:
    return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap());
  case Intrinsic::ctpop:
    return ConstantInt::get(Ty, Op->getValue().popcount());
  case Intrinsic::bitreverse:
    return ConstantInt::get(Ty->getContext(), Op->getValue().reverseBits());
  case Intrinsic::convert_from_fp16: {
    APFloat Val(APFloat::IEEEhalf(), Op->getValue());

    bool lost = false;
    APFloat::opStatus status = Val.convert(
        Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &lost);

    // Conversion is always precise.
    (void)status;
    assert(status != APFloat::opInexact && !lost &&(static_cast <bool> (status != APFloat::opInexact &&
 !lost && "Precision lost during fp16 constfolding") ?
 void (0) : __assert_fail ("status != APFloat::opInexact && !lost && \"Precision lost during fp16 constfolding\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2411, __extension__
 __PRETTY_FUNCTION__))
           "Precision lost during fp16 constfolding")(static_cast <bool> (status != APFloat::opInexact &&
 !lost && "Precision lost during fp16 constfolding") ?
 void (0) : __assert_fail ("status != APFloat::opInexact && !lost && \"Precision lost during fp16 constfolding\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2411, __extension__
 __PRETTY_FUNCTION__));

    return ConstantFP::get(Ty->getContext(), Val);
  }
  default:
    return nullptr;
  }
}

switch (IntrinsicID) {
default: break;
case Intrinsic::vector_reduce_add:
case Intrinsic::vector_reduce_mul:
case Intrinsic::vector_reduce_and:
case Intrinsic::vector_reduce_or:
case Intrinsic::vector_reduce_xor:
case Intrinsic::vector_reduce_smin:
case Intrinsic::vector_reduce_smax:
case Intrinsic::vector_reduce_umin:
case Intrinsic::vector_reduce_umax:
  if (Constant *C = constantFoldVectorReduce(IntrinsicID, Operands[0]))
    return C;
  break;
}

// Support ConstantVector in case we have an Undef in the top.
if (isa<ConstantVector>(Operands[0]) ||
    isa<ConstantDataVector>(Operands[0])) {
  auto *Op = cast<Constant>(Operands[0]);
  switch (IntrinsicID) {
  default: break;
  case Intrinsic::x86_sse_cvtss2si:
  case Intrinsic::x86_sse_cvtss2si64:
  case Intrinsic::x86_sse2_cvtsd2si:
  case Intrinsic::x86_sse2_cvtsd2si64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/false, Ty,
                                         /*IsSigned*/true);
    break;
  case Intrinsic::x86_sse_cvttss2si:
  case Intrinsic::x86_sse_cvttss2si64:
  case Intrinsic::x86_sse2_cvttsd2si:
  case Intrinsic::x86_sse2_cvttsd2si64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/true, Ty,
                                         /*IsSigned*/true);
    break;
  }
}

return nullptr;
2466}

2468static Constant *evaluateCompare(const APFloat &Op1, const APFloat &Op2,
                               const ConstrainedFPIntrinsic *Call) {
APFloat::opStatus St = APFloat::opOK;
auto *FCmp = cast<ConstrainedFPCmpIntrinsic>(Call);
FCmpInst::Predicate Cond = FCmp->getPredicate();
if (FCmp->isSignaling()) {
  if (Op1.isNaN() || Op2.isNaN())
    St = APFloat::opInvalidOp;
} else {
  if (Op1.isSignaling() || Op2.isSignaling())
    St = APFloat::opInvalidOp;
}
bool Result = FCmpInst::compare(Op1, Op2, Cond);
if (mayFoldConstrained(const_cast<ConstrainedFPCmpIntrinsic *>(FCmp), St))
  return ConstantInt::get(Call->getType()->getScalarType(), Result);
return nullptr;
2484}

2486static Constant *ConstantFoldScalarCall2(StringRef Name,
                                       Intrinsic::ID IntrinsicID,
                                       Type *Ty,
                                       ArrayRef<Constant *> Operands,
                                       const TargetLibraryInfo *TLI,
                                       const CallBase *Call) {
assert(Operands.size() == 2 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 2 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 2 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2492, __extension__
 __PRETTY_FUNCTION__));

if (Ty->isFloatingPointTy()) {
  // TODO: We should have undef handling for all of the FP intrinsics that
  //       are attempted to be folded in this function.
  bool IsOp0Undef = isa<UndefValue>(Operands[0]);
  bool IsOp1Undef = isa<UndefValue>(Operands[1]);
  switch (IntrinsicID) {
  case Intrinsic::maxnum:
  case Intrinsic::minnum:
  case Intrinsic::maximum:
  case Intrinsic::minimum:
    // If one argument is undef, return the other argument.
    if (IsOp0Undef)
      return Operands[1];
    if (IsOp1Undef)
      return Operands[0];
    break;
  }
}

if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
  const APFloat &Op1V = Op1->getValueAPF();

  if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
    if (Op2->getType() != Op1->getType())
      return nullptr;
    const APFloat &Op2V = Op2->getValueAPF();

    if (const auto *ConstrIntr = dyn_cast<ConstrainedFPIntrinsic>(Call)) {
      RoundingMode RM = getEvaluationRoundingMode(ConstrIntr);
      APFloat Res = Op1V;
      APFloat::opStatus St;
      switch (IntrinsicID) {
      default:
        return nullptr;
      case Intrinsic::experimental_constrained_fadd:
        St = Res.add(Op2V, RM);
        break;
      case Intrinsic::experimental_constrained_fsub:
        St = Res.subtract(Op2V, RM);
        break;
      case Intrinsic::experimental_constrained_fmul:
        St = Res.multiply(Op2V, RM);
        break;
      case Intrinsic::experimental_constrained_fdiv:
        St = Res.divide(Op2V, RM);
        break;
      case Intrinsic::experimental_constrained_frem:
        St = Res.mod(Op2V);
        break;
      case Intrinsic::experimental_constrained_fcmp:
      case Intrinsic::experimental_constrained_fcmps:
        return evaluateCompare(Op1V, Op2V, ConstrIntr);
      }
      if (mayFoldConstrained(const_cast<ConstrainedFPIntrinsic *>(ConstrIntr),
                             St))
        return ConstantFP::get(Ty->getContext(), Res);
      return nullptr;
    }

    switch (IntrinsicID) {
    default:
      break;
    case Intrinsic::copysign:
      return ConstantFP::get(Ty->getContext(), APFloat::copySign(Op1V, Op2V));
    case Intrinsic::minnum:
      return ConstantFP::get(Ty->getContext(), minnum(Op1V, Op2V));
    case Intrinsic::maxnum:
      return ConstantFP::get(Ty->getContext(), maxnum(Op1V, Op2V));
    case Intrinsic::minimum:
      return ConstantFP::get(Ty->getContext(), minimum(Op1V, Op2V));
    case Intrinsic::maximum:
      return ConstantFP::get(Ty->getContext(), maximum(Op1V, Op2V));
    }

    if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
      return nullptr;

    switch (IntrinsicID) {
    default:
      break;
    case Intrinsic::pow:
      return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
    case Intrinsic::amdgcn_fmul_legacy:
      // The legacy behaviour is that multiplying +/- 0.0 by anything, even
      // NaN or infinity, gives +0.0.
      if (Op1V.isZero() || Op2V.isZero())
        return ConstantFP::getNullValue(Ty);
      return ConstantFP::get(Ty->getContext(), Op1V * Op2V);
    }

    if (!TLI)
      return nullptr;

    LibFunc Func = NotLibFunc;
    if (!TLI->getLibFunc(Name, Func))
      return nullptr;

    switch (Func) {
    default:
      break;
    case LibFunc_pow:
    case LibFunc_powf:
    case LibFunc_pow_finite:
    case LibFunc_powf_finite:
      if (TLI->has(Func))
        return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
      break;
    case LibFunc_fmod:
    case LibFunc_fmodf:
      if (TLI->has(Func)) {
        APFloat V = Op1->getValueAPF();
        if (APFloat::opStatus::opOK == V.mod(Op2->getValueAPF()))
          return ConstantFP::get(Ty->getContext(), V);
      }
      break;
    case LibFunc_remainder:
    case LibFunc_remainderf:
      if (TLI->has(Func)) {
        APFloat V = Op1->getValueAPF();
        if (APFloat::opStatus::opOK == V.remainder(Op2->getValueAPF()))
          return ConstantFP::get(Ty->getContext(), V);
      }
      break;
    case LibFunc_atan2:
    case LibFunc_atan2f:
      // atan2(+/-0.0, +/-0.0) is known to raise an exception on some libm
      // (Solaris), so we do not assume a known result for that.
      if (Op1V.isZero() && Op2V.isZero())
        return nullptr;
      [[fallthrough]];
    case LibFunc_atan2_finite:
    case LibFunc_atan2f_finite:
      if (TLI->has(Func))
        return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty);
      break;
    }
  } else if (auto *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
    switch (IntrinsicID) {
    case Intrinsic::is_fpclass: {
      uint32_t Mask = Op2C->getZExtValue();
      bool Result =
        ((Mask & fcSNan) && Op1V.isNaN() && Op1V.isSignaling()) ||
        ((Mask & fcQNan) && Op1V.isNaN() && !Op1V.isSignaling()) ||
        ((Mask & fcNegInf) && Op1V.isInfinity() && Op1V.isNegative()) ||
        ((Mask & fcNegNormal) && Op1V.isNormal() && Op1V.isNegative()) ||
        ((Mask & fcNegSubnormal) && Op1V.isDenormal() && Op1V.isNegative()) ||
        ((Mask & fcNegZero) && Op1V.isZero() && Op1V.isNegative()) ||
        ((Mask & fcPosZero) && Op1V.isZero() && !Op1V.isNegative()) ||
        ((Mask & fcPosSubnormal) && Op1V.isDenormal() && !Op1V.isNegative()) ||
        ((Mask & fcPosNormal) && Op1V.isNormal() && !Op1V.isNegative()) ||
        ((Mask & fcPosInf) && Op1V.isInfinity() && !Op1V.isNegative());
      return ConstantInt::get(Ty, Result);
    }
    default:
      break;
    }

    if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
      return nullptr;
    if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy())
      return ConstantFP::get(
          Ty->getContext(),
          APFloat((float)std::pow((float)Op1V.convertToDouble(),
                                  (int)Op2C->getZExtValue())));
    if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy())
      return ConstantFP::get(
          Ty->getContext(),
          APFloat((float)std::pow((float)Op1V.convertToDouble(),
                                  (int)Op2C->getZExtValue())));
    if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy())
      return ConstantFP::get(
          Ty->getContext(),
          APFloat((double)std::pow(Op1V.convertToDouble(),
                                   (int)Op2C->getZExtValue())));

    if (IntrinsicID == Intrinsic::amdgcn_ldexp) {
      // FIXME: Should flush denorms depending on FP mode, but that's ignored
      // everywhere else.

      // scalbn is equivalent to ldexp with float radix 2
      APFloat Result = scalbn(Op1->getValueAPF(), Op2C->getSExtValue(),
                              APFloat::rmNearestTiesToEven);
      return ConstantFP::get(Ty->getContext(), Result);
    }
  }
  return nullptr;
}

if (Operands[0]->getType()->isIntegerTy() &&
    Operands[1]->getType()->isIntegerTy()) {
  const APInt *C0, *C1;
  if (!getConstIntOrUndef(Operands[0], C0) ||
      !getConstIntOrUndef(Operands[1], C1))
    return nullptr;

  switch (IntrinsicID) {
  default: break;
  case Intrinsic::smax:
  case Intrinsic::smin:
  case Intrinsic::umax:
  case Intrinsic::umin:
    // This is the same as for binary ops - poison propagates.
    // TODO: Poison handling should be consolidated.
    if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
      return PoisonValue::get(Ty);

    if (!C0 && !C1)
      return UndefValue::get(Ty);
    if (!C0 || !C1)
      return MinMaxIntrinsic::getSaturationPoint(IntrinsicID, Ty);
    return ConstantInt::get(
        Ty, ICmpInst::compare(*C0, *C1,
                              MinMaxIntrinsic::getPredicate(IntrinsicID))
                ? *C0
                : *C1);

  case Intrinsic::usub_with_overflow:
  case Intrinsic::ssub_with_overflow:
    // X - undef -> { 0, false }
    // undef - X -> { 0, false }
    if (!C0 || !C1)
      return Constant::getNullValue(Ty);
    [[fallthrough]];
  case Intrinsic::uadd_with_overflow:
  case Intrinsic::sadd_with_overflow:
    // X + undef -> { -1, false }
    // undef + x -> { -1, false }
    if (!C0 || !C1) {
      return ConstantStruct::get(
          cast<StructType>(Ty),
          {Constant::getAllOnesValue(Ty->getStructElementType(0)),
           Constant::getNullValue(Ty->getStructElementType(1))});
    }
    [[fallthrough]];
  case Intrinsic::smul_with_overflow:
  case Intrinsic::umul_with_overflow: {
    // undef * X -> { 0, false }
    // X * undef -> { 0, false }
    if (!C0 || !C1)
      return Constant::getNullValue(Ty);

    APInt Res;
    bool Overflow;
    switch (IntrinsicID) {
    default: llvm_unreachable("Invalid case")::llvm::llvm_unreachable_internal("Invalid case", "llvm/lib/Analysis/ConstantFolding.cpp"
, 2738);
    case Intrinsic::sadd_with_overflow:
      Res = C0->sadd_ov(*C1, Overflow);
      break;
    case Intrinsic::uadd_with_overflow:
      Res = C0->uadd_ov(*C1, Overflow);
      break;
    case Intrinsic::ssub_with_overflow:
      Res = C0->ssub_ov(*C1, Overflow);
      break;
    case Intrinsic::usub_with_overflow:
      Res = C0->usub_ov(*C1, Overflow);
      break;
    case Intrinsic::smul_with_overflow:
      Res = C0->smul_ov(*C1, Overflow);
      break;
    case Intrinsic::umul_with_overflow:
      Res = C0->umul_ov(*C1, Overflow);
      break;
    }
    Constant *Ops[] = {
      ConstantInt::get(Ty->getContext(), Res),
      ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow)
    };
    return ConstantStruct::get(cast<StructType>(Ty), Ops);
  }
  case Intrinsic::uadd_sat:
  case Intrinsic::sadd_sat:
    // This is the same as for binary ops - poison propagates.
    // TODO: Poison handling should be consolidated.
    if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
      return PoisonValue::get(Ty);

    if (!C0 && !C1)
      return UndefValue::get(Ty);
    if (!C0 || !C1)
      return Constant::getAllOnesValue(Ty);
    if (IntrinsicID == Intrinsic::uadd_sat)
      return ConstantInt::get(Ty, C0->uadd_sat(*C1));
    else
      return ConstantInt::get(Ty, C0->sadd_sat(*C1));
  case Intrinsic::usub_sat:
  case Intrinsic::ssub_sat:
    // This is the same as for binary ops - poison propagates.
    // TODO: Poison handling should be consolidated.
    if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
      return PoisonValue::get(Ty);

    if (!C0 && !C1)
      return UndefValue::get(Ty);
    if (!C0 || !C1)
      return Constant::getNullValue(Ty);
    if (IntrinsicID == Intrinsic::usub_sat)
      return ConstantInt::get(Ty, C0->usub_sat(*C1));
    else
      return ConstantInt::get(Ty, C0->ssub_sat(*C1));
  case Intrinsic::cttz:
  case Intrinsic::ctlz:
    assert(C1 && "Must be constant int")(static_cast <bool> (C1 && "Must be constant int"
) ? void (0) : __assert_fail ("C1 && \"Must be constant int\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2796, __extension__
 __PRETTY_FUNCTION__));

    // cttz(0, 1) and ctlz(0, 1) are poison.
    if (C1->isOne() && (!C0 || C0->isZero()))
      return PoisonValue::get(Ty);
    if (!C0)
      return Constant::getNullValue(Ty);
    if (IntrinsicID == Intrinsic::cttz)
      return ConstantInt::get(Ty, C0->countr_zero());
    else
      return ConstantInt::get(Ty, C0->countl_zero());

  case Intrinsic::abs:
    assert(C1 && "Must be constant int")(static_cast <bool> (C1 && "Must be constant int"
) ? void (0) : __assert_fail ("C1 && \"Must be constant int\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2809, __extension__
 __PRETTY_FUNCTION__));
    assert((C1->isOne() || C1->isZero()) && "Must be 0 or 1")(static_cast <bool> ((C1->isOne() || C1->isZero()
) && "Must be 0 or 1") ? void (0) : __assert_fail ("(C1->isOne() || C1->isZero()) && \"Must be 0 or 1\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2810, __extension__
 __PRETTY_FUNCTION__));

    // Undef or minimum val operand with poison min --> undef
    if (C1->isOne() && (!C0 || C0->isMinSignedValue()))
      return UndefValue::get(Ty);

    // Undef operand with no poison min --> 0 (sign bit must be clear)
    if (!C0)
      return Constant::getNullValue(Ty);

    return ConstantInt::get(Ty, C0->abs());
  }

  return nullptr;
}

// Support ConstantVector in case we have an Undef in the top.
if ((isa<ConstantVector>(Operands[0]) ||
     isa<ConstantDataVector>(Operands[0])) &&
    // Check for default rounding mode.
    // FIXME: Support other rounding modes?
    isa<ConstantInt>(Operands[1]) &&
    cast<ConstantInt>(Operands[1])->getValue() == 4) {
  auto *Op = cast<Constant>(Operands[0]);
  switch (IntrinsicID) {
  default: break;
  case Intrinsic::x86_avx512_vcvtss2si32:
  case Intrinsic::x86_avx512_vcvtss2si64:
  case Intrinsic::x86_avx512_vcvtsd2si32:
  case Intrinsic::x86_avx512_vcvtsd2si64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/false, Ty,
                                         /*IsSigned*/true);
    break;
  case Intrinsic::x86_avx512_vcvtss2usi32:
  case Intrinsic::x86_avx512_vcvtss2usi64:
  case Intrinsic::x86_avx512_vcvtsd2usi32:
  case Intrinsic::x86_avx512_vcvtsd2usi64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/false, Ty,
                                         /*IsSigned*/false);
    break;
  case Intrinsic::x86_avx512_cvttss2si:
  case Intrinsic::x86_avx512_cvttss2si64:
  case Intrinsic::x86_avx512_cvttsd2si:
  case Intrinsic::x86_avx512_cvttsd2si64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/true, Ty,
                                         /*IsSigned*/true);
    break;
  case Intrinsic::x86_avx512_cvttss2usi:
  case Intrinsic::x86_avx512_cvttss2usi64:
  case Intrinsic::x86_avx512_cvttsd2usi:
  case Intrinsic::x86_avx512_cvttsd2usi64:
    if (ConstantFP *FPOp =
            dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U)))
      return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(),
                                         /*roundTowardZero=*/true, Ty,
                                         /*IsSigned*/false);
    break;
  }
}
return nullptr;
2879}

2881static APFloat ConstantFoldAMDGCNCubeIntrinsic(Intrinsic::ID IntrinsicID,
                                             const APFloat &S0,
                                             const APFloat &S1,
                                             const APFloat &S2) {
unsigned ID;
const fltSemantics &Sem = S0.getSemantics();
APFloat MA(Sem), SC(Sem), TC(Sem);
if (abs(S2) >= abs(S0) && abs(S2) >= abs(S1)) {
  if (S2.isNegative() && S2.isNonZero() && !S2.isNaN()) {
    // S2 < 0
    ID = 5;
    SC = -S0;
  } else {
    ID = 4;
    SC = S0;
  }
  MA = S2;
  TC = -S1;
} else if (abs(S1) >= abs(S0)) {
  if (S1.isNegative() && S1.isNonZero() && !S1.isNaN()) {
    // S1 < 0
    ID = 3;
    TC = -S2;
  } else {
    ID = 2;
    TC = S2;
  }
  MA = S1;
  SC = S0;
} else {
  if (S0.isNegative() && S0.isNonZero() && !S0.isNaN()) {
    // S0 < 0
    ID = 1;
    SC = S2;
  } else {
    ID = 0;
    SC = -S2;
  }
  MA = S0;
  TC = -S1;
}
switch (IntrinsicID) {
default:
  llvm_unreachable("unhandled amdgcn cube intrinsic")::llvm::llvm_unreachable_internal("unhandled amdgcn cube intrinsic"
, "llvm/lib/Analysis/ConstantFolding.cpp", 2924);
case Intrinsic::amdgcn_cubeid:
  return APFloat(Sem, ID);
case Intrinsic::amdgcn_cubema:
  return MA + MA;
case Intrinsic::amdgcn_cubesc:
  return SC;
case Intrinsic::amdgcn_cubetc:
  return TC;
}
2934}

2936static Constant *ConstantFoldAMDGCNPermIntrinsic(ArrayRef<Constant *> Operands,
                                               Type *Ty) {
const APInt *C0, *C1, *C2;
if (!getConstIntOrUndef(Operands[0], C0) ||
    !getConstIntOrUndef(Operands[1], C1) ||
    !getConstIntOrUndef(Operands[2], C2))
  return nullptr;

if (!C2)
  return UndefValue::get(Ty);

APInt Val(32, 0);
unsigned NumUndefBytes = 0;
for (unsigned I = 0; I < 32; I += 8) {
  unsigned Sel = C2->extractBitsAsZExtValue(8, I);
  unsigned B = 0;

  if (Sel >= 13)
    B = 0xff;
  else if (Sel == 12)
    B = 0x00;
  else {
    const APInt *Src = ((Sel & 10) == 10 || (Sel & 12) == 4) ? C0 : C1;
    if (!Src)
      ++NumUndefBytes;
    else if (Sel < 8)
      B = Src->extractBitsAsZExtValue(8, (Sel & 3) * 8);
    else
      B = Src->extractBitsAsZExtValue(1, (Sel & 1) ? 31 : 15) * 0xff;
  }

  Val.insertBits(B, I, 8);
}

if (NumUndefBytes == 4)
  return UndefValue::get(Ty);

return ConstantInt::get(Ty, Val);
2974}

2976static Constant *ConstantFoldScalarCall3(StringRef Name,
                                       Intrinsic::ID IntrinsicID,
                                       Type *Ty,
                                       ArrayRef<Constant *> Operands,
                                       const TargetLibraryInfo *TLI,
                                       const CallBase *Call) {
assert(Operands.size() == 3 && "Wrong number of operands.")(static_cast <bool> (Operands.size() == 3 && "Wrong number of operands."
) ? void (0) : __assert_fail ("Operands.size() == 3 && \"Wrong number of operands.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 2982, __extension__
 __PRETTY_FUNCTION__));

if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) {
  if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) {
    if (const auto *Op3 = dyn_cast<ConstantFP>(Operands[2])) {
      const APFloat &C1 = Op1->getValueAPF();
      const APFloat &C2 = Op2->getValueAPF();
      const APFloat &C3 = Op3->getValueAPF();

      if (const auto *ConstrIntr = dyn_cast<ConstrainedFPIntrinsic>(Call)) {
        RoundingMode RM = getEvaluationRoundingMode(ConstrIntr);
        APFloat Res = C1;
        APFloat::opStatus St;
        switch (IntrinsicID) {
        default:
          return nullptr;
        case Intrinsic::experimental_constrained_fma:
        case Intrinsic::experimental_constrained_fmuladd:
          St = Res.fusedMultiplyAdd(C2, C3, RM);
          break;
        }
        if (mayFoldConstrained(
                const_cast<ConstrainedFPIntrinsic *>(ConstrIntr), St))
          return ConstantFP::get(Ty->getContext(), Res);
        return nullptr;
      }

      switch (IntrinsicID) {
      default: break;
      case Intrinsic::amdgcn_fma_legacy: {
        // The legacy behaviour is that multiplying +/- 0.0 by anything, even
        // NaN or infinity, gives +0.0.
        if (C1.isZero() || C2.isZero()) {
          // It's tempting to just return C3 here, but that would give the
          // wrong result if C3 was -0.0.
          return ConstantFP::get(Ty->getContext(), APFloat(0.0f) + C3);
        }
        [[fallthrough]];
      }
      case Intrinsic::fma:
      case Intrinsic::fmuladd: {
        APFloat V = C1;
        V.fusedMultiplyAdd(C2, C3, APFloat::rmNearestTiesToEven);
        return ConstantFP::get(Ty->getContext(), V);
      }
      case Intrinsic::amdgcn_cubeid:
      case Intrinsic::amdgcn_cubema:
      case Intrinsic::amdgcn_cubesc:
      case Intrinsic::amdgcn_cubetc: {
        APFloat V = ConstantFoldAMDGCNCubeIntrinsic(IntrinsicID, C1, C2, C3);
        return ConstantFP::get(Ty->getContext(), V);
      }
      }
    }
  }
}

if (IntrinsicID == Intrinsic::smul_fix ||
    IntrinsicID == Intrinsic::smul_fix_sat) {
  // poison * C -> poison
  // C * poison -> poison
  if (isa<PoisonValue>(Operands[0]) || isa<PoisonValue>(Operands[1]))
    return PoisonValue::get(Ty);

  const APInt *C0, *C1;
  if (!getConstIntOrUndef(Operands[0], C0) ||
      !getConstIntOrUndef(Operands[1], C1))
    return nullptr;

  // undef * C -> 0
  // C * undef -> 0
  if (!C0 || !C1)
    return Constant::getNullValue(Ty);

  // This code performs rounding towards negative infinity in case the result
  // cannot be represented exactly for the given scale. Targets that do care
  // about rounding should use a target hook for specifying how rounding
  // should be done, and provide their own folding to be consistent with
  // rounding. This is the same approach as used by
  // DAGTypeLegalizer::ExpandIntRes_MULFIX.
  unsigned Scale = cast<ConstantInt>(Operands[2])->getZExtValue();
  unsigned Width = C0->getBitWidth();
  assert(Scale < Width && "Illegal scale.")(static_cast <bool> (Scale < Width && "Illegal scale."
) ? void (0) : __assert_fail ("Scale < Width && \"Illegal scale.\""
, "llvm/lib/Analysis/ConstantFolding.cpp", 3064, __extension__
 __PRETTY_FUNCTION__));
  unsigned ExtendedWidth = Width * 2;
  APInt Product =
      (C0->sext(ExtendedWidth) * C1->sext(ExtendedWidth)).ashr(Scale);
  if (IntrinsicID == Intrinsic::smul_fix_sat) {
    APInt Max = APInt::getSignedMaxValue(Width).sext(ExtendedWidth);
    APInt Min = APInt::getSignedMinValue(Width).sext(ExtendedWidth);
    Product = APIntOps::smin(Product, Max);
    Product = APIntOps::smax(Product, Min);
  }
  return ConstantInt::get(Ty->getContext(), Product.sextOrTrunc(Width));
}

if (IntrinsicID == Intrinsic::fshl || IntrinsicID == Intrinsic::fshr) {
  const APInt *C0, *C1, *C2;
  if (!getConstIntOrUndef(Operands[0], C0) ||
      !getConstIntOrUndef(Operands[1], C1) ||
      !getConstIntOrUndef(Operands[2], C2))
    return nullptr;

  bool IsRight = IntrinsicID == Intrinsic::fshr;
  if (!C2)
    return Operands[IsRight ? 1 : 0];
  if (!C0 && !C1)
    return UndefValue::get(Ty);

  // The shift amount is interpreted as modulo the bitwidth. If the shift
  // amount is effectively 0, avoid UB due to oversized inverse shift below.
  unsigned BitWidth = C2->getBitWidth();
  unsigned ShAmt = C2->urem(BitWidth);
  if (!ShAmt)
    return Operands[IsRight ? 1 : 0];

  // (C0 << ShlAmt) | (C1 >> LshrAmt)
  unsigned LshrAmt = IsRight ? ShAmt : BitWidth - ShAmt;
  unsigned ShlAmt = !IsRight ? ShAmt : BitWidth - ShAmt;
  if (!C0)
    return ConstantInt::get(Ty, C1->lshr(LshrAmt));
  if (!C1)
    return ConstantInt::get(Ty, C0->shl(ShlAmt));
  return ConstantInt::get(Ty, C0->shl(ShlAmt) | C1->lshr(LshrAmt));
}

if (IntrinsicID == Intrinsic::amdgcn_perm)
  return ConstantFoldAMDGCNPermIntrinsic(Operands, Ty);

return nullptr;
3111}

3113static Constant *ConstantFoldScalarCall(StringRef Name,
                                      Intrinsic::ID IntrinsicID,
                                      Type *Ty,
                                      ArrayRef<Constant *> Operands,
                                      const TargetLibraryInfo *TLI,
                                      const CallBase *Call) {
if (Operands.size() == 1)
  return ConstantFoldScalarCall1(Name, IntrinsicID, Ty, Operands, TLI, Call);

if (Operands.size() == 2)
  return ConstantFoldScalarCall2(Name, IntrinsicID, Ty, Operands, TLI, Call);

if (Operands.size() == 3)
  return ConstantFoldScalarCall3(Name, IntrinsicID, Ty, Operands, TLI, Call);

return nullptr;
3129}

3131static Constant *ConstantFoldFixedVectorCall(
  StringRef Name, Intrinsic::ID IntrinsicID, FixedVectorType *FVTy,
  ArrayRef<Constant *> Operands, const DataLayout &DL,
  const TargetLibraryInfo *TLI, const CallBase *Call) {
SmallVector<Constant *, 4> Result(FVTy->getNumElements());
SmallVector<Constant *, 4> Lane(Operands.size());
Type *Ty = FVTy->getElementType();

switch (IntrinsicID) {
case Intrinsic::masked_load: {
  auto *SrcPtr = Operands[0];
  auto *Mask = Operands[2];
  auto *Passthru = Operands[3];

  Constant *VecData = ConstantFoldLoadFromConstPtr(SrcPtr, FVTy, DL);

  SmallVector<Constant *, 32> NewElements;
  for (unsigned I = 0, E = FVTy->getNumElements(); I != E; ++I) {
    auto *MaskElt = Mask->getAggregateElement(I);
    if (!MaskElt)
      break;
    auto *PassthruElt = Passthru->getAggregateElement(I);
    auto *VecElt = VecData ? VecData->getAggregateElement(I) : nullptr;
    if (isa<UndefValue>(MaskElt)) {
      if (PassthruElt)
        NewElements.push_back(PassthruElt);
      else if (VecElt)
        NewElements.push_back(VecElt);
      else
        return nullptr;
    }
    if (MaskElt->isNullValue()) {
      if (!PassthruElt)
        return nullptr;
      NewElements.push_back(PassthruElt);
    } else if (MaskElt->isOneValue()) {
      if (!VecElt)
        return nullptr;
      NewElements.push_back(VecElt);
    } else {
      return nullptr;
    }
  }
  if (NewElements.size() != FVTy->getNumElements())
    return nullptr;
  return ConstantVector::get(NewElements);
}
case Intrinsic::arm_mve_vctp8:
case Intrinsic::arm_mve_vctp16:
case Intrinsic::arm_mve_vctp32:
case Intrinsic::arm_mve_vctp64: {
  if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) {
    unsigned Lanes = FVTy->getNumElements();
    uint64_t Limit = Op->getZExtValue();

    SmallVector<Constant *, 16> NCs;
    for (unsigned i = 0; i < Lanes; i++) {
      if (i < Limit)
        NCs.push_back(ConstantInt::getTrue(Ty));
      else
        NCs.push_back(ConstantInt::getFalse(Ty));
    }
    return ConstantVector::get(NCs);
  }
  return nullptr;
}
case Intrinsic::get_active_lane_mask: {
  auto *Op0 = dyn_cast<ConstantInt>(Operands[0]);
  auto *Op1 = dyn_cast<ConstantInt>(Operands[1]);
  if (Op0 && Op1) {
    unsigned Lanes = FVTy->getNumElements();
    uint64_t Base = Op0->getZExtValue();
    uint64_t Limit = Op1->getZExtValue();

    SmallVector<Constant *, 16> NCs;
    for (unsigned i = 0; i < Lanes; i++) {
      if (Base + i < Limit)
        NCs.push_back(ConstantInt::getTrue(Ty));
      else
        NCs.push_back(ConstantInt::getFalse(Ty));
    }
    return ConstantVector::get(NCs);
  }
  return nullptr;
}
default:
  break;
}

for (unsigned I = 0, E = FVTy->getNumElements(); I != E; ++I) {
  // Gather a column of constants.
  for (unsigned J = 0, JE = Operands.size(); J != JE; ++J) {
    // Some intrinsics use a scalar type for certain arguments.
    if (isVectorIntrinsicWithScalarOpAtArg(IntrinsicID, J)) {
      Lane[J] = Operands[J];
      continue;
    }

    Constant *Agg = Operands[J]->getAggregateElement(I);
    if (!Agg)
      return nullptr;

    Lane[J] = Agg;
  }

  // Use the regular scalar folding to simplify this column.
  Constant *Folded =
      ConstantFoldScalarCall(Name, IntrinsicID, Ty, Lane, TLI, Call);
  if (!Folded)
    return nullptr;
  Result[I] = Folded;
}

return ConstantVector::get(Result);
3245}

3247static Constant *ConstantFoldScalableVectorCall(
  StringRef Name, Intrinsic::ID IntrinsicID, ScalableVectorType *SVTy,
  ArrayRef<Constant *> Operands, const DataLayout &DL,
  const TargetLibraryInfo *TLI, const CallBase *Call) {
switch (IntrinsicID) {
case Intrinsic::aarch64_sve_convert_from_svbool: {
  auto *Src = dyn_cast<Constant>(Operands[0]);
  if (!Src || !Src->isNullValue())
    break;

  return ConstantInt::getFalse(SVTy);
}
default:
  break;
}
return nullptr;
3263}

3265} // end anonymous namespace

3267Constant *llvm::ConstantFoldCall(const CallBase *Call, Function *F,
                               ArrayRef<Constant *> Operands,
                               const TargetLibraryInfo *TLI) {
if (Call->isNoBuiltin())
  return nullptr;
if (!F->hasName())
  return nullptr;

// If this is not an intrinsic and not recognized as a library call, bail out.
if (F->getIntrinsicID() == Intrinsic::not_intrinsic) {
  if (!TLI)
    return nullptr;
  LibFunc LibF;
  if (!TLI->getLibFunc(*F, LibF))
    return nullptr;
}

StringRef Name = F->getName();
Type *Ty = F->getReturnType();
if (auto *FVTy = dyn_cast<FixedVectorType>(Ty))
  return ConstantFoldFixedVectorCall(
      Name, F->getIntrinsicID(), FVTy, Operands,
      F->getParent()->getDataLayout(), TLI, Call);

if (auto *SVTy = dyn_cast<ScalableVectorType>(Ty))
  return ConstantFoldScalableVectorCall(
      Name, F->getIntrinsicID(), SVTy, Operands,
      F->getParent()->getDataLayout(), TLI, Call);

// TODO: If this is a library function, we already discovered that above,
//       so we should pass the LibFunc, not the name (and it might be better
//       still to separate intrinsic handling from libcalls).
return ConstantFoldScalarCall(Name, F->getIntrinsicID(), Ty, Operands, TLI,
                              Call);
3301}

3303bool llvm::isMathLibCallNoop(const CallBase *Call,
                           const TargetLibraryInfo *TLI) {
// FIXME: Refactor this code; this duplicates logic in LibCallsShrinkWrap
// (and to some extent ConstantFoldScalarCall).
if (Call->isNoBuiltin() || Call->isStrictFP())
  return false;
Function *F = Call->getCalledFunction();
if (!F)
  return false;

LibFunc Func;
if (!TLI || !TLI->getLibFunc(*F, Func))
  return false;

if (Call->arg_size() == 1) {
  if (ConstantFP *OpC = dyn_cast<ConstantFP>(Call->getArgOperand(0))) {
    const APFloat &Op = OpC->getValueAPF();
    switch (Func) {
    case LibFunc_logl:
    case LibFunc_log:
    case LibFunc_logf:
    case LibFunc_log2l:
    case LibFunc_log2:
    case LibFunc_log2f:
    case LibFunc_log10l:
    case LibFunc_log10:
    case LibFunc_log10f:
      return Op.isNaN() || (!Op.isZero() && !Op.isNegative());

    case LibFunc_expl:
    case LibFunc_exp:
    case LibFunc_expf:
      // FIXME: These boundaries are slightly conservative.
      if (OpC->getType()->isDoubleTy())
        return !(Op < APFloat(-745.0) || Op > APFloat(709.0));
      if (OpC->getType()->isFloatTy())
        return !(Op < APFloat(-103.0f) || Op > APFloat(88.0f));
      break;

    case LibFunc_exp2l:
    case LibFunc_exp2:
    case LibFunc_exp2f:
      // FIXME: These boundaries are slightly conservative.
      if (OpC->getType()->isDoubleTy())
        return !(Op < APFloat(-1074.0) || Op > APFloat(1023.0));
      if (OpC->getType()->isFloatTy())
        return !(Op < APFloat(-149.0f) || Op > APFloat(127.0f));
      break;

    case LibFunc_sinl:
    case LibFunc_sin:
    case LibFunc_sinf:
    case LibFunc_cosl:
    case LibFunc_cos:
    case LibFunc_cosf:
      return !Op.isInfinity();

    case LibFunc_tanl:
    case LibFunc_tan:
    case LibFunc_tanf: {
      // FIXME: Stop using the host math library.
      // FIXME: The computation isn't done in the right precision.
      Type *Ty = OpC->getType();
      if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy())
        return ConstantFoldFP(tan, OpC->getValueAPF(), Ty) != nullptr;
      break;
    }

    case LibFunc_atan:
    case LibFunc_atanf:
    case LibFunc_atanl:
      // Per POSIX, this MAY fail if Op is denormal. We choose not failing.
      return true;


    case LibFunc_asinl:
    case LibFunc_asin:
    case LibFunc_asinf:
    case LibFunc_acosl:
    case LibFunc_acos:
    case LibFunc_acosf:
      return !(Op < APFloat(Op.getSemantics(), "-1") ||
               Op > APFloat(Op.getSemantics(), "1"));

    case LibFunc_sinh:
    case LibFunc_cosh:
    case LibFunc_sinhf:
    case LibFunc_coshf:
    case LibFunc_sinhl:
    case LibFunc_coshl:
      // FIXME: These boundaries are slightly conservative.
      if (OpC->getType()->isDoubleTy())
        return !(Op < APFloat(-710.0) || Op > APFloat(710.0));
      if (OpC->getType()->isFloatTy())
        return !(Op < APFloat(-89.0f) || Op > APFloat(89.0f));
      break;

    case LibFunc_sqrtl:
    case LibFunc_sqrt:
    case LibFunc_sqrtf:
      return Op.isNaN() || Op.isZero() || !Op.isNegative();

    // FIXME: Add more functions: sqrt_finite, atanh, expm1, log1p,
    // maybe others?
    default:
      break;
    }
  }
}

if (Call->arg_size() == 2) {
  ConstantFP *Op0C = dyn_cast<ConstantFP>(Call->getArgOperand(0));
  ConstantFP *Op1C = dyn_cast<ConstantFP>(Call->getArgOperand(1));
  if (Op0C && Op1C) {
    const APFloat &Op0 = Op0C->getValueAPF();
    const APFloat &Op1 = Op1C->getValueAPF();

    switch (Func) {
    case LibFunc_powl:
    case LibFunc_pow:
    case LibFunc_powf: {
      // FIXME: Stop using the host math library.
      // FIXME: The computation isn't done in the right precision.
      Type *Ty = Op0C->getType();
      if (Ty->isDoubleTy() || Ty->isFloatTy() || Ty->isHalfTy()) {
        if (Ty == Op1C->getType())
          return ConstantFoldBinaryFP(pow, Op0, Op1, Ty) != nullptr;
      }
      break;
    }

    case LibFunc_fmodl:
    case LibFunc_fmod:
    case LibFunc_fmodf:
    case LibFunc_remainderl:
    case LibFunc_remainder:
    case LibFunc_remainderf:
      return Op0.isNaN() || Op1.isNaN() ||
             (!Op0.isInfinity() && !Op1.isZero());

    case LibFunc_atan2:
    case LibFunc_atan2f:
    case LibFunc_atan2l:
      // Although IEEE-754 says atan2(+/-0.0, +/-0.0) are well-defined, and
      // GLIBC and MSVC do not appear to raise an error on those, we
      // cannot rely on that behavior. POSIX and C11 say that a domain error
      // may occur, so allow for that possibility.
      return !Op0.isZero() || !Op1.isZero();

    default:
      break;
    }
  }
}

return false;
3459}

3461void TargetFolder::anchor() {}

←

/build/source/llvm/include/llvm/IR/Instruction.h

1//===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file contains the declaration of the Instruction class, which is the
10// base class for all of the LLVM instructions.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_IR_INSTRUCTION_H
15#define LLVM_IR_INSTRUCTION_H

17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/Bitfields.h"
19#include "llvm/ADT/StringRef.h"
20#include "llvm/ADT/ilist_node.h"
21#include "llvm/IR/DebugLoc.h"
22#include "llvm/IR/SymbolTableListTraits.h"
23#include "llvm/IR/User.h"
24#include "llvm/IR/Value.h"
25#include "llvm/Support/AtomicOrdering.h"
26#include <cstdint>
27#include <utility>

29namespace llvm {

31class BasicBlock;
32class FastMathFlags;
33class MDNode;
34class Module;
35struct AAMDNodes;

37template <> struct ilist_alloc_traits<Instruction> {
static inline void deleteNode(Instruction *V);
39};

41class Instruction : public User,
                  public ilist_node_with_parent<Instruction, BasicBlock> {
BasicBlock *Parent;
DebugLoc DbgLoc;                         // 'dbg' Metadata cache.

/// Relative order of this instruction in its parent basic block. Used for
/// O(1) local dominance checks between instructions.
mutable unsigned Order = 0;

50protected:
// The 15 first bits of `Value::SubclassData` are available for subclasses of
// `Instruction` to use.
using OpaqueField = Bitfield::Element<uint16_t, 0, 15>;

// Template alias so that all Instruction storing alignment use the same
// definiton.
// Valid alignments are powers of two from 2^0 to 2^MaxAlignmentExponent =
// 2^32. We store them as Log2(Alignment), so we need 6 bits to encode the 33
// possible values.
template <unsigned Offset>
using AlignmentBitfieldElementT =
    typename Bitfield::Element<unsigned, Offset, 6,
                               Value::MaxAlignmentExponent>;

template <unsigned Offset>
using BoolBitfieldElementT = typename Bitfield::Element<bool, Offset, 1>;

template <unsigned Offset>
using AtomicOrderingBitfieldElementT =
    typename Bitfield::Element<AtomicOrdering, Offset, 3,
                               AtomicOrdering::LAST>;

73private:
// The last bit is used to store whether the instruction has metadata attached
// or not.
using HasMetadataField = Bitfield::Element<bool, 15, 1>;

78protected:
~Instruction(); // Use deleteValue() to delete a generic Instruction.

81public:
Instruction(const Instruction &) = delete;
Instruction &operator=(const Instruction &) = delete;

/// Specialize the methods defined in Value, as we know that an instruction
/// can only be used by other instructions.
Instruction       *user_back()       { return cast<Instruction>(*user_begin());}
const Instruction *user_back() const { return cast<Instruction>(*user_begin());}

inline const BasicBlock *getParent() const { return Parent; }
inline       BasicBlock *getParent()       { return Parent; }

/// Return the module owning the function this instruction belongs to
/// or nullptr it the function does not have a module.
///
/// Note: this is undefined behavior if the instruction does not have a
/// parent, or the parent basic block does not have a parent function.
const Module *getModule() const;
Module *getModule() {
  return const_cast<Module *>(
                         static_cast<const Instruction *>(this)->getModule());
}

/// Return the function this instruction belongs to.
///
/// Note: it is undefined behavior to call this on an instruction not
/// currently inserted into a function.
const Function *getFunction() const;
Function *getFunction() {
  return const_cast<Function *>(
                       static_cast<const Instruction *>(this)->getFunction());
}

/// This method unlinks 'this' from the containing basic block, but does not
/// delete it.
void removeFromParent();

/// This method unlinks 'this' from the containing basic block and deletes it.
///
/// \returns an iterator pointing to the element after the erased one
SymbolTableList<Instruction>::iterator eraseFromParent();

/// Insert an unlinked instruction into a basic block immediately before
/// the specified instruction.
void insertBefore(Instruction *InsertPos);

/// Insert an unlinked instruction into a basic block immediately after the
/// specified instruction.
void insertAfter(Instruction *InsertPos);

/// Inserts an unlinked instruction into \p ParentBB at position \p It and
/// returns the iterator of the inserted instruction.
SymbolTableList<Instruction>::iterator
insertInto(BasicBlock *ParentBB, SymbolTableList<Instruction>::iterator It);

/// Unlink this instruction from its current basic block and insert it into
/// the basic block that MovePos lives in, right before MovePos.
void moveBefore(Instruction *MovePos);

/// Unlink this instruction and insert into BB before I.
///
/// \pre I is a valid iterator into BB.
void moveBefore(BasicBlock &BB, SymbolTableList<Instruction>::iterator I);

/// Unlink this instruction from its current basic block and insert it into
/// the basic block that MovePos lives in, right after MovePos.
void moveAfter(Instruction *MovePos);

/// Given an instruction Other in the same basic block as this instruction,
/// return true if this instruction comes before Other. In this worst case,
/// this takes linear time in the number of instructions in the block. The
/// results are cached, so in common cases when the block remains unmodified,
/// it takes constant time.
bool comesBefore(const Instruction *Other) const;

/// Get the first insertion point at which the result of this instruction
/// is defined. This is *not* the directly following instruction in a number
/// of cases, e.g. phi nodes or terminators that return values. This function
/// may return null if the insertion after the definition is not possible,
/// e.g. due to a catchswitch terminator.
Instruction *getInsertionPointAfterDef();

//===--------------------------------------------------------------------===//
// Subclass classification.
//===--------------------------------------------------------------------===//

/// Returns a member of one of the enums like Instruction::Add.
unsigned getOpcode() const { return getValueID() - InstructionVal; }

const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
bool isTerminator() const { return isTerminator(getOpcode()); }
bool isUnaryOp() const { return isUnaryOp(getOpcode()); }
bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
bool isIntDivRem() const { return isIntDivRem(getOpcode()); }
bool isShift() const { return isShift(getOpcode()); }
bool isCast() const { return isCast(getOpcode()); }
bool isFuncletPad() const { return isFuncletPad(getOpcode()); }
bool isExceptionalTerminator() const {
  return isExceptionalTerminator(getOpcode());
}

/// It checks if this instruction is the only user of at least one of
/// its operands.
bool isOnlyUserOfAnyOperand();

static const char *getOpcodeName(unsigned Opcode);

static inline bool isTerminator(unsigned Opcode) {
  return Opcode >= TermOpsBegin && Opcode < TermOpsEnd;
}

static inline bool isUnaryOp(unsigned Opcode) {
  return Opcode >= UnaryOpsBegin && Opcode < UnaryOpsEnd;
10
←
Assuming 'Opcode' is >= UnaryOpsBegin, which participates in a condition later→
11
←
Assuming 'Opcode' is >= UnaryOpsEnd, which participates in a condition later→
}
static inline bool isBinaryOp(unsigned Opcode) {
  return Opcode14.1
'Opcode' is >= BinaryOpsBegin, which participates in a condition later
1
'Opcode' is >= BinaryOpsBegin, which participates in a condition later
 >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
15
←
Assuming 'Opcode' is >= BinaryOpsEnd, which participates in a condition later→
}

static inline bool isIntDivRem(unsigned Opcode) {
  return Opcode == UDiv || Opcode == SDiv || Opcode == URem || Opcode == SRem;
}

/// Determine if the Opcode is one of the shift instructions.
static inline bool isShift(unsigned Opcode) {
  return Opcode >= Shl && Opcode <= AShr;
}

/// Return true if this is a logical shift left or a logical shift right.
inline bool isLogicalShift() const {
  return getOpcode() == Shl || getOpcode() == LShr;
}

/// Return true if this is an arithmetic shift right.
inline bool isArithmeticShift() const {
  return getOpcode() == AShr;
}

/// Determine if the Opcode is and/or/xor.
static inline bool isBitwiseLogicOp(unsigned Opcode) {
  return Opcode == And || Opcode == Or || Opcode == Xor;
}

/// Return true if this is and/or/xor.
inline bool isBitwiseLogicOp() const {
  return isBitwiseLogicOp(getOpcode());
}

/// Determine if the Opcode is one of the CastInst instructions.
static inline bool isCast(unsigned Opcode) {
  return Opcode >= CastOpsBegin && Opcode < CastOpsEnd;
19
←
Assuming 'Opcode' is < CastOpsBegin, which participates in a condition later→
}

/// Determine if the Opcode is one of the FuncletPadInst instructions.
static inline bool isFuncletPad(unsigned Opcode) {
  return Opcode >= FuncletPadOpsBegin && Opcode < FuncletPadOpsEnd;
}

/// Returns true if the Opcode is a terminator related to exception handling.
static inline bool isExceptionalTerminator(unsigned Opcode) {
  switch (Opcode) {
  case Instruction::CatchSwitch:
  case Instruction::CatchRet:
  case Instruction::CleanupRet:
  case Instruction::Invoke:
  case Instruction::Resume:
    return true;
  default:
    return false;
  }
}

//===--------------------------------------------------------------------===//
// Metadata manipulation.
//===--------------------------------------------------------------------===//

/// Return true if this instruction has any metadata attached to it.
bool hasMetadata() const { return DbgLoc || Value::hasMetadata(); }

/// Return true if this instruction has metadata attached to it other than a
/// debug location.
bool hasMetadataOtherThanDebugLoc() const { return Value::hasMetadata(); }

/// Return true if this instruction has the given type of metadata attached.
bool hasMetadata(unsigned KindID) const {
  return getMetadata(KindID) != nullptr;
}

/// Return true if this instruction has the given type of metadata attached.
bool hasMetadata(StringRef Kind) const {
  return getMetadata(Kind) != nullptr;
}

/// Get the metadata of given kind attached to this Instruction.
/// If the metadata is not found then return null.
MDNode *getMetadata(unsigned KindID) const {
  if (!hasMetadata()) return nullptr;
  return getMetadataImpl(KindID);
}

/// Get the metadata of given kind attached to this Instruction.
/// If the metadata is not found then return null.
MDNode *getMetadata(StringRef Kind) const {
  if (!hasMetadata()) return nullptr;
  return getMetadataImpl(Kind);
}

/// Get all metadata attached to this Instruction. The first element of each
/// pair returned is the KindID, the second element is the metadata value.
/// This list is returned sorted by the KindID.
void
getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
  if (hasMetadata())
    getAllMetadataImpl(MDs);
}

/// This does the same thing as getAllMetadata, except that it filters out the
/// debug location.
void getAllMetadataOtherThanDebugLoc(
    SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
  Value::getAllMetadata(MDs);
}

/// Set the metadata of the specified kind to the specified node. This updates
/// or replaces metadata if already present, or removes it if Node is null.
void setMetadata(unsigned KindID, MDNode *Node);
void setMetadata(StringRef Kind, MDNode *Node);

/// Copy metadata from \p SrcInst to this instruction. \p WL, if not empty,
/// specifies the list of meta data that needs to be copied. If \p WL is
/// empty, all meta data will be copied.
void copyMetadata(const Instruction &SrcInst,
                  ArrayRef<unsigned> WL = ArrayRef<unsigned>());

/// If the instruction has "branch_weights" MD_prof metadata and the MDNode
/// has three operands (including name string), swap the order of the
/// metadata.
void swapProfMetadata();

/// Drop all unknown metadata except for debug locations.
/// @{
/// Passes are required to drop metadata they don't understand. This is a
/// convenience method for passes to do so.
/// dropUndefImplyingAttrsAndUnknownMetadata should be used instead of
/// this API if the Instruction being modified is a call.
void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs);
void dropUnknownNonDebugMetadata() {
  return dropUnknownNonDebugMetadata(std::nullopt);
}
void dropUnknownNonDebugMetadata(unsigned ID1) {
  return dropUnknownNonDebugMetadata(ArrayRef(ID1));
}
void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) {
  unsigned IDs[] = {ID1, ID2};
  return dropUnknownNonDebugMetadata(IDs);
}
/// @}

/// Adds an !annotation metadata node with \p Annotation to this instruction.
/// If this instruction already has !annotation metadata, append \p Annotation
/// to the existing node.
void addAnnotationMetadata(StringRef Annotation);

/// Returns the AA metadata for this instruction.
AAMDNodes getAAMetadata() const;

/// Sets the AA metadata on this instruction from the AAMDNodes structure.
void setAAMetadata(const AAMDNodes &N);

/// Retrieve total raw weight values of a branch.
/// Returns true on success with profile total weights filled in.
/// Returns false if no metadata was found.
bool extractProfTotalWeight(uint64_t &TotalVal) const;

/// Set the debug location information for this instruction.
void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }

/// Return the debug location for this node as a DebugLoc.
const DebugLoc &getDebugLoc() const { return DbgLoc; }

/// Set or clear the nuw flag on this instruction, which must be an operator
/// which supports this flag. See LangRef.html for the meaning of this flag.
void setHasNoUnsignedWrap(bool b = true);

/// Set or clear the nsw flag on this instruction, which must be an operator
/// which supports this flag. See LangRef.html for the meaning of this flag.
void setHasNoSignedWrap(bool b = true);

/// Set or clear the exact flag on this instruction, which must be an operator
/// which supports this flag. See LangRef.html for the meaning of this flag.
void setIsExact(bool b = true);

/// Determine whether the no unsigned wrap flag is set.
bool hasNoUnsignedWrap() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the no signed wrap flag is set.
bool hasNoSignedWrap() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this operator has flags which may cause this instruction
/// to evaluate to poison despite having non-poison inputs.
bool hasPoisonGeneratingFlags() const LLVM_READONLY__attribute__((__pure__));

/// Drops flags that may cause this instruction to evaluate to poison despite
/// having non-poison inputs.
void dropPoisonGeneratingFlags();

/// Return true if this instruction has poison-generating metadata.
bool hasPoisonGeneratingMetadata() const LLVM_READONLY__attribute__((__pure__));

/// Drops metadata that may generate poison.
void dropPoisonGeneratingMetadata();

/// Return true if this instruction has poison-generating flags or metadata.
bool hasPoisonGeneratingFlagsOrMetadata() const {
  return hasPoisonGeneratingFlags() || hasPoisonGeneratingMetadata();
}

/// Drops flags and metadata that may generate poison.
void dropPoisonGeneratingFlagsAndMetadata() {
  dropPoisonGeneratingFlags();
  dropPoisonGeneratingMetadata();
}

/// This function drops non-debug unknown metadata (through
/// dropUnknownNonDebugMetadata). For calls, it also drops parameter and 
/// return attributes that can cause undefined behaviour. Both of these should
/// be done by passes which move instructions in IR.
void
dropUndefImplyingAttrsAndUnknownMetadata(ArrayRef<unsigned> KnownIDs = {});

/// Determine whether the exact flag is set.
bool isExact() const LLVM_READONLY__attribute__((__pure__));

/// Set or clear all fast-math-flags on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setFast(bool B);

/// Set or clear the reassociation flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasAllowReassoc(bool B);

/// Set or clear the no-nans flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoNaNs(bool B);

/// Set or clear the no-infs flag on this instruction, which must be an
/// operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoInfs(bool B);

/// Set or clear the no-signed-zeros flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasNoSignedZeros(bool B);

/// Set or clear the allow-reciprocal flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasAllowReciprocal(bool B);

/// Set or clear the allow-contract flag on this instruction, which must be
/// an operator which supports this flag. See LangRef.html for the meaning of
/// this flag.
void setHasAllowContract(bool B);

/// Set or clear the approximate-math-functions flag on this instruction,
/// which must be an operator which supports this flag. See LangRef.html for
/// the meaning of this flag.
void setHasApproxFunc(bool B);

/// Convenience function for setting multiple fast-math flags on this
/// instruction, which must be an operator which supports these flags. See
/// LangRef.html for the meaning of these flags.
void setFastMathFlags(FastMathFlags FMF);

/// Convenience function for transferring all fast-math flag values to this
/// instruction, which must be an operator which supports these flags. See
/// LangRef.html for the meaning of these flags.
void copyFastMathFlags(FastMathFlags FMF);

/// Determine whether all fast-math-flags are set.
bool isFast() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the allow-reassociation flag is set.
bool hasAllowReassoc() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the no-NaNs flag is set.
bool hasNoNaNs() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the no-infs flag is set.
bool hasNoInfs() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the no-signed-zeros flag is set.
bool hasNoSignedZeros() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the allow-reciprocal flag is set.
bool hasAllowReciprocal() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the allow-contract flag is set.
bool hasAllowContract() const LLVM_READONLY__attribute__((__pure__));

/// Determine whether the approximate-math-functions flag is set.
bool hasApproxFunc() const LLVM_READONLY__attribute__((__pure__));

/// Convenience function for getting all the fast-math flags, which must be an
/// operator which supports these flags. See LangRef.html for the meaning of
/// these flags.
FastMathFlags getFastMathFlags() const LLVM_READONLY__attribute__((__pure__));

/// Copy I's fast-math flags
void copyFastMathFlags(const Instruction *I);

/// Convenience method to copy supported exact, fast-math, and (optionally)
/// wrapping flags from V to this instruction.
void copyIRFlags(const Value *V, bool IncludeWrapFlags = true);

/// Logical 'and' of any supported wrapping, exact, and fast-math flags of
/// V and this instruction.
void andIRFlags(const Value *V);

/// Merge 2 debug locations and apply it to the Instruction. If the
/// instruction is a CallIns, we need to traverse the inline chain to find
/// the common scope. This is not efficient for N-way merging as each time
/// you merge 2 iterations, you need to rebuild the hashmap to find the
/// common scope. However, we still choose this API because:
///  1) Simplicity: it takes 2 locations instead of a list of locations.
///  2) In worst case, it increases the complexity from O(N*I) to
///     O(2*N*I), where N is # of Instructions to merge, and I is the
///     maximum level of inline stack. So it is still linear.
///  3) Merging of call instructions should be extremely rare in real
///     applications, thus the N-way merging should be in code path.
/// The DebugLoc attached to this instruction will be overwritten by the
/// merged DebugLoc.
void applyMergedLocation(const DILocation *LocA, const DILocation *LocB);

/// Updates the debug location given that the instruction has been hoisted
/// from a block to a predecessor of that block.
/// Note: it is undefined behavior to call this on an instruction not
/// currently inserted into a function.
void updateLocationAfterHoist();

/// Drop the instruction's debug location. This does not guarantee removal
/// of the !dbg source location attachment, as it must set a line 0 location
/// with scope information attached on call instructions. To guarantee
/// removal of the !dbg attachment, use the \ref setDebugLoc() API.
/// Note: it is undefined behavior to call this on an instruction not
/// currently inserted into a function.
void dropLocation();

/// Merge the DIAssignID metadata from this instruction and those attached to
/// instructions in \p SourceInstructions. This process performs a RAUW on
/// the MetadataAsValue uses of the merged DIAssignID nodes. Not every
/// instruction in \p SourceInstructions needs to have DIAssignID
/// metadata. If none of them do then nothing happens. If this instruction
/// does not have a DIAssignID attachment but at least one in \p
/// SourceInstructions does then the merged one will be attached to
/// it. However, instructions without attachments in \p SourceInstructions
/// are not modified.
void mergeDIAssignID(ArrayRef<const Instruction *> SourceInstructions);

543private:
// These are all implemented in Metadata.cpp.
MDNode *getMetadataImpl(unsigned KindID) const;
MDNode *getMetadataImpl(StringRef Kind) const;
void
getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;

/// Update the LLVMContext ID-to-Instruction(s) mapping. If \p ID is nullptr
/// then clear the mapping for this instruction.
void updateDIAssignIDMapping(DIAssignID *ID);

554public:
//===--------------------------------------------------------------------===//
// Predicates and helper methods.
//===--------------------------------------------------------------------===//

/// Return true if the instruction is associative:
///
///   Associative operators satisfy:  x op (y op z) === (x op y) op z
///
/// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
///
bool isAssociative() const LLVM_READONLY__attribute__((__pure__));
static bool isAssociative(unsigned Opcode) {
  return Opcode == And || Opcode == Or || Opcode == Xor ||
         Opcode == Add || Opcode == Mul;
}

/// Return true if the instruction is commutative:
///
///   Commutative operators satisfy: (x op y) === (y op x)
///
/// In LLVM, these are the commutative operators, plus SetEQ and SetNE, when
/// applied to any type.
///
bool isCommutative() const LLVM_READONLY__attribute__((__pure__));
static bool isCommutative(unsigned Opcode) {
  switch (Opcode) {
  case Add: case FAdd:
  case Mul: case FMul:
  case And: case Or: case Xor:
    return true;
  default:
    return false;
}
}

/// Return true if the instruction is idempotent:
///
///   Idempotent operators satisfy:  x op x === x
///
/// In LLVM, the And and Or operators are idempotent.
///
bool isIdempotent() const { return isIdempotent(getOpcode()); }
static bool isIdempotent(unsigned Opcode) {
  return Opcode == And || Opcode == Or;
}

/// Return true if the instruction is nilpotent:
///
///   Nilpotent operators satisfy:  x op x === Id,
///
///   where Id is the identity for the operator, i.e. a constant such that
///     x op Id === x and Id op x === x for all x.
///
/// In LLVM, the Xor operator is nilpotent.
///
bool isNilpotent() const { return isNilpotent(getOpcode()); }
static bool isNilpotent(unsigned Opcode) {
  return Opcode == Xor;
}

/// Return true if this instruction may modify memory.
bool mayWriteToMemory() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this instruction may read memory.
bool mayReadFromMemory() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this instruction may read or write memory.
bool mayReadOrWriteMemory() const {
  return mayReadFromMemory() || mayWriteToMemory();
}

/// Return true if this instruction has an AtomicOrdering of unordered or
/// higher.
bool isAtomic() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this atomic instruction loads from memory.
bool hasAtomicLoad() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this atomic instruction stores to memory.
bool hasAtomicStore() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this instruction has a volatile memory access.
bool isVolatile() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this instruction may throw an exception.
bool mayThrow() const LLVM_READONLY__attribute__((__pure__));

/// Return true if this instruction behaves like a memory fence: it can load
/// or store to memory location without being given a memory location.
bool isFenceLike() const {
  switch (getOpcode()) {
  default:
    return false;
  // This list should be kept in sync with the list in mayWriteToMemory for
  // all opcodes which don't have a memory location.
  case Instruction::Fence:
  case Instruction::CatchPad:
  case Instruction::CatchRet:
  case Instruction::Call:
  case Instruction::Invoke:
    return true;
  }
}

/// Return true if the instruction may have side effects.
///
/// Side effects are:
///  * Writing to memory.
///  * Unwinding.
///  * Not returning (e.g. an infinite loop).
///
/// Note that this does not consider malloc and alloca to have side
/// effects because the newly allocated memory is completely invisible to
/// instructions which don't use the returned value.  For cases where this
/// matters, isSafeToSpeculativelyExecute may be more appropriate.
bool mayHaveSideEffects() const LLVM_READONLY__attribute__((__pure__));

/// Return true if the instruction can be removed if the result is unused.
///
/// When constant folding some instructions cannot be removed even if their
/// results are unused. Specifically terminator instructions and calls that
/// may have side effects cannot be removed without semantically changing the
/// generated program.
bool isSafeToRemove() const LLVM_READONLY__attribute__((__pure__));

/// Return true if the instruction will return (unwinding is considered as
/// a form of returning control flow here).
bool willReturn() const LLVM_READONLY__attribute__((__pure__));

/// Return true if the instruction is a variety of EH-block.
bool isEHPad() const {
  switch (getOpcode()) {
  case Instruction::CatchSwitch:
  case Instruction::CatchPad:
  case Instruction::CleanupPad:
  case Instruction::LandingPad:
    return true;
  default:
    return false;
  }
}

/// Return true if the instruction is a llvm.lifetime.start or
/// llvm.lifetime.end marker.
bool isLifetimeStartOrEnd() const LLVM_READONLY__attribute__((__pure__));

/// Return true if the instruction is a llvm.launder.invariant.group or
/// llvm.strip.invariant.group.
bool isLaunderOrStripInvariantGroup() const LLVM_READONLY__attribute__((__pure__));

/// Return true if the instruction is a DbgInfoIntrinsic or PseudoProbeInst.
bool isDebugOrPseudoInst() const LLVM_READONLY__attribute__((__pure__));

/// Return a pointer to the next non-debug instruction in the same basic
/// block as 'this', or nullptr if no such instruction exists. Skip any pseudo
/// operations if \c SkipPseudoOp is true.
const Instruction *
getNextNonDebugInstruction(bool SkipPseudoOp = false) const;
Instruction *getNextNonDebugInstruction(bool SkipPseudoOp = false) {
  return const_cast<Instruction *>(
      static_cast<const Instruction *>(this)->getNextNonDebugInstruction(
          SkipPseudoOp));
}

/// Return a pointer to the previous non-debug instruction in the same basic
/// block as 'this', or nullptr if no such instruction exists. Skip any pseudo
/// operations if \c SkipPseudoOp is true.
const Instruction *
getPrevNonDebugInstruction(bool SkipPseudoOp = false) const;
Instruction *getPrevNonDebugInstruction(bool SkipPseudoOp = false) {
  return const_cast<Instruction *>(
      static_cast<const Instruction *>(this)->getPrevNonDebugInstruction(
          SkipPseudoOp));
}

/// Create a copy of 'this' instruction that is identical in all ways except
/// the following:
///   * The instruction has no parent
///   * The instruction has no name
///
Instruction *clone() const;

/// Return true if the specified instruction is exactly identical to the
/// current one. This means that all operands match and any extra information
/// (e.g. load is volatile) agree.
bool isIdenticalTo(const Instruction *I) const LLVM_READONLY__attribute__((__pure__));

/// This is like isIdenticalTo, except that it ignores the
/// SubclassOptionalData flags, which may specify conditions under which the
/// instruction's result is undefined.
bool isIdenticalToWhenDefined(const Instruction *I) const LLVM_READONLY__attribute__((__pure__));

/// When checking for operation equivalence (using isSameOperationAs) it is
/// sometimes useful to ignore certain attributes.
enum OperationEquivalenceFlags {
  /// Check for equivalence ignoring load/store alignment.
  CompareIgnoringAlignment = 1<<0,
  /// Check for equivalence treating a type and a vector of that type
  /// as equivalent.
  CompareUsingScalarTypes = 1<<1
};

/// This function determines if the specified instruction executes the same
/// operation as the current one. This means that the opcodes, type, operand
/// types and any other factors affecting the operation must be the same. This
/// is similar to isIdenticalTo except the operands themselves don't have to
/// be identical.
/// @returns true if the specified instruction is the same operation as
/// the current one.
/// Determine if one instruction is the same operation as another.
bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const LLVM_READONLY__attribute__((__pure__));

/// Return true if there are any uses of this instruction in blocks other than
/// the specified block. Note that PHI nodes are considered to evaluate their
/// operands in the corresponding predecessor block.
bool isUsedOutsideOfBlock(const BasicBlock *BB) const LLVM_READONLY__attribute__((__pure__));

/// Return the number of successors that this instruction has. The instruction
/// must be a terminator.
unsigned getNumSuccessors() const LLVM_READONLY__attribute__((__pure__));

/// Return the specified successor. This instruction must be a terminator.
BasicBlock *getSuccessor(unsigned Idx) const LLVM_READONLY__attribute__((__pure__));

/// Update the specified successor to point at the provided block. This
/// instruction must be a terminator.
void setSuccessor(unsigned Idx, BasicBlock *BB);

/// Replace specified successor OldBB to point at the provided block.
/// This instruction must be a terminator.
void replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB);

/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
  return V->getValueID() >= Value::InstructionVal;
}

//----------------------------------------------------------------------
// Exported enumerations.
//
enum TermOps {       // These terminate basic blocks
796#define  FIRST_TERM_INST(N)             TermOpsBegin = N,
797#define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
798#define   LAST_TERM_INST(N)             TermOpsEnd = N+1
799#include "llvm/IR/Instruction.def"
};

enum UnaryOps {
803#define  FIRST_UNARY_INST(N)             UnaryOpsBegin = N,
804#define HANDLE_UNARY_INST(N, OPC, CLASS) OPC = N,
805#define   LAST_UNARY_INST(N)             UnaryOpsEnd = N+1
806#include "llvm/IR/Instruction.def"
};

enum BinaryOps {
810#define  FIRST_BINARY_INST(N)             BinaryOpsBegin = N,
811#define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
812#define   LAST_BINARY_INST(N)             BinaryOpsEnd = N+1
813#include "llvm/IR/Instruction.def"
};

enum MemoryOps {
817#define  FIRST_MEMORY_INST(N)             MemoryOpsBegin = N,
818#define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
819#define   LAST_MEMORY_INST(N)             MemoryOpsEnd = N+1
820#include "llvm/IR/Instruction.def"
};

enum CastOps {
824#define  FIRST_CAST_INST(N)             CastOpsBegin = N,
825#define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
826#define   LAST_CAST_INST(N)             CastOpsEnd = N+1
827#include "llvm/IR/Instruction.def"
};

enum FuncletPadOps {
831#define  FIRST_FUNCLETPAD_INST(N)             FuncletPadOpsBegin = N,
832#define HANDLE_FUNCLETPAD_INST(N, OPC, CLASS) OPC = N,
833#define   LAST_FUNCLETPAD_INST(N)             FuncletPadOpsEnd = N+1
834#include "llvm/IR/Instruction.def"
};

enum OtherOps {
838#define  FIRST_OTHER_INST(N)             OtherOpsBegin = N,
839#define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
840#define   LAST_OTHER_INST(N)             OtherOpsEnd = N+1
841#include "llvm/IR/Instruction.def"
};

844private:
friend class SymbolTableListTraits<Instruction>;
friend class BasicBlock; // For renumbering.

// Shadow Value::setValueSubclassData with a private forwarding method so that
// subclasses cannot accidentally use it.
void setValueSubclassData(unsigned short D) {
  Value::setValueSubclassData(D);
}

unsigned short getSubclassDataFromValue() const {
  return Value::getSubclassDataFromValue();
}

void setParent(BasicBlock *P);

860protected:
// Instruction subclasses can stick up to 15 bits of stuff into the
// SubclassData field of instruction with these members.

template <typename BitfieldElement>
typename BitfieldElement::Type getSubclassData() const {
  static_assert(
      std::is_same<BitfieldElement, HasMetadataField>::value ||
          !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(),
      "Must not overlap with the metadata bit");
  return Bitfield::get<BitfieldElement>(getSubclassDataFromValue());
}

template <typename BitfieldElement>
void setSubclassData(typename BitfieldElement::Type Value) {
  static_assert(
      std::is_same<BitfieldElement, HasMetadataField>::value ||
          !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(),
      "Must not overlap with the metadata bit");
  auto Storage = getSubclassDataFromValue();
  Bitfield::set<BitfieldElement>(Storage, Value);
  setValueSubclassData(Storage);
}

Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
            Instruction *InsertBefore = nullptr);
Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
            BasicBlock *InsertAtEnd);

889private:
/// Create a copy of this instruction.
Instruction *cloneImpl() const;
892};

894inline void ilist_alloc_traits<Instruction>::deleteNode(Instruction *V) {
V->deleteValue();
896}

898} // end namespace llvm

900#endif // LLVM_IR_INSTRUCTION_H