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android / platform / external / llvm / refs/heads/android15-tests-dev / . / lib / Transforms / InstCombine / InstCombineCalls.cpp
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//===- InstCombineCalls.cpp -----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the visitCall and visitInvoke functions.
//
//===----------------------------------------------------------------------===//
#include "InstCombineInternal.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/SimplifyLibCalls.h"
using namespace llvm;
using namespace PatternMatch;
#define DEBUG_TYPE "instcombine"
STATISTIC(NumSimplified, "Number of library calls simplified");
/// Return the specified type promoted as it would be to pass though a va_arg
/// area.
static Type *getPromotedType(Type *Ty) {
if (IntegerType* ITy = dyn_cast<IntegerType>(Ty)) {
if (ITy->getBitWidth() < 32)
return Type::getInt32Ty(Ty->getContext());
}
return Ty;
}
/// Given an aggregate type which ultimately holds a single scalar element,
/// like {{{type}}} or [1 x type], return type.
static Type *reduceToSingleValueType(Type *T) {
while (!T->isSingleValueType()) {
if (StructType *STy = dyn_cast<StructType>(T)) {
if (STy->getNumElements() == 1)
T = STy->getElementType(0);
else
break;
} else if (ArrayType *ATy = dyn_cast<ArrayType>(T)) {
if (ATy->getNumElements() == 1)
T = ATy->getElementType();
else
break;
} else
break;
}
return T;
}
/// Return a constant boolean vector that has true elements in all positions
/// where the input constant data vector has an element with the sign bit set.
static Constant *getNegativeIsTrueBoolVec(ConstantDataVector *V) {
SmallVector<Constant *, 32> BoolVec;
IntegerType *BoolTy = Type::getInt1Ty(V->getContext());
for (unsigned I = 0, E = V->getNumElements(); I != E; ++I) {
Constant *Elt = V->getElementAsConstant(I);
assert((isa<ConstantInt>(Elt) || isa<ConstantFP>(Elt)) &&
"Unexpected constant data vector element type");
bool Sign = V->getElementType()->isIntegerTy()
? cast<ConstantInt>(Elt)->isNegative()
: cast<ConstantFP>(Elt)->isNegative();
BoolVec.push_back(ConstantInt::get(BoolTy, Sign));
}
return ConstantVector::get(BoolVec);
}
Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), DL, MI, AC, DT);
unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), DL, MI, AC, DT);
unsigned MinAlign = std::min(DstAlign, SrcAlign);
unsigned CopyAlign = MI->getAlignment();
if (CopyAlign < MinAlign) {
MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), MinAlign, false));
return MI;
}
// If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with
// load/store.
ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getArgOperand(2));
if (!MemOpLength) return nullptr;
// Source and destination pointer types are always "i8*" for intrinsic. See
// if the size is something we can handle with a single primitive load/store.
// A single load+store correctly handles overlapping memory in the memmove
// case.
uint64_t Size = MemOpLength->getLimitedValue();
assert(Size && "0-sized memory transferring should be removed already.");
if (Size > 8 || (Size&(Size-1)))
return nullptr; // If not 1/2/4/8 bytes, exit.
// Use an integer load+store unless we can find something better.
unsigned SrcAddrSp =
cast<PointerType>(MI->getArgOperand(1)->getType())->getAddressSpace();
unsigned DstAddrSp =
cast<PointerType>(MI->getArgOperand(0)->getType())->getAddressSpace();
IntegerType* IntType = IntegerType::get(MI->getContext(), Size<<3);
Type *NewSrcPtrTy = PointerType::get(IntType, SrcAddrSp);
Type *NewDstPtrTy = PointerType::get(IntType, DstAddrSp);
// Memcpy forces the use of i8* for the source and destination. That means
// that if you're using memcpy to move one double around, you'll get a cast
// from double* to i8*. We'd much rather use a double load+store rather than
// an i64 load+store, here because this improves the odds that the source or
// dest address will be promotable. See if we can find a better type than the
// integer datatype.
Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts();
MDNode *CopyMD = nullptr;
if (StrippedDest != MI->getArgOperand(0)) {
Type *SrcETy = cast<PointerType>(StrippedDest->getType())
->getElementType();
if (SrcETy->isSized() && DL.getTypeStoreSize(SrcETy) == Size) {
// The SrcETy might be something like {{{double}}} or [1 x double]. Rip
// down through these levels if so.
SrcETy = reduceToSingleValueType(SrcETy);
if (SrcETy->isSingleValueType()) {
NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp);
NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp);
// If the memcpy has metadata describing the members, see if we can
// get the TBAA tag describing our copy.
if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) {
if (M->getNumOperands() == 3 && M->getOperand(0) &&
mdconst::hasa<ConstantInt>(M->getOperand(0)) &&
mdconst::extract<ConstantInt>(M->getOperand(0))->isNullValue() &&
M->getOperand(1) &&
mdconst::hasa<ConstantInt>(M->getOperand(1)) &&
mdconst::extract<ConstantInt>(M->getOperand(1))->getValue() ==
Size &&
M->getOperand(2) && isa<MDNode>(M->getOperand(2)))
CopyMD = cast<MDNode>(M->getOperand(2));
}
}
}
}
// If the memcpy/memmove provides better alignment info than we can
// infer, use it.
SrcAlign = std::max(SrcAlign, CopyAlign);
DstAlign = std::max(DstAlign, CopyAlign);
Value *Src = Builder->CreateBitCast(MI->getArgOperand(1), NewSrcPtrTy);
Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy);
LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile());
L->setAlignment(SrcAlign);
if (CopyMD)
L->setMetadata(LLVMContext::MD_tbaa, CopyMD);
StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile());
S->setAlignment(DstAlign);
if (CopyMD)
S->setMetadata(LLVMContext::MD_tbaa, CopyMD);
// Set the size of the copy to 0, it will be deleted on the next iteration.
MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType()));
return MI;
}
Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
unsigned Alignment = getKnownAlignment(MI->getDest(), DL, MI, AC, DT);
if (MI->getAlignment() < Alignment) {
MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
Alignment, false));
return MI;
}
// Extract the length and alignment and fill if they are constant.
ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength());
ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
return nullptr;
uint64_t Len = LenC->getLimitedValue();
Alignment = MI->getAlignment();
assert(Len && "0-sized memory setting should be removed already.");
// memset(s,c,n) -> store s, c (for n=1,2,4,8)
if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {
Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8.
Value *Dest = MI->getDest();
unsigned DstAddrSp = cast<PointerType>(Dest->getType())->getAddressSpace();
Type *NewDstPtrTy = PointerType::get(ITy, DstAddrSp);
Dest = Builder->CreateBitCast(Dest, NewDstPtrTy);
// Alignment 0 is identity for alignment 1 for memset, but not store.
if (Alignment == 0) Alignment = 1;
// Extract the fill value and store.
uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL;
StoreInst *S = Builder->CreateStore(ConstantInt::get(ITy, Fill), Dest,
MI->isVolatile());
S->setAlignment(Alignment);
// Set the size of the copy to 0, it will be deleted on the next iteration.
MI->setLength(Constant::getNullValue(LenC->getType()));
return MI;
}
return nullptr;
}
static Value *simplifyX86immShift(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
bool LogicalShift = false;
bool ShiftLeft = false;
switch (II.getIntrinsicID()) {
default:
return nullptr;
case Intrinsic::x86_sse2_psra_d:
case Intrinsic::x86_sse2_psra_w:
case Intrinsic::x86_sse2_psrai_d:
case Intrinsic::x86_sse2_psrai_w:
case Intrinsic::x86_avx2_psra_d:
case Intrinsic::x86_avx2_psra_w:
case Intrinsic::x86_avx2_psrai_d:
case Intrinsic::x86_avx2_psrai_w:
LogicalShift = false; ShiftLeft = false;
break;
case Intrinsic::x86_sse2_psrl_d:
case Intrinsic::x86_sse2_psrl_q:
case Intrinsic::x86_sse2_psrl_w:
case Intrinsic::x86_sse2_psrli_d:
case Intrinsic::x86_sse2_psrli_q:
case Intrinsic::x86_sse2_psrli_w:
case Intrinsic::x86_avx2_psrl_d:
case Intrinsic::x86_avx2_psrl_q:
case Intrinsic::x86_avx2_psrl_w:
case Intrinsic::x86_avx2_psrli_d:
case Intrinsic::x86_avx2_psrli_q:
case Intrinsic::x86_avx2_psrli_w:
LogicalShift = true; ShiftLeft = false;
break;
case Intrinsic::x86_sse2_psll_d:
case Intrinsic::x86_sse2_psll_q:
case Intrinsic::x86_sse2_psll_w:
case Intrinsic::x86_sse2_pslli_d:
case Intrinsic::x86_sse2_pslli_q:
case Intrinsic::x86_sse2_pslli_w:
case Intrinsic::x86_avx2_psll_d:
case Intrinsic::x86_avx2_psll_q:
case Intrinsic::x86_avx2_psll_w:
case Intrinsic::x86_avx2_pslli_d:
case Intrinsic::x86_avx2_pslli_q:
case Intrinsic::x86_avx2_pslli_w:
LogicalShift = true; ShiftLeft = true;
break;
}
assert((LogicalShift || !ShiftLeft) && "Only logical shifts can shift left");
// Simplify if count is constant.
auto Arg1 = II.getArgOperand(1);
auto CAZ = dyn_cast<ConstantAggregateZero>(Arg1);
auto CDV = dyn_cast<ConstantDataVector>(Arg1);
auto CInt = dyn_cast<ConstantInt>(Arg1);
if (!CAZ && !CDV && !CInt)
return nullptr;
APInt Count(64, 0);
if (CDV) {
// SSE2/AVX2 uses all the first 64-bits of the 128-bit vector
// operand to compute the shift amount.
auto VT = cast<VectorType>(CDV->getType());
unsigned BitWidth = VT->getElementType()->getPrimitiveSizeInBits();
assert((64 % BitWidth) == 0 && "Unexpected packed shift size");
unsigned NumSubElts = 64 / BitWidth;
// Concatenate the sub-elements to create the 64-bit value.
for (unsigned i = 0; i != NumSubElts; ++i) {
unsigned SubEltIdx = (NumSubElts - 1) - i;
auto SubElt = cast<ConstantInt>(CDV->getElementAsConstant(SubEltIdx));
Count = Count.shl(BitWidth);
Count |= SubElt->getValue().zextOrTrunc(64);
}
}
else if (CInt)
Count = CInt->getValue();
auto Vec = II.getArgOperand(0);
auto VT = cast<VectorType>(Vec->getType());
auto SVT = VT->getElementType();
unsigned VWidth = VT->getNumElements();
unsigned BitWidth = SVT->getPrimitiveSizeInBits();
// If shift-by-zero then just return the original value.
if (Count == 0)
return Vec;
// Handle cases when Shift >= BitWidth.
if (Count.uge(BitWidth)) {
// If LogicalShift - just return zero.
if (LogicalShift)
return ConstantAggregateZero::get(VT);
// If ArithmeticShift - clamp Shift to (BitWidth - 1).
Count = APInt(64, BitWidth - 1);
}
// Get a constant vector of the same type as the first operand.
auto ShiftAmt = ConstantInt::get(SVT, Count.zextOrTrunc(BitWidth));
auto ShiftVec = Builder.CreateVectorSplat(VWidth, ShiftAmt);
if (ShiftLeft)
return Builder.CreateShl(Vec, ShiftVec);
if (LogicalShift)
return Builder.CreateLShr(Vec, ShiftVec);
return Builder.CreateAShr(Vec, ShiftVec);
}
// Attempt to simplify AVX2 per-element shift intrinsics to a generic IR shift.
// Unlike the generic IR shifts, the intrinsics have defined behaviour for out
// of range shift amounts (logical - set to zero, arithmetic - splat sign bit).
static Value *simplifyX86varShift(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
bool LogicalShift = false;
bool ShiftLeft = false;
switch (II.getIntrinsicID()) {
default:
return nullptr;
case Intrinsic::x86_avx2_psrav_d:
case Intrinsic::x86_avx2_psrav_d_256:
LogicalShift = false;
ShiftLeft = false;
break;
case Intrinsic::x86_avx2_psrlv_d:
case Intrinsic::x86_avx2_psrlv_d_256:
case Intrinsic::x86_avx2_psrlv_q:
case Intrinsic::x86_avx2_psrlv_q_256:
LogicalShift = true;
ShiftLeft = false;
break;
case Intrinsic::x86_avx2_psllv_d:
case Intrinsic::x86_avx2_psllv_d_256:
case Intrinsic::x86_avx2_psllv_q:
case Intrinsic::x86_avx2_psllv_q_256:
LogicalShift = true;
ShiftLeft = true;
break;
}
assert((LogicalShift || !ShiftLeft) && "Only logical shifts can shift left");
// Simplify if all shift amounts are constant/undef.
auto *CShift = dyn_cast<Constant>(II.getArgOperand(1));
if (!CShift)
return nullptr;
auto Vec = II.getArgOperand(0);
auto VT = cast<VectorType>(II.getType());
auto SVT = VT->getVectorElementType();
int NumElts = VT->getNumElements();
int BitWidth = SVT->getIntegerBitWidth();
// Collect each element's shift amount.
// We also collect special cases: UNDEF = -1, OUT-OF-RANGE = BitWidth.
bool AnyOutOfRange = false;
SmallVector<int, 8> ShiftAmts;
for (int I = 0; I < NumElts; ++I) {
auto *CElt = CShift->getAggregateElement(I);
if (CElt && isa<UndefValue>(CElt)) {
ShiftAmts.push_back(-1);
continue;
}
auto *COp = dyn_cast_or_null<ConstantInt>(CElt);
if (!COp)
return nullptr;
// Handle out of range shifts.
// If LogicalShift - set to BitWidth (special case).
// If ArithmeticShift - set to (BitWidth - 1) (sign splat).
APInt ShiftVal = COp->getValue();
if (ShiftVal.uge(BitWidth)) {
AnyOutOfRange = LogicalShift;
ShiftAmts.push_back(LogicalShift ? BitWidth : BitWidth - 1);
continue;
}
ShiftAmts.push_back((int)ShiftVal.getZExtValue());
}
// If all elements out of range or UNDEF, return vector of zeros/undefs.
// ArithmeticShift should only hit this if they are all UNDEF.
auto OutOfRange = [&](int Idx) { return (Idx < 0) || (BitWidth <= Idx); };
if (llvm::all_of(ShiftAmts, OutOfRange)) {
SmallVector<Constant *, 8> ConstantVec;
for (int Idx : ShiftAmts) {
if (Idx < 0) {
ConstantVec.push_back(UndefValue::get(SVT));
} else {
assert(LogicalShift && "Logical shift expected");
ConstantVec.push_back(ConstantInt::getNullValue(SVT));
}
}
return ConstantVector::get(ConstantVec);
}
// We can't handle only some out of range values with generic logical shifts.
if (AnyOutOfRange)
return nullptr;
// Build the shift amount constant vector.
SmallVector<Constant *, 8> ShiftVecAmts;
for (int Idx : ShiftAmts) {
if (Idx < 0)
ShiftVecAmts.push_back(UndefValue::get(SVT));
else
ShiftVecAmts.push_back(ConstantInt::get(SVT, Idx));
}
auto ShiftVec = ConstantVector::get(ShiftVecAmts);
if (ShiftLeft)
return Builder.CreateShl(Vec, ShiftVec);
if (LogicalShift)
return Builder.CreateLShr(Vec, ShiftVec);
return Builder.CreateAShr(Vec, ShiftVec);
}
static Value *simplifyX86movmsk(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
Value *Arg = II.getArgOperand(0);
Type *ResTy = II.getType();
Type *ArgTy = Arg->getType();
// movmsk(undef) -> zero as we must ensure the upper bits are zero.
if (isa<UndefValue>(Arg))
return Constant::getNullValue(ResTy);
// We can't easily peek through x86_mmx types.
if (!ArgTy->isVectorTy())
return nullptr;
auto *C = dyn_cast<Constant>(Arg);
if (!C)
return nullptr;
// Extract signbits of the vector input and pack into integer result.
APInt Result(ResTy->getPrimitiveSizeInBits(), 0);
for (unsigned I = 0, E = ArgTy->getVectorNumElements(); I != E; ++I) {
auto *COp = C->getAggregateElement(I);
if (!COp)
return nullptr;
if (isa<UndefValue>(COp))
continue;
auto *CInt = dyn_cast<ConstantInt>(COp);
auto *CFp = dyn_cast<ConstantFP>(COp);
if (!CInt && !CFp)
return nullptr;
if ((CInt && CInt->isNegative()) || (CFp && CFp->isNegative()))
Result.setBit(I);
}
return Constant::getIntegerValue(ResTy, Result);
}
static Value *simplifyX86insertps(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
auto *CInt = dyn_cast<ConstantInt>(II.getArgOperand(2));
if (!CInt)
return nullptr;
VectorType *VecTy = cast<VectorType>(II.getType());
assert(VecTy->getNumElements() == 4 && "insertps with wrong vector type");
// The immediate permute control byte looks like this:
// [3:0] - zero mask for each 32-bit lane
// [5:4] - select one 32-bit destination lane
// [7:6] - select one 32-bit source lane
uint8_t Imm = CInt->getZExtValue();
uint8_t ZMask = Imm & 0xf;
uint8_t DestLane = (Imm >> 4) & 0x3;
uint8_t SourceLane = (Imm >> 6) & 0x3;
ConstantAggregateZero *ZeroVector = ConstantAggregateZero::get(VecTy);
// If all zero mask bits are set, this was just a weird way to
// generate a zero vector.
if (ZMask == 0xf)
return ZeroVector;
// Initialize by passing all of the first source bits through.
uint32_t ShuffleMask[4] = { 0, 1, 2, 3 };
// We may replace the second operand with the zero vector.
Value *V1 = II.getArgOperand(1);
if (ZMask) {
// If the zero mask is being used with a single input or the zero mask
// overrides the destination lane, this is a shuffle with the zero vector.
if ((II.getArgOperand(0) == II.getArgOperand(1)) ||
(ZMask & (1 << DestLane))) {
V1 = ZeroVector;
// We may still move 32-bits of the first source vector from one lane
// to another.
ShuffleMask[DestLane] = SourceLane;
// The zero mask may override the previous insert operation.
for (unsigned i = 0; i < 4; ++i)
if ((ZMask >> i) & 0x1)
ShuffleMask[i] = i + 4;
} else {
// TODO: Model this case as 2 shuffles or a 'logical and' plus shuffle?
return nullptr;
}
} else {
// Replace the selected destination lane with the selected source lane.
ShuffleMask[DestLane] = SourceLane + 4;
}
return Builder.CreateShuffleVector(II.getArgOperand(0), V1, ShuffleMask);
}
/// Attempt to simplify SSE4A EXTRQ/EXTRQI instructions using constant folding
/// or conversion to a shuffle vector.
static Value *simplifyX86extrq(IntrinsicInst &II, Value *Op0,
ConstantInt *CILength, ConstantInt *CIIndex,
InstCombiner::BuilderTy &Builder) {
auto LowConstantHighUndef = [&](uint64_t Val) {
Type *IntTy64 = Type::getInt64Ty(II.getContext());
Constant *Args[] = {ConstantInt::get(IntTy64, Val),
UndefValue::get(IntTy64)};
return ConstantVector::get(Args);
};
// See if we're dealing with constant values.
Constant *C0 = dyn_cast<Constant>(Op0);
ConstantInt *CI0 =
C0 ? dyn_cast<ConstantInt>(C0->getAggregateElement((unsigned)0))
: nullptr;
// Attempt to constant fold.
if (CILength && CIIndex) {
// From AMD documentation: "The bit index and field length are each six
// bits in length other bits of the field are ignored."
APInt APIndex = CIIndex->getValue().zextOrTrunc(6);
APInt APLength = CILength->getValue().zextOrTrunc(6);
unsigned Index = APIndex.getZExtValue();
// From AMD documentation: "a value of zero in the field length is
// defined as length of 64".
unsigned Length = APLength == 0 ? 64 : APLength.getZExtValue();
// From AMD documentation: "If the sum of the bit index + length field
// is greater than 64, the results are undefined".
unsigned End = Index + Length;
// Note that both field index and field length are 8-bit quantities.
// Since variables 'Index' and 'Length' are unsigned values
// obtained from zero-extending field index and field length
// respectively, their sum should never wrap around.
if (End > 64)
return UndefValue::get(II.getType());
// If we are inserting whole bytes, we can convert this to a shuffle.
// Lowering can recognize EXTRQI shuffle masks.
if ((Length % 8) == 0 && (Index % 8) == 0) {
// Convert bit indices to byte indices.
Length /= 8;
Index /= 8;
Type *IntTy8 = Type::getInt8Ty(II.getContext());
Type *IntTy32 = Type::getInt32Ty(II.getContext());
VectorType *ShufTy = VectorType::get(IntTy8, 16);
SmallVector<Constant *, 16> ShuffleMask;
for (int i = 0; i != (int)Length; ++i)
ShuffleMask.push_back(
Constant::getIntegerValue(IntTy32, APInt(32, i + Index)));
for (int i = Length; i != 8; ++i)
ShuffleMask.push_back(
Constant::getIntegerValue(IntTy32, APInt(32, i + 16)));
for (int i = 8; i != 16; ++i)
ShuffleMask.push_back(UndefValue::get(IntTy32));
Value *SV = Builder.CreateShuffleVector(
Builder.CreateBitCast(Op0, ShufTy),
ConstantAggregateZero::get(ShufTy), ConstantVector::get(ShuffleMask));
return Builder.CreateBitCast(SV, II.getType());
}
// Constant Fold - shift Index'th bit to lowest position and mask off
// Length bits.
if (CI0) {
APInt Elt = CI0->getValue();
Elt = Elt.lshr(Index).zextOrTrunc(Length);
return LowConstantHighUndef(Elt.getZExtValue());
}
// If we were an EXTRQ call, we'll save registers if we convert to EXTRQI.
if (II.getIntrinsicID() == Intrinsic::x86_sse4a_extrq) {
Value *Args[] = {Op0, CILength, CIIndex};
Module *M = II.getModule();
Value *F = Intrinsic::getDeclaration(M, Intrinsic::x86_sse4a_extrqi);
return Builder.CreateCall(F, Args);
}
}
// Constant Fold - extraction from zero is always {zero, undef}.
if (CI0 && CI0->equalsInt(0))
return LowConstantHighUndef(0);
return nullptr;
}
/// Attempt to simplify SSE4A INSERTQ/INSERTQI instructions using constant
/// folding or conversion to a shuffle vector.
static Value *simplifyX86insertq(IntrinsicInst &II, Value *Op0, Value *Op1,
APInt APLength, APInt APIndex,
InstCombiner::BuilderTy &Builder) {
// From AMD documentation: "The bit index and field length are each six bits
// in length other bits of the field are ignored."
APIndex = APIndex.zextOrTrunc(6);
APLength = APLength.zextOrTrunc(6);
// Attempt to constant fold.
unsigned Index = APIndex.getZExtValue();
// From AMD documentation: "a value of zero in the field length is
// defined as length of 64".
unsigned Length = APLength == 0 ? 64 : APLength.getZExtValue();
// From AMD documentation: "If the sum of the bit index + length field
// is greater than 64, the results are undefined".
unsigned End = Index + Length;
// Note that both field index and field length are 8-bit quantities.
// Since variables 'Index' and 'Length' are unsigned values
// obtained from zero-extending field index and field length
// respectively, their sum should never wrap around.
if (End > 64)
return UndefValue::get(II.getType());
// If we are inserting whole bytes, we can convert this to a shuffle.
// Lowering can recognize INSERTQI shuffle masks.
if ((Length % 8) == 0 && (Index % 8) == 0) {
// Convert bit indices to byte indices.
Length /= 8;
Index /= 8;
Type *IntTy8 = Type::getInt8Ty(II.getContext());
Type *IntTy32 = Type::getInt32Ty(II.getContext());
VectorType *ShufTy = VectorType::get(IntTy8, 16);
SmallVector<Constant *, 16> ShuffleMask;
for (int i = 0; i != (int)Index; ++i)
ShuffleMask.push_back(Constant::getIntegerValue(IntTy32, APInt(32, i)));
for (int i = 0; i != (int)Length; ++i)
ShuffleMask.push_back(
Constant::getIntegerValue(IntTy32, APInt(32, i + 16)));
for (int i = Index + Length; i != 8; ++i)
ShuffleMask.push_back(Constant::getIntegerValue(IntTy32, APInt(32, i)));
for (int i = 8; i != 16; ++i)
ShuffleMask.push_back(UndefValue::get(IntTy32));
Value *SV = Builder.CreateShuffleVector(Builder.CreateBitCast(Op0, ShufTy),
Builder.CreateBitCast(Op1, ShufTy),
ConstantVector::get(ShuffleMask));
return Builder.CreateBitCast(SV, II.getType());
}
// See if we're dealing with constant values.
Constant *C0 = dyn_cast<Constant>(Op0);
Constant *C1 = dyn_cast<Constant>(Op1);
ConstantInt *CI00 =
C0 ? dyn_cast<ConstantInt>(C0->getAggregateElement((unsigned)0))
: nullptr;
ConstantInt *CI10 =
C1 ? dyn_cast<ConstantInt>(C1->getAggregateElement((unsigned)0))
: nullptr;
// Constant Fold - insert bottom Length bits starting at the Index'th bit.
if (CI00 && CI10) {
APInt V00 = CI00->getValue();
APInt V10 = CI10->getValue();
APInt Mask = APInt::getLowBitsSet(64, Length).shl(Index);
V00 = V00 & ~Mask;
V10 = V10.zextOrTrunc(Length).zextOrTrunc(64).shl(Index);
APInt Val = V00 | V10;
Type *IntTy64 = Type::getInt64Ty(II.getContext());
Constant *Args[] = {ConstantInt::get(IntTy64, Val.getZExtValue()),
UndefValue::get(IntTy64)};
return ConstantVector::get(Args);
}
// If we were an INSERTQ call, we'll save demanded elements if we convert to
// INSERTQI.
if (II.getIntrinsicID() == Intrinsic::x86_sse4a_insertq) {
Type *IntTy8 = Type::getInt8Ty(II.getContext());
Constant *CILength = ConstantInt::get(IntTy8, Length, false);
Constant *CIIndex = ConstantInt::get(IntTy8, Index, false);
Value *Args[] = {Op0, Op1, CILength, CIIndex};
Module *M = II.getModule();
Value *F = Intrinsic::getDeclaration(M, Intrinsic::x86_sse4a_insertqi);
return Builder.CreateCall(F, Args);
}
return nullptr;
}
/// Attempt to convert pshufb* to shufflevector if the mask is constant.
static Value *simplifyX86pshufb(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
Constant *V = dyn_cast<Constant>(II.getArgOperand(1));
if (!V)
return nullptr;
auto *VecTy = cast<VectorType>(II.getType());
auto *MaskEltTy = Type::getInt32Ty(II.getContext());
unsigned NumElts = VecTy->getNumElements();
assert((NumElts == 16 || NumElts == 32) &&
"Unexpected number of elements in shuffle mask!");
// Construct a shuffle mask from constant integers or UNDEFs.
Constant *Indexes[32] = {NULL};
// Each byte in the shuffle control mask forms an index to permute the
// corresponding byte in the destination operand.
for (unsigned I = 0; I < NumElts; ++I) {
Constant *COp = V->getAggregateElement(I);
if (!COp || (!isa<UndefValue>(COp) && !isa<ConstantInt>(COp)))
return nullptr;
if (isa<UndefValue>(COp)) {
Indexes[I] = UndefValue::get(MaskEltTy);
continue;
}
int8_t Index = cast<ConstantInt>(COp)->getValue().getZExtValue();
// If the most significant bit (bit[7]) of each byte of the shuffle
// control mask is set, then zero is written in the result byte.
// The zero vector is in the right-hand side of the resulting
// shufflevector.
// The value of each index for the high 128-bit lane is the least
// significant 4 bits of the respective shuffle control byte.
Index = ((Index < 0) ? NumElts : Index & 0x0F) + (I & 0xF0);
Indexes[I] = ConstantInt::get(MaskEltTy, Index);
}
auto ShuffleMask = ConstantVector::get(makeArrayRef(Indexes, NumElts));
auto V1 = II.getArgOperand(0);
auto V2 = Constant::getNullValue(VecTy);
return Builder.CreateShuffleVector(V1, V2, ShuffleMask);
}
/// Attempt to convert vpermilvar* to shufflevector if the mask is constant.
static Value *simplifyX86vpermilvar(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
Constant *V = dyn_cast<Constant>(II.getArgOperand(1));
if (!V)
return nullptr;
auto *MaskEltTy = Type::getInt32Ty(II.getContext());
unsigned NumElts = cast<VectorType>(V->getType())->getNumElements();
assert(NumElts == 8 || NumElts == 4 || NumElts == 2);
// Construct a shuffle mask from constant integers or UNDEFs.
Constant *Indexes[8] = {NULL};
// The intrinsics only read one or two bits, clear the rest.
for (unsigned I = 0; I < NumElts; ++I) {
Constant *COp = V->getAggregateElement(I);
if (!COp || (!isa<UndefValue>(COp) && !isa<ConstantInt>(COp)))
return nullptr;
if (isa<UndefValue>(COp)) {
Indexes[I] = UndefValue::get(MaskEltTy);
continue;
}
APInt Index = cast<ConstantInt>(COp)->getValue();
Index = Index.zextOrTrunc(32).getLoBits(2);
// The PD variants uses bit 1 to select per-lane element index, so
// shift down to convert to generic shuffle mask index.
if (II.getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd ||
II.getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256)
Index = Index.lshr(1);
// The _256 variants are a bit trickier since the mask bits always index
// into the corresponding 128 half. In order to convert to a generic
// shuffle, we have to make that explicit.
if ((II.getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_ps_256 ||
II.getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256) &&
((NumElts / 2) <= I)) {
Index += APInt(32, NumElts / 2);
}
Indexes[I] = ConstantInt::get(MaskEltTy, Index);
}
auto ShuffleMask = ConstantVector::get(makeArrayRef(Indexes, NumElts));
auto V1 = II.getArgOperand(0);
auto V2 = UndefValue::get(V1->getType());
return Builder.CreateShuffleVector(V1, V2, ShuffleMask);
}
/// Attempt to convert vpermd/vpermps to shufflevector if the mask is constant.
static Value *simplifyX86vpermv(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
auto *V = dyn_cast<Constant>(II.getArgOperand(1));
if (!V)
return nullptr;
auto *VecTy = cast<VectorType>(II.getType());
auto *MaskEltTy = Type::getInt32Ty(II.getContext());
unsigned Size = VecTy->getNumElements();
assert(Size == 8 && "Unexpected shuffle mask size");
// Construct a shuffle mask from constant integers or UNDEFs.
Constant *Indexes[8] = {NULL};
for (unsigned I = 0; I < Size; ++I) {
Constant *COp = V->getAggregateElement(I);
if (!COp || (!isa<UndefValue>(COp) && !isa<ConstantInt>(COp)))
return nullptr;
if (isa<UndefValue>(COp)) {
Indexes[I] = UndefValue::get(MaskEltTy);
continue;
}
APInt Index = cast<ConstantInt>(COp)->getValue();
Index = Index.zextOrTrunc(32).getLoBits(3);
Indexes[I] = ConstantInt::get(MaskEltTy, Index);
}
auto ShuffleMask = ConstantVector::get(makeArrayRef(Indexes, Size));
auto V1 = II.getArgOperand(0);
auto V2 = UndefValue::get(VecTy);
return Builder.CreateShuffleVector(V1, V2, ShuffleMask);
}
/// The shuffle mask for a perm2*128 selects any two halves of two 256-bit
/// source vectors, unless a zero bit is set. If a zero bit is set,
/// then ignore that half of the mask and clear that half of the vector.
static Value *simplifyX86vperm2(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
auto *CInt = dyn_cast<ConstantInt>(II.getArgOperand(2));
if (!CInt)
return nullptr;
VectorType *VecTy = cast<VectorType>(II.getType());
ConstantAggregateZero *ZeroVector = ConstantAggregateZero::get(VecTy);
// The immediate permute control byte looks like this:
// [1:0] - select 128 bits from sources for low half of destination
// [2] - ignore
// [3] - zero low half of destination
// [5:4] - select 128 bits from sources for high half of destination
// [6] - ignore
// [7] - zero high half of destination
uint8_t Imm = CInt->getZExtValue();
bool LowHalfZero = Imm & 0x08;
bool HighHalfZero = Imm & 0x80;
// If both zero mask bits are set, this was just a weird way to
// generate a zero vector.
if (LowHalfZero && HighHalfZero)
return ZeroVector;
// If 0 or 1 zero mask bits are set, this is a simple shuffle.
unsigned NumElts = VecTy->getNumElements();
unsigned HalfSize = NumElts / 2;
SmallVector<uint32_t, 8> ShuffleMask(NumElts);
// The high bit of the selection field chooses the 1st or 2nd operand.
bool LowInputSelect = Imm & 0x02;
bool HighInputSelect = Imm & 0x20;
// The low bit of the selection field chooses the low or high half
// of the selected operand.
bool LowHalfSelect = Imm & 0x01;
bool HighHalfSelect = Imm & 0x10;
// Determine which operand(s) are actually in use for this instruction.
Value *V0 = LowInputSelect ? II.getArgOperand(1) : II.getArgOperand(0);
Value *V1 = HighInputSelect ? II.getArgOperand(1) : II.getArgOperand(0);
// If needed, replace operands based on zero mask.
V0 = LowHalfZero ? ZeroVector : V0;
V1 = HighHalfZero ? ZeroVector : V1;
// Permute low half of result.
unsigned StartIndex = LowHalfSelect ? HalfSize : 0;
for (unsigned i = 0; i < HalfSize; ++i)
ShuffleMask[i] = StartIndex + i;
// Permute high half of result.
StartIndex = HighHalfSelect ? HalfSize : 0;
StartIndex += NumElts;
for (unsigned i = 0; i < HalfSize; ++i)
ShuffleMask[i + HalfSize] = StartIndex + i;
return Builder.CreateShuffleVector(V0, V1, ShuffleMask);
}
/// Decode XOP integer vector comparison intrinsics.
static Value *simplifyX86vpcom(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder,
bool IsSigned) {
if (auto *CInt = dyn_cast<ConstantInt>(II.getArgOperand(2))) {
uint64_t Imm = CInt->getZExtValue() & 0x7;
VectorType *VecTy = cast<VectorType>(II.getType());
CmpInst::Predicate Pred = ICmpInst::BAD_ICMP_PREDICATE;
switch (Imm) {
case 0x0:
Pred = IsSigned ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
break;
case 0x1:
Pred = IsSigned ? ICmpInst::ICMP_SLE : ICmpInst::ICMP_ULE;
break;
case 0x2:
Pred = IsSigned ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
break;
case 0x3:
Pred = IsSigned ? ICmpInst::ICMP_SGE : ICmpInst::ICMP_UGE;
break;
case 0x4:
Pred = ICmpInst::ICMP_EQ; break;
case 0x5:
Pred = ICmpInst::ICMP_NE; break;
case 0x6:
return ConstantInt::getSigned(VecTy, 0); // FALSE
case 0x7:
return ConstantInt::getSigned(VecTy, -1); // TRUE
}
if (Value *Cmp = Builder.CreateICmp(Pred, II.getArgOperand(0),
II.getArgOperand(1)))
return Builder.CreateSExtOrTrunc(Cmp, VecTy);
}
return nullptr;
}
static Value *simplifyMinnumMaxnum(const IntrinsicInst &II) {
Value *Arg0 = II.getArgOperand(0);
Value *Arg1 = II.getArgOperand(1);
// fmin(x, x) -> x
if (Arg0 == Arg1)
return Arg0;
const auto *C1 = dyn_cast<ConstantFP>(Arg1);
// fmin(x, nan) -> x
if (C1 && C1->isNaN())
return Arg0;
// This is the value because if undef were NaN, we would return the other
// value and cannot return a NaN unless both operands are.
//
// fmin(undef, x) -> x
if (isa<UndefValue>(Arg0))
return Arg1;
// fmin(x, undef) -> x
if (isa<UndefValue>(Arg1))
return Arg0;
Value *X = nullptr;
Value *Y = nullptr;
if (II.getIntrinsicID() == Intrinsic::minnum) {
// fmin(x, fmin(x, y)) -> fmin(x, y)
// fmin(y, fmin(x, y)) -> fmin(x, y)
if (match(Arg1, m_FMin(m_Value(X), m_Value(Y)))) {
if (Arg0 == X || Arg0 == Y)
return Arg1;
}
// fmin(fmin(x, y), x) -> fmin(x, y)
// fmin(fmin(x, y), y) -> fmin(x, y)
if (match(Arg0, m_FMin(m_Value(X), m_Value(Y)))) {
if (Arg1 == X || Arg1 == Y)
return Arg0;
}
// TODO: fmin(nnan x, inf) -> x
// TODO: fmin(nnan ninf x, flt_max) -> x
if (C1 && C1->isInfinity()) {
// fmin(x, -inf) -> -inf
if (C1->isNegative())
return Arg1;
}
} else {
assert(II.getIntrinsicID() == Intrinsic::maxnum);
// fmax(x, fmax(x, y)) -> fmax(x, y)
// fmax(y, fmax(x, y)) -> fmax(x, y)
if (match(Arg1, m_FMax(m_Value(X), m_Value(Y)))) {
if (Arg0 == X || Arg0 == Y)
return Arg1;
}
// fmax(fmax(x, y), x) -> fmax(x, y)
// fmax(fmax(x, y), y) -> fmax(x, y)
if (match(Arg0, m_FMax(m_Value(X), m_Value(Y)))) {
if (Arg1 == X || Arg1 == Y)
return Arg0;
}
// TODO: fmax(nnan x, -inf) -> x
// TODO: fmax(nnan ninf x, -flt_max) -> x
if (C1 && C1->isInfinity()) {
// fmax(x, inf) -> inf
if (!C1->isNegative())
return Arg1;
}
}
return nullptr;
}
static bool maskIsAllOneOrUndef(Value *Mask) {
auto *ConstMask = dyn_cast<Constant>(Mask);
if (!ConstMask)
return false;
if (ConstMask->isAllOnesValue() || isa<UndefValue>(ConstMask))
return true;
for (unsigned I = 0, E = ConstMask->getType()->getVectorNumElements(); I != E;
++I) {
if (auto *MaskElt = ConstMask->getAggregateElement(I))
if (MaskElt->isAllOnesValue() || isa<UndefValue>(MaskElt))
continue;
return false;
}
return true;
}
static Value *simplifyMaskedLoad(const IntrinsicInst &II,
InstCombiner::BuilderTy &Builder) {
// If the mask is all ones or undefs, this is a plain vector load of the 1st
// argument.
if (maskIsAllOneOrUndef(II.getArgOperand(2))) {
Value *LoadPtr = II.getArgOperand(0);
unsigned Alignment = cast<ConstantInt>(II.getArgOperand(1))->getZExtValue();
return Builder.CreateAlignedLoad(LoadPtr, Alignment, "unmaskedload");
}
return nullptr;
}
static Instruction *simplifyMaskedStore(IntrinsicInst &II, InstCombiner &IC) {
auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
if (!ConstMask)
return nullptr;
// If the mask is all zeros, this instruction does nothing.
if (ConstMask->isNullValue())
return IC.eraseInstFromFunction(II);
// If the mask is all ones, this is a plain vector store of the 1st argument.
if (ConstMask->isAllOnesValue()) {
Value *StorePtr = II.getArgOperand(1);
unsigned Alignment = cast<ConstantInt>(II.getArgOperand(2))->getZExtValue();
return new StoreInst(II.getArgOperand(0), StorePtr, false, Alignment);
}
return nullptr;
}
static Instruction *simplifyMaskedGather(IntrinsicInst &II, InstCombiner &IC) {
// If the mask is all zeros, return the "passthru" argument of the gather.
auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(2));
if (ConstMask && ConstMask->isNullValue())
return IC.replaceInstUsesWith(II, II.getArgOperand(3));
return nullptr;
}
static Instruction *simplifyMaskedScatter(IntrinsicInst &II, InstCombiner &IC) {
// If the mask is all zeros, a scatter does nothing.
auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
if (ConstMask && ConstMask->isNullValue())
return IC.eraseInstFromFunction(II);
return nullptr;
}
// TODO: If the x86 backend knew how to convert a bool vector mask back to an
// XMM register mask efficiently, we could transform all x86 masked intrinsics
// to LLVM masked intrinsics and remove the x86 masked intrinsic defs.
static Instruction *simplifyX86MaskedLoad(IntrinsicInst &II, InstCombiner &IC) {
Value *Ptr = II.getOperand(0);
Value *Mask = II.getOperand(1);
Constant *ZeroVec = Constant::getNullValue(II.getType());
// Special case a zero mask since that's not a ConstantDataVector.
// This masked load instruction creates a zero vector.
if (isa<ConstantAggregateZero>(Mask))
return IC.replaceInstUsesWith(II, ZeroVec);
auto *ConstMask = dyn_cast<ConstantDataVector>(Mask);
if (!ConstMask)
return nullptr;
// The mask is constant. Convert this x86 intrinsic to the LLVM instrinsic
// to allow target-independent optimizations.
// First, cast the x86 intrinsic scalar pointer to a vector pointer to match
// the LLVM intrinsic definition for the pointer argument.
unsigned AddrSpace = cast<PointerType>(Ptr->getType())->getAddressSpace();
PointerType *VecPtrTy = PointerType::get(II.getType(), AddrSpace);
Value *PtrCast = IC.Builder->CreateBitCast(Ptr, VecPtrTy, "castvec");
// Second, convert the x86 XMM integer vector mask to a vector of bools based
// on each element's most significant bit (the sign bit).
Constant *BoolMask = getNegativeIsTrueBoolVec(ConstMask);
// The pass-through vector for an x86 masked load is a zero vector.
CallInst *NewMaskedLoad =
IC.Builder->CreateMaskedLoad(PtrCast, 1, BoolMask, ZeroVec);
return IC.replaceInstUsesWith(II, NewMaskedLoad);
}
// TODO: If the x86 backend knew how to convert a bool vector mask back to an
// XMM register mask efficiently, we could transform all x86 masked intrinsics
// to LLVM masked intrinsics and remove the x86 masked intrinsic defs.
static bool simplifyX86MaskedStore(IntrinsicInst &II, InstCombiner &IC) {
Value *Ptr = II.getOperand(0);
Value *Mask = II.getOperand(1);
Value *Vec = II.getOperand(2);
// Special case a zero mask since that's not a ConstantDataVector:
// this masked store instruction does nothing.
if (isa<ConstantAggregateZero>(Mask)) {
IC.eraseInstFromFunction(II);
return true;
}
// The SSE2 version is too weird (eg, unaligned but non-temporal) to do
// anything else at this level.
if (II.getIntrinsicID() == Intrinsic::x86_sse2_maskmov_dqu)
return false;
auto *ConstMask = dyn_cast<ConstantDataVector>(Mask);
if (!ConstMask)
return false;
// The mask is constant. Convert this x86 intrinsic to the LLVM instrinsic
// to allow target-independent optimizations.
// First, cast the x86 intrinsic scalar pointer to a vector pointer to match
// the LLVM intrinsic definition for the pointer argument.
unsigned AddrSpace = cast<PointerType>(Ptr->getType())->getAddressSpace();
PointerType *VecPtrTy = PointerType::get(Vec->getType(), AddrSpace);
Value *PtrCast = IC.Builder->CreateBitCast(Ptr, VecPtrTy, "castvec");
// Second, convert the x86 XMM integer vector mask to a vector of bools based
// on each element's most significant bit (the sign bit).
Constant *BoolMask = getNegativeIsTrueBoolVec(ConstMask);
IC.Builder->CreateMaskedStore(Vec, PtrCast, 1, BoolMask);
// 'Replace uses' doesn't work for stores. Erase the original masked store.
IC.eraseInstFromFunction(II);
return true;
}
// Returns true iff the 2 intrinsics have the same operands, limiting the
// comparison to the first NumOperands.
static bool haveSameOperands(const IntrinsicInst &I, const IntrinsicInst &E,
unsigned NumOperands) {
assert(I.getNumArgOperands() >= NumOperands && "Not enough operands");
assert(E.getNumArgOperands() >= NumOperands && "Not enough operands");
for (unsigned i = 0; i < NumOperands; i++)
if (I.getArgOperand(i) != E.getArgOperand(i))
return false;
return true;
}
// Remove trivially empty start/end intrinsic ranges, i.e. a start
// immediately followed by an end (ignoring debuginfo or other
// start/end intrinsics in between). As this handles only the most trivial
// cases, tracking the nesting level is not needed:
//
// call @llvm.foo.start(i1 0) ; &I
// call @llvm.foo.start(i1 0)
// call @llvm.foo.end(i1 0) ; This one will not be skipped: it will be removed
// call @llvm.foo.end(i1 0)
static bool removeTriviallyEmptyRange(IntrinsicInst &I, unsigned StartID,
unsigned EndID, InstCombiner &IC) {
assert(I.getIntrinsicID() == StartID &&
"Start intrinsic does not have expected ID");
BasicBlock::iterator BI(I), BE(I.getParent()->end());
for (++BI; BI != BE; ++BI) {
if (auto *E = dyn_cast<IntrinsicInst>(BI)) {
if (isa<DbgInfoIntrinsic>(E) || E->getIntrinsicID() == StartID)
continue;
if (E->getIntrinsicID() == EndID &&
haveSameOperands(I, *E, E->getNumArgOperands())) {
IC.eraseInstFromFunction(*E);
IC.eraseInstFromFunction(I);
return true;
}
}
break;
}
return false;
}
Instruction *InstCombiner::visitVAStartInst(VAStartInst &I) {
removeTriviallyEmptyRange(I, Intrinsic::vastart, Intrinsic::vaend, *this);
return nullptr;
}
Instruction *InstCombiner::visitVACopyInst(VACopyInst &I) {
removeTriviallyEmptyRange(I, Intrinsic::vacopy, Intrinsic::vaend, *this);
return nullptr;
}
/// CallInst simplification. This mostly only handles folding of intrinsic
/// instructions. For normal calls, it allows visitCallSite to do the heavy
/// lifting.
Instruction *InstCombiner::visitCallInst(CallInst &CI) {
auto Args = CI.arg_operands();
if (Value *V = SimplifyCall(CI.getCalledValue(), Args.begin(), Args.end(), DL,
TLI, DT, AC))
return replaceInstUsesWith(CI, V);
if (isFreeCall(&CI, TLI))
return visitFree(CI);
// If the caller function is nounwind, mark the call as nounwind, even if the
// callee isn't.
if (CI.getParent()->getParent()->doesNotThrow() &&
!CI.doesNotThrow()) {
CI.setDoesNotThrow();
return &CI;
}
IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI);
if (!II) return visitCallSite(&CI);
// Intrinsics cannot occur in an invoke, so handle them here instead of in
// visitCallSite.
if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) {
bool Changed = false;
// memmove/cpy/set of zero bytes is a noop.
if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) {
if (NumBytes->isNullValue())
return eraseInstFromFunction(CI);
if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes))
if (CI->getZExtValue() == 1) {
// Replace the instruction with just byte operations. We would
// transform other cases to loads/stores, but we don't know if
// alignment is sufficient.
}
}
// No other transformations apply to volatile transfers.
if (MI->isVolatile())
return nullptr;
// If we have a memmove and the source operation is a constant global,
// then the source and dest pointers can't alias, so we can change this
// into a call to memcpy.
if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) {
if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource()))
if (GVSrc->isConstant()) {
Module *M = CI.getModule();
Intrinsic::ID MemCpyID = Intrinsic::memcpy;
Type *Tys[3] = { CI.getArgOperand(0)->getType(),
CI.getArgOperand(1)->getType(),
CI.getArgOperand(2)->getType() };
CI.setCalledFunction(Intrinsic::getDeclaration(M, MemCpyID, Tys));
Changed = true;
}
}
if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) {
// memmove(x,x,size) -> noop.
if (MTI->getSource() == MTI->getDest())
return eraseInstFromFunction(CI);
}
// If we can determine a pointer alignment that is bigger than currently
// set, update the alignment.
if (isa<MemTransferInst>(MI)) {
if (Instruction *I = SimplifyMemTransfer(MI))
return I;
} else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) {
if (Instruction *I = SimplifyMemSet(MSI))
return I;
}
if (Changed) return II;
}
auto SimplifyDemandedVectorEltsLow = [this](Value *Op, unsigned Width,
unsigned DemandedWidth) {
APInt UndefElts(Width, 0);
APInt DemandedElts = APInt::getLowBitsSet(Width, DemandedWidth);
return SimplifyDemandedVectorElts(Op, DemandedElts, UndefElts);
};
auto SimplifyDemandedVectorEltsHigh = [this](Value *Op, unsigned Width,
unsigned DemandedWidth) {
APInt UndefElts(Width, 0);
APInt DemandedElts = APInt::getHighBitsSet(Width, DemandedWidth);
return SimplifyDemandedVectorElts(Op, DemandedElts, UndefElts);
};
switch (II->getIntrinsicID()) {
default: break;
case Intrinsic::objectsize: {
uint64_t Size;
if (getObjectSize(II->getArgOperand(0), Size, DL, TLI)) {
APInt APSize(II->getType()->getIntegerBitWidth(), Size);
// Equality check to be sure that `Size` can fit in a value of type
// `II->getType()`
if (APSize == Size)
return replaceInstUsesWith(CI, ConstantInt::get(II->getType(), APSize));
}
return nullptr;
}
case Intrinsic::bswap: {
Value *IIOperand = II->getArgOperand(0);
Value *X = nullptr;
// bswap(bswap(x)) -> x
if (match(IIOperand, m_BSwap(m_Value(X))))
return replaceInstUsesWith(CI, X);
// bswap(trunc(bswap(x))) -> trunc(lshr(x, c))
if (match(IIOperand, m_Trunc(m_BSwap(m_Value(X))))) {
unsigned C = X->getType()->getPrimitiveSizeInBits() -
IIOperand->getType()->getPrimitiveSizeInBits();
Value *CV = ConstantInt::get(X->getType(), C);
Value *V = Builder->CreateLShr(X, CV);
return new TruncInst(V, IIOperand->getType());
}
break;
}
case Intrinsic::bitreverse: {
Value *IIOperand = II->getArgOperand(0);
Value *X = nullptr;
// bitreverse(bitreverse(x)) -> x
if (match(IIOperand, m_Intrinsic<Intrinsic::bitreverse>(m_Value(X))))
return replaceInstUsesWith(CI, X);
break;
}
case Intrinsic::masked_load:
if (Value *SimplifiedMaskedOp = simplifyMaskedLoad(*II, *Builder))
return replaceInstUsesWith(CI, SimplifiedMaskedOp);
break;
case Intrinsic::masked_store:
return simplifyMaskedStore(*II, *this);
case Intrinsic::masked_gather:
return simplifyMaskedGather(*II, *this);
case Intrinsic::masked_scatter:
return simplifyMaskedScatter(*II, *this);
case Intrinsic::powi:
if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
// powi(x, 0) -> 1.0
if (Power->isZero())
return replaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0));
// powi(x, 1) -> x
if (Power->isOne())
return replaceInstUsesWith(CI, II->getArgOperand(0));
// powi(x, -1) -> 1/x
if (Power->isAllOnesValue())
return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0),
II->getArgOperand(0));
}
break;
case Intrinsic::cttz: {
// If all bits below the first known one are known zero,
// this value is constant.
IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType());
// FIXME: Try to simplify vectors of integers.
if (!IT) break;
uint32_t BitWidth = IT->getBitWidth();
APInt KnownZero(BitWidth, 0);
APInt KnownOne(BitWidth, 0);
computeKnownBits(II->getArgOperand(0), KnownZero, KnownOne, 0, II);
unsigned TrailingZeros = KnownOne.countTrailingZeros();
APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros));
if ((Mask & KnownZero) == Mask)
return replaceInstUsesWith(CI, ConstantInt::get(IT,
APInt(BitWidth, TrailingZeros)));
}
break;
case Intrinsic::ctlz: {
// If all bits above the first known one are known zero,
// this value is constant.
IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType());
// FIXME: Try to simplify vectors of integers.
if (!IT) break;
uint32_t BitWidth = IT->getBitWidth();
APInt KnownZero(BitWidth, 0);
APInt KnownOne(BitWidth, 0);
computeKnownBits(II->getArgOperand(0), KnownZero, KnownOne, 0, II);
unsigned LeadingZeros = KnownOne.countLeadingZeros();
APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros));
if ((Mask & KnownZero) == Mask)
return replaceInstUsesWith(CI, ConstantInt::get(IT,
APInt(BitWidth, LeadingZeros)));
}
break;
case Intrinsic::uadd_with_overflow:
case Intrinsic::sadd_with_overflow:
case Intrinsic::umul_with_overflow:
case Intrinsic::smul_with_overflow:
if (isa<Constant>(II->getArgOperand(0)) &&
!isa<Constant>(II->getArgOperand(1))) {
// Canonicalize constants into the RHS.
Value *LHS = II->getArgOperand(0);
II->setArgOperand(0, II->getArgOperand(1));
II->setArgOperand(1, LHS);
return II;
}
// fall through
case Intrinsic::usub_with_overflow:
case Intrinsic::ssub_with_overflow: {
OverflowCheckFlavor OCF =
IntrinsicIDToOverflowCheckFlavor(II->getIntrinsicID());
assert(OCF != OCF_INVALID && "unexpected!");
Value *OperationResult = nullptr;
Constant *OverflowResult = nullptr;
if (OptimizeOverflowCheck(OCF, II->getArgOperand(0), II->getArgOperand(1),
*II, OperationResult, OverflowResult))
return CreateOverflowTuple(II, OperationResult, OverflowResult);
break;
}
case Intrinsic::minnum:
case Intrinsic::maxnum: {
Value *Arg0 = II->getArgOperand(0);
Value *Arg1 = II->getArgOperand(1);
// Canonicalize constants to the RHS.
if (isa<ConstantFP>(Arg0) && !isa<ConstantFP>(Arg1)) {
II->setArgOperand(0, Arg1);
II->setArgOperand(1, Arg0);
return II;
}
if (Value *V = simplifyMinnumMaxnum(*II))
return replaceInstUsesWith(*II, V);
break;
}
case Intrinsic::ppc_altivec_lvx:
case Intrinsic::ppc_altivec_lvxl:
// Turn PPC lvx -> load if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, II, AC, DT) >=
16) {
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr);
}
break;
case Intrinsic::ppc_vsx_lxvw4x:
case Intrinsic::ppc_vsx_lxvd2x: {
// Turn PPC VSX loads into normal loads.
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr, Twine(""), false, 1);
}
case Intrinsic::ppc_altivec_stvx:
case Intrinsic::ppc_altivec_stvxl:
// Turn stvx -> store if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(1), 16, DL, II, AC, DT) >=
16) {
Type *OpPtrTy =
PointerType::getUnqual(II->getArgOperand(0)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
return new StoreInst(II->getArgOperand(0), Ptr);
}
break;
case Intrinsic::ppc_vsx_stxvw4x:
case Intrinsic::ppc_vsx_stxvd2x: {
// Turn PPC VSX stores into normal stores.
Type *OpPtrTy = PointerType::getUnqual(II->getArgOperand(0)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
return new StoreInst(II->getArgOperand(0), Ptr, false, 1);
}
case Intrinsic::ppc_qpx_qvlfs:
// Turn PPC QPX qvlfs -> load if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, DL, II, AC, DT) >=
16) {
Type *VTy = VectorType::get(Builder->getFloatTy(),
II->getType()->getVectorNumElements());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(VTy));
Value *Load = Builder->CreateLoad(Ptr);
return new FPExtInst(Load, II->getType());
}
break;
case Intrinsic::ppc_qpx_qvlfd:
// Turn PPC QPX qvlfd -> load if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(0), 32, DL, II, AC, DT) >=
32) {
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr);
}
break;
case Intrinsic::ppc_qpx_qvstfs:
// Turn PPC QPX qvstfs -> store if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(1), 16, DL, II, AC, DT) >=
16) {
Type *VTy = VectorType::get(Builder->getFloatTy(),
II->getArgOperand(0)->getType()->getVectorNumElements());
Value *TOp = Builder->CreateFPTrunc(II->getArgOperand(0), VTy);
Type *OpPtrTy = PointerType::getUnqual(VTy);
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
return new StoreInst(TOp, Ptr);
}
break;
case Intrinsic::ppc_qpx_qvstfd:
// Turn PPC QPX qvstfd -> store if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(1), 32, DL, II, AC, DT) >=
32) {
Type *OpPtrTy =
PointerType::getUnqual(II->getArgOperand(0)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
return new StoreInst(II->getArgOperand(0), Ptr);
}
break;
case Intrinsic::x86_vcvtph2ps_128:
case Intrinsic::x86_vcvtph2ps_256: {
auto Arg = II->getArgOperand(0);
auto ArgType = cast<VectorType>(Arg->getType());
auto RetType = cast<VectorType>(II->getType());
unsigned ArgWidth = ArgType->getNumElements();
unsigned RetWidth = RetType->getNumElements();
assert(RetWidth <= ArgWidth && "Unexpected input/return vector widths");
assert(ArgType->isIntOrIntVectorTy() &&
ArgType->getScalarSizeInBits() == 16 &&
"CVTPH2PS input type should be 16-bit integer vector");
assert(RetType->getScalarType()->isFloatTy() &&
"CVTPH2PS output type should be 32-bit float vector");
// Constant folding: Convert to generic half to single conversion.
if (isa<ConstantAggregateZero>(Arg))
return replaceInstUsesWith(*II, ConstantAggregateZero::get(RetType));
if (isa<ConstantDataVector>(Arg)) {
auto VectorHalfAsShorts = Arg;
if (RetWidth < ArgWidth) {
SmallVector<uint32_t, 8> SubVecMask;
for (unsigned i = 0; i != RetWidth; ++i)
SubVecMask.push_back((int)i);
VectorHalfAsShorts = Builder->CreateShuffleVector(
Arg, UndefValue::get(ArgType), SubVecMask);
}
auto VectorHalfType =
VectorType::get(Type::getHalfTy(II->getContext()), RetWidth);
auto VectorHalfs =
Builder->CreateBitCast(VectorHalfAsShorts, VectorHalfType);
auto VectorFloats = Builder->CreateFPExt(VectorHalfs, RetType);
return replaceInstUsesWith(*II, VectorFloats);
}
// We only use the lowest lanes of the argument.
if (Value *V = SimplifyDemandedVectorEltsLow(Arg, ArgWidth, RetWidth)) {
II->setArgOperand(0, V);
return II;
}
break;
}
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: {
// These intrinsics only demand the 0th element of their input vectors. If
// we can simplify the input based on that, do so now.
Value *Arg = II->getArgOperand(0);
unsigned VWidth = Arg->getType()->getVectorNumElements();
if (Value *V = SimplifyDemandedVectorEltsLow(Arg, VWidth, 1)) {
II->setArgOperand(0, V);
return II;
}
break;
}
case Intrinsic::x86_mmx_pmovmskb:
case Intrinsic::x86_sse_movmsk_ps:
case Intrinsic::x86_sse2_movmsk_pd:
case Intrinsic::x86_sse2_pmovmskb_128:
case Intrinsic::x86_avx_movmsk_pd_256:
case Intrinsic::x86_avx_movmsk_ps_256:
case Intrinsic::x86_avx2_pmovmskb: {
if (Value *V = simplifyX86movmsk(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
}
case Intrinsic::x86_sse_comieq_ss:
case Intrinsic::x86_sse_comige_ss:
case Intrinsic::x86_sse_comigt_ss:
case Intrinsic::x86_sse_comile_ss:
case Intrinsic::x86_sse_comilt_ss:
case Intrinsic::x86_sse_comineq_ss:
case Intrinsic::x86_sse_ucomieq_ss:
case Intrinsic::x86_sse_ucomige_ss:
case Intrinsic::x86_sse_ucomigt_ss:
case Intrinsic::x86_sse_ucomile_ss:
case Intrinsic::x86_sse_ucomilt_ss:
case Intrinsic::x86_sse_ucomineq_ss:
case Intrinsic::x86_sse2_comieq_sd:
case Intrinsic::x86_sse2_comige_sd:
case Intrinsic::x86_sse2_comigt_sd:
case Intrinsic::x86_sse2_comile_sd:
case Intrinsic::x86_sse2_comilt_sd:
case Intrinsic::x86_sse2_comineq_sd:
case Intrinsic::x86_sse2_ucomieq_sd:
case Intrinsic::x86_sse2_ucomige_sd:
case Intrinsic::x86_sse2_ucomigt_sd:
case Intrinsic::x86_sse2_ucomile_sd:
case Intrinsic::x86_sse2_ucomilt_sd:
case Intrinsic::x86_sse2_ucomineq_sd: {
// These intrinsics only demand the 0th element of their input vectors. If
// we can simplify the input based on that, do so now.
bool MadeChange = false;
Value *Arg0 = II->getArgOperand(0);
Value *Arg1 = II->getArgOperand(1);
unsigned VWidth = Arg0->getType()->getVectorNumElements();
if (Value *V = SimplifyDemandedVectorEltsLow(Arg0, VWidth, 1)) {
II->setArgOperand(0, V);
MadeChange = true;
}
if (Value *V = SimplifyDemandedVectorEltsLow(Arg1, VWidth, 1)) {
II->setArgOperand(1, V);
MadeChange = true;
}
if (MadeChange)
return II;
break;
}
case Intrinsic::x86_sse_add_ss:
case Intrinsic::x86_sse_sub_ss:
case Intrinsic::x86_sse_mul_ss:
case Intrinsic::x86_sse_div_ss:
case Intrinsic::x86_sse_min_ss:
case Intrinsic::x86_sse_max_ss:
case Intrinsic::x86_sse_cmp_ss:
case Intrinsic::x86_sse2_add_sd:
case Intrinsic::x86_sse2_sub_sd:
case Intrinsic::x86_sse2_mul_sd:
case Intrinsic::x86_sse2_div_sd:
case Intrinsic::x86_sse2_min_sd:
case Intrinsic::x86_sse2_max_sd:
case Intrinsic::x86_sse2_cmp_sd: {
// These intrinsics only demand the lowest element of the second input
// vector.
Value *Arg1 = II->getArgOperand(1);
unsigned VWidth = Arg1->getType()->getVectorNumElements();
if (Value *V = SimplifyDemandedVectorEltsLow(Arg1, VWidth, 1)) {
II->setArgOperand(1, V);
return II;
}
break;
}
case Intrinsic::x86_sse41_round_ss:
case Intrinsic::x86_sse41_round_sd: {
// These intrinsics demand the upper elements of the first input vector and
// the lowest element of the second input vector.
bool MadeChange = false;
Value *Arg0 = II->getArgOperand(0);
Value *Arg1 = II->getArgOperand(1);
unsigned VWidth = Arg0->getType()->getVectorNumElements();
if (Value *V = SimplifyDemandedVectorEltsHigh(Arg0, VWidth, VWidth - 1)) {
II->setArgOperand(0, V);
MadeChange = true;
}
if (Value *V = SimplifyDemandedVectorEltsLow(Arg1, VWidth, 1)) {
II->setArgOperand(1, V);
MadeChange = true;
}
if (MadeChange)
return II;
break;
}
// Constant fold ashr( <A x Bi>, Ci ).
// Constant fold lshr( <A x Bi>, Ci ).
// Constant fold shl( <A x Bi>, Ci ).
case Intrinsic::x86_sse2_psrai_d:
case Intrinsic::x86_sse2_psrai_w:
case Intrinsic::x86_avx2_psrai_d:
case Intrinsic::x86_avx2_psrai_w:
case Intrinsic::x86_sse2_psrli_d:
case Intrinsic::x86_sse2_psrli_q:
case Intrinsic::x86_sse2_psrli_w:
case Intrinsic::x86_avx2_psrli_d:
case Intrinsic::x86_avx2_psrli_q:
case Intrinsic::x86_avx2_psrli_w:
case Intrinsic::x86_sse2_pslli_d:
case Intrinsic::x86_sse2_pslli_q:
case Intrinsic::x86_sse2_pslli_w:
case Intrinsic::x86_avx2_pslli_d:
case Intrinsic::x86_avx2_pslli_q:
case Intrinsic::x86_avx2_pslli_w:
if (Value *V = simplifyX86immShift(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_sse2_psra_d:
case Intrinsic::x86_sse2_psra_w:
case Intrinsic::x86_avx2_psra_d:
case Intrinsic::x86_avx2_psra_w:
case Intrinsic::x86_sse2_psrl_d:
case Intrinsic::x86_sse2_psrl_q:
case Intrinsic::x86_sse2_psrl_w:
case Intrinsic::x86_avx2_psrl_d:
case Intrinsic::x86_avx2_psrl_q:
case Intrinsic::x86_avx2_psrl_w:
case Intrinsic::x86_sse2_psll_d:
case Intrinsic::x86_sse2_psll_q:
case Intrinsic::x86_sse2_psll_w:
case Intrinsic::x86_avx2_psll_d:
case Intrinsic::x86_avx2_psll_q:
case Intrinsic::x86_avx2_psll_w: {
if (Value *V = simplifyX86immShift(*II, *Builder))
return replaceInstUsesWith(*II, V);
// SSE2/AVX2 uses only the first 64-bits of the 128-bit vector
// operand to compute the shift amount.
Value *Arg1 = II->getArgOperand(1);
assert(Arg1->getType()->getPrimitiveSizeInBits() == 128 &&
"Unexpected packed shift size");
unsigned VWidth = Arg1->getType()->getVectorNumElements();
if (Value *V = SimplifyDemandedVectorEltsLow(Arg1, VWidth, VWidth / 2)) {
II->setArgOperand(1, V);
return II;
}
break;
}
case Intrinsic::x86_avx2_psllv_d:
case Intrinsic::x86_avx2_psllv_d_256:
case Intrinsic::x86_avx2_psllv_q:
case Intrinsic::x86_avx2_psllv_q_256:
case Intrinsic::x86_avx2_psrav_d:
case Intrinsic::x86_avx2_psrav_d_256:
case Intrinsic::x86_avx2_psrlv_d:
case Intrinsic::x86_avx2_psrlv_d_256:
case Intrinsic::x86_avx2_psrlv_q:
case Intrinsic::x86_avx2_psrlv_q_256:
if (Value *V = simplifyX86varShift(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_sse41_insertps:
if (Value *V = simplifyX86insertps(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_sse4a_extrq: {
Value *Op0 = II->getArgOperand(0);
Value *Op1 = II->getArgOperand(1);
unsigned VWidth0 = Op0->getType()->getVectorNumElements();
unsigned VWidth1 = Op1->getType()->getVectorNumElements();
assert(Op0->getType()->getPrimitiveSizeInBits() == 128 &&
Op1->getType()->getPrimitiveSizeInBits() == 128 && VWidth0 == 2 &&
VWidth1 == 16 && "Unexpected operand sizes");
// See if we're dealing with constant values.
Constant *C1 = dyn_cast<Constant>(Op1);
ConstantInt *CILength =
C1 ? dyn_cast<ConstantInt>(C1->getAggregateElement((unsigned)0))
: nullptr;
ConstantInt *CIIndex =
C1 ? dyn_cast<ConstantInt>(C1->getAggregateElement((unsigned)1))
: nullptr;
// Attempt to simplify to a constant, shuffle vector or EXTRQI call.
if (Value *V = simplifyX86extrq(*II, Op0, CILength, CIIndex, *Builder))
return replaceInstUsesWith(*II, V);
// EXTRQ only uses the lowest 64-bits of the first 128-bit vector
// operands and the lowest 16-bits of the second.
bool MadeChange = false;
if (Value *V = SimplifyDemandedVectorEltsLow(Op0, VWidth0, 1)) {
II->setArgOperand(0, V);
MadeChange = true;
}
if (Value *V = SimplifyDemandedVectorEltsLow(Op1, VWidth1, 2)) {
II->setArgOperand(1, V);
MadeChange = true;
}
if (MadeChange)
return II;
break;
}
case Intrinsic::x86_sse4a_extrqi: {
// EXTRQI: Extract Length bits starting from Index. Zero pad the remaining
// bits of the lower 64-bits. The upper 64-bits are undefined.
Value *Op0 = II->getArgOperand(0);
unsigned VWidth = Op0->getType()->getVectorNumElements();
assert(Op0->getType()->getPrimitiveSizeInBits() == 128 && VWidth == 2 &&
"Unexpected operand size");
// See if we're dealing with constant values.
ConstantInt *CILength = dyn_cast<ConstantInt>(II->getArgOperand(1));
ConstantInt *CIIndex = dyn_cast<ConstantInt>(II->getArgOperand(2));
// Attempt to simplify to a constant or shuffle vector.
if (Value *V = simplifyX86extrq(*II, Op0, CILength, CIIndex, *Builder))
return replaceInstUsesWith(*II, V);
// EXTRQI only uses the lowest 64-bits of the first 128-bit vector
// operand.
if (Value *V = SimplifyDemandedVectorEltsLow(Op0, VWidth, 1)) {
II->setArgOperand(0, V);
return II;
}
break;
}
case Intrinsic::x86_sse4a_insertq: {
Value *Op0 = II->getArgOperand(0);
Value *Op1 = II->getArgOperand(1);
unsigned VWidth = Op0->getType()->getVectorNumElements();
assert(Op0->getType()->getPrimitiveSizeInBits() == 128 &&
Op1->getType()->getPrimitiveSizeInBits() == 128 && VWidth == 2 &&
Op1->getType()->getVectorNumElements() == 2 &&
"Unexpected operand size");
// See if we're dealing with constant values.
Constant *C1 = dyn_cast<Constant>(Op1);
ConstantInt *CI11 =
C1 ? dyn_cast<ConstantInt>(C1->getAggregateElement((unsigned)1))
: nullptr;
// Attempt to simplify to a constant, shuffle vector or INSERTQI call.
if (CI11) {
const APInt &V11 = CI11->getValue();
APInt Len = V11.zextOrTrunc(6);
APInt Idx = V11.lshr(8).zextOrTrunc(6);
if (Value *V = simplifyX86insertq(*II, Op0, Op1, Len, Idx, *Builder))
return replaceInstUsesWith(*II, V);
}
// INSERTQ only uses the lowest 64-bits of the first 128-bit vector
// operand.
if (Value *V = SimplifyDemandedVectorEltsLow(Op0, VWidth, 1)) {
II->setArgOperand(0, V);
return II;
}
break;
}
case Intrinsic::x86_sse4a_insertqi: {
// INSERTQI: Extract lowest Length bits from lower half of second source and
// insert over first source starting at Index bit. The upper 64-bits are
// undefined.
Value *Op0 = II->getArgOperand(0);
Value *Op1 = II->getArgOperand(1);
unsigned VWidth0 = Op0->getType()->getVectorNumElements();
unsigned VWidth1 = Op1->getType()->getVectorNumElements();
assert(Op0->getType()->getPrimitiveSizeInBits() == 128 &&
Op1->getType()->getPrimitiveSizeInBits() == 128 && VWidth0 == 2 &&
VWidth1 == 2 && "Unexpected operand sizes");
// See if we're dealing with constant values.
ConstantInt *CILength = dyn_cast<ConstantInt>(II->getArgOperand(2));
ConstantInt *CIIndex = dyn_cast<ConstantInt>(II->getArgOperand(3));
// Attempt to simplify to a constant or shuffle vector.
if (CILength && CIIndex) {
APInt Len = CILength->getValue().zextOrTrunc(6);
APInt Idx = CIIndex->getValue().zextOrTrunc(6);
if (Value *V = simplifyX86insertq(*II, Op0, Op1, Len, Idx, *Builder))
return replaceInstUsesWith(*II, V);
}
// INSERTQI only uses the lowest 64-bits of the first two 128-bit vector
// operands.
bool MadeChange = false;
if (Value *V = SimplifyDemandedVectorEltsLow(Op0, VWidth0, 1)) {
II->setArgOperand(0, V);
MadeChange = true;
}
if (Value *V = SimplifyDemandedVectorEltsLow(Op1, VWidth1, 1)) {
II->setArgOperand(1, V);
MadeChange = true;
}
if (MadeChange)
return II;
break;
}
case Intrinsic::x86_sse41_pblendvb:
case Intrinsic::x86_sse41_blendvps:
case Intrinsic::x86_sse41_blendvpd:
case Intrinsic::x86_avx_blendv_ps_256:
case Intrinsic::x86_avx_blendv_pd_256:
case Intrinsic::x86_avx2_pblendvb: {
// Convert blendv* to vector selects if the mask is constant.
// This optimization is convoluted because the intrinsic is defined as
// getting a vector of floats or doubles for the ps and pd versions.
// FIXME: That should be changed.
Value *Op0 = II->getArgOperand(0);
Value *Op1 = II->getArgOperand(1);
Value *Mask = II->getArgOperand(2);
// fold (blend A, A, Mask) -> A
if (Op0 == Op1)
return replaceInstUsesWith(CI, Op0);
// Zero Mask - select 1st argument.
if (isa<ConstantAggregateZero>(Mask))
return replaceInstUsesWith(CI, Op0);
// Constant Mask - select 1st/2nd argument lane based on top bit of mask.
if (auto *ConstantMask = dyn_cast<ConstantDataVector>(Mask)) {
Constant *NewSelector = getNegativeIsTrueBoolVec(ConstantMask);
return SelectInst::Create(NewSelector, Op1, Op0, "blendv");
}
break;
}
case Intrinsic::x86_ssse3_pshuf_b_128:
case Intrinsic::x86_avx2_pshuf_b:
if (Value *V = simplifyX86pshufb(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_avx_vpermilvar_ps:
case Intrinsic::x86_avx_vpermilvar_ps_256:
case Intrinsic::x86_avx_vpermilvar_pd:
case Intrinsic::x86_avx_vpermilvar_pd_256:
if (Value *V = simplifyX86vpermilvar(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_avx2_permd:
case Intrinsic::x86_avx2_permps:
if (Value *V = simplifyX86vpermv(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_avx_vperm2f128_pd_256:
case Intrinsic::x86_avx_vperm2f128_ps_256:
case Intrinsic::x86_avx_vperm2f128_si_256:
case Intrinsic::x86_avx2_vperm2i128:
if (Value *V = simplifyX86vperm2(*II, *Builder))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_avx_maskload_ps:
case Intrinsic::x86_avx_maskload_pd:
case Intrinsic::x86_avx_maskload_ps_256:
case Intrinsic::x86_avx_maskload_pd_256:
case Intrinsic::x86_avx2_maskload_d:
case Intrinsic::x86_avx2_maskload_q:
case Intrinsic::x86_avx2_maskload_d_256:
case Intrinsic::x86_avx2_maskload_q_256:
if (Instruction *I = simplifyX86MaskedLoad(*II, *this))
return I;
break;
case Intrinsic::x86_sse2_maskmov_dqu:
case Intrinsic::x86_avx_maskstore_ps:
case Intrinsic::x86_avx_maskstore_pd:
case Intrinsic::x86_avx_maskstore_ps_256:
case Intrinsic::x86_avx_maskstore_pd_256:
case Intrinsic::x86_avx2_maskstore_d:
case Intrinsic::x86_avx2_maskstore_q:
case Intrinsic::x86_avx2_maskstore_d_256:
case Intrinsic::x86_avx2_maskstore_q_256:
if (simplifyX86MaskedStore(*II, *this))
return nullptr;
break;
case Intrinsic::x86_xop_vpcomb:
case Intrinsic::x86_xop_vpcomd:
case Intrinsic::x86_xop_vpcomq:
case Intrinsic::x86_xop_vpcomw:
if (Value *V = simplifyX86vpcom(*II, *Builder, true))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::x86_xop_vpcomub:
case Intrinsic::x86_xop_vpcomud:
case Intrinsic::x86_xop_vpcomuq:
case Intrinsic::x86_xop_vpcomuw:
if (Value *V = simplifyX86vpcom(*II, *Builder, false))
return replaceInstUsesWith(*II, V);
break;
case Intrinsic::ppc_altivec_vperm:
// Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
// Note that ppc_altivec_vperm has a big-endian bias, so when creating
// a vectorshuffle for little endian, we must undo the transformation
// performed on vec_perm in altivec.h. That is, we must complement
// the permutation mask with respect to 31 and reverse the order of
// V1 and V2.
if (Constant *Mask = dyn_cast<Constant>(II->getArgOperand(2))) {
assert(Mask->getType()->getVectorNumElements() == 16 &&
"Bad type for intrinsic!");
// Check that all of the elements are integer constants or undefs.
bool AllEltsOk = true;
for (unsigned i = 0; i != 16; ++i) {
Constant *Elt = Mask->getAggregateElement(i);
if (!Elt || !(isa<ConstantInt>(Elt) || isa<UndefValue>(Elt))) {
AllEltsOk = false;
break;
}
}
if (AllEltsOk) {
// Cast the input vectors to byte vectors.
Value *Op0 = Builder->CreateBitCast(II->getArgOperand(0),
Mask->getType());
Value *Op1 = Builder->CreateBitCast(II->getArgOperand(1),
Mask->getType());
Value *Result = UndefValue::get(Op0->getType());
// Only extract each element once.
Value *ExtractedElts[32];
memset(ExtractedElts, 0, sizeof(ExtractedElts));
for (unsigned i = 0; i != 16; ++i) {
if (isa<UndefValue>(Mask->getAggregateElement(i)))
continue;
unsigned Idx =
cast<ConstantInt>(Mask->getAggregateElement(i))->getZExtValue();
Idx &= 31; // Match the hardware behavior.
if (DL.isLittleEndian())
Idx = 31 - Idx;
if (!ExtractedElts[Idx]) {
Value *Op0ToUse = (DL.isLittleEndian()) ? Op1 : Op0;
Value *Op1ToUse = (DL.isLittleEndian()) ? Op0 : Op1;
ExtractedElts[Idx] =
Builder->CreateExtractElement(Idx < 16 ? Op0ToUse : Op1ToUse,
Builder->getInt32(Idx&15));
}
// Insert this value into the result vector.
Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx],
Builder->getInt32(i));
}
return CastInst::Create(Instruction::BitCast, Result, CI.getType());
}
}
break;
case Intrinsic::arm_neon_vld1:
case Intrinsic::arm_neon_vld2:
case Intrinsic::arm_neon_vld3:
case Intrinsic::arm_neon_vld4:
case Intrinsic::arm_neon_vld2lane:
case Intrinsic::arm_neon_vld3lane:
case Intrinsic::arm_neon_vld4lane:
case Intrinsic::arm_neon_vst1:
case Intrinsic::arm_neon_vst2:
case Intrinsic::arm_neon_vst3:
case Intrinsic::arm_neon_vst4:
case Intrinsic::arm_neon_vst2lane:
case Intrinsic::arm_neon_vst3lane:
case Intrinsic::arm_neon_vst4lane: {
unsigned MemAlign = getKnownAlignment(II->getArgOperand(0), DL, II, AC, DT);
unsigned AlignArg = II->getNumArgOperands() - 1;
ConstantInt *IntrAlign = dyn_cast<ConstantInt>(II->getArgOperand(AlignArg));
if (IntrAlign && IntrAlign->getZExtValue() < MemAlign) {
II->setArgOperand(AlignArg,
ConstantInt::get(Type::getInt32Ty(II->getContext()),
MemAlign, false));
return II;
}
break;
}
case Intrinsic::arm_neon_vmulls:
case Intrinsic::arm_neon_vmullu:
case Intrinsic::aarch64_neon_smull:
case Intrinsic::aarch64_neon_umull: {
Value *Arg0 = II->getArgOperand(0);
Value *Arg1 = II->getArgOperand(1);
// Handle mul by zero first:
if (isa<ConstantAggregateZero>(Arg0) || isa<ConstantAggregateZero>(Arg1)) {
return replaceInstUsesWith(CI, ConstantAggregateZero::get(II->getType()));
}
// Check for constant LHS & RHS - in this case we just simplify.
bool Zext = (II->getIntrinsicID() == Intrinsic::arm_neon_vmullu ||
II->getIntrinsicID() == Intrinsic::aarch64_neon_umull);
VectorType *NewVT = cast<VectorType>(II->getType());
if (Constant *CV0 = dyn_cast<Constant>(Arg0)) {
if (Constant *CV1 = dyn_cast<Constant>(Arg1)) {
CV0 = ConstantExpr::getIntegerCast(CV0, NewVT, /*isSigned=*/!Zext);
CV1 = ConstantExpr::getIntegerCast(CV1, NewVT, /*isSigned=*/!Zext);
return replaceInstUsesWith(CI, ConstantExpr::getMul(CV0, CV1));
}
// Couldn't simplify - canonicalize constant to the RHS.
std::swap(Arg0, Arg1);
}
// Handle mul by one:
if (Constant *CV1 = dyn_cast<Constant>(Arg1))
if (ConstantInt *Splat =
dyn_cast_or_null<ConstantInt>(CV1->getSplatValue()))
if (Splat->isOne())
return CastInst::CreateIntegerCast(Arg0, II->getType(),
/*isSigned=*/!Zext);
break;
}
case Intrinsic::amdgcn_rcp: {
if (const ConstantFP *C = dyn_cast<ConstantFP>(II->getArgOperand(0))) {
const APFloat &ArgVal = C->getValueAPF();
APFloat Val(ArgVal.getSemantics(), 1.0);
APFloat::opStatus Status = Val.divide(ArgVal,
APFloat::rmNearestTiesToEven);
// Only do this if it was exact and therefore not dependent on the
// rounding mode.
if (Status == APFloat::opOK)
return replaceInstUsesWith(CI, ConstantFP::get(II->getContext(), Val));
}
break;
}
case Intrinsic::amdgcn_frexp_mant:
case Intrinsic::amdgcn_frexp_exp: {
Value *Src = II->getArgOperand(0);
if (const ConstantFP *C = dyn_cast<ConstantFP>(Src)) {
int Exp;
APFloat Significand = frexp(C->getValueAPF(), Exp,
APFloat::rmNearestTiesToEven);
if (II->getIntrinsicID() == Intrinsic::amdgcn_frexp_mant) {
return replaceInstUsesWith(CI, ConstantFP::get(II->getContext(),
Significand));
}
// Match instruction special case behavior.
if (Exp == APFloat::IEK_NaN || Exp == APFloat::IEK_Inf)
Exp = 0;
return replaceInstUsesWith(CI, ConstantInt::get(II->getType(), Exp));
}
if (isa<UndefValue>(Src))
return replaceInstUsesWith(CI, UndefValue::get(II->getType()));
break;
}
case Intrinsic::stackrestore: {
// If the save is right next to the restore, remove the restore. This can
// happen when variable allocas are DCE'd.
if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) {
if (SS->getIntrinsicID() == Intrinsic::stacksave) {
if (&*++SS->getIterator() == II)
return eraseInstFromFunction(CI);
}
}
// Scan down this block to see if there is another stack restore in the
// same block without an intervening call/alloca.
BasicBlock::iterator BI(II);
TerminatorInst *TI = II->getParent()->getTerminator();
bool CannotRemove = false;
for (++BI; &*BI != TI; ++BI) {
if (isa<AllocaInst>(BI)) {
CannotRemove = true;
break;
}
if (CallInst *BCI = dyn_cast<CallInst>(BI)) {
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) {
// If there is a stackrestore below this one, remove this one.
if (II->getIntrinsicID() == Intrinsic::stackrestore)
return eraseInstFromFunction(CI);
// Bail if we cross over an intrinsic with side effects, such as
// llvm.stacksave, llvm.read_register, or llvm.setjmp.
if (II->mayHaveSideEffects()) {
CannotRemove = true;
break;
}
} else {
// If we found a non-intrinsic call, we can't remove the stack
// restore.
CannotRemove = true;
break;
}
}
}
// If the stack restore is in a return, resume, or unwind block and if there
// are no allocas or calls between the restore and the return, nuke the
// restore.
if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI)))
return eraseInstFromFunction(CI);
break;
}
case Intrinsic::lifetime_start:
if (removeTriviallyEmptyRange(*II, Intrinsic::lifetime_start,
Intrinsic::lifetime_end, *this))
return nullptr;
break;
case Intrinsic::assume: {
Value *IIOperand = II->getArgOperand(0);
// Remove an assume if it is immediately followed by an identical assume.
if (match(II->getNextNode(),
m_Intrinsic<Intrinsic::assume>(m_Specific(IIOperand))))
return eraseInstFromFunction(CI);
// Canonicalize assume(a && b) -> assume(a); assume(b);
// Note: New assumption intrinsics created here are registered by
// the InstCombineIRInserter object.
Value *AssumeIntrinsic = II->getCalledValue(), *A, *B;
if (match(IIOperand, m_And(m_Value(A), m_Value(B)))) {
Builder->CreateCall(AssumeIntrinsic, A, II->getName());
Builder->CreateCall(AssumeIntrinsic, B, II->getName());
return eraseInstFromFunction(*II);
}
// assume(!(a || b)) -> assume(!a); assume(!b);
if (match(IIOperand, m_Not(m_Or(m_Value(A), m_Value(B))))) {
Builder->CreateCall(AssumeIntrinsic, Builder->CreateNot(A),
II->getName());
Builder->CreateCall(AssumeIntrinsic, Builder->CreateNot(B),
II->getName());
return eraseInstFromFunction(*II);
}
// assume( (load addr) != null ) -> add 'nonnull' metadata to load
// (if assume is valid at the load)
if (ICmpInst* ICmp = dyn_cast<ICmpInst>(IIOperand)) {
Value *LHS = ICmp->getOperand(0);
Value *RHS = ICmp->getOperand(1);
if (ICmpInst::ICMP_NE == ICmp->getPredicate() &&
isa<LoadInst>(LHS) &&
isa<Constant>(RHS) &&
RHS->getType()->isPointerTy() &&
cast<Constant>(RHS)->isNullValue()) {
LoadInst* LI = cast<LoadInst>(LHS);
if (isValidAssumeForContext(II, LI, DT)) {
MDNode *MD = MDNode::get(II->getContext(), None);
LI->setMetadata(LLVMContext::MD_nonnull, MD);
return eraseInstFromFunction(*II);
}
}
// TODO: apply nonnull return attributes to calls and invokes
// TODO: apply range metadata for range check patterns?
}
// If there is a dominating assume with the same condition as this one,
// then this one is redundant, and should be removed.
APInt KnownZero(1, 0), KnownOne(1, 0);
computeKnownBits(IIOperand, KnownZero, KnownOne, 0, II);
if (KnownOne.isAllOnesValue())
return eraseInstFromFunction(*II);
break;
}
case Intrinsic::experimental_gc_relocate: {
// Translate facts known about a pointer before relocating into
// facts about the relocate value, while being careful to
// preserve relocation semantics.
Value *DerivedPtr = cast<GCRelocateInst>(II)->getDerivedPtr();
// Remove the relocation if unused, note that this check is required
// to prevent the cases below from looping forever.
if (II->use_empty())
return eraseInstFromFunction(*II);
// Undef is undef, even after relocation.
// TODO: provide a hook for this in GCStrategy. This is clearly legal for
// most practical collectors, but there was discussion in the review thread
// about whether it was legal for all possible collectors.
if (isa<UndefValue>(DerivedPtr))
// Use undef of gc_relocate's type to replace it.
return replaceInstUsesWith(*II, UndefValue::get(II->getType()));
if (auto *PT = dyn_cast<PointerType>(II->getType())) {
// The relocation of null will be null for most any collector.
// TODO: provide a hook for this in GCStrategy. There might be some
// weird collector this property does not hold for.
if (isa<ConstantPointerNull>(DerivedPtr))
// Use null-pointer of gc_relocate's type to replace it.
return replaceInstUsesWith(*II, ConstantPointerNull::get(PT));
// isKnownNonNull -> nonnull attribute
if (isKnownNonNullAt(DerivedPtr, II, DT))
II->addAttribute(AttributeSet::ReturnIndex, Attribute::NonNull);
}
// TODO: bitcast(relocate(p)) -> relocate(bitcast(p))
// Canonicalize on the type from the uses to the defs
// TODO: relocate((gep p, C, C2, ...)) -> gep(relocate(p), C, C2, ...)
break;
}
}
return visitCallSite(II);
}
// InvokeInst simplification
//
Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
return visitCallSite(&II);
}
/// If this cast does not affect the value passed through the varargs area, we
/// can eliminate the use of the cast.
static bool isSafeToEliminateVarargsCast(const CallSite CS,
const DataLayout &DL,
const CastInst *const CI,
const int ix) {
if (!CI->isLosslessCast())
return false;
// If this is a GC intrinsic, avoid munging types. We need types for
// statepoint reconstruction in SelectionDAG.
// TODO: This is probably something which should be expanded to all
// intrinsics since the entire point of intrinsics is that
// they are understandable by the optimizer.
if (isStatepoint(CS) || isGCRelocate(CS) || isGCResult(CS))
return false;
// The size of ByVal or InAlloca arguments is derived from the type, so we
// can't change to a type with a different size. If the size were
// passed explicitly we could avoid this check.
if (!CS.isByValOrInAllocaArgument(ix))
return true;
Type* SrcTy =
cast<PointerType>(CI->getOperand(0)->getType())->getElementType();
Type* DstTy = cast<PointerType>(CI->getType())->getElementType();
if (!SrcTy->isSized() || !DstTy->isSized())
return false;
if (DL.getTypeAllocSize(SrcTy) != DL.getTypeAllocSize(DstTy))
return false;
return true;
}
Instruction *InstCombiner::tryOptimizeCall(CallInst *CI) {
if (!CI->getCalledFunction()) return nullptr;
auto InstCombineRAUW = [this](Instruction *From, Value *With) {
replaceInstUsesWith(*From, With);
};
LibCallSimplifier Simplifier(DL, TLI, InstCombineRAUW);
if (Value *With = Simplifier.optimizeCall(CI)) {
++NumSimplified;
return CI->use_empty() ? CI : replaceInstUsesWith(*CI, With);
}
return nullptr;
}
static IntrinsicInst *findInitTrampolineFromAlloca(Value *TrampMem) {
// Strip off at most one level of pointer casts, looking for an alloca. This
// is good enough in practice and simpler than handling any number of casts.
Value *Underlying = TrampMem->stripPointerCasts();
if (Underlying != TrampMem &&
(!Underlying->hasOneUse() || Underlying->user_back() != TrampMem))
return nullptr;
if (!isa<AllocaInst>(Underlying))
return nullptr;
IntrinsicInst *InitTrampoline = nullptr;
for (User *U : TrampMem->users()) {
IntrinsicInst *II = dyn_cast<IntrinsicInst>(U);
if (!II)
return nullptr;
if (II->getIntrinsicID() == Intrinsic::init_trampoline) {
if (InitTrampoline)
// More than one init_trampoline writes to this value. Give up.
return nullptr;
InitTrampoline = II;
continue;
}
if (II->getIntrinsicID() == Intrinsic::adjust_trampoline)
// Allow any number of calls to adjust.trampoline.
continue;
return nullptr;
}
// No call to init.trampoline found.
if (!InitTrampoline)
return nullptr;
// Check that the alloca is being used in the expected way.
if (InitTrampoline->getOperand(0) != TrampMem)
return nullptr;
return InitTrampoline;
}
static IntrinsicInst *findInitTrampolineFromBB(IntrinsicInst *AdjustTramp,
Value *TrampMem) {
// Visit all the previous instructions in the basic block, and try to find a
// init.trampoline which has a direct path to the adjust.trampoline.
for (BasicBlock::iterator I = AdjustTramp->getIterator(),
E = AdjustTramp->getParent()->begin();
I != E;) {
Instruction *Inst = &*--I;
if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
if (II->getIntrinsicID() == Intrinsic::init_trampoline &&
II->getOperand(0) == TrampMem)
return II;
if (Inst->mayWriteToMemory())
return nullptr;
}
return nullptr;
}
// Given a call to llvm.adjust.trampoline, find and return the corresponding
// call to llvm.init.trampoline if the call to the trampoline can be optimized
// to a direct call to a function. Otherwise return NULL.
//
static IntrinsicInst *findInitTrampoline(Value *Callee) {
Callee = Callee->stripPointerCasts();
IntrinsicInst *AdjustTramp = dyn_cast<IntrinsicInst>(Callee);
if (!AdjustTramp ||
AdjustTramp->getIntrinsicID() != Intrinsic::adjust_trampoline)
return nullptr;
Value *TrampMem = AdjustTramp->getOperand(0);
if (IntrinsicInst *IT = findInitTrampolineFromAlloca(TrampMem))
return IT;
if (IntrinsicInst *IT = findInitTrampolineFromBB(AdjustTramp, TrampMem))
return IT;
return nullptr;
}
/// Improvements for call and invoke instructions.
Instruction *InstCombiner::visitCallSite(CallSite CS) {
if (isAllocLikeFn(CS.getInstruction(), TLI))
return visitAllocSite(*CS.getInstruction());
bool Changed = false;
// Mark any parameters that are known to be non-null with the nonnull
// attribute. This is helpful for inlining calls to functions with null
// checks on their arguments.
SmallVector<unsigned, 4> Indices;
unsigned ArgNo = 0;
for (Value *V : CS.args()) {
if (V->getType()->isPointerTy() &&
!CS.paramHasAttr(ArgNo + 1, Attribute::NonNull) &&
isKnownNonNullAt(V, CS.getInstruction(), DT))
Indices.push_back(ArgNo + 1);
ArgNo++;
}
assert(ArgNo == CS.arg_size() && "sanity check");
if (!Indices.empty()) {
AttributeSet AS = CS.getAttributes();
LLVMContext &Ctx = CS.getInstruction()->getContext();
AS = AS.addAttribute(Ctx, Indices,
Attribute::get(Ctx, Attribute::NonNull));
CS.setAttributes(AS);
Changed = true;
}
// If the callee is a pointer to a function, attempt to move any casts to the
// arguments of the call/invoke.
Value *Callee = CS.getCalledValue();
if (!isa<Function>(Callee) && transformConstExprCastCall(CS))
return nullptr;
if (Function *CalleeF = dyn_cast<Function>(Callee)) {
// Remove the convergent attr on calls when the callee is not convergent.
if (CS.isConvergent() && !CalleeF->isConvergent() &&
!CalleeF->isIntrinsic()) {
DEBUG(dbgs() << "Removing convergent attr from instr "
<< CS.getInstruction() << "\n");
CS.setNotConvergent();
return CS.getInstruction();
}
// If the call and callee calling conventions don't match, this call must
// be unreachable, as the call is undefined.
if (CalleeF->getCallingConv() != CS.getCallingConv() &&
// Only do this for calls to a function with a body. A prototype may
// not actually end up matching the implementation's calling conv for a
// variety of reasons (e.g. it may be written in assembly).
!CalleeF->isDeclaration()) {
Instruction *OldCall = CS.getInstruction();
new StoreInst(ConstantInt::getTrue(Callee->getContext()),
UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
OldCall);
// If OldCall does not return void then replaceAllUsesWith undef.
// This allows ValueHandlers and custom metadata to adjust itself.
if (!OldCall->getType()->isVoidTy())
replaceInstUsesWith(*OldCall, UndefValue::get(OldCall->getType()));
if (isa<CallInst>(OldCall))
return eraseInstFromFunction(*OldCall);
// We cannot remove an invoke, because it would change the CFG, just
// change the callee to a null pointer.
cast<InvokeInst>(OldCall)->setCalledFunction(
Constant::getNullValue(CalleeF->getType()));
return nullptr;
}
}
if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
// If CS does not return void then replaceAllUsesWith undef.
// This allows ValueHandlers and custom metadata to adjust itself.
if (!CS.getInstruction()->getType()->isVoidTy())
replaceInstUsesWith(*CS.getInstruction(),
UndefValue::get(CS.getInstruction()->getType()));
if (isa<InvokeInst>(CS.getInstruction())) {
// Can't remove an invoke because we cannot change the CFG.
return nullptr;
}
// This instruction is not reachable, just remove it. We insert a store to
// undef so that we know that this code is not reachable, despite the fact
// that we can't modify the CFG here.
new StoreInst(ConstantInt::getTrue(Callee->getContext()),
UndefValue::get(Type::getInt1PtrTy(Callee->getContext())),
CS.getInstruction());
return eraseInstFromFunction(*CS.getInstruction());
}
if (IntrinsicInst *II = findInitTrampoline(Callee))
return transformCallThroughTrampoline(CS, II);
PointerType *PTy = cast<PointerType>(Callee->getType());
FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
if (FTy->isVarArg()) {
int ix = FTy->getNumParams();
// See if we can optimize any arguments passed through the varargs area of
// the call.
for (CallSite::arg_iterator I = CS.arg_begin() + FTy->getNumParams(),
E = CS.arg_end(); I != E; ++I, ++ix) {
CastInst *CI = dyn_cast<CastInst>(*I);
if (CI && isSafeToEliminateVarargsCast(CS, DL, CI, ix)) {
*I = CI->getOperand(0);
Changed = true;
}
}
}
if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
// Inline asm calls cannot throw - mark them 'nounwind'.
CS.setDoesNotThrow();
Changed = true;
}
// Try to optimize the call if possible, we require DataLayout for most of
// this. None of these calls are seen as possibly dead so go ahead and
// delete the instruction now.
if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) {
Instruction *I = tryOptimizeCall(CI);
// If we changed something return the result, etc. Otherwise let
// the fallthrough check.
if (I) return eraseInstFromFunction(*I);
}
return Changed ? CS.getInstruction() : nullptr;
}
/// If the callee is a constexpr cast of a function, attempt to move the cast to
/// the arguments of the call/invoke.
bool InstCombiner::transformConstExprCastCall(CallSite CS) {
Function *Callee =
dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts());
if (!Callee)
return false;
// The prototype of thunks are a lie, don't try to directly call such
// functions.
if (Callee->hasFnAttribute("thunk"))
return false;
Instruction *Caller = CS.getInstruction();
const AttributeSet &CallerPAL = CS.getAttributes();
// Okay, this is a cast from a function to a different type. Unless doing so
// would cause a type conversion of one of our arguments, change this call to
// be a direct call with arguments casted to the appropriate types.
//
FunctionType *FT = Callee->getFunctionType();
Type *OldRetTy = Caller->getType();
Type *NewRetTy = FT->getReturnType();
// Check to see if we are changing the return type...
if (OldRetTy != NewRetTy) {
if (NewRetTy->isStructTy())
return false; // TODO: Handle multiple return values.
if (!CastInst::isBitOrNoopPointerCastable(NewRetTy, OldRetTy, DL)) {
if (Callee->isDeclaration())
return false; // Cannot transform this return value.
if (!Caller->use_empty() &&
// void -> non-void is handled specially
!NewRetTy->isVoidTy())
return false; // Cannot transform this return value.
}
if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex);
if (RAttrs.overlaps(AttributeFuncs::typeIncompatible(NewRetTy)))
return false; // Attribute not compatible with transformed value.
}
// If the callsite is an invoke instruction, and the return value is used by
// a PHI node in a successor, we cannot change the return type of the call
// because there is no place to put the cast instruction (without breaking
// the critical edge). Bail out in this case.
if (!Caller->use_empty())
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller))
for (User *U : II->users())
if (PHINode *PN = dyn_cast<PHINode>(U))
if (PN->getParent() == II->getNormalDest() ||
PN->getParent() == II->getUnwindDest())
return false;
}
unsigned NumActualArgs = CS.arg_size();
unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
// Prevent us turning:
// declare void @takes_i32_inalloca(i32* inalloca)
// call void bitcast (void (i32*)* @takes_i32_inalloca to void (i32)*)(i32 0)
//
// into:
// call void @takes_i32_inalloca(i32* null)
//
// Similarly, avoid folding away bitcasts of byval calls.
if (Callee->getAttributes().hasAttrSomewhere(Attribute::InAlloca) ||
Callee->getAttributes().hasAttrSomewhere(Attribute::ByVal))
return false;
CallSite::arg_iterator AI = CS.arg_begin();
for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) {
Type *ParamTy = FT->getParamType(i);
Type *ActTy = (*AI)->getType();
if (!CastInst::isBitOrNoopPointerCastable(ActTy, ParamTy, DL))
return false; // Cannot transform this parameter value.
if (AttrBuilder(CallerPAL.getParamAttributes(i + 1), i + 1).
overlaps(AttributeFuncs::typeIncompatible(ParamTy)))
return false; // Attribute not compatible with transformed value.
if (CS.isInAllocaArgument(i))
return false; // Cannot transform to and from inalloca.
// If the parameter is passed as a byval argument, then we have to have a
// sized type and the sized type has to have the same size as the old type.
if (ParamTy != ActTy &&
CallerPAL.getParamAttributes(i + 1).hasAttribute(i + 1,
Attribute::ByVal)) {
PointerType *ParamPTy = dyn_cast<PointerType>(ParamTy);
if (!ParamPTy || !ParamPTy->getElementType()->isSized())
return false;
Type *CurElTy = ActTy->getPointerElementType();
if (DL.getTypeAllocSize(CurElTy) !=
DL.getTypeAllocSize(ParamPTy->getElementType()))
return false;
}
}
if (Callee->isDeclaration()) {
// Do not delete arguments unless we have a function body.
if (FT->getNumParams() < NumActualArgs && !FT->isVarArg())
return false;
// If the callee is just a declaration, don't change the varargsness of the
// call. We don't want to introduce a varargs call where one doesn't
// already exist.
PointerType *APTy = cast<PointerType>(CS.getCalledValue()->getType());
if (FT->isVarArg()!=cast<FunctionType>(APTy->getElementType())->isVarArg())
return false;
// If both the callee and the cast type are varargs, we still have to make
// sure the number of fixed parameters are the same or we have the same
// ABI issues as if we introduce a varargs call.
if (FT->isVarArg() &&
cast<FunctionType>(APTy->getElementType())->isVarArg() &&
FT->getNumParams() !=
cast<FunctionType>(APTy->getElementType())->getNumParams())
return false;
}
if (FT->getNumParams() < NumActualArgs && FT->isVarArg() &&
!CallerPAL.isEmpty())
// In this case we have more arguments than the new function type, but we
// won't be dropping them. Check that these extra arguments have attributes
// that are compatible with being a vararg call argument.
for (unsigned i = CallerPAL.getNumSlots(); i; --i) {
unsigned Index = CallerPAL.getSlotIndex(i - 1);
if (Index <= FT->getNumParams())
break;
// Check if it has an attribute that's incompatible with varargs.
AttributeSet PAttrs = CallerPAL.getSlotAttributes(i - 1);
if (PAttrs.hasAttribute(Index, Attribute::StructRet))
return false;
}
// Okay, we decided that this is a safe thing to do: go ahead and start
// inserting cast instructions as necessary.
std::vector<Value*> Args;
Args.reserve(NumActualArgs);
SmallVector<AttributeSet, 8> attrVec;
attrVec.reserve(NumCommonArgs);
// Get any return attributes.
AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex);
// If the return value is not being used, the type may not be compatible
// with the existing attributes. Wipe out any problematic attributes.
RAttrs.remove(AttributeFuncs::typeIncompatible(NewRetTy));
// Add the new return attributes.
if (RAttrs.hasAttributes())
attrVec.push_back(AttributeSet::get(Caller->getContext(),
AttributeSet::ReturnIndex, RAttrs));
AI = CS.arg_begin();
for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) {
Type *ParamTy = FT->getParamType(i);
if ((*AI)->getType() == ParamTy) {
Args.push_back(*AI);
} else {
Args.push_back(Builder->CreateBitOrPointerCast(*AI, ParamTy));
}
// Add any parameter attributes.
AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1);
if (PAttrs.hasAttributes())
attrVec.push_back(AttributeSet::get(Caller->getContext(), i + 1,
PAttrs));
}
// If the function takes more arguments than the call was taking, add them
// now.
for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i)
Args.push_back(Constant::getNullValue(FT->getParamType(i)));
// If we are removing arguments to the function, emit an obnoxious warning.
if (FT->getNumParams() < NumActualArgs) {
// TODO: if (!FT->isVarArg()) this call may be unreachable. PR14722
if (FT->isVarArg()) {
// Add all of the arguments in their promoted form to the arg list.
for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) {
Type *PTy = getPromotedType((*AI)->getType());
if (PTy != (*AI)->getType()) {
// Must promote to pass through va_arg area!
Instruction::CastOps opcode =
CastInst::getCastOpcode(*AI, false, PTy, false);
Args.push_back(Builder->CreateCast(opcode, *AI, PTy));
} else {
Args.push_back(*AI);
}
// Add any parameter attributes.
AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1);
if (PAttrs.hasAttributes())
attrVec.push_back(AttributeSet::get(FT->getContext(), i + 1,
PAttrs));
}
}
}
AttributeSet FnAttrs = CallerPAL.getFnAttributes();
if (CallerPAL.hasAttributes(AttributeSet::FunctionIndex))
attrVec.push_back(AttributeSet::get(Callee->getContext(), FnAttrs));
if (NewRetTy->isVoidTy())
Caller->setName(""); // Void type should not have a name.
const AttributeSet &NewCallerPAL = AttributeSet::get(Callee->getContext(),
attrVec);
SmallVector<OperandBundleDef, 1> OpBundles;
CS.getOperandBundlesAsDefs(OpBundles);
Instruction *NC;
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
NC = Builder->CreateInvoke(Callee, II->getNormalDest(), II->getUnwindDest(),
Args, OpBundles);
NC->takeName(II);
cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv());
cast<InvokeInst>(NC)->setAttributes(NewCallerPAL);
} else {
CallInst *CI = cast<CallInst>(Caller);
NC = Builder->CreateCall(Callee, Args, OpBundles);
NC->takeName(CI);
if (CI->isTailCall())
cast<CallInst>(NC)->setTailCall();
cast<CallInst>(NC)->setCallingConv(CI->getCallingConv());
cast<CallInst>(NC)->setAttributes(NewCallerPAL);
}
// Insert a cast of the return type as necessary.
Value *NV = NC;
if (OldRetTy != NV->getType() && !Caller->use_empty()) {
if (!NV->getType()->isVoidTy()) {
NV = NC = CastInst::CreateBitOrPointerCast(NC, OldRetTy);
NC->setDebugLoc(Caller->getDebugLoc());
// If this is an invoke instruction, we should insert it after the first
// non-phi, instruction in the normal successor block.
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
BasicBlock::iterator I = II->getNormalDest()->getFirstInsertionPt();
InsertNewInstBefore(NC, *I);
} else {
// Otherwise, it's a call, just insert cast right after the call.
InsertNewInstBefore(NC, *Caller);
}
Worklist.AddUsersToWorkList(*Caller);
} else {
NV = UndefValue::get(Caller->getType());
}
}
if (!Caller->use_empty())
replaceInstUsesWith(*Caller, NV);
else if (Caller->hasValueHandle()) {
if (OldRetTy == NV->getType())
ValueHandleBase::ValueIsRAUWd(Caller, NV);
else
// We cannot call ValueIsRAUWd with a different type, and the
// actual tracked value will disappear.
ValueHandleBase::ValueIsDeleted(Caller);
}
eraseInstFromFunction(*Caller);
return true;
}
/// Turn a call to a function created by init_trampoline / adjust_trampoline
/// intrinsic pair into a direct call to the underlying function.
Instruction *
InstCombiner::transformCallThroughTrampoline(CallSite CS,
IntrinsicInst *Tramp) {
Value *Callee = CS.getCalledValue();
PointerType *PTy = cast<PointerType>(Callee->getType());
FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
const AttributeSet &Attrs = CS.getAttributes();
// If the call already has the 'nest' attribute somewhere then give up -
// otherwise 'nest' would occur twice after splicing in the chain.
if (Attrs.hasAttrSomewhere(Attribute::Nest))
return nullptr;
assert(Tramp &&
"transformCallThroughTrampoline called with incorrect CallSite.");
Function *NestF =cast<Function>(Tramp->getArgOperand(1)->stripPointerCasts());
FunctionType *NestFTy = cast<FunctionType>(NestF->getValueType());
const AttributeSet &NestAttrs = NestF->getAttributes();
if (!NestAttrs.isEmpty()) {
unsigned NestIdx = 1;
Type *NestTy = nullptr;
AttributeSet NestAttr;
// Look for a parameter marked with the 'nest' attribute.
for (FunctionType::param_iterator I = NestFTy->param_begin(),
E = NestFTy->param_end(); I != E; ++NestIdx, ++I)
if (NestAttrs.hasAttribute(NestIdx, Attribute::Nest)) {
// Record the parameter type and any other attributes.
NestTy = *I;
NestAttr = NestAttrs.getParamAttributes(NestIdx);
break;
}
if (NestTy) {
Instruction *Caller = CS.getInstruction();
std::vector<Value*> NewArgs;
NewArgs.reserve(CS.arg_size() + 1);
SmallVector<AttributeSet, 8> NewAttrs;
NewAttrs.reserve(Attrs.getNumSlots() + 1);
// Insert the nest argument into the call argument list, which may
// mean appending it. Likewise for attributes.
// Add any result attributes.
if (Attrs.hasAttributes(AttributeSet::ReturnIndex))
NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
Attrs.getRetAttributes()));
{
unsigned Idx = 1;
CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
do {
if (Idx == NestIdx) {
// Add the chain argument and attributes.
Value *NestVal = Tramp->getArgOperand(2);
if (NestVal->getType() != NestTy)
NestVal = Builder->CreateBitCast(NestVal, NestTy, "nest");
NewArgs.push_back(NestVal);
NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
NestAttr));
}
if (I == E)
break;
// Add the original argument and attributes.
NewArgs.push_back(*I);
AttributeSet Attr = Attrs.getParamAttributes(Idx);
if (Attr.hasAttributes(Idx)) {
AttrBuilder B(Attr, Idx);
NewAttrs.push_back(AttributeSet::get(Caller->getContext(),
Idx + (Idx >= NestIdx), B));
}
++Idx;
++I;
} while (1);
}
// Add any function attributes.
if (Attrs.hasAttributes(AttributeSet::FunctionIndex))
NewAttrs.push_back(AttributeSet::get(FTy->getContext(),
Attrs.getFnAttributes()));
// The trampoline may have been bitcast to a bogus type (FTy).
// Handle this by synthesizing a new function type, equal to FTy
// with the chain parameter inserted.
std::vector<Type*> NewTypes;
NewTypes.reserve(FTy->getNumParams()+1);
// Insert the chain's type into the list of parameter types, which may
// mean appending it.
{
unsigned Idx = 1;
FunctionType::param_iterator I = FTy->param_begin(),
E = FTy->param_end();
do {
if (Idx == NestIdx)
// Add the chain's type.
NewTypes.push_back(NestTy);
if (I == E)
break;
// Add the original type.
NewTypes.push_back(*I);
++Idx;
++I;
} while (1);
}
// Replace the trampoline call with a direct call. Let the generic
// code sort out any function type mismatches.
FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes,
FTy->isVarArg());
Constant *NewCallee =
NestF->getType() == PointerType::getUnqual(NewFTy) ?
NestF : ConstantExpr::getBitCast(NestF,
PointerType::getUnqual(NewFTy));
const AttributeSet &NewPAL =
AttributeSet::get(FTy->getContext(), NewAttrs);
SmallVector<OperandBundleDef, 1> OpBundles;
CS.getOperandBundlesAsDefs(OpBundles);
Instruction *NewCaller;
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
NewCaller = InvokeInst::Create(NewCallee,
II->getNormalDest(), II->getUnwindDest(),
NewArgs, OpBundles);
cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
} else {
NewCaller = CallInst::Create(NewCallee, NewArgs, OpBundles);
if (cast<CallInst>(Caller)->isTailCall())
cast<CallInst>(NewCaller)->setTailCall();
cast<CallInst>(NewCaller)->
setCallingConv(cast<CallInst>(Caller)->getCallingConv());
cast<CallInst>(NewCaller)->setAttributes(NewPAL);
}
return NewCaller;
}
}
// Replace the trampoline call with a direct call. Since there is no 'nest'
// parameter, there is no need to adjust the argument list. Let the generic
// code sort out any function type mismatches.
Constant *NewCallee =
NestF->getType() == PTy ? NestF :
ConstantExpr::getBitCast(NestF, PTy);
CS.setCalledFunction(NewCallee);
return CS.getInstruction();
}