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llvm-6502/lib/Transforms/InstCombine/InstCombineCalls.cpp
Bill Wendling ac90696722 Use the AttributeSet instead of AttributeWithIndex. 
In the future, AttributeWithIndex won't be used anymore. Besides, it exposes the
internals of the AttributeSet to outside users, which isn't goodness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173602 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-27 02:08:22 +00:00

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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 "InstCombine.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Support/PatternMatch.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
using namespace PatternMatch;
STATISTIC(NumSimplified, "Number of library calls simplified");
/// getPromotedType - 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;
}
/// reduceToSingleValueType - 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;
}
Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), TD);
unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), TD);
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 == 0) return 0;
// 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 transfering should be removed already.");
if (Size > 8 || (Size&(Size-1)))
return 0; // 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 = 0;
if (StrippedDest != MI->getArgOperand(0)) {
Type *SrcETy = cast<PointerType>(StrippedDest->getType())
->getElementType();
if (TD && SrcETy->isSized() && TD->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) &&
isa<ConstantInt>(M->getOperand(0)) &&
cast<ConstantInt>(M->getOperand(0))->isNullValue() &&
M->getOperand(1) &&
isa<ConstantInt>(M->getOperand(1)) &&
cast<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(), TD);
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 0;
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 0;
}
/// visitCallInst - 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) {
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 0;
// 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.getParent()->getParent()->getParent();
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;
}
switch (II->getIntrinsicID()) {
default: break;
case Intrinsic::objectsize: {
uint64_t Size;
if (getObjectSize(II->getArgOperand(0), Size, TD, TLI))
return ReplaceInstUsesWith(CI, ConstantInt::get(CI.getType(), Size));
return 0;
}
case Intrinsic::bswap: {
Value *IIOperand = II->getArgOperand(0);
Value *X = 0;
// 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::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);
ComputeMaskedBits(II->getArgOperand(0), KnownZero, KnownOne);
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);
ComputeMaskedBits(II->getArgOperand(0), KnownZero, KnownOne);
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: {
Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
IntegerType *IT = cast<IntegerType>(II->getArgOperand(0)->getType());
uint32_t BitWidth = IT->getBitWidth();
APInt LHSKnownZero(BitWidth, 0);
APInt LHSKnownOne(BitWidth, 0);
ComputeMaskedBits(LHS, LHSKnownZero, LHSKnownOne);
bool LHSKnownNegative = LHSKnownOne[BitWidth - 1];
bool LHSKnownPositive = LHSKnownZero[BitWidth - 1];
if (LHSKnownNegative || LHSKnownPositive) {
APInt RHSKnownZero(BitWidth, 0);
APInt RHSKnownOne(BitWidth, 0);
ComputeMaskedBits(RHS, RHSKnownZero, RHSKnownOne);
bool RHSKnownNegative = RHSKnownOne[BitWidth - 1];
bool RHSKnownPositive = RHSKnownZero[BitWidth - 1];
if (LHSKnownNegative && RHSKnownNegative) {
// The sign bit is set in both cases: this MUST overflow.
// Create a simple add instruction, and insert it into the struct.
Value *Add = Builder->CreateAdd(LHS, RHS);
Add->takeName(&CI);
Constant *V[] = {
UndefValue::get(LHS->getType()),
ConstantInt::getTrue(II->getContext())
};
StructType *ST = cast<StructType>(II->getType());
Constant *Struct = ConstantStruct::get(ST, V);
return InsertValueInst::Create(Struct, Add, 0);
}
if (LHSKnownPositive && RHSKnownPositive) {
// The sign bit is clear in both cases: this CANNOT overflow.
// Create a simple add instruction, and insert it into the struct.
Value *Add = Builder->CreateNUWAdd(LHS, RHS);
Add->takeName(&CI);
Constant *V[] = {
UndefValue::get(LHS->getType()),
ConstantInt::getFalse(II->getContext())
};
StructType *ST = cast<StructType>(II->getType());
Constant *Struct = ConstantStruct::get(ST, V);
return InsertValueInst::Create(Struct, Add, 0);
}
}
}
// FALL THROUGH uadd into sadd
case Intrinsic::sadd_with_overflow:
// Canonicalize constants into the RHS.
if (isa<Constant>(II->getArgOperand(0)) &&
!isa<Constant>(II->getArgOperand(1))) {
Value *LHS = II->getArgOperand(0);
II->setArgOperand(0, II->getArgOperand(1));
II->setArgOperand(1, LHS);
return II;
}
// X + undef -> undef
if (isa<UndefValue>(II->getArgOperand(1)))
return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
// X + 0 -> {X, false}
if (RHS->isZero()) {
Constant *V[] = {
UndefValue::get(II->getArgOperand(0)->getType()),
ConstantInt::getFalse(II->getContext())
};
Constant *Struct =
ConstantStruct::get(cast<StructType>(II->getType()), V);
return InsertValueInst::Create(Struct, II->getArgOperand(0), 0);
}
}
break;
case Intrinsic::usub_with_overflow:
case Intrinsic::ssub_with_overflow:
// undef - X -> undef
// X - undef -> undef
if (isa<UndefValue>(II->getArgOperand(0)) ||
isa<UndefValue>(II->getArgOperand(1)))
return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
// X - 0 -> {X, false}
if (RHS->isZero()) {
Constant *V[] = {
UndefValue::get(II->getArgOperand(0)->getType()),
ConstantInt::getFalse(II->getContext())
};
Constant *Struct =
ConstantStruct::get(cast<StructType>(II->getType()), V);
return InsertValueInst::Create(Struct, II->getArgOperand(0), 0);
}
}
break;
case Intrinsic::umul_with_overflow: {
Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1);
unsigned BitWidth = cast<IntegerType>(LHS->getType())->getBitWidth();
APInt LHSKnownZero(BitWidth, 0);
APInt LHSKnownOne(BitWidth, 0);
ComputeMaskedBits(LHS, LHSKnownZero, LHSKnownOne);
APInt RHSKnownZero(BitWidth, 0);
APInt RHSKnownOne(BitWidth, 0);
ComputeMaskedBits(RHS, RHSKnownZero, RHSKnownOne);
// Get the largest possible values for each operand.
APInt LHSMax = ~LHSKnownZero;
APInt RHSMax = ~RHSKnownZero;
// If multiplying the maximum values does not overflow then we can turn
// this into a plain NUW mul.
bool Overflow;
LHSMax.umul_ov(RHSMax, Overflow);
if (!Overflow) {
Value *Mul = Builder->CreateNUWMul(LHS, RHS, "umul_with_overflow");
Constant *V[] = {
UndefValue::get(LHS->getType()),
Builder->getFalse()
};
Constant *Struct = ConstantStruct::get(cast<StructType>(II->getType()),V);
return InsertValueInst::Create(Struct, Mul, 0);
}
} // FALL THROUGH
case Intrinsic::smul_with_overflow:
// Canonicalize constants into the RHS.
if (isa<Constant>(II->getArgOperand(0)) &&
!isa<Constant>(II->getArgOperand(1))) {
Value *LHS = II->getArgOperand(0);
II->setArgOperand(0, II->getArgOperand(1));
II->setArgOperand(1, LHS);
return II;
}
// X * undef -> undef
if (isa<UndefValue>(II->getArgOperand(1)))
return ReplaceInstUsesWith(CI, UndefValue::get(II->getType()));
if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getArgOperand(1))) {
// X*0 -> {0, false}
if (RHSI->isZero())
return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType()));
// X * 1 -> {X, false}
if (RHSI->equalsInt(1)) {
Constant *V[] = {
UndefValue::get(II->getArgOperand(0)->getType()),
ConstantInt::getFalse(II->getContext())
};
Constant *Struct =
ConstantStruct::get(cast<StructType>(II->getType()), V);
return InsertValueInst::Create(Struct, II->getArgOperand(0), 0);
}
}
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, TD) >= 16) {
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr);
}
break;
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, TD) >= 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::x86_sse_storeu_ps:
case Intrinsic::x86_sse2_storeu_pd:
case Intrinsic::x86_sse2_storeu_dq:
// Turn X86 storeu -> store if the pointer is known aligned.
if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) {
Type *OpPtrTy =
PointerType::getUnqual(II->getArgOperand(1)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), OpPtrTy);
return new StoreInst(II->getArgOperand(1), Ptr);
}
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.
unsigned VWidth =
cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements();
APInt DemandedElts(VWidth, 1);
APInt UndefElts(VWidth, 0);
if (Value *V = SimplifyDemandedVectorElts(II->getArgOperand(0),
DemandedElts, UndefElts)) {
II->setArgOperand(0, V);
return II;
}
break;
}
case Intrinsic::x86_sse41_pmovsxbw:
case Intrinsic::x86_sse41_pmovsxwd:
case Intrinsic::x86_sse41_pmovsxdq:
case Intrinsic::x86_sse41_pmovzxbw:
case Intrinsic::x86_sse41_pmovzxwd:
case Intrinsic::x86_sse41_pmovzxdq: {
// pmov{s|z}x ignores the upper half of their input vectors.
unsigned VWidth =
cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements();
unsigned LowHalfElts = VWidth / 2;
APInt InputDemandedElts(APInt::getBitsSet(VWidth, 0, LowHalfElts));
APInt UndefElts(VWidth, 0);
if (Value *TmpV = SimplifyDemandedVectorElts(II->getArgOperand(0),
InputDemandedElts,
UndefElts)) {
II->setArgOperand(0, TmpV);
return II;
}
break;
}
case Intrinsic::ppc_altivec_vperm:
// Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant.
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 == 0 ||
!(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 (ExtractedElts[Idx] == 0) {
ExtractedElts[Idx] =
Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1,
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), TD);
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: {
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);
VectorType *NewVT = cast<VectorType>(II->getType());
unsigned NewWidth = NewVT->getElementType()->getIntegerBitWidth();
if (ConstantDataVector *CV0 = dyn_cast<ConstantDataVector>(Arg0)) {
if (ConstantDataVector *CV1 = dyn_cast<ConstantDataVector>(Arg1)) {
VectorType* VT = cast<VectorType>(CV0->getType());
SmallVector<Constant*, 4> NewElems;
for (unsigned i = 0; i < VT->getNumElements(); ++i) {
APInt CV0E =
(cast<ConstantInt>(CV0->getAggregateElement(i)))->getValue();
CV0E = Zext ? CV0E.zext(NewWidth) : CV0E.sext(NewWidth);
APInt CV1E =
(cast<ConstantInt>(CV1->getAggregateElement(i)))->getValue();
CV1E = Zext ? CV1E.zext(NewWidth) : CV1E.sext(NewWidth);
NewElems.push_back(
ConstantInt::get(NewVT->getElementType(), CV0E * CV1E));
}
return ReplaceInstUsesWith(CI, ConstantVector::get(NewElems));
}
// Couldn't simplify - cannonicalize constant to the RHS.
std::swap(Arg0, Arg1);
}
// Handle mul by one:
if (ConstantDataVector *CV1 = dyn_cast<ConstantDataVector>(Arg1)) {
if (ConstantInt *Splat =
dyn_cast_or_null<ConstantInt>(CV1->getSplatValue())) {
if (Splat->isOne()) {
if (Zext)
return CastInst::CreateZExtOrBitCast(Arg0, II->getType());
// else
return CastInst::CreateSExtOrBitCast(Arg0, 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) {
BasicBlock::iterator BI = SS;
if (&*++BI == 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);
// Otherwise, ignore the intrinsic.
} 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;
}
}
return visitCallSite(II);
}
// InvokeInst simplification
//
Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) {
return visitCallSite(&II);
}
/// isSafeToEliminateVarargsCast - 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 CastInst * const CI,
const DataLayout * const TD,
const int ix) {
if (!CI->isLosslessCast())
return false;
// The size of ByVal 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.isByValArgument(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 (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy))
return false;
return true;
}
// Try to fold some different type of calls here.
// Currently we're only working with the checking functions, memcpy_chk,
// mempcpy_chk, memmove_chk, memset_chk, strcpy_chk, stpcpy_chk, strncpy_chk,
// strcat_chk and strncat_chk.
Instruction *InstCombiner::tryOptimizeCall(CallInst *CI, const DataLayout *TD) {
if (CI->getCalledFunction() == 0) return 0;
if (Value *With = Simplifier->optimizeCall(CI)) {
++NumSimplified;
return CI->use_empty() ? CI : ReplaceInstUsesWith(*CI, With);
}
return 0;
}
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->use_begin() != TrampMem))
return 0;
if (!isa<AllocaInst>(Underlying))
return 0;
IntrinsicInst *InitTrampoline = 0;
for (Value::use_iterator I = TrampMem->use_begin(), E = TrampMem->use_end();
I != E; I++) {
IntrinsicInst *II = dyn_cast<IntrinsicInst>(*I);
if (!II)
return 0;
if (II->getIntrinsicID() == Intrinsic::init_trampoline) {
if (InitTrampoline)
// More than one init_trampoline writes to this value. Give up.
return 0;
InitTrampoline = II;
continue;
}
if (II->getIntrinsicID() == Intrinsic::adjust_trampoline)
// Allow any number of calls to adjust.trampoline.
continue;
return 0;
}
// No call to init.trampoline found.
if (!InitTrampoline)
return 0;
// Check that the alloca is being used in the expected way.
if (InitTrampoline->getOperand(0) != TrampMem)
return 0;
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,
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 0;
}
return 0;
}
// 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 0;
Value *TrampMem = AdjustTramp->getOperand(0);
if (IntrinsicInst *IT = FindInitTrampolineFromAlloca(TrampMem))
return IT;
if (IntrinsicInst *IT = FindInitTrampolineFromBB(AdjustTramp, TrampMem))
return IT;
return 0;
}
// visitCallSite - Improvements for call and invoke instructions.
//
Instruction *InstCombiner::visitCallSite(CallSite CS) {
if (isAllocLikeFn(CS.getInstruction(), TLI))
return visitAllocSite(*CS.getInstruction());
bool Changed = false;
// 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 0;
if (Function *CalleeF = dyn_cast<Function>(Callee))
// 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 0;
}
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 0;
}
// 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, CI, TD, 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, TD);
// If we changed something return the result, etc. Otherwise let
// the fallthrough check.
if (I) return EraseInstFromFunction(*I);
}
return Changed ? CS.getInstruction() : 0;
}
// transformConstExprCastCall - 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 == 0)
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();
if (NewRetTy->isStructTy())
return false; // TODO: Handle multiple return values.
// Check to see if we are changing the return type...
if (OldRetTy != NewRetTy) {
if (Callee->isDeclaration() &&
// Conversion is ok if changing from one pointer type to another or from
// a pointer to an integer of the same size.
!((OldRetTy->isPointerTy() || !TD ||
OldRetTy == TD->getIntPtrType(Caller->getContext())) &&
(NewRetTy->isPointerTy() || !TD ||
NewRetTy == TD->getIntPtrType(Caller->getContext()))))
return false; // Cannot transform this return value.
if (!Caller->use_empty() &&
// void -> non-void is handled specially
!NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy))
return false; // Cannot transform this return value.
if (!CallerPAL.isEmpty() && !Caller->use_empty()) {
AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex);
if (RAttrs.hasAttributes(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 (Value::use_iterator UI = II->use_begin(), E = II->use_end();
UI != E; ++UI)
if (PHINode *PN = dyn_cast<PHINode>(*UI))
if (PN->getParent() == II->getNormalDest() ||
PN->getParent() == II->getUnwindDest())
return false;
}
unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin());
unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs);
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::isCastable(ActTy, ParamTy))
return false; // Cannot transform this parameter value.
if (AttrBuilder(CallerPAL.getParamAttributes(i + 1), i + 1).
hasAttributes(AttributeFuncs::typeIncompatible(ParamTy)))
return false; // Attribute not compatible with transformed value.
// 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 == 0 || !ParamPTy->getElementType()->isSized() || TD == 0)
return false;
Type *CurElTy = cast<PointerType>(ActTy)->getElementType();
if (TD->getTypeAllocSize(CurElTy) !=
TD->getTypeAllocSize(ParamPTy->getElementType()))
return false;
}
// Converting from one pointer type to another or between a pointer and an
// integer of the same size is safe even if we do not have a body.
bool isConvertible = ActTy == ParamTy ||
(TD && ((ParamTy->isPointerTy() ||
ParamTy == TD->getIntPtrType(Caller->getContext())) &&
(ActTy->isPointerTy() ||
ActTy == TD->getIntPtrType(Caller->getContext()))));
if (Callee->isDeclaration() && !isConvertible) 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.removeAttributes(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 {
Instruction::CastOps opcode = CastInst::getCastOpcode(*AI,
false, ParamTy, false);
Args.push_back(Builder->CreateCast(opcode, *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);
Instruction *NC;
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
NC = Builder->CreateInvoke(Callee, II->getNormalDest(),
II->getUnwindDest(), Args);
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);
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()) {
Instruction::CastOps opcode =
CastInst::getCastOpcode(NC, false, OldRetTy, false);
NV = NC = CastInst::Create(opcode, 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);
EraseInstFromFunction(*Caller);
return true;
}
// transformCallThroughTrampoline - 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 0;
assert(Tramp &&
"transformCallThroughTrampoline called with incorrect CallSite.");
Function *NestF =cast<Function>(Tramp->getArgOperand(1)->stripPointerCasts());
PointerType *NestFPTy = cast<PointerType>(NestF->getType());
FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType());
const AttributeSet &NestAttrs = NestF->getAttributes();
if (!NestAttrs.isEmpty()) {
unsigned NestIdx = 1;
Type *NestTy = 0;
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(unsigned(CS.arg_end()-CS.arg_begin())+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);
Instruction *NewCaller;
if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) {
NewCaller = InvokeInst::Create(NewCallee,
II->getNormalDest(), II->getUnwindDest(),
NewArgs);
cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv());
cast<InvokeInst>(NewCaller)->setAttributes(NewPAL);
} else {
NewCaller = CallInst::Create(NewCallee, NewArgs);
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();
}
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