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Diffstat (limited to 'contrib/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp')
| -rw-r--r-- | contrib/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 1923 |
1 files changed, 1923 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp new file mode 100644 index 0000000..e83b9dd --- /dev/null +++ b/contrib/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -0,0 +1,1923 @@ +//===- 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/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"); + +/// 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), 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 *SimplifyX86insertps(const IntrinsicInst &II, + InstCombiner::BuilderTy &Builder) { + if (auto *CInt = dyn_cast<ConstantInt>(II.getArgOperand(2))) { + 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. + int 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); + } + return nullptr; +} + +/// 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) { + if (auto *CInt = dyn_cast<ConstantInt>(II.getArgOperand(2))) { + 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<int, 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); + } + return nullptr; +} + +/// 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) { + 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.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, DL, TLI)) + return ReplaceInstUsesWith(CI, ConstantInt::get(CI.getType(), Size)); + 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::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); + + // fmin(x, x) -> x + if (Arg0 == Arg1) + return ReplaceInstUsesWith(CI, Arg0); + + const ConstantFP *C0 = dyn_cast<ConstantFP>(Arg0); + const ConstantFP *C1 = dyn_cast<ConstantFP>(Arg1); + + // Canonicalize constants into the RHS. + if (C0 && !C1) { + II->setArgOperand(0, Arg1); + II->setArgOperand(1, Arg0); + return II; + } + + // fmin(x, nan) -> x + if (C1 && C1->isNaN()) + return ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, Arg1); + + // fmin(x, undef) -> x + if (isa<UndefValue>(Arg1)) + return ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, 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 ReplaceInstUsesWith(CI, Arg1); + } + } + 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_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, DL, II, AC, DT) >= + 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; + } + + // Constant fold <A x Bi> << Ci. + // FIXME: We don't handle _dq because it's a shift of an i128, but is + // represented in the IR as <2 x i64>. A per element shift is wrong. + 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: + 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: { + // Simplify if count is constant. To 0 if >= BitWidth, + // otherwise to shl/lshr. + auto CDV = dyn_cast<ConstantDataVector>(II->getArgOperand(1)); + auto CInt = dyn_cast<ConstantInt>(II->getArgOperand(1)); + if (!CDV && !CInt) + break; + ConstantInt *Count; + if (CDV) + Count = cast<ConstantInt>(CDV->getElementAsConstant(0)); + else + Count = CInt; + + auto Vec = II->getArgOperand(0); + auto VT = cast<VectorType>(Vec->getType()); + if (Count->getZExtValue() > + VT->getElementType()->getPrimitiveSizeInBits() - 1) + return ReplaceInstUsesWith( + CI, ConstantAggregateZero::get(Vec->getType())); + + bool isPackedShiftLeft = true; + switch (II->getIntrinsicID()) { + default : 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: isPackedShiftLeft = false; break; + } + + unsigned VWidth = VT->getNumElements(); + // Get a constant vector of the same type as the first operand. + auto VTCI = ConstantInt::get(VT->getElementType(), Count->getZExtValue()); + if (isPackedShiftLeft) + return BinaryOperator::CreateShl(Vec, + Builder->CreateVectorSplat(VWidth, VTCI)); + + return BinaryOperator::CreateLShr(Vec, + Builder->CreateVectorSplat(VWidth, VTCI)); + } + + 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::x86_sse41_insertps: + if (Value *V = SimplifyX86insertps(*II, *Builder)) + return ReplaceInstUsesWith(*II, V); + break; + + case Intrinsic::x86_sse4a_insertqi: { + // insertqi x, y, 64, 0 can just copy y's lower bits and leave the top + // ones undef + // TODO: eventually we should lower this intrinsic to IR + if (auto CIWidth = dyn_cast<ConstantInt>(II->getArgOperand(2))) { + if (auto CIStart = dyn_cast<ConstantInt>(II->getArgOperand(3))) { + unsigned Index = CIStart->getZExtValue(); + // From AMD documentation: "a value of zero in the field length is + // defined as length of 64". + unsigned Length = CIWidth->equalsInt(0) ? 64 : CIWidth->getZExtValue(); + + // From AMD documentation: "If the sum of the bit index + length field + // is greater than 64, the results are undefined". + + // 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 ((Index + Length) > 64) + return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); + + if (Length == 64 && Index == 0) { + Value *Vec = II->getArgOperand(1); + Value *Undef = UndefValue::get(Vec->getType()); + const uint32_t Mask[] = { 0, 2 }; + return ReplaceInstUsesWith( + CI, + Builder->CreateShuffleVector( + Vec, Undef, ConstantDataVector::get( + II->getContext(), makeArrayRef(Mask)))); + + } else if (auto Source = + dyn_cast<IntrinsicInst>(II->getArgOperand(0))) { + if (Source->hasOneUse() && + Source->getArgOperand(1) == II->getArgOperand(1)) { + // If the source of the insert has only one use and it's another + // insert (and they're both inserting from the same vector), try to + // bundle both together. + auto CISourceWidth = + dyn_cast<ConstantInt>(Source->getArgOperand(2)); + auto CISourceStart = + dyn_cast<ConstantInt>(Source->getArgOperand(3)); + if (CISourceStart && CISourceWidth) { + unsigned Start = CIStart->getZExtValue(); + unsigned Width = CIWidth->getZExtValue(); + unsigned End = Start + Width; + unsigned SourceStart = CISourceStart->getZExtValue(); + unsigned SourceWidth = CISourceWidth->getZExtValue(); + unsigned SourceEnd = SourceStart + SourceWidth; + unsigned NewStart, NewWidth; + bool ShouldReplace = false; + if (Start <= SourceStart && SourceStart <= End) { + NewStart = Start; + NewWidth = std::max(End, SourceEnd) - NewStart; + ShouldReplace = true; + } else if (SourceStart <= Start && Start <= SourceEnd) { + NewStart = SourceStart; + NewWidth = std::max(SourceEnd, End) - NewStart; + ShouldReplace = true; + } + + if (ShouldReplace) { + Constant *ConstantWidth = ConstantInt::get( + II->getArgOperand(2)->getType(), NewWidth, false); + Constant *ConstantStart = ConstantInt::get( + II->getArgOperand(3)->getType(), NewStart, false); + Value *Args[4] = { Source->getArgOperand(0), + II->getArgOperand(1), ConstantWidth, + ConstantStart }; + Module *M = CI.getParent()->getParent()->getParent(); + Value *F = + Intrinsic::getDeclaration(M, Intrinsic::x86_sse4a_insertqi); + return ReplaceInstUsesWith(CI, Builder->CreateCall(F, Args)); + } + } + } + } + } + } + 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 *Mask = II->getArgOperand(2); + if (auto C = dyn_cast<ConstantDataVector>(Mask)) { + auto Tyi1 = Builder->getInt1Ty(); + auto SelectorType = cast<VectorType>(Mask->getType()); + auto EltTy = SelectorType->getElementType(); + unsigned Size = SelectorType->getNumElements(); + unsigned BitWidth = + EltTy->isFloatTy() + ? 32 + : (EltTy->isDoubleTy() ? 64 : EltTy->getIntegerBitWidth()); + assert((BitWidth == 64 || BitWidth == 32 || BitWidth == 8) && + "Wrong arguments for variable blend intrinsic"); + SmallVector<Constant *, 32> Selectors; + for (unsigned I = 0; I < Size; ++I) { + // The intrinsics only read the top bit + uint64_t Selector; + if (BitWidth == 8) + Selector = C->getElementAsInteger(I); + else + Selector = C->getElementAsAPFloat(I).bitcastToAPInt().getZExtValue(); + Selectors.push_back(ConstantInt::get(Tyi1, Selector >> (BitWidth - 1))); + } + auto NewSelector = ConstantVector::get(Selectors); + return SelectInst::Create(NewSelector, II->getArgOperand(1), + II->getArgOperand(0), "blendv"); + } else { + 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: { + // Convert vpermil* to shufflevector if the mask is constant. + Value *V = II->getArgOperand(1); + unsigned Size = cast<VectorType>(V->getType())->getNumElements(); + assert(Size == 8 || Size == 4 || Size == 2); + uint32_t Indexes[8]; + if (auto C = dyn_cast<ConstantDataVector>(V)) { + // The intrinsics only read one or two bits, clear the rest. + for (unsigned I = 0; I < Size; ++I) { + uint32_t Index = C->getElementAsInteger(I) & 0x3; + if (II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd || + II->getIntrinsicID() == Intrinsic::x86_avx_vpermilvar_pd_256) + Index >>= 1; + Indexes[I] = Index; + } + } else if (isa<ConstantAggregateZero>(V)) { + for (unsigned I = 0; I < Size; ++I) + Indexes[I] = 0; + } else { + break; + } + // 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) { + for (unsigned I = Size / 2; I < Size; ++I) + Indexes[I] += Size / 2; + } + auto NewC = + ConstantDataVector::get(V->getContext(), makeArrayRef(Indexes, Size)); + auto V1 = II->getArgOperand(0); + auto V2 = UndefValue::get(V1->getType()); + auto Shuffle = Builder->CreateShuffleVector(V1, V2, NewC); + return ReplaceInstUsesWith(CI, Shuffle); + } + + 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::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::AMDGPU_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::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; + } + case Intrinsic::assume: { + // Canonicalize assume(a && b) -> assume(a); assume(b); + // Note: New assumption intrinsics created here are registered by + // the InstCombineIRInserter object. + Value *IIOperand = II->getArgOperand(0), *A, *B, + *AssumeIntrinsic = II->getCalledValue(); + 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. + GCRelocateOperands Operands(II); + Value *DerivedPtr = Operands.getDerivedPtr(); + auto *GCRelocateType = cast<PointerType>(II->getType()); + + // 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)) { + // gc_relocate is uncasted. Use undef of gc_relocate's type to replace it. + return ReplaceInstUsesWith(*II, UndefValue::get(GCRelocateType)); + } + + // 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)) { + // gc_relocate is uncasted. Use null-pointer of gc_relocate's type to replace it. + return ReplaceInstUsesWith(*II, ConstantPointerNull::get(GCRelocateType)); + } + + // isKnownNonNull -> nonnull attribute + if (isKnownNonNull(DerivedPtr)) + II->addAttribute(AttributeSet::ReturnIndex, Attribute::NonNull); + + // isDereferenceablePointer -> deref attribute + if (isDereferenceablePointer(DerivedPtr, DL)) { + if (Argument *A = dyn_cast<Argument>(DerivedPtr)) { + uint64_t Bytes = A->getDereferenceableBytes(); + II->addDereferenceableAttr(AttributeSet::ReturnIndex, Bytes); + } + } + + // 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, ...) + } + } + + 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 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; +} + +// 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) { + 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, + 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; +} + +// 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 nullptr; + + 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 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; +} + +// 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) + 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); + + 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()) { + 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; +} + +// 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 nullptr; + + 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 = 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); + + 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(); +} |
