| //===-- ConstantFolding.cpp - Fold instructions into constants ------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines routines for folding instructions into constants. |
| // |
| // Also, to supplement the basic IR ConstantExpr simplifications, |
| // this file defines some additional folding routines that can make use of |
| // DataLayout information. These functions cannot go in IR due to library |
| // dependency issues. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/ConstantFolding.h" |
| #include "llvm/ADT/APFloat.h" |
| #include "llvm/ADT/APInt.h" |
| #include "llvm/ADT/APSInt.h" |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/ADT/DenseMap.h" |
| #include "llvm/ADT/STLExtras.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/ADT/StringRef.h" |
| #include "llvm/Analysis/TargetFolder.h" |
| #include "llvm/Analysis/TargetLibraryInfo.h" |
| #include "llvm/Analysis/ValueTracking.h" |
| #include "llvm/Analysis/VectorUtils.h" |
| #include "llvm/Config/config.h" |
| #include "llvm/IR/Constant.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/GlobalValue.h" |
| #include "llvm/IR/GlobalVariable.h" |
| #include "llvm/IR/InstrTypes.h" |
| #include "llvm/IR/Instruction.h" |
| #include "llvm/IR/Instructions.h" |
| #include "llvm/IR/IntrinsicInst.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/IntrinsicsAArch64.h" |
| #include "llvm/IR/IntrinsicsAMDGPU.h" |
| #include "llvm/IR/IntrinsicsARM.h" |
| #include "llvm/IR/IntrinsicsWebAssembly.h" |
| #include "llvm/IR/IntrinsicsX86.h" |
| #include "llvm/IR/Operator.h" |
| #include "llvm/IR/Type.h" |
| #include "llvm/IR/Value.h" |
| #include "llvm/Support/Casting.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/Support/KnownBits.h" |
| #include "llvm/Support/MathExtras.h" |
| #include <cassert> |
| #include <cerrno> |
| #include <cfenv> |
| #include <cmath> |
| #include <cstddef> |
| #include <cstdint> |
| |
| using namespace llvm; |
| |
| namespace { |
| |
| //===----------------------------------------------------------------------===// |
| // Constant Folding internal helper functions |
| //===----------------------------------------------------------------------===// |
| |
| static Constant *foldConstVectorToAPInt(APInt &Result, Type *DestTy, |
| Constant *C, Type *SrcEltTy, |
| unsigned NumSrcElts, |
| const DataLayout &DL) { |
| // Now that we know that the input value is a vector of integers, just shift |
| // and insert them into our result. |
| unsigned BitShift = DL.getTypeSizeInBits(SrcEltTy); |
| for (unsigned i = 0; i != NumSrcElts; ++i) { |
| Constant *Element; |
| if (DL.isLittleEndian()) |
| Element = C->getAggregateElement(NumSrcElts - i - 1); |
| else |
| Element = C->getAggregateElement(i); |
| |
| if (Element && isa<UndefValue>(Element)) { |
| Result <<= BitShift; |
| continue; |
| } |
| |
| auto *ElementCI = dyn_cast_or_null<ConstantInt>(Element); |
| if (!ElementCI) |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| Result <<= BitShift; |
| Result |= ElementCI->getValue().zextOrSelf(Result.getBitWidth()); |
| } |
| |
| return nullptr; |
| } |
| |
| /// Constant fold bitcast, symbolically evaluating it with DataLayout. |
| /// This always returns a non-null constant, but it may be a |
| /// ConstantExpr if unfoldable. |
| Constant *FoldBitCast(Constant *C, Type *DestTy, const DataLayout &DL) { |
| assert(CastInst::castIsValid(Instruction::BitCast, C, DestTy) && |
| "Invalid constantexpr bitcast!"); |
| |
| // Catch the obvious splat cases. |
| if (C->isNullValue() && !DestTy->isX86_MMXTy() && !DestTy->isX86_AMXTy()) |
| return Constant::getNullValue(DestTy); |
| if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() && !DestTy->isX86_AMXTy() && |
| !DestTy->isPtrOrPtrVectorTy()) // Don't get ones for ptr types! |
| return Constant::getAllOnesValue(DestTy); |
| |
| if (auto *VTy = dyn_cast<VectorType>(C->getType())) { |
| // Handle a vector->scalar integer/fp cast. |
| if (isa<IntegerType>(DestTy) || DestTy->isFloatingPointTy()) { |
| unsigned NumSrcElts = cast<FixedVectorType>(VTy)->getNumElements(); |
| Type *SrcEltTy = VTy->getElementType(); |
| |
| // If the vector is a vector of floating point, convert it to vector of int |
| // to simplify things. |
| if (SrcEltTy->isFloatingPointTy()) { |
| unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); |
| auto *SrcIVTy = FixedVectorType::get( |
| IntegerType::get(C->getContext(), FPWidth), NumSrcElts); |
| // Ask IR to do the conversion now that #elts line up. |
| C = ConstantExpr::getBitCast(C, SrcIVTy); |
| } |
| |
| APInt Result(DL.getTypeSizeInBits(DestTy), 0); |
| if (Constant *CE = foldConstVectorToAPInt(Result, DestTy, C, |
| SrcEltTy, NumSrcElts, DL)) |
| return CE; |
| |
| if (isa<IntegerType>(DestTy)) |
| return ConstantInt::get(DestTy, Result); |
| |
| APFloat FP(DestTy->getFltSemantics(), Result); |
| return ConstantFP::get(DestTy->getContext(), FP); |
| } |
| } |
| |
| // The code below only handles casts to vectors currently. |
| auto *DestVTy = dyn_cast<VectorType>(DestTy); |
| if (!DestVTy) |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| // If this is a scalar -> vector cast, convert the input into a <1 x scalar> |
| // vector so the code below can handle it uniformly. |
| if (isa<ConstantFP>(C) || isa<ConstantInt>(C)) { |
| Constant *Ops = C; // don't take the address of C! |
| return FoldBitCast(ConstantVector::get(Ops), DestTy, DL); |
| } |
| |
| // If this is a bitcast from constant vector -> vector, fold it. |
| if (!isa<ConstantDataVector>(C) && !isa<ConstantVector>(C)) |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| // If the element types match, IR can fold it. |
| unsigned NumDstElt = cast<FixedVectorType>(DestVTy)->getNumElements(); |
| unsigned NumSrcElt = cast<FixedVectorType>(C->getType())->getNumElements(); |
| if (NumDstElt == NumSrcElt) |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| Type *SrcEltTy = cast<VectorType>(C->getType())->getElementType(); |
| Type *DstEltTy = DestVTy->getElementType(); |
| |
| // Otherwise, we're changing the number of elements in a vector, which |
| // requires endianness information to do the right thing. For example, |
| // bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) |
| // folds to (little endian): |
| // <4 x i32> <i32 0, i32 0, i32 1, i32 0> |
| // and to (big endian): |
| // <4 x i32> <i32 0, i32 0, i32 0, i32 1> |
| |
| // First thing is first. We only want to think about integer here, so if |
| // we have something in FP form, recast it as integer. |
| if (DstEltTy->isFloatingPointTy()) { |
| // Fold to an vector of integers with same size as our FP type. |
| unsigned FPWidth = DstEltTy->getPrimitiveSizeInBits(); |
| auto *DestIVTy = FixedVectorType::get( |
| IntegerType::get(C->getContext(), FPWidth), NumDstElt); |
| // Recursively handle this integer conversion, if possible. |
| C = FoldBitCast(C, DestIVTy, DL); |
| |
| // Finally, IR can handle this now that #elts line up. |
| return ConstantExpr::getBitCast(C, DestTy); |
| } |
| |
| // Okay, we know the destination is integer, if the input is FP, convert |
| // it to integer first. |
| if (SrcEltTy->isFloatingPointTy()) { |
| unsigned FPWidth = SrcEltTy->getPrimitiveSizeInBits(); |
| auto *SrcIVTy = FixedVectorType::get( |
| IntegerType::get(C->getContext(), FPWidth), NumSrcElt); |
| // Ask IR to do the conversion now that #elts line up. |
| C = ConstantExpr::getBitCast(C, SrcIVTy); |
| // If IR wasn't able to fold it, bail out. |
| if (!isa<ConstantVector>(C) && // FIXME: Remove ConstantVector. |
| !isa<ConstantDataVector>(C)) |
| return C; |
| } |
| |
| // Now we know that the input and output vectors are both integer vectors |
| // of the same size, and that their #elements is not the same. Do the |
| // conversion here, which depends on whether the input or output has |
| // more elements. |
| bool isLittleEndian = DL.isLittleEndian(); |
| |
| SmallVector<Constant*, 32> Result; |
| if (NumDstElt < NumSrcElt) { |
| // Handle: bitcast (<4 x i32> <i32 0, i32 1, i32 2, i32 3> to <2 x i64>) |
| Constant *Zero = Constant::getNullValue(DstEltTy); |
| unsigned Ratio = NumSrcElt/NumDstElt; |
| unsigned SrcBitSize = SrcEltTy->getPrimitiveSizeInBits(); |
| unsigned SrcElt = 0; |
| for (unsigned i = 0; i != NumDstElt; ++i) { |
| // Build each element of the result. |
| Constant *Elt = Zero; |
| unsigned ShiftAmt = isLittleEndian ? 0 : SrcBitSize*(Ratio-1); |
| for (unsigned j = 0; j != Ratio; ++j) { |
| Constant *Src = C->getAggregateElement(SrcElt++); |
| if (Src && isa<UndefValue>(Src)) |
| Src = Constant::getNullValue( |
| cast<VectorType>(C->getType())->getElementType()); |
| else |
| Src = dyn_cast_or_null<ConstantInt>(Src); |
| if (!Src) // Reject constantexpr elements. |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| // Zero extend the element to the right size. |
| Src = ConstantExpr::getZExt(Src, Elt->getType()); |
| |
| // Shift it to the right place, depending on endianness. |
| Src = ConstantExpr::getShl(Src, |
| ConstantInt::get(Src->getType(), ShiftAmt)); |
| ShiftAmt += isLittleEndian ? SrcBitSize : -SrcBitSize; |
| |
| // Mix it in. |
| Elt = ConstantExpr::getOr(Elt, Src); |
| } |
| Result.push_back(Elt); |
| } |
| return ConstantVector::get(Result); |
| } |
| |
| // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) |
| unsigned Ratio = NumDstElt/NumSrcElt; |
| unsigned DstBitSize = DL.getTypeSizeInBits(DstEltTy); |
| |
| // Loop over each source value, expanding into multiple results. |
| for (unsigned i = 0; i != NumSrcElt; ++i) { |
| auto *Element = C->getAggregateElement(i); |
| |
| if (!Element) // Reject constantexpr elements. |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| if (isa<UndefValue>(Element)) { |
| // Correctly Propagate undef values. |
| Result.append(Ratio, UndefValue::get(DstEltTy)); |
| continue; |
| } |
| |
| auto *Src = dyn_cast<ConstantInt>(Element); |
| if (!Src) |
| return ConstantExpr::getBitCast(C, DestTy); |
| |
| unsigned ShiftAmt = isLittleEndian ? 0 : DstBitSize*(Ratio-1); |
| for (unsigned j = 0; j != Ratio; ++j) { |
| // Shift the piece of the value into the right place, depending on |
| // endianness. |
| Constant *Elt = ConstantExpr::getLShr(Src, |
| ConstantInt::get(Src->getType(), ShiftAmt)); |
| ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize; |
| |
| // Truncate the element to an integer with the same pointer size and |
| // convert the element back to a pointer using a inttoptr. |
| if (DstEltTy->isPointerTy()) { |
| IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize); |
| Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy); |
| Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy)); |
| continue; |
| } |
| |
| // Truncate and remember this piece. |
| Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy)); |
| } |
| } |
| |
| return ConstantVector::get(Result); |
| } |
| |
| } // end anonymous namespace |
| |
| /// If this constant is a constant offset from a global, return the global and |
| /// the constant. Because of constantexprs, this function is recursive. |
| bool llvm::IsConstantOffsetFromGlobal(Constant *C, GlobalValue *&GV, |
| APInt &Offset, const DataLayout &DL, |
| DSOLocalEquivalent **DSOEquiv) { |
| if (DSOEquiv) |
| *DSOEquiv = nullptr; |
| |
| // Trivial case, constant is the global. |
| if ((GV = dyn_cast<GlobalValue>(C))) { |
| unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType()); |
| Offset = APInt(BitWidth, 0); |
| return true; |
| } |
| |
| if (auto *FoundDSOEquiv = dyn_cast<DSOLocalEquivalent>(C)) { |
| if (DSOEquiv) |
| *DSOEquiv = FoundDSOEquiv; |
| GV = FoundDSOEquiv->getGlobalValue(); |
| unsigned BitWidth = DL.getIndexTypeSizeInBits(GV->getType()); |
| Offset = APInt(BitWidth, 0); |
| return true; |
| } |
| |
| // Otherwise, if this isn't a constant expr, bail out. |
| auto *CE = dyn_cast<ConstantExpr>(C); |
| if (!CE) return false; |
| |
| // Look through ptr->int and ptr->ptr casts. |
| if (CE->getOpcode() == Instruction::PtrToInt || |
| CE->getOpcode() == Instruction::BitCast) |
| return IsConstantOffsetFromGlobal(CE->getOperand(0), GV, Offset, DL, |
| DSOEquiv); |
| |
| // i32* getelementptr ([5 x i32]* @a, i32 0, i32 5) |
| auto *GEP = dyn_cast<GEPOperator>(CE); |
| if (!GEP) |
| return false; |
| |
| unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType()); |
| APInt TmpOffset(BitWidth, 0); |
| |
| // If the base isn't a global+constant, we aren't either. |
| if (!IsConstantOffsetFromGlobal(CE->getOperand(0), GV, TmpOffset, DL, |
| DSOEquiv)) |
| return false; |
| |
| // Otherwise, add any offset that our operands provide. |
| if (!GEP->accumulateConstantOffset(DL, TmpOffset)) |
| return false; |
| |
| Offset = TmpOffset; |
| return true; |
| } |
| |
| Constant *llvm::ConstantFoldLoadThroughBitcast(Constant *C, Type *DestTy, |
| const DataLayout &DL) { |
| do { |
| Type *SrcTy = C->getType(); |
| TypeSize DestSize = DL.getTypeSizeInBits(DestTy); |
| TypeSize SrcSize = DL.getTypeSizeInBits(SrcTy); |
| if (!TypeSize::isKnownGE(SrcSize, DestSize)) |
| return nullptr; |
| |
| // Catch the obvious splat cases (since all-zeros can coerce non-integral |
| // pointers legally). |
| if (C->isNullValue() && !DestTy->isX86_MMXTy() && !DestTy->isX86_AMXTy()) |
| return Constant::getNullValue(DestTy); |
| if (C->isAllOnesValue() && |
| (DestTy->isIntegerTy() || DestTy->isFloatingPointTy() || |
| DestTy->isVectorTy()) && |
| !DestTy->isX86_AMXTy() && !DestTy->isX86_MMXTy() && |
| !DestTy->isPtrOrPtrVectorTy()) |
| // Get ones when the input is trivial, but |
| // only for supported types inside getAllOnesValue. |
| return Constant::getAllOnesValue(DestTy); |
| |
| // If the type sizes are the same and a cast is legal, just directly |
| // cast the constant. |
| // But be careful not to coerce non-integral pointers illegally. |
| if (SrcSize == DestSize && |
| DL.isNonIntegralPointerType(SrcTy->getScalarType()) == |
| DL.isNonIntegralPointerType(DestTy->getScalarType())) { |
| Instruction::CastOps Cast = Instruction::BitCast; |
| // If we are going from a pointer to int or vice versa, we spell the cast |
| // differently. |
| if (SrcTy->isIntegerTy() && DestTy->isPointerTy()) |
| Cast = Instruction::IntToPtr; |
| else if (SrcTy->isPointerTy() && DestTy->isIntegerTy()) |
| Cast = Instruction::PtrToInt; |
| |
| if (CastInst::castIsValid(Cast, C, DestTy)) |
| return ConstantExpr::getCast(Cast, C, DestTy); |
| } |
| |
| // If this isn't an aggregate type, there is nothing we can do to drill down |
| // and find a bitcastable constant. |
| if (!SrcTy->isAggregateType() && !SrcTy->isVectorTy()) |
| return nullptr; |
| |
| // We're simulating a load through a pointer that was bitcast to point to |
| // a different type, so we can try to walk down through the initial |
| // elements of an aggregate to see if some part of the aggregate is |
| // castable to implement the "load" semantic model. |
| if (SrcTy->isStructTy()) { |
| // Struct types might have leading zero-length elements like [0 x i32], |
| // which are certainly not what we are looking for, so skip them. |
| unsigned Elem = 0; |
| Constant *ElemC; |
| do { |
| ElemC = C->getAggregateElement(Elem++); |
| } while (ElemC && DL.getTypeSizeInBits(ElemC->getType()).isZero()); |
| C = ElemC; |
| } else { |
| C = C->getAggregateElement(0u); |
| } |
| } while (C); |
| |
| return nullptr; |
| } |
| |
| namespace { |
| |
| /// Recursive helper to read bits out of global. C is the constant being copied |
| /// out of. ByteOffset is an offset into C. CurPtr is the pointer to copy |
| /// results into and BytesLeft is the number of bytes left in |
| /// the CurPtr buffer. DL is the DataLayout. |
| bool ReadDataFromGlobal(Constant *C, uint64_t ByteOffset, unsigned char *CurPtr, |
| unsigned BytesLeft, const DataLayout &DL) { |
| assert(ByteOffset <= DL.getTypeAllocSize(C->getType()) && |
| "Out of range access"); |
| |
| // If this element is zero or undefined, we can just return since *CurPtr is |
| // zero initialized. |
| if (isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) |
| return true; |
| |
| if (auto *CI = dyn_cast<ConstantInt>(C)) { |
| if (CI->getBitWidth() > 64 || |
| (CI->getBitWidth() & 7) != 0) |
| return false; |
| |
| uint64_t Val = CI->getZExtValue(); |
| unsigned IntBytes = unsigned(CI->getBitWidth()/8); |
| |
| for (unsigned i = 0; i != BytesLeft && ByteOffset != IntBytes; ++i) { |
| int n = ByteOffset; |
| if (!DL.isLittleEndian()) |
| n = IntBytes - n - 1; |
| CurPtr[i] = (unsigned char)(Val >> (n * 8)); |
| ++ByteOffset; |
| } |
| return true; |
| } |
| |
| if (auto *CFP = dyn_cast<ConstantFP>(C)) { |
| if (CFP->getType()->isDoubleTy()) { |
| C = FoldBitCast(C, Type::getInt64Ty(C->getContext()), DL); |
| return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL); |
| } |
| if (CFP->getType()->isFloatTy()){ |
| C = FoldBitCast(C, Type::getInt32Ty(C->getContext()), DL); |
| return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL); |
| } |
| if (CFP->getType()->isHalfTy()){ |
| C = FoldBitCast(C, Type::getInt16Ty(C->getContext()), DL); |
| return ReadDataFromGlobal(C, ByteOffset, CurPtr, BytesLeft, DL); |
| } |
| return false; |
| } |
| |
| if (auto *CS = dyn_cast<ConstantStruct>(C)) { |
| const StructLayout *SL = DL.getStructLayout(CS->getType()); |
| unsigned Index = SL->getElementContainingOffset(ByteOffset); |
| uint64_t CurEltOffset = SL->getElementOffset(Index); |
| ByteOffset -= CurEltOffset; |
| |
| while (true) { |
| // If the element access is to the element itself and not to tail padding, |
| // read the bytes from the element. |
| uint64_t EltSize = DL.getTypeAllocSize(CS->getOperand(Index)->getType()); |
| |
| if (ByteOffset < EltSize && |
| !ReadDataFromGlobal(CS->getOperand(Index), ByteOffset, CurPtr, |
| BytesLeft, DL)) |
| return false; |
| |
| ++Index; |
| |
| // Check to see if we read from the last struct element, if so we're done. |
| if (Index == CS->getType()->getNumElements()) |
| return true; |
| |
| // If we read all of the bytes we needed from this element we're done. |
| uint64_t NextEltOffset = SL->getElementOffset(Index); |
| |
| if (BytesLeft <= NextEltOffset - CurEltOffset - ByteOffset) |
| return true; |
| |
| // Move to the next element of the struct. |
| CurPtr += NextEltOffset - CurEltOffset - ByteOffset; |
| BytesLeft -= NextEltOffset - CurEltOffset - ByteOffset; |
| ByteOffset = 0; |
| CurEltOffset = NextEltOffset; |
| } |
| // not reached. |
| } |
| |
| if (isa<ConstantArray>(C) || isa<ConstantVector>(C) || |
| isa<ConstantDataSequential>(C)) { |
| uint64_t NumElts; |
| Type *EltTy; |
| if (auto *AT = dyn_cast<ArrayType>(C->getType())) { |
| NumElts = AT->getNumElements(); |
| EltTy = AT->getElementType(); |
| } else { |
| NumElts = cast<FixedVectorType>(C->getType())->getNumElements(); |
| EltTy = cast<FixedVectorType>(C->getType())->getElementType(); |
| } |
| uint64_t EltSize = DL.getTypeAllocSize(EltTy); |
| uint64_t Index = ByteOffset / EltSize; |
| uint64_t Offset = ByteOffset - Index * EltSize; |
| |
| for (; Index != NumElts; ++Index) { |
| if (!ReadDataFromGlobal(C->getAggregateElement(Index), Offset, CurPtr, |
| BytesLeft, DL)) |
| return false; |
| |
| uint64_t BytesWritten = EltSize - Offset; |
| assert(BytesWritten <= EltSize && "Not indexing into this element?"); |
| if (BytesWritten >= BytesLeft) |
| return true; |
| |
| Offset = 0; |
| BytesLeft -= BytesWritten; |
| CurPtr += BytesWritten; |
| } |
| return true; |
| } |
| |
| if (auto *CE = dyn_cast<ConstantExpr>(C)) { |
| if (CE->getOpcode() == Instruction::IntToPtr && |
| CE->getOperand(0)->getType() == DL.getIntPtrType(CE->getType())) { |
| return ReadDataFromGlobal(CE->getOperand(0), ByteOffset, CurPtr, |
| BytesLeft, DL); |
| } |
| } |
| |
| // Otherwise, unknown initializer type. |
| return false; |
| } |
| |
| Constant *FoldReinterpretLoadFromConst(Constant *C, Type *LoadTy, |
| int64_t Offset, const DataLayout &DL) { |
| // Bail out early. Not expect to load from scalable global variable. |
| if (isa<ScalableVectorType>(LoadTy)) |
| return nullptr; |
| |
| auto *IntType = dyn_cast<IntegerType>(LoadTy); |
| |
| // If this isn't an integer load we can't fold it directly. |
| if (!IntType) { |
| // If this is a float/double load, we can try folding it as an int32/64 load |
| // and then bitcast the result. This can be useful for union cases. Note |
| // that address spaces don't matter here since we're not going to result in |
| // an actual new load. |
| Type *MapTy; |
| if (LoadTy->isHalfTy()) |
| MapTy = Type::getInt16Ty(C->getContext()); |
| else if (LoadTy->isFloatTy()) |
| MapTy = Type::getInt32Ty(C->getContext()); |
| else if (LoadTy->isDoubleTy()) |
| MapTy = Type::getInt64Ty(C->getContext()); |
| else if (LoadTy->isVectorTy()) { |
| MapTy = PointerType::getIntNTy( |
| C->getContext(), DL.getTypeSizeInBits(LoadTy).getFixedSize()); |
| } else |
| return nullptr; |
| |
| if (Constant *Res = FoldReinterpretLoadFromConst(C, MapTy, Offset, DL)) { |
| if (Res->isNullValue() && !LoadTy->isX86_MMXTy() && |
| !LoadTy->isX86_AMXTy()) |
| // Materializing a zero can be done trivially without a bitcast |
| return Constant::getNullValue(LoadTy); |
| Type *CastTy = LoadTy->isPtrOrPtrVectorTy() ? DL.getIntPtrType(LoadTy) : LoadTy; |
| Res = FoldBitCast(Res, CastTy, DL); |
| if (LoadTy->isPtrOrPtrVectorTy()) { |
| // For vector of pointer, we needed to first convert to a vector of integer, then do vector inttoptr |
| if (Res->isNullValue() && !LoadTy->isX86_MMXTy() && |
| !LoadTy->isX86_AMXTy()) |
| return Constant::getNullValue(LoadTy); |
| if (DL.isNonIntegralPointerType(LoadTy->getScalarType())) |
| // Be careful not to replace a load of an addrspace value with an inttoptr here |
| return nullptr; |
| Res = ConstantExpr::getCast(Instruction::IntToPtr, Res, LoadTy); |
| } |
| return Res; |
| } |
| return nullptr; |
| } |
| |
| unsigned BytesLoaded = (IntType->getBitWidth() + 7) / 8; |
| if (BytesLoaded > 32 || BytesLoaded == 0) |
| return nullptr; |
| |
| int64_t InitializerSize = DL.getTypeAllocSize(C->getType()).getFixedSize(); |
| |
| // If we're not accessing anything in this constant, the result is undefined. |
| if (Offset <= -1 * static_cast<int64_t>(BytesLoaded)) |
| return UndefValue::get(IntType); |
| |
| // If we're not accessing anything in this constant, the result is undefined. |
| if (Offset >= InitializerSize) |
| return UndefValue::get(IntType); |
| |
| unsigned char RawBytes[32] = {0}; |
| unsigned char *CurPtr = RawBytes; |
| unsigned BytesLeft = BytesLoaded; |
| |
| // If we're loading off the beginning of the global, some bytes may be valid. |
| if (Offset < 0) { |
| CurPtr += -Offset; |
| BytesLeft += Offset; |
| Offset = 0; |
| } |
| |
| if (!ReadDataFromGlobal(C, Offset, CurPtr, BytesLeft, DL)) |
| return nullptr; |
| |
| APInt ResultVal = APInt(IntType->getBitWidth(), 0); |
| if (DL.isLittleEndian()) { |
| ResultVal = RawBytes[BytesLoaded - 1]; |
| for (unsigned i = 1; i != BytesLoaded; ++i) { |
| ResultVal <<= 8; |
| ResultVal |= RawBytes[BytesLoaded - 1 - i]; |
| } |
| } else { |
| ResultVal = RawBytes[0]; |
| for (unsigned i = 1; i != BytesLoaded; ++i) { |
| ResultVal <<= 8; |
| ResultVal |= RawBytes[i]; |
| } |
| } |
| |
| return ConstantInt::get(IntType->getContext(), ResultVal); |
| } |
| |
| /// If this Offset points exactly to the start of an aggregate element, return |
| /// that element, otherwise return nullptr. |
| Constant *getConstantAtOffset(Constant *Base, APInt Offset, |
| const DataLayout &DL) { |
| if (Offset.isZero()) |
| return Base; |
| |
| if (!isa<ConstantAggregate>(Base) && !isa<ConstantDataSequential>(Base)) |
| return nullptr; |
| |
| Type *ElemTy = Base->getType(); |
| SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset); |
| if (!Offset.isZero() || !Indices[0].isZero()) |
| return nullptr; |
| |
| Constant *C = Base; |
| for (const APInt &Index : drop_begin(Indices)) { |
| if (Index.isNegative() || Index.getActiveBits() >= 32) |
| return nullptr; |
| |
| C = C->getAggregateElement(Index.getZExtValue()); |
| if (!C) |
| return nullptr; |
| } |
| |
| return C; |
| } |
| |
| } // end anonymous namespace |
| |
| Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty, |
| const APInt &Offset, |
| const DataLayout &DL) { |
| if (Constant *AtOffset = getConstantAtOffset(C, Offset, DL)) |
| if (Constant *Result = ConstantFoldLoadThroughBitcast(AtOffset, Ty, DL)) |
| return Result; |
| |
| // Try hard to fold loads from bitcasted strange and non-type-safe things. |
| if (Offset.getMinSignedBits() <= 64) |
| return FoldReinterpretLoadFromConst(C, Ty, Offset.getSExtValue(), DL); |
| |
| return nullptr; |
| } |
| |
| Constant *llvm::ConstantFoldLoadFromConst(Constant *C, Type *Ty, |
| const DataLayout &DL) { |
| return ConstantFoldLoadFromConst(C, Ty, APInt(64, 0), DL); |
| } |
| |
| Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty, |
| APInt Offset, |
| const DataLayout &DL) { |
| C = cast<Constant>(C->stripAndAccumulateConstantOffsets( |
| DL, Offset, /* AllowNonInbounds */ true)); |
| |
| if (auto *GV = dyn_cast<GlobalVariable>(C)) |
| if (GV->isConstant() && GV->hasDefinitiveInitializer()) |
| if (Constant *Result = ConstantFoldLoadFromConst(GV->getInitializer(), Ty, |
| Offset, DL)) |
| return Result; |
| |
| // If this load comes from anywhere in a constant global, and if the global |
| // is all undef or zero, we know what it loads. |
| if (auto *GV = dyn_cast<GlobalVariable>(getUnderlyingObject(C))) { |
| if (GV->isConstant() && GV->hasDefinitiveInitializer()) { |
| if (GV->getInitializer()->isNullValue()) |
| return Constant::getNullValue(Ty); |
| if (isa<UndefValue>(GV->getInitializer())) |
| return UndefValue::get(Ty); |
| } |
| } |
| |
| return nullptr; |
| } |
| |
| Constant *llvm::ConstantFoldLoadFromConstPtr(Constant *C, Type *Ty, |
| const DataLayout &DL) { |
| APInt Offset(DL.getIndexTypeSizeInBits(C->getType()), 0); |
| return ConstantFoldLoadFromConstPtr(C, Ty, Offset, DL); |
| } |
| |
| namespace { |
| |
| /// One of Op0/Op1 is a constant expression. |
| /// Attempt to symbolically evaluate the result of a binary operator merging |
| /// these together. If target data info is available, it is provided as DL, |
| /// otherwise DL is null. |
| Constant *SymbolicallyEvaluateBinop(unsigned Opc, Constant *Op0, Constant *Op1, |
| const DataLayout &DL) { |
| // SROA |
| |
| // Fold (and 0xffffffff00000000, (shl x, 32)) -> shl. |
| // Fold (lshr (or X, Y), 32) -> (lshr [X/Y], 32) if one doesn't contribute |
| // bits. |
| |
| if (Opc == Instruction::And) { |
| KnownBits Known0 = computeKnownBits(Op0, DL); |
| KnownBits Known1 = computeKnownBits(Op1, DL); |
| if ((Known1.One | Known0.Zero).isAllOnes()) { |
| // All the bits of Op0 that the 'and' could be masking are already zero. |
| return Op0; |
| } |
| if ((Known0.One | Known1.Zero).isAllOnes()) { |
| // All the bits of Op1 that the 'and' could be masking are already zero. |
| return Op1; |
| } |
| |
| Known0 &= Known1; |
| if (Known0.isConstant()) |
| return ConstantInt::get(Op0->getType(), Known0.getConstant()); |
| } |
| |
| // If the constant expr is something like &A[123] - &A[4].f, fold this into a |
| // constant. This happens frequently when iterating over a global array. |
| if (Opc == Instruction::Sub) { |
| GlobalValue *GV1, *GV2; |
| APInt Offs1, Offs2; |
| |
| if (IsConstantOffsetFromGlobal(Op0, GV1, Offs1, DL)) |
| if (IsConstantOffsetFromGlobal(Op1, GV2, Offs2, DL) && GV1 == GV2) { |
| unsigned OpSize = DL.getTypeSizeInBits(Op0->getType()); |
| |
| // (&GV+C1) - (&GV+C2) -> C1-C2, pointer arithmetic cannot overflow. |
| // PtrToInt may change the bitwidth so we have convert to the right size |
| // first. |
| return ConstantInt::get(Op0->getType(), Offs1.zextOrTrunc(OpSize) - |
| Offs2.zextOrTrunc(OpSize)); |
| } |
| } |
| |
| return nullptr; |
| } |
| |
| /// If array indices are not pointer-sized integers, explicitly cast them so |
| /// that they aren't implicitly casted by the getelementptr. |
| Constant *CastGEPIndices(Type *SrcElemTy, ArrayRef<Constant *> Ops, |
| Type *ResultTy, Optional<unsigned> InRangeIndex, |
| const DataLayout &DL, const TargetLibraryInfo *TLI) { |
| Type *IntIdxTy = DL.getIndexType(ResultTy); |
| Type *IntIdxScalarTy = IntIdxTy->getScalarType(); |
| |
| bool Any = false; |
| SmallVector<Constant*, 32> NewIdxs; |
| for (unsigned i = 1, e = Ops.size(); i != e; ++i) { |
| if ((i == 1 || |
| !isa<StructType>(GetElementPtrInst::getIndexedType( |
| SrcElemTy, Ops.slice(1, i - 1)))) && |
| Ops[i]->getType()->getScalarType() != IntIdxScalarTy) { |
| Any = true; |
| Type *NewType = Ops[i]->getType()->isVectorTy() |
| ? IntIdxTy |
| : IntIdxScalarTy; |
| NewIdxs.push_back(ConstantExpr::getCast(CastInst::getCastOpcode(Ops[i], |
| true, |
| NewType, |
| true), |
| Ops[i], NewType)); |
| } else |
| NewIdxs.push_back(Ops[i]); |
| } |
| |
| if (!Any) |
| return nullptr; |
| |
| Constant *C = ConstantExpr::getGetElementPtr( |
| SrcElemTy, Ops[0], NewIdxs, /*InBounds=*/false, InRangeIndex); |
| return ConstantFoldConstant(C, DL, TLI); |
| } |
| |
| /// Strip the pointer casts, but preserve the address space information. |
| Constant *StripPtrCastKeepAS(Constant *Ptr) { |
| assert(Ptr->getType()->isPointerTy() && "Not a pointer type"); |
| auto *OldPtrTy = cast<PointerType>(Ptr->getType()); |
| Ptr = cast<Constant>(Ptr->stripPointerCasts()); |
| auto *NewPtrTy = cast<PointerType>(Ptr->getType()); |
| |
| // Preserve the address space number of the pointer. |
| if (NewPtrTy->getAddressSpace() != OldPtrTy->getAddressSpace()) { |
| Ptr = ConstantExpr::getPointerCast( |
| Ptr, PointerType::getWithSamePointeeType(NewPtrTy, |
| OldPtrTy->getAddressSpace())); |
| } |
| return Ptr; |
| } |
| |
| /// If we can symbolically evaluate the GEP constant expression, do so. |
| Constant *SymbolicallyEvaluateGEP(const GEPOperator *GEP, |
| ArrayRef<Constant *> Ops, |
| const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| const GEPOperator *InnermostGEP = GEP; |
| bool InBounds = GEP->isInBounds(); |
| |
| Type *SrcElemTy = GEP->getSourceElementType(); |
| Type *ResElemTy = GEP->getResultElementType(); |
| Type *ResTy = GEP->getType(); |
| if (!SrcElemTy->isSized() || isa<ScalableVectorType>(SrcElemTy)) |
| return nullptr; |
| |
| if (Constant *C = CastGEPIndices(SrcElemTy, Ops, ResTy, |
| GEP->getInRangeIndex(), DL, TLI)) |
| return C; |
| |
| Constant *Ptr = Ops[0]; |
| if (!Ptr->getType()->isPointerTy()) |
| return nullptr; |
| |
| Type *IntIdxTy = DL.getIndexType(Ptr->getType()); |
| |
| // If this is "gep i8* Ptr, (sub 0, V)", fold this as: |
| // "inttoptr (sub (ptrtoint Ptr), V)" |
| if (Ops.size() == 2 && ResElemTy->isIntegerTy(8)) { |
| auto *CE = dyn_cast<ConstantExpr>(Ops[1]); |
| assert((!CE || CE->getType() == IntIdxTy) && |
| "CastGEPIndices didn't canonicalize index types!"); |
| if (CE && CE->getOpcode() == Instruction::Sub && |
| CE->getOperand(0)->isNullValue()) { |
| Constant *Res = ConstantExpr::getPtrToInt(Ptr, CE->getType()); |
| Res = ConstantExpr::getSub(Res, CE->getOperand(1)); |
| Res = ConstantExpr::getIntToPtr(Res, ResTy); |
| return ConstantFoldConstant(Res, DL, TLI); |
| } |
| } |
| |
| for (unsigned i = 1, e = Ops.size(); i != e; ++i) |
| if (!isa<ConstantInt>(Ops[i])) |
| return nullptr; |
| |
| unsigned BitWidth = DL.getTypeSizeInBits(IntIdxTy); |
| APInt Offset = |
| APInt(BitWidth, |
| DL.getIndexedOffsetInType( |
| SrcElemTy, |
| makeArrayRef((Value * const *)Ops.data() + 1, Ops.size() - 1))); |
| Ptr = StripPtrCastKeepAS(Ptr); |
| |
| // If this is a GEP of a GEP, fold it all into a single GEP. |
| while (auto *GEP = dyn_cast<GEPOperator>(Ptr)) { |
| InnermostGEP = GEP; |
| InBounds &= GEP->isInBounds(); |
| |
| SmallVector<Value *, 4> NestedOps(GEP->op_begin() + 1, GEP->op_end()); |
| |
| // Do not try the incorporate the sub-GEP if some index is not a number. |
| bool AllConstantInt = true; |
| for (Value *NestedOp : NestedOps) |
| if (!isa<ConstantInt>(NestedOp)) { |
| AllConstantInt = false; |
| break; |
| } |
| if (!AllConstantInt) |
| break; |
| |
| Ptr = cast<Constant>(GEP->getOperand(0)); |
| SrcElemTy = GEP->getSourceElementType(); |
| Offset += APInt(BitWidth, DL.getIndexedOffsetInType(SrcElemTy, NestedOps)); |
| Ptr = StripPtrCastKeepAS(Ptr); |
| } |
| |
| // If the base value for this address is a literal integer value, fold the |
| // getelementptr to the resulting integer value casted to the pointer type. |
| APInt BasePtr(BitWidth, 0); |
| if (auto *CE = dyn_cast<ConstantExpr>(Ptr)) { |
| if (CE->getOpcode() == Instruction::IntToPtr) { |
| if (auto *Base = dyn_cast<ConstantInt>(CE->getOperand(0))) |
| BasePtr = Base->getValue().zextOrTrunc(BitWidth); |
| } |
| } |
| |
| auto *PTy = cast<PointerType>(Ptr->getType()); |
| if ((Ptr->isNullValue() || BasePtr != 0) && |
| !DL.isNonIntegralPointerType(PTy)) { |
| Constant *C = ConstantInt::get(Ptr->getContext(), Offset + BasePtr); |
| return ConstantExpr::getIntToPtr(C, ResTy); |
| } |
| |
| // Otherwise form a regular getelementptr. Recompute the indices so that |
| // we eliminate over-indexing of the notional static type array bounds. |
| // This makes it easy to determine if the getelementptr is "inbounds". |
| // Also, this helps GlobalOpt do SROA on GlobalVariables. |
| |
| // For GEPs of GlobalValues, use the value type even for opaque pointers. |
| // Otherwise use an i8 GEP. |
| if (auto *GV = dyn_cast<GlobalValue>(Ptr)) |
| SrcElemTy = GV->getValueType(); |
| else if (!PTy->isOpaque()) |
| SrcElemTy = PTy->getElementType(); |
| else |
| SrcElemTy = Type::getInt8Ty(Ptr->getContext()); |
| |
| if (!SrcElemTy->isSized()) |
| return nullptr; |
| |
| Type *ElemTy = SrcElemTy; |
| SmallVector<APInt> Indices = DL.getGEPIndicesForOffset(ElemTy, Offset); |
| if (Offset != 0) |
| return nullptr; |
| |
| // Try to add additional zero indices to reach the desired result element |
| // type. |
| // TODO: Should we avoid extra zero indices if ResElemTy can't be reached and |
| // we'll have to insert a bitcast anyway? |
| while (ElemTy != ResElemTy) { |
| Type *NextTy = GetElementPtrInst::getTypeAtIndex(ElemTy, (uint64_t)0); |
| if (!NextTy) |
| break; |
| |
| Indices.push_back(APInt::getZero(isa<StructType>(ElemTy) ? 32 : BitWidth)); |
| ElemTy = NextTy; |
| } |
| |
| SmallVector<Constant *, 32> NewIdxs; |
| for (const APInt &Index : Indices) |
| NewIdxs.push_back(ConstantInt::get( |
| Type::getIntNTy(Ptr->getContext(), Index.getBitWidth()), Index)); |
| |
| // Preserve the inrange index from the innermost GEP if possible. We must |
| // have calculated the same indices up to and including the inrange index. |
| Optional<unsigned> InRangeIndex; |
| if (Optional<unsigned> LastIRIndex = InnermostGEP->getInRangeIndex()) |
| if (SrcElemTy == InnermostGEP->getSourceElementType() && |
| NewIdxs.size() > *LastIRIndex) { |
| InRangeIndex = LastIRIndex; |
| for (unsigned I = 0; I <= *LastIRIndex; ++I) |
| if (NewIdxs[I] != InnermostGEP->getOperand(I + 1)) |
| return nullptr; |
| } |
| |
| // Create a GEP. |
| Constant *C = ConstantExpr::getGetElementPtr(SrcElemTy, Ptr, NewIdxs, |
| InBounds, InRangeIndex); |
| assert( |
| cast<PointerType>(C->getType())->isOpaqueOrPointeeTypeMatches(ElemTy) && |
| "Computed GetElementPtr has unexpected type!"); |
| |
| // If we ended up indexing a member with a type that doesn't match |
| // the type of what the original indices indexed, add a cast. |
| if (C->getType() != ResTy) |
| C = FoldBitCast(C, ResTy, DL); |
| |
| return C; |
| } |
| |
| /// Attempt to constant fold an instruction with the |
| /// specified opcode and operands. If successful, the constant result is |
| /// returned, if not, null is returned. Note that this function can fail when |
| /// attempting to fold instructions like loads and stores, which have no |
| /// constant expression form. |
| Constant *ConstantFoldInstOperandsImpl(const Value *InstOrCE, unsigned Opcode, |
| ArrayRef<Constant *> Ops, |
| const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| Type *DestTy = InstOrCE->getType(); |
| |
| if (Instruction::isUnaryOp(Opcode)) |
| return ConstantFoldUnaryOpOperand(Opcode, Ops[0], DL); |
| |
| if (Instruction::isBinaryOp(Opcode)) |
| return ConstantFoldBinaryOpOperands(Opcode, Ops[0], Ops[1], DL); |
| |
| if (Instruction::isCast(Opcode)) |
| return ConstantFoldCastOperand(Opcode, Ops[0], DestTy, DL); |
| |
| if (auto *GEP = dyn_cast<GEPOperator>(InstOrCE)) { |
| if (Constant *C = SymbolicallyEvaluateGEP(GEP, Ops, DL, TLI)) |
| return C; |
| |
| return ConstantExpr::getGetElementPtr(GEP->getSourceElementType(), Ops[0], |
| Ops.slice(1), GEP->isInBounds(), |
| GEP->getInRangeIndex()); |
| } |
| |
| if (auto *CE = dyn_cast<ConstantExpr>(InstOrCE)) |
| return CE->getWithOperands(Ops); |
| |
| switch (Opcode) { |
| default: return nullptr; |
| case Instruction::ICmp: |
| case Instruction::FCmp: llvm_unreachable("Invalid for compares"); |
| case Instruction::Freeze: |
| return isGuaranteedNotToBeUndefOrPoison(Ops[0]) ? Ops[0] : nullptr; |
| case Instruction::Call: |
| if (auto *F = dyn_cast<Function>(Ops.back())) { |
| const auto *Call = cast<CallBase>(InstOrCE); |
| if (canConstantFoldCallTo(Call, F)) |
| return ConstantFoldCall(Call, F, Ops.slice(0, Ops.size() - 1), TLI); |
| } |
| return nullptr; |
| case Instruction::Select: |
| return ConstantExpr::getSelect(Ops[0], Ops[1], Ops[2]); |
| case Instruction::ExtractElement: |
| return ConstantExpr::getExtractElement(Ops[0], Ops[1]); |
| case Instruction::ExtractValue: |
| return ConstantExpr::getExtractValue( |
| Ops[0], cast<ExtractValueInst>(InstOrCE)->getIndices()); |
| case Instruction::InsertElement: |
| return ConstantExpr::getInsertElement(Ops[0], Ops[1], Ops[2]); |
| case Instruction::ShuffleVector: |
| return ConstantExpr::getShuffleVector( |
| Ops[0], Ops[1], cast<ShuffleVectorInst>(InstOrCE)->getShuffleMask()); |
| } |
| } |
| |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // Constant Folding public APIs |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| |
| Constant * |
| ConstantFoldConstantImpl(const Constant *C, const DataLayout &DL, |
| const TargetLibraryInfo *TLI, |
| SmallDenseMap<Constant *, Constant *> &FoldedOps) { |
| if (!isa<ConstantVector>(C) && !isa<ConstantExpr>(C)) |
| return const_cast<Constant *>(C); |
| |
| SmallVector<Constant *, 8> Ops; |
| for (const Use &OldU : C->operands()) { |
| Constant *OldC = cast<Constant>(&OldU); |
| Constant *NewC = OldC; |
| // Recursively fold the ConstantExpr's operands. If we have already folded |
| // a ConstantExpr, we don't have to process it again. |
| if (isa<ConstantVector>(OldC) || isa<ConstantExpr>(OldC)) { |
| auto It = FoldedOps.find(OldC); |
| if (It == FoldedOps.end()) { |
| NewC = ConstantFoldConstantImpl(OldC, DL, TLI, FoldedOps); |
| FoldedOps.insert({OldC, NewC}); |
| } else { |
| NewC = It->second; |
| } |
| } |
| Ops.push_back(NewC); |
| } |
| |
| if (auto *CE = dyn_cast<ConstantExpr>(C)) { |
| if (CE->isCompare()) |
| return ConstantFoldCompareInstOperands(CE->getPredicate(), Ops[0], Ops[1], |
| DL, TLI); |
| |
| return ConstantFoldInstOperandsImpl(CE, CE->getOpcode(), Ops, DL, TLI); |
| } |
| |
| assert(isa<ConstantVector>(C)); |
| return ConstantVector::get(Ops); |
| } |
| |
| } // end anonymous namespace |
| |
| Constant *llvm::ConstantFoldInstruction(Instruction *I, const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| // Handle PHI nodes quickly here... |
| if (auto *PN = dyn_cast<PHINode>(I)) { |
| Constant *CommonValue = nullptr; |
| |
| SmallDenseMap<Constant *, Constant *> FoldedOps; |
| for (Value *Incoming : PN->incoming_values()) { |
| // If the incoming value is undef then skip it. Note that while we could |
| // skip the value if it is equal to the phi node itself we choose not to |
| // because that would break the rule that constant folding only applies if |
| // all operands are constants. |
| if (isa<UndefValue>(Incoming)) |
| continue; |
| // If the incoming value is not a constant, then give up. |
| auto *C = dyn_cast<Constant>(Incoming); |
| if (!C) |
| return nullptr; |
| // Fold the PHI's operands. |
| C = ConstantFoldConstantImpl(C, DL, TLI, FoldedOps); |
| // If the incoming value is a different constant to |
| // the one we saw previously, then give up. |
| if (CommonValue && C != CommonValue) |
| return nullptr; |
| CommonValue = C; |
| } |
| |
| // If we reach here, all incoming values are the same constant or undef. |
| return CommonValue ? CommonValue : UndefValue::get(PN->getType()); |
| } |
| |
| // Scan the operand list, checking to see if they are all constants, if so, |
| // hand off to ConstantFoldInstOperandsImpl. |
| if (!all_of(I->operands(), [](Use &U) { return isa<Constant>(U); })) |
| return nullptr; |
| |
| SmallDenseMap<Constant *, Constant *> FoldedOps; |
| SmallVector<Constant *, 8> Ops; |
| for (const Use &OpU : I->operands()) { |
| auto *Op = cast<Constant>(&OpU); |
| // Fold the Instruction's operands. |
| Op = ConstantFoldConstantImpl(Op, DL, TLI, FoldedOps); |
| Ops.push_back(Op); |
| } |
| |
| if (const auto *CI = dyn_cast<CmpInst>(I)) |
| return ConstantFoldCompareInstOperands(CI->getPredicate(), Ops[0], Ops[1], |
| DL, TLI); |
| |
| if (const auto *LI = dyn_cast<LoadInst>(I)) { |
| if (LI->isVolatile()) |
| return nullptr; |
| return ConstantFoldLoadFromConstPtr(Ops[0], LI->getType(), DL); |
| } |
| |
| if (auto *IVI = dyn_cast<InsertValueInst>(I)) |
| return ConstantExpr::getInsertValue(Ops[0], Ops[1], IVI->getIndices()); |
| |
| if (auto *EVI = dyn_cast<ExtractValueInst>(I)) |
| return ConstantExpr::getExtractValue(Ops[0], EVI->getIndices()); |
| |
| return ConstantFoldInstOperands(I, Ops, DL, TLI); |
| } |
| |
| Constant *llvm::ConstantFoldConstant(const Constant *C, const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| SmallDenseMap<Constant *, Constant *> FoldedOps; |
| return ConstantFoldConstantImpl(C, DL, TLI, FoldedOps); |
| } |
| |
| Constant *llvm::ConstantFoldInstOperands(Instruction *I, |
| ArrayRef<Constant *> Ops, |
| const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| return ConstantFoldInstOperandsImpl(I, I->getOpcode(), Ops, DL, TLI); |
| } |
| |
| Constant *llvm::ConstantFoldCompareInstOperands(unsigned Predicate, |
| Constant *Ops0, Constant *Ops1, |
| const DataLayout &DL, |
| const TargetLibraryInfo *TLI) { |
| // fold: icmp (inttoptr x), null -> icmp x, 0 |
| // fold: icmp null, (inttoptr x) -> icmp 0, x |
| // fold: icmp (ptrtoint x), 0 -> icmp x, null |
| // fold: icmp 0, (ptrtoint x) -> icmp null, x |
| // fold: icmp (inttoptr x), (inttoptr y) -> icmp trunc/zext x, trunc/zext y |
| // fold: icmp (ptrtoint x), (ptrtoint y) -> icmp x, y |
| // |
| // FIXME: The following comment is out of data and the DataLayout is here now. |
| // ConstantExpr::getCompare cannot do this, because it doesn't have DL |
| // around to know if bit truncation is happening. |
| if (auto *CE0 = dyn_cast<ConstantExpr>(Ops0)) { |
| if (Ops1->isNullValue()) { |
| if (CE0->getOpcode() == Instruction::IntToPtr) { |
| Type *IntPtrTy = DL.getIntPtrType(CE0->getType()); |
| // Convert the integer value to the right size to ensure we get the |
| // proper extension or truncation. |
| Constant *C = ConstantExpr::getIntegerCast(CE0->getOperand(0), |
| IntPtrTy, false); |
| Constant *Null = Constant::getNullValue(C->getType()); |
| return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI); |
| } |
| |
| // Only do this transformation if the int is intptrty in size, otherwise |
| // there is a truncation or extension that we aren't modeling. |
| if (CE0->getOpcode() == Instruction::PtrToInt) { |
| Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType()); |
| if (CE0->getType() == IntPtrTy) { |
| Constant *C = CE0->getOperand(0); |
| Constant *Null = Constant::getNullValue(C->getType()); |
| return ConstantFoldCompareInstOperands(Predicate, C, Null, DL, TLI); |
| } |
| } |
| } |
| |
| if (auto *CE1 = dyn_cast<ConstantExpr>(Ops1)) { |
| if (CE0->getOpcode() == CE1->getOpcode()) { |
| if (CE0->getOpcode() == Instruction::IntToPtr) { |
| Type *IntPtrTy = DL.getIntPtrType(CE0->getType()); |
| |
| // Convert the integer value to the right size to ensure we get the |
| // proper extension or truncation. |
| Constant *C0 = ConstantExpr::getIntegerCast(CE0->getOperand(0), |
| IntPtrTy, false); |
| Constant *C1 = ConstantExpr::getIntegerCast(CE1->getOperand(0), |
| IntPtrTy, false); |
| return ConstantFoldCompareInstOperands(Predicate, C0, C1, DL, TLI); |
| } |
| |
| // Only do this transformation if the int is intptrty in size, otherwise |
| // there is a truncation or extension that we aren't modeling. |
| if (CE0->getOpcode() == Instruction::PtrToInt) { |
| Type *IntPtrTy = DL.getIntPtrType(CE0->getOperand(0)->getType()); |
| if (CE0->getType() == IntPtrTy && |
| CE0->getOperand(0)->getType() == CE1->getOperand(0)->getType()) { |
| return ConstantFoldCompareInstOperands( |
| Predicate, CE0->getOperand(0), CE1->getOperand(0), DL, TLI); |
| } |
| } |
| } |
| } |
| |
| // icmp eq (or x, y), 0 -> (icmp eq x, 0) & (icmp eq y, 0) |
| // icmp ne (or x, y), 0 -> (icmp ne x, 0) | (icmp ne y, 0) |
| if ((Predicate == ICmpInst::ICMP_EQ || Predicate == ICmpInst::ICMP_NE) && |
| CE0->getOpcode() == Instruction::Or && Ops1->isNullValue()) { |
| Constant *LHS = ConstantFoldCompareInstOperands( |
| Predicate, CE0->getOperand(0), Ops1, DL, TLI); |
| Constant *RHS = ConstantFoldCompareInstOperands( |
| Predicate, CE0->getOperand(1), Ops1, DL, TLI); |
| unsigned OpC = |
| Predicate == ICmpInst::ICMP_EQ ? Instruction::And : Instruction::Or; |
| return ConstantFoldBinaryOpOperands(OpC, LHS, RHS, DL); |
| } |
| } else if (isa<ConstantExpr>(Ops1)) { |
| // If RHS is a constant expression, but the left side isn't, swap the |
| // operands and try again. |
| Predicate = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)Predicate); |
| return ConstantFoldCompareInstOperands(Predicate, Ops1, Ops0, DL, TLI); |
| } |
| |
| return ConstantExpr::getCompare(Predicate, Ops0, Ops1); |
| } |
| |
| Constant *llvm::ConstantFoldUnaryOpOperand(unsigned Opcode, Constant *Op, |
| const DataLayout &DL) { |
| assert(Instruction::isUnaryOp(Opcode)); |
| |
| return ConstantExpr::get(Opcode, Op); |
| } |
| |
| Constant *llvm::ConstantFoldBinaryOpOperands(unsigned Opcode, Constant *LHS, |
| Constant *RHS, |
| const DataLayout &DL) { |
| assert(Instruction::isBinaryOp(Opcode)); |
| if (isa<ConstantExpr>(LHS) || isa<ConstantExpr>(RHS)) |
| if (Constant *C = SymbolicallyEvaluateBinop(Opcode, LHS, RHS, DL)) |
| return C; |
| |
| return ConstantExpr::get(Opcode, LHS, RHS); |
| } |
| |
| Constant *llvm::ConstantFoldCastOperand(unsigned Opcode, Constant *C, |
| Type *DestTy, const DataLayout &DL) { |
| assert(Instruction::isCast(Opcode)); |
| switch (Opcode) { |
| default: |
| llvm_unreachable("Missing case"); |
| case Instruction::PtrToInt: |
| if (auto *CE = dyn_cast<ConstantExpr>(C)) { |
| Constant *FoldedValue = nullptr; |
| // If the input is a inttoptr, eliminate the pair. This requires knowing |
| // the width of a pointer, so it can't be done in ConstantExpr::getCast. |
| if (CE->getOpcode() == Instruction::IntToPtr) { |
| // zext/trunc the inttoptr to pointer size. |
| FoldedValue = ConstantExpr::getIntegerCast( |
| CE->getOperand(0), DL.getIntPtrType(CE->getType()), |
| /*IsSigned=*/false); |
| } else if (auto *GEP = dyn_cast<GEPOperator>(CE)) { |
| // If we have GEP, we can perform the following folds: |
| // (ptrtoint (gep null, x)) -> x |
| // (ptrtoint (gep (gep null, x), y) -> x + y, etc. |
| unsigned BitWidth = DL.getIndexTypeSizeInBits(GEP->getType()); |
| APInt BaseOffset(BitWidth, 0); |
| auto *Base = cast<Constant>(GEP->stripAndAccumulateConstantOffsets( |
| DL, BaseOffset, /*AllowNonInbounds=*/true)); |
| if (Base->isNullValue()) { |
| FoldedValue = ConstantInt::get(CE->getContext(), BaseOffset); |
| } |
| } |
| if (FoldedValue) { |
| // Do a zext or trunc to get to the ptrtoint dest size. |
| return ConstantExpr::getIntegerCast(FoldedValue, DestTy, |
| /*IsSigned=*/false); |
| } |
| } |
| return ConstantExpr::getCast(Opcode, C, DestTy); |
| case Instruction::IntToPtr: |
| // If the input is a ptrtoint, turn the pair into a ptr to ptr bitcast if |
| // the int size is >= the ptr size and the address spaces are the same. |
| // This requires knowing the width of a pointer, so it can't be done in |
| // ConstantExpr::getCast. |
| if (auto *CE = dyn_cast<ConstantExpr>(C)) { |
| if (CE->getOpcode() == Instruction::PtrToInt) { |
| Constant *SrcPtr = CE->getOperand(0); |
| unsigned SrcPtrSize = DL.getPointerTypeSizeInBits(SrcPtr->getType()); |
| unsigned MidIntSize = CE->getType()->getScalarSizeInBits(); |
| |
| if (MidIntSize >= SrcPtrSize) { |
| unsigned SrcAS = SrcPtr->getType()->getPointerAddressSpace(); |
| if (SrcAS == DestTy->getPointerAddressSpace()) |
| return FoldBitCast(CE->getOperand(0), DestTy, DL); |
| } |
| } |
| } |
| |
| return ConstantExpr::getCast(Opcode, C, DestTy); |
| case Instruction::Trunc: |
| case Instruction::ZExt: |
| case Instruction::SExt: |
| case Instruction::FPTrunc: |
| case Instruction::FPExt: |
| case Instruction::UIToFP: |
| case Instruction::SIToFP: |
| case Instruction::FPToUI: |
| case Instruction::FPToSI: |
| case Instruction::AddrSpaceCast: |
| return ConstantExpr::getCast(Opcode, C, DestTy); |
| case Instruction::BitCast: |
| return FoldBitCast(C, DestTy, DL); |
| } |
| } |
| |
| Constant *llvm::ConstantFoldLoadThroughGEPConstantExpr(Constant *C, |
| ConstantExpr *CE, |
| Type *Ty, |
| const DataLayout &DL) { |
| if (!CE->getOperand(1)->isNullValue()) |
| return nullptr; // Do not allow stepping over the value! |
| |
| // Loop over all of the operands, tracking down which value we are |
| // addressing. |
| for (unsigned i = 2, e = CE->getNumOperands(); i != e; ++i) { |
| C = C->getAggregateElement(CE->getOperand(i)); |
| if (!C) |
| return nullptr; |
| } |
| return ConstantFoldLoadThroughBitcast(C, Ty, DL); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Constant Folding for Calls |
| // |
| |
| bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) { |
| if (Call->isNoBuiltin()) |
| return false; |
| switch (F->getIntrinsicID()) { |
| // Operations that do not operate floating-point numbers and do not depend on |
| // FP environment can be folded even in strictfp functions. |
| case Intrinsic::bswap: |
| case Intrinsic::ctpop: |
| case Intrinsic::ctlz: |
| case Intrinsic::cttz: |
| case Intrinsic::fshl: |
| case Intrinsic::fshr: |
| case Intrinsic::launder_invariant_group: |
| case Intrinsic::strip_invariant_group: |
| case Intrinsic::masked_load: |
| case Intrinsic::get_active_lane_mask: |
| case Intrinsic::abs: |
| case Intrinsic::smax: |
| case Intrinsic::smin: |
| case Intrinsic::umax: |
| case Intrinsic::umin: |
| case Intrinsic::sadd_with_overflow: |
| case Intrinsic::uadd_with_overflow: |
| case Intrinsic::ssub_with_overflow: |
| case Intrinsic::usub_with_overflow: |
| case Intrinsic::smul_with_overflow: |
| case Intrinsic::umul_with_overflow: |
| case Intrinsic::sadd_sat: |
| case Intrinsic::uadd_sat: |
| case Intrinsic::ssub_sat: |
| case Intrinsic::usub_sat: |
| case Intrinsic::smul_fix: |
| case Intrinsic::smul_fix_sat: |
| case Intrinsic::bitreverse: |
| case Intrinsic::is_constant: |
| case Intrinsic::vector_reduce_add: |
| case Intrinsic::vector_reduce_mul: |
| case Intrinsic::vector_reduce_and: |
| case Intrinsic::vector_reduce_or: |
| case Intrinsic::vector_reduce_xor: |
| case Intrinsic::vector_reduce_smin: |
| case Intrinsic::vector_reduce_smax: |
| case Intrinsic::vector_reduce_umin: |
| case Intrinsic::vector_reduce_umax: |
| // Target intrinsics |
| case Intrinsic::amdgcn_perm: |
| case Intrinsic::arm_mve_vctp8: |
| case Intrinsic::arm_mve_vctp16: |
| case Intrinsic::arm_mve_vctp32: |
| case Intrinsic::arm_mve_vctp64: |
| case Intrinsic::aarch64_sve_convert_from_svbool: |
| // WebAssembly float semantics are always known |
| case Intrinsic::wasm_trunc_signed: |
| case Intrinsic::wasm_trunc_unsigned: |
| return true; |
| |
| // Floating point operations cannot be folded in strictfp functions in |
| // general case. They can be folded if FP environment is known to compiler. |
| case Intrinsic::minnum: |
| case Intrinsic::maxnum: |
| case Intrinsic::minimum: |
| case Intrinsic::maximum: |
| case Intrinsic::log: |
| case Intrinsic::log2: |
| case Intrinsic::log10: |
| case Intrinsic::exp: |
| case Intrinsic::exp2: |
| case Intrinsic::sqrt: |
| case Intrinsic::sin: |
| case Intrinsic::cos: |
| case Intrinsic::pow: |
| case Intrinsic::powi: |
| case Intrinsic::fma: |
| case Intrinsic::fmuladd: |
| case Intrinsic::fptoui_sat: |
| case Intrinsic::fptosi_sat: |
| case Intrinsic::convert_from_fp16: |
| case Intrinsic::convert_to_fp16: |
| case Intrinsic::amdgcn_cos: |
| case Intrinsic::amdgcn_cubeid: |
| case Intrinsic::amdgcn_cubema: |
| case Intrinsic::amdgcn_cubesc: |
| case Intrinsic::amdgcn_cubetc: |
| case Intrinsic::amdgcn_fmul_legacy: |
| case Intrinsic::amdgcn_fma_legacy: |
| case Intrinsic::amdgcn_fract: |
| case Intrinsic::amdgcn_ldexp: |
| case Intrinsic::amdgcn_sin: |
| // The intrinsics below depend on rounding mode in MXCSR. |
| case Intrinsic::x86_sse_cvtss2si: |
| case Intrinsic::x86_sse_cvtss2si64: |
| case Intrinsic::x86_sse_cvttss2si: |
| case Intrinsic::x86_sse_cvttss2si64: |
| case Intrinsic::x86_sse2_cvtsd2si: |
| case Intrinsic::x86_sse2_cvtsd2si64: |
| case Intrinsic::x86_sse2_cvttsd2si: |
| case Intrinsic::x86_sse2_cvttsd2si64: |
| case Intrinsic::x86_avx512_vcvtss2si32: |
| case Intrinsic::x86_avx512_vcvtss2si64: |
| case Intrinsic::x86_avx512_cvttss2si: |
| case Intrinsic::x86_avx512_cvttss2si64: |
| case Intrinsic::x86_avx512_vcvtsd2si32: |
| case Intrinsic::x86_avx512_vcvtsd2si64: |
| case Intrinsic::x86_avx512_cvttsd2si: |
| case Intrinsic::x86_avx512_cvttsd2si64: |
| case Intrinsic::x86_avx512_vcvtss2usi32: |
| case Intrinsic::x86_avx512_vcvtss2usi64: |
| case Intrinsic::x86_avx512_cvttss2usi: |
| case Intrinsic::x86_avx512_cvttss2usi64: |
| case Intrinsic::x86_avx512_vcvtsd2usi32: |
| case Intrinsic::x86_avx512_vcvtsd2usi64: |
| case Intrinsic::x86_avx512_cvttsd2usi: |
| case Intrinsic::x86_avx512_cvttsd2usi64: |
| return !Call->isStrictFP(); |
| |
| // Sign operations are actually bitwise operations, they do not raise |
| // exceptions even for SNANs. |
| case Intrinsic::fabs: |
| case Intrinsic::copysign: |
| // Non-constrained variants of rounding operations means default FP |
| // environment, they can be folded in any case. |
| case Intrinsic::ceil: |
| case Intrinsic::floor: |
| case Intrinsic::round: |
| case Intrinsic::roundeven: |
| case Intrinsic::trunc: |
| case Intrinsic::nearbyint: |
| case Intrinsic::rint: |
| // Constrained intrinsics can be folded if FP environment is known |
| // to compiler. |
| case Intrinsic::experimental_constrained_fma: |
| case Intrinsic::experimental_constrained_fmuladd: |
| case Intrinsic::experimental_constrained_fadd: |
| case Intrinsic::experimental_constrained_fsub: |
| case Intrinsic::experimental_constrained_fmul: |
| case Intrinsic::experimental_constrained_fdiv: |
| case Intrinsic::experimental_constrained_frem: |
| case Intrinsic::experimental_constrained_ceil: |
| case Intrinsic::experimental_constrained_floor: |
| case Intrinsic::experimental_constrained_round: |
| case Intrinsic::experimental_constrained_roundeven: |
| case Intrinsic::experimental_constrained_trunc: |
| case Intrinsic::experimental_constrained_nearbyint: |
| case Intrinsic::experimental_constrained_rint: |
| return true; |
| default: |
| return false; |
| case Intrinsic::not_intrinsic: break; |
| } |
| |
| if (!F->hasName() || Call->isStrictFP()) |
| return false; |
| |
| // In these cases, the check of the length is required. We don't want to |
| // return true for a name like "cos\0blah" which strcmp would return equal to |
| // "cos", but has length 8. |
| StringRef Name = F->getName(); |
| switch (Name[0]) { |
| default: |
| return false; |
| case 'a': |
| return Name == "acos" || Name == "acosf" || |
| Name == "asin" || Name == "asinf" || |
| Name == "atan" || Name == "atanf" || |
| Name == "atan2" || Name == "atan2f"; |
| case 'c': |
| return Name == "ceil" || Name == "ceilf" || |
| Name == "cos" || Name == "cosf" || |
| Name == "cosh" || Name == "coshf"; |
| case 'e': |
| return Name == "exp" || Name == "expf" || |
| Name == "exp2" || Name == "exp2f"; |
| case 'f': |
| return Name == "fabs" || Name == "fabsf" || |
| Name == "floor" || Name == "floorf" || |
| Name == "fmod" || Name == "fmodf"; |
| case 'l': |
| return Name == "log" || Name == "logf" || |
| Name == "log2" || Name == "log2f" || |
| Name == "log10" || Name == "log10f"; |
| case 'n': |
| return Name == "nearbyint" || Name == "nearbyintf"; |
| case 'p': |
| return Name == "pow" || Name == "powf"; |
| case 'r': |
| return Name == "remainder" || Name == "remainderf" || |
| Name == "rint" || Name == "rintf" || |
| Name == "round" || Name == "roundf"; |
| case 's': |
| return Name == "sin" || Name == "sinf" || |
| Name == "sinh" || Name == "sinhf" || |
| Name == "sqrt" || Name == "sqrtf"; |
| case 't': |
| return Name == "tan" || Name == "tanf" || |
| Name == "tanh" || Name == "tanhf" || |
| Name == "trunc" || Name == "truncf"; |
| case '_': |
| // Check for various function names that get used for the math functions |
| // when the header files are preprocessed with the macro |
| // __FINITE_MATH_ONLY__ enabled. |
| // The '12' here is the length of the shortest name that can match. |
| // We need to check the size before looking at Name[1] and Name[2] |
| // so we may as well check a limit that will eliminate mismatches. |
| if (Name.size() < 12 || Name[1] != '_') |
| return false; |
| switch (Name[2]) { |
| default: |
| return false; |
| case 'a': |
| return Name == "__acos_finite" || Name == "__acosf_finite" || |
| Name == "__asin_finite" || Name == "__asinf_finite" || |
| Name == "__atan2_finite" || Name == "__atan2f_finite"; |
| case 'c': |
| return Name == "__cosh_finite" || Name == "__coshf_finite"; |
| case 'e': |
| return Name == "__exp_finite" || Name == "__expf_finite" || |
| Name == "__exp2_finite" || Name == "__exp2f_finite"; |
| case 'l': |
| return Name == "__log_finite" || Name == "__logf_finite" || |
| Name == "__log10_finite" || Name == "__log10f_finite"; |
| case 'p': |
| return Name == "__pow_finite" || Name == "__powf_finite"; |
| case 's': |
| return Name == "__sinh_finite" || Name == "__sinhf_finite"; |
| } |
| } |
| } |
| |
| namespace { |
| |
| Constant *GetConstantFoldFPValue(double V, Type *Ty) { |
| if (Ty->isHalfTy() || Ty->isFloatTy()) { |
| APFloat APF(V); |
| bool unused; |
| APF.convert(Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &unused); |
| return ConstantFP::get(Ty->getContext(), APF); |
| } |
| if (Ty->isDoubleTy()) |
| return ConstantFP::get(Ty->getContext(), APFloat(V)); |
| llvm_unreachable("Can only constant fold half/float/double"); |
| } |
| |
| /// Clear the floating-point exception state. |
| inline void llvm_fenv_clearexcept() { |
| #if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT |
| feclearexcept(FE_ALL_EXCEPT); |
| #endif |
| errno = 0; |
| } |
| |
| /// Test if a floating-point exception was raised. |
| inline bool llvm_fenv_testexcept() { |
| int errno_val = errno; |
| if (errno_val == ERANGE || errno_val == EDOM) |
| return true; |
| #if defined(HAVE_FENV_H) && HAVE_DECL_FE_ALL_EXCEPT && HAVE_DECL_FE_INEXACT |
| if (fetestexcept(FE_ALL_EXCEPT & ~FE_INEXACT)) |
| return true; |
| #endif |
| return false; |
| } |
| |
| Constant *ConstantFoldFP(double (*NativeFP)(double), const APFloat &V, |
| Type *Ty) { |
| llvm_fenv_clearexcept(); |
| double Result = NativeFP(V.convertToDouble()); |
| if (llvm_fenv_testexcept()) { |
| llvm_fenv_clearexcept(); |
| return nullptr; |
| } |
| |
| return GetConstantFoldFPValue(Result, Ty); |
| } |
| |
| Constant *ConstantFoldBinaryFP(double (*NativeFP)(double, double), |
| const APFloat &V, const APFloat &W, Type *Ty) { |
| llvm_fenv_clearexcept(); |
| double Result = NativeFP(V.convertToDouble(), W.convertToDouble()); |
| if (llvm_fenv_testexcept()) { |
| llvm_fenv_clearexcept(); |
| return nullptr; |
| } |
| |
| return GetConstantFoldFPValue(Result, Ty); |
| } |
| |
| Constant *constantFoldVectorReduce(Intrinsic::ID IID, Constant *Op) { |
| FixedVectorType *VT = dyn_cast<FixedVectorType>(Op->getType()); |
| if (!VT) |
| return nullptr; |
| |
| // This isn't strictly necessary, but handle the special/common case of zero: |
| // all integer reductions of a zero input produce zero. |
| if (isa<ConstantAggregateZero>(Op)) |
| return ConstantInt::get(VT->getElementType(), 0); |
| |
| // This is the same as the underlying binops - poison propagates. |
| if (isa<PoisonValue>(Op) || Op->containsPoisonElement()) |
| return PoisonValue::get(VT->getElementType()); |
| |
| // TODO: Handle undef. |
| if (!isa<ConstantVector>(Op) && !isa<ConstantDataVector>(Op)) |
| return nullptr; |
| |
| auto *EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(0U)); |
| if (!EltC) |
| return nullptr; |
| |
| APInt Acc = EltC->getValue(); |
| for (unsigned I = 1, E = VT->getNumElements(); I != E; I++) { |
| if (!(EltC = dyn_cast<ConstantInt>(Op->getAggregateElement(I)))) |
| return nullptr; |
| const APInt &X = EltC->getValue(); |
| switch (IID) { |
| case Intrinsic::vector_reduce_add: |
| Acc = Acc + X; |
| break; |
| case Intrinsic::vector_reduce_mul: |
| Acc = Acc * X; |
| break; |
| case Intrinsic::vector_reduce_and: |
| Acc = Acc & X; |
| break; |
| case Intrinsic::vector_reduce_or: |
| Acc = Acc | X; |
| break; |
| case Intrinsic::vector_reduce_xor: |
| Acc = Acc ^ X; |
| break; |
| case Intrinsic::vector_reduce_smin: |
| Acc = APIntOps::smin(Acc, X); |
| break; |
| case Intrinsic::vector_reduce_smax: |
| Acc = APIntOps::smax(Acc, X); |
| break; |
| case Intrinsic::vector_reduce_umin: |
| Acc = APIntOps::umin(Acc, X); |
| break; |
| case Intrinsic::vector_reduce_umax: |
| Acc = APIntOps::umax(Acc, X); |
| break; |
| } |
| } |
| |
| return ConstantInt::get(Op->getContext(), Acc); |
| } |
| |
| /// Attempt to fold an SSE floating point to integer conversion of a constant |
| /// floating point. If roundTowardZero is false, the default IEEE rounding is |
| /// used (toward nearest, ties to even). This matches the behavior of the |
| /// non-truncating SSE instructions in the default rounding mode. The desired |
| /// integer type Ty is used to select how many bits are available for the |
| /// result. Returns null if the conversion cannot be performed, otherwise |
| /// returns the Constant value resulting from the conversion. |
| Constant *ConstantFoldSSEConvertToInt(const APFloat &Val, bool roundTowardZero, |
| Type *Ty, bool IsSigned) { |
| // All of these conversion intrinsics form an integer of at most 64bits. |
| unsigned ResultWidth = Ty->getIntegerBitWidth(); |
| assert(ResultWidth <= 64 && |
| "Can only constant fold conversions to 64 and 32 bit ints"); |
| |
| uint64_t UIntVal; |
| bool isExact = false; |
| APFloat::roundingMode mode = roundTowardZero? APFloat::rmTowardZero |
| : APFloat::rmNearestTiesToEven; |
| APFloat::opStatus status = |
| Val.convertToInteger(makeMutableArrayRef(UIntVal), ResultWidth, |
| IsSigned, mode, &isExact); |
| if (status != APFloat::opOK && |
| (!roundTowardZero || status != APFloat::opInexact)) |
| return nullptr; |
| return ConstantInt::get(Ty, UIntVal, IsSigned); |
| } |
| |
| double getValueAsDouble(ConstantFP *Op) { |
| Type *Ty = Op->getType(); |
| |
| if (Ty->isBFloatTy() || Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) |
| return Op->getValueAPF().convertToDouble(); |
| |
| bool unused; |
| APFloat APF = Op->getValueAPF(); |
| APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &unused); |
| return APF.convertToDouble(); |
| } |
| |
| static bool getConstIntOrUndef(Value *Op, const APInt *&C) { |
| if (auto *CI = dyn_cast<ConstantInt>(Op)) { |
| C = &CI->getValue(); |
| return true; |
| } |
| if (isa<UndefValue>(Op)) { |
| C = nullptr; |
| return true; |
| } |
| return false; |
| } |
| |
| /// Checks if the given intrinsic call, which evaluates to constant, is allowed |
| /// to be folded. |
| /// |
| /// \param CI Constrained intrinsic call. |
| /// \param St Exception flags raised during constant evaluation. |
| static bool mayFoldConstrained(ConstrainedFPIntrinsic *CI, |
| APFloat::opStatus St) { |
| Optional<RoundingMode> ORM = CI->getRoundingMode(); |
| Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior(); |
| |
| // If the operation does not change exception status flags, it is safe |
| // to fold. |
| if (St == APFloat::opStatus::opOK) { |
| // When FP exceptions are not ignored, intrinsic call will not be |
| // eliminated, because it is considered as having side effect. But we |
| // know that its evaluation does not raise exceptions, so side effect |
| // is absent. To allow removing the call, mark it as not accessing memory. |
| if (EB && *EB != fp::ExceptionBehavior::ebIgnore) |
| CI->addFnAttr(Attribute::ReadNone); |
| return true; |
| } |
| |
| // If evaluation raised FP exception, the result can depend on rounding |
| // mode. If the latter is unknown, folding is not possible. |
| if (!ORM || *ORM == RoundingMode::Dynamic) |
| return false; |
| |
| // If FP exceptions are ignored, fold the call, even if such exception is |
| // raised. |
| if (!EB || *EB != fp::ExceptionBehavior::ebStrict) |
| return true; |
| |
| // Leave the calculation for runtime so that exception flags be correctly set |
| // in hardware. |
| return false; |
| } |
| |
| /// Returns the rounding mode that should be used for constant evaluation. |
| static RoundingMode |
| getEvaluationRoundingMode(const ConstrainedFPIntrinsic *CI) { |
| Optional<RoundingMode> ORM = CI->getRoundingMode(); |
| if (!ORM || *ORM == RoundingMode::Dynamic) |
| // Even if the rounding mode is unknown, try evaluating the operation. |
| // If it does not raise inexact exception, rounding was not applied, |
| // so the result is exact and does not depend on rounding mode. Whether |
| // other FP exceptions are raised, it does not depend on rounding mode. |
| return RoundingMode::NearestTiesToEven; |
| return *ORM; |
| } |
| |
| static Constant *ConstantFoldScalarCall1(StringRef Name, |
| Intrinsic::ID IntrinsicID, |
| Type *Ty, |
| ArrayRef<Constant *> Operands, |
| const TargetLibraryInfo *TLI, |
| const CallBase *Call) { |
| assert(Operands.size() == 1 && "Wrong number of operands."); |
| |
| if (IntrinsicID == Intrinsic::is_constant) { |
| // We know we have a "Constant" argument. But we want to only |
| // return true for manifest constants, not those that depend on |
| // constants with unknowable values, e.g. GlobalValue or BlockAddress. |
| if (Operands[0]->isManifestConstant()) |
| return ConstantInt::getTrue(Ty->getContext()); |
| return nullptr; |
| } |
| if (isa<UndefValue>(Operands[0])) { |
| // cosine(arg) is between -1 and 1. cosine(invalid arg) is NaN. |
| // ctpop() is between 0 and bitwidth, pick 0 for undef. |
| // fptoui.sat and fptosi.sat can always fold to zero (for a zero input). |
| if (IntrinsicID == Intrinsic::cos || |
| IntrinsicID == Intrinsic::ctpop || |
| IntrinsicID == Intrinsic::fptoui_sat || |
| IntrinsicID == Intrinsic::fptosi_sat) |
| return Constant::getNullValue(Ty); |
| if (IntrinsicID == Intrinsic::bswap || |
| IntrinsicID == Intrinsic::bitreverse || |
| IntrinsicID == Intrinsic::launder_invariant_group || |
| IntrinsicID == Intrinsic::strip_invariant_group) |
| return Operands[0]; |
| } |
| |
| if (isa<ConstantPointerNull>(Operands[0])) { |
| // launder(null) == null == strip(null) iff in addrspace 0 |
| if (IntrinsicID == Intrinsic::launder_invariant_group || |
| IntrinsicID == Intrinsic::strip_invariant_group) { |
| // If instruction is not yet put in a basic block (e.g. when cloning |
| // a function during inlining), Call's caller may not be available. |
| // So check Call's BB first before querying Call->getCaller. |
| const Function *Caller = |
| Call->getParent() ? Call->getCaller() : nullptr; |
| if (Caller && |
| !NullPointerIsDefined( |
| Caller, Operands[0]->getType()->getPointerAddressSpace())) { |
| return Operands[0]; |
| } |
| return nullptr; |
| } |
| } |
| |
| if (auto *Op = dyn_cast<ConstantFP>(Operands[0])) { |
| if (IntrinsicID == Intrinsic::convert_to_fp16) { |
| APFloat Val(Op->getValueAPF()); |
| |
| bool lost = false; |
| Val.convert(APFloat::IEEEhalf(), APFloat::rmNearestTiesToEven, &lost); |
| |
| return ConstantInt::get(Ty->getContext(), Val.bitcastToAPInt()); |
| } |
| |
| APFloat U = Op->getValueAPF(); |
| |
| if (IntrinsicID == Intrinsic::wasm_trunc_signed || |
| IntrinsicID == Intrinsic::wasm_trunc_unsigned) { |
| bool Signed = IntrinsicID == Intrinsic::wasm_trunc_signed; |
| |
| if (U.isNaN()) |
| return nullptr; |
| |
| unsigned Width = Ty->getIntegerBitWidth(); |
| APSInt Int(Width, !Signed); |
| bool IsExact = false; |
| APFloat::opStatus Status = |
| U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact); |
| |
| if (Status == APFloat::opOK || Status == APFloat::opInexact) |
| return ConstantInt::get(Ty, Int); |
| |
| return nullptr; |
| } |
| |
| if (IntrinsicID == Intrinsic::fptoui_sat || |
| IntrinsicID == Intrinsic::fptosi_sat) { |
| // convertToInteger() already has the desired saturation semantics. |
| APSInt Int(Ty->getIntegerBitWidth(), |
| IntrinsicID == Intrinsic::fptoui_sat); |
| bool IsExact; |
| U.convertToInteger(Int, APFloat::rmTowardZero, &IsExact); |
| return ConstantInt::get(Ty, Int); |
| } |
| |
| if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) |
| return nullptr; |
| |
| // Use internal versions of these intrinsics. |
| |
| if (IntrinsicID == Intrinsic::nearbyint || IntrinsicID == Intrinsic::rint) { |
| U.roundToIntegral(APFloat::rmNearestTiesToEven); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::round) { |
| U.roundToIntegral(APFloat::rmNearestTiesToAway); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::roundeven) { |
| U.roundToIntegral(APFloat::rmNearestTiesToEven); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::ceil) { |
| U.roundToIntegral(APFloat::rmTowardPositive); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::floor) { |
| U.roundToIntegral(APFloat::rmTowardNegative); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::trunc) { |
| U.roundToIntegral(APFloat::rmTowardZero); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::fabs) { |
| U.clearSign(); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| if (IntrinsicID == Intrinsic::amdgcn_fract) { |
| // The v_fract instruction behaves like the OpenCL spec, which defines |
| // fract(x) as fmin(x - floor(x), 0x1.fffffep-1f): "The min() operator is |
| // there to prevent fract(-small) from returning 1.0. It returns the |
| // largest positive floating-point number less than 1.0." |
| APFloat FloorU(U); |
| FloorU.roundToIntegral(APFloat::rmTowardNegative); |
| APFloat FractU(U - FloorU); |
| APFloat AlmostOne(U.getSemantics(), 1); |
| AlmostOne.next(/*nextDown*/ true); |
| return ConstantFP::get(Ty->getContext(), minimum(FractU, AlmostOne)); |
| } |
| |
| // Rounding operations (floor, trunc, ceil, round and nearbyint) do not |
| // raise FP exceptions, unless the argument is signaling NaN. |
| |
| Optional<APFloat::roundingMode> RM; |
| switch (IntrinsicID) { |
| default: |
| break; |
| case Intrinsic::experimental_constrained_nearbyint: |
| case Intrinsic::experimental_constrained_rint: { |
| auto CI = cast<ConstrainedFPIntrinsic>(Call); |
| RM = CI->getRoundingMode(); |
| if (!RM || RM.getValue() == RoundingMode::Dynamic) |
| return nullptr; |
| break; |
| } |
| case Intrinsic::experimental_constrained_round: |
| RM = APFloat::rmNearestTiesToAway; |
| break; |
| case Intrinsic::experimental_constrained_ceil: |
| RM = APFloat::rmTowardPositive; |
| break; |
| case Intrinsic::experimental_constrained_floor: |
| RM = APFloat::rmTowardNegative; |
| break; |
| case Intrinsic::experimental_constrained_trunc: |
| RM = APFloat::rmTowardZero; |
| break; |
| } |
| if (RM) { |
| auto CI = cast<ConstrainedFPIntrinsic>(Call); |
| if (U.isFinite()) { |
| APFloat::opStatus St = U.roundToIntegral(*RM); |
| if (IntrinsicID == Intrinsic::experimental_constrained_rint && |
| St == APFloat::opInexact) { |
| Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior(); |
| if (EB && *EB == fp::ebStrict) |
| return nullptr; |
| } |
| } else if (U.isSignaling()) { |
| Optional<fp::ExceptionBehavior> EB = CI->getExceptionBehavior(); |
| if (EB && *EB != fp::ebIgnore) |
| return nullptr; |
| U = APFloat::getQNaN(U.getSemantics()); |
| } |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| |
| /// We only fold functions with finite arguments. Folding NaN and inf is |
| /// likely to be aborted with an exception anyway, and some host libms |
| /// have known errors raising exceptions. |
| if (!U.isFinite()) |
| return nullptr; |
| |
| /// Currently APFloat versions of these functions do not exist, so we use |
| /// the host native double versions. Float versions are not called |
| /// directly but for all these it is true (float)(f((double)arg)) == |
| /// f(arg). Long double not supported yet. |
| const APFloat &APF = Op->getValueAPF(); |
| |
| switch (IntrinsicID) { |
| default: break; |
| case Intrinsic::log: |
| return ConstantFoldFP(log, APF, Ty); |
| case Intrinsic::log2: |
| // TODO: What about hosts that lack a C99 library? |
| return ConstantFoldFP(Log2, APF, Ty); |
| case Intrinsic::log10: |
| // TODO: What about hosts that lack a C99 library? |
| return ConstantFoldFP(log10, APF, Ty); |
| case Intrinsic::exp: |
| return ConstantFoldFP(exp, APF, Ty); |
| case Intrinsic::exp2: |
| // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library. |
| return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty); |
| case Intrinsic::sin: |
| return ConstantFoldFP(sin, APF, Ty); |
| case Intrinsic::cos: |
| return ConstantFoldFP(cos, APF, Ty); |
| case Intrinsic::sqrt: |
| return ConstantFoldFP(sqrt, APF, Ty); |
| case Intrinsic::amdgcn_cos: |
| case Intrinsic::amdgcn_sin: { |
| double V = getValueAsDouble(Op); |
| if (V < -256.0 || V > 256.0) |
| // The gfx8 and gfx9 architectures handle arguments outside the range |
| // [-256, 256] differently. This should be a rare case so bail out |
| // rather than trying to handle the difference. |
| return nullptr; |
| bool IsCos = IntrinsicID == Intrinsic::amdgcn_cos; |
| double V4 = V * 4.0; |
| if (V4 == floor(V4)) { |
| // Force exact results for quarter-integer inputs. |
| const double SinVals[4] = { 0.0, 1.0, 0.0, -1.0 }; |
| V = SinVals[((int)V4 + (IsCos ? 1 : 0)) & 3]; |
| } else { |
| if (IsCos) |
| V = cos(V * 2.0 * numbers::pi); |
| else |
| V = sin(V * 2.0 * numbers::pi); |
| } |
| return GetConstantFoldFPValue(V, Ty); |
| } |
| } |
| |
| if (!TLI) |
| return nullptr; |
| |
| LibFunc Func = NotLibFunc; |
| if (!TLI->getLibFunc(Name, Func)) |
| return nullptr; |
| |
| switch (Func) { |
| default: |
| break; |
| case LibFunc_acos: |
| case LibFunc_acosf: |
| case LibFunc_acos_finite: |
| case LibFunc_acosf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(acos, APF, Ty); |
| break; |
| case LibFunc_asin: |
| case LibFunc_asinf: |
| case LibFunc_asin_finite: |
| case LibFunc_asinf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(asin, APF, Ty); |
| break; |
| case LibFunc_atan: |
| case LibFunc_atanf: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(atan, APF, Ty); |
| break; |
| case LibFunc_ceil: |
| case LibFunc_ceilf: |
| if (TLI->has(Func)) { |
| U.roundToIntegral(APFloat::rmTowardPositive); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| case LibFunc_cos: |
| case LibFunc_cosf: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(cos, APF, Ty); |
| break; |
| case LibFunc_cosh: |
| case LibFunc_coshf: |
| case LibFunc_cosh_finite: |
| case LibFunc_coshf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(cosh, APF, Ty); |
| break; |
| case LibFunc_exp: |
| case LibFunc_expf: |
| case LibFunc_exp_finite: |
| case LibFunc_expf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(exp, APF, Ty); |
| break; |
| case LibFunc_exp2: |
| case LibFunc_exp2f: |
| case LibFunc_exp2_finite: |
| case LibFunc_exp2f_finite: |
| if (TLI->has(Func)) |
| // Fold exp2(x) as pow(2, x), in case the host lacks a C99 library. |
| return ConstantFoldBinaryFP(pow, APFloat(2.0), APF, Ty); |
| break; |
| case LibFunc_fabs: |
| case LibFunc_fabsf: |
| if (TLI->has(Func)) { |
| U.clearSign(); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| case LibFunc_floor: |
| case LibFunc_floorf: |
| if (TLI->has(Func)) { |
| U.roundToIntegral(APFloat::rmTowardNegative); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| case LibFunc_log: |
| case LibFunc_logf: |
| case LibFunc_log_finite: |
| case LibFunc_logf_finite: |
| if (!APF.isNegative() && !APF.isZero() && TLI->has(Func)) |
| return ConstantFoldFP(log, APF, Ty); |
| break; |
| case LibFunc_log2: |
| case LibFunc_log2f: |
| case LibFunc_log2_finite: |
| case LibFunc_log2f_finite: |
| if (!APF.isNegative() && !APF.isZero() && TLI->has(Func)) |
| // TODO: What about hosts that lack a C99 library? |
| return ConstantFoldFP(Log2, APF, Ty); |
| break; |
| case LibFunc_log10: |
| case LibFunc_log10f: |
| case LibFunc_log10_finite: |
| case LibFunc_log10f_finite: |
| if (!APF.isNegative() && !APF.isZero() && TLI->has(Func)) |
| // TODO: What about hosts that lack a C99 library? |
| return ConstantFoldFP(log10, APF, Ty); |
| break; |
| case LibFunc_nearbyint: |
| case LibFunc_nearbyintf: |
| case LibFunc_rint: |
| case LibFunc_rintf: |
| if (TLI->has(Func)) { |
| U.roundToIntegral(APFloat::rmNearestTiesToEven); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| case LibFunc_round: |
| case LibFunc_roundf: |
| if (TLI->has(Func)) { |
| U.roundToIntegral(APFloat::rmNearestTiesToAway); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| case LibFunc_sin: |
| case LibFunc_sinf: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(sin, APF, Ty); |
| break; |
| case LibFunc_sinh: |
| case LibFunc_sinhf: |
| case LibFunc_sinh_finite: |
| case LibFunc_sinhf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(sinh, APF, Ty); |
| break; |
| case LibFunc_sqrt: |
| case LibFunc_sqrtf: |
| if (!APF.isNegative() && TLI->has(Func)) |
| return ConstantFoldFP(sqrt, APF, Ty); |
| break; |
| case LibFunc_tan: |
| case LibFunc_tanf: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(tan, APF, Ty); |
| break; |
| case LibFunc_tanh: |
| case LibFunc_tanhf: |
| if (TLI->has(Func)) |
| return ConstantFoldFP(tanh, APF, Ty); |
| break; |
| case LibFunc_trunc: |
| case LibFunc_truncf: |
| if (TLI->has(Func)) { |
| U.roundToIntegral(APFloat::rmTowardZero); |
| return ConstantFP::get(Ty->getContext(), U); |
| } |
| break; |
| } |
| return nullptr; |
| } |
| |
| if (auto *Op = dyn_cast<ConstantInt>(Operands[0])) { |
| switch (IntrinsicID) { |
| case Intrinsic::bswap: |
| return ConstantInt::get(Ty->getContext(), Op->getValue().byteSwap()); |
| case Intrinsic::ctpop: |
| return ConstantInt::get(Ty, Op->getValue().countPopulation()); |
| case Intrinsic::bitreverse: |
| return ConstantInt::get(Ty->getContext(), Op->getValue().reverseBits()); |
| case Intrinsic::convert_from_fp16: { |
| APFloat Val(APFloat::IEEEhalf(), Op->getValue()); |
| |
| bool lost = false; |
| APFloat::opStatus status = Val.convert( |
| Ty->getFltSemantics(), APFloat::rmNearestTiesToEven, &lost); |
| |
| // Conversion is always precise. |
| (void)status; |
| assert(status == APFloat::opOK && !lost && |
| "Precision lost during fp16 constfolding"); |
| |
| return ConstantFP::get(Ty->getContext(), Val); |
| } |
| default: |
| return nullptr; |
| } |
| } |
| |
| switch (IntrinsicID) { |
| default: break; |
| case Intrinsic::vector_reduce_add: |
| case Intrinsic::vector_reduce_mul: |
| case Intrinsic::vector_reduce_and: |
| case Intrinsic::vector_reduce_or: |
| case Intrinsic::vector_reduce_xor: |
| case Intrinsic::vector_reduce_smin: |
| case Intrinsic::vector_reduce_smax: |
| case Intrinsic::vector_reduce_umin: |
| case Intrinsic::vector_reduce_umax: |
| if (Constant *C = constantFoldVectorReduce(IntrinsicID, Operands[0])) |
| return C; |
| break; |
| } |
| |
| // Support ConstantVector in case we have an Undef in the top. |
| if (isa<ConstantVector>(Operands[0]) || |
| isa<ConstantDataVector>(Operands[0])) { |
| auto *Op = cast<Constant>(Operands[0]); |
| switch (IntrinsicID) { |
| default: break; |
| case Intrinsic::x86_sse_cvtss2si: |
| case Intrinsic::x86_sse_cvtss2si64: |
| case Intrinsic::x86_sse2_cvtsd2si: |
| case Intrinsic::x86_sse2_cvtsd2si64: |
| if (ConstantFP *FPOp = |
| dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U))) |
| return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(), |
| /*roundTowardZero=*/false, Ty, |
| /*IsSigned*/true); |
| break; |
| case Intrinsic::x86_sse_cvttss2si: |
| case Intrinsic::x86_sse_cvttss2si64: |
| case Intrinsic::x86_sse2_cvttsd2si: |
| case Intrinsic::x86_sse2_cvttsd2si64: |
| if (ConstantFP *FPOp = |
| dyn_cast_or_null<ConstantFP>(Op->getAggregateElement(0U))) |
| return ConstantFoldSSEConvertToInt(FPOp->getValueAPF(), |
| /*roundTowardZero=*/true, Ty, |
| /*IsSigned*/true); |
| break; |
| } |
| } |
| |
| return nullptr; |
| } |
| |
| static Constant *ConstantFoldScalarCall2(StringRef Name, |
| Intrinsic::ID IntrinsicID, |
| Type *Ty, |
| ArrayRef<Constant *> Operands, |
| const TargetLibraryInfo *TLI, |
| const CallBase *Call) { |
| assert(Operands.size() == 2 && "Wrong number of operands."); |
| |
| if (Ty->isFloatingPointTy()) { |
| // TODO: We should have undef handling for all of the FP intrinsics that |
| // are attempted to be folded in this function. |
| bool IsOp0Undef = isa<UndefValue>(Operands[0]); |
| bool IsOp1Undef = isa<UndefValue>(Operands[1]); |
| switch (IntrinsicID) { |
| case Intrinsic::maxnum: |
| case Intrinsic::minnum: |
| case Intrinsic::maximum: |
| case Intrinsic::minimum: |
| // If one argument is undef, return the other argument. |
| if (IsOp0Undef) |
| return Operands[1]; |
| if (IsOp1Undef) |
| return Operands[0]; |
| break; |
| } |
| } |
| |
| if (const auto *Op1 = dyn_cast<ConstantFP>(Operands[0])) { |
| if (!Ty->isFloatingPointTy()) |
| return nullptr; |
| const APFloat &Op1V = Op1->getValueAPF(); |
| |
| if (const auto *Op2 = dyn_cast<ConstantFP>(Operands[1])) { |
| if (Op2->getType() != Op1->getType()) |
| return nullptr; |
| const APFloat &Op2V = Op2->getValueAPF(); |
| |
| if (const auto *ConstrIntr = dyn_cast<ConstrainedFPIntrinsic>(Call)) { |
| RoundingMode RM = getEvaluationRoundingMode(ConstrIntr); |
| APFloat Res = Op1V; |
| APFloat::opStatus St; |
| switch (IntrinsicID) { |
| default: |
| return nullptr; |
| case Intrinsic::experimental_constrained_fadd: |
| St = Res.add(Op2V, RM); |
| break; |
| case Intrinsic::experimental_constrained_fsub: |
| St = Res.subtract(Op2V, RM); |
| break; |
| case Intrinsic::experimental_constrained_fmul: |
| St = Res.multiply(Op2V, RM); |
| break; |
| case Intrinsic::experimental_constrained_fdiv: |
| St = Res.divide(Op2V, RM); |
| break; |
| case Intrinsic::experimental_constrained_frem: |
| St = Res.mod(Op2V); |
| break; |
| } |
| if (mayFoldConstrained(const_cast<ConstrainedFPIntrinsic *>(ConstrIntr), |
| St)) |
| return ConstantFP::get(Ty->getContext(), Res); |
| return nullptr; |
| } |
| |
| switch (IntrinsicID) { |
| default: |
| break; |
| case Intrinsic::copysign: |
| return ConstantFP::get(Ty->getContext(), APFloat::copySign(Op1V, Op2V)); |
| case Intrinsic::minnum: |
| return ConstantFP::get(Ty->getContext(), minnum(Op1V, Op2V)); |
| case Intrinsic::maxnum: |
| return ConstantFP::get(Ty->getContext(), maxnum(Op1V, Op2V)); |
| case Intrinsic::minimum: |
| return ConstantFP::get(Ty->getContext(), minimum(Op1V, Op2V)); |
| case Intrinsic::maximum: |
| return ConstantFP::get(Ty->getContext(), maximum(Op1V, Op2V)); |
| } |
| |
| if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) |
| return nullptr; |
| |
| switch (IntrinsicID) { |
| default: |
| break; |
| case Intrinsic::pow: |
| return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); |
| case Intrinsic::amdgcn_fmul_legacy: |
| // The legacy behaviour is that multiplying +/- 0.0 by anything, even |
| // NaN or infinity, gives +0.0. |
| if (Op1V.isZero() || Op2V.isZero()) |
| return ConstantFP::getNullValue(Ty); |
| return ConstantFP::get(Ty->getContext(), Op1V * Op2V); |
| } |
| |
| if (!TLI) |
| return nullptr; |
| |
| LibFunc Func = NotLibFunc; |
| if (!TLI->getLibFunc(Name, Func)) |
| return nullptr; |
| |
| switch (Func) { |
| default: |
| break; |
| case LibFunc_pow: |
| case LibFunc_powf: |
| case LibFunc_pow_finite: |
| case LibFunc_powf_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty); |
| break; |
| case LibFunc_fmod: |
| case LibFunc_fmodf: |
| if (TLI->has(Func)) { |
| APFloat V = Op1->getValueAPF(); |
| if (APFloat::opStatus::opOK == V.mod(Op2->getValueAPF())) |
| return ConstantFP::get(Ty->getContext(), V); |
| } |
| break; |
| case LibFunc_remainder: |
| case LibFunc_remainderf: |
| if (TLI->has(Func)) { |
| APFloat V = Op1->getValueAPF(); |
| if (APFloat::opStatus::opOK == V.remainder(Op2->getValueAPF())) |
| return ConstantFP::get(Ty->getContext(), V); |
| } |
| break; |
| case LibFunc_atan2: |
| case LibFunc_atan2f: |
| case LibFunc_atan2_finite: |
| case LibFunc_atan2f_finite: |
| if (TLI->has(Func)) |
| return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty); |
| break; |
| } |
| } else if (auto *Op2C = dyn_cast<ConstantInt>(Operands[1])) { |
| if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy()) |
| return nullptr; |
| if (IntrinsicID == Intrinsic::powi && Ty->isHalfTy()) |
| return ConstantFP::get( |
| Ty->getContext(), |
| APFloat((float)std::pow((float)Op1V.convertToDouble(), |
| (int)Op2C->getZExtValue()))); |
| if (IntrinsicID == Intrinsic::powi && Ty->isFloatTy()) |
| return ConstantFP::get( |
| Ty->getContext(), |
| APFloat((float)std::pow((float)Op1V.convertToDouble(), |
| (int)Op2C->getZExtValue()))); |
| if (IntrinsicID == Intrinsic::powi && Ty->isDoubleTy()) |
| return ConstantFP::get( |
| Ty->getContext(), |
| APFloat((double)std::pow(Op1V.convertToDouble(), |
| (int)Op2C->getZExtValue()))); |
| |
| if (IntrinsicID == Intrinsic::amdgcn_ldexp) { |
| // FIXME: Should flush denorms depending on FP mode, but that's ignored |
| // everywhere else. |
| |
| // scalbn is equivalent to ldexp with float radix 2 |
| APFloat Result = scalbn(Op1->getValueAPF(), Op2C->getSExtValue(), |
| APFloat::rmNearestTiesToEven); |
| return ConstantFP::get(Ty->getContext(), Result); |
| } |
| } |
| return nullptr; |
| } |
| |
| if (Operands[0]->getType()->isIntegerTy() && |
| Operands[1]->getType()->isIntegerTy()) { |
| const APInt *C0, *C1; |
| if (!getConstIntOrUndef(Operands[0], C0) || |
| !getConstIntOrUndef(Operands[1], C1)) |
| return nullptr; |
| |
| unsigned BitWidth = Ty->getScalarSizeInBits(); |
| switch (IntrinsicID) { |
| default: break; |
| case Intrinsic::smax: |
| if (!C0 && !C1) |
| return UndefValue::get(Ty); |
| if (!C0 || !C1) |
| return ConstantInt::get(Ty, APInt::getSignedMaxValue(BitWidth)); |
| return ConstantInt::get(Ty, C0->sgt(*C1) ? *C0 : *C1); |
| |
| case Intrinsic::smin: |
| if (!C0 && !C1) |
| return UndefValue::get(Ty); |
| if (!C0 || !C1) |
| return ConstantInt::get(Ty, APInt::getSignedMinValue(BitWidth)); |
| return ConstantInt::get(Ty, C0->slt(*C1) ? *C0 : *C1); |
| |
| case Intrinsic::umax: |
| if (!C0 && !C1) |
| return UndefValue::get(Ty); |
| if (!C0 || !C1) |
| return ConstantInt::get(Ty, APInt::getMaxValue(BitWidth)); |
| return ConstantInt::get(Ty, C0->ugt(*C1) ? *C0 : *C1); |
| |
| case Intrinsic::umin: |
| if (!C0 && !C1) |
| return UndefValue::get(Ty); |
| if (!C0 || !C1) |
| return ConstantInt::get(Ty, APInt::getMinValue(BitWidth)); |
| return ConstantInt::get(Ty, C0->ult(*C1) ? *C0 : *C1); |
| |
| case Intrinsic::usub_with_overflow: |
| case Intrinsic::ssub_with_overflow: |
| // X - undef -> { 0, false } |
| // undef - X -> { 0, false } |
| if (!C0 || !C1) |
| return Constant::getNullValue(Ty); |
| LLVM_FALLTHROUGH; |
| case Intrinsic::uadd_with_overflow: |
| case Intrinsic::sadd_with_overflow: |
| // X + undef -> { -1, false } |
| // undef + x -> { -1, false } |
| if (!C0 || !C1) { |
| return ConstantStruct::get( |
| cast<StructType>(Ty), |
| {Constant::getAllOnesValue(Ty->getStructElementType(0)), |
| Constant::getNullValue(Ty->getStructElementType(1))}); |
| } |
| LLVM_FALLTHROUGH; |
| case Intrinsic::smul_with_overflow: |
| case Intrinsic::umul_with_overflow: { |
| // undef * X -> { 0, false } |
| // X * undef -> { 0, false } |
| if (!C0 || !C1) |
| return Constant::getNullValue(Ty); |
| |
| APInt Res; |
| bool Overflow; |
| switch (IntrinsicID) { |
| default: llvm_unreachable("Invalid case"); |
| case Intrinsic::sadd_with_overflow: |
| Res = C0->sadd_ov(*C1, Overflow); |
| break; |
| case Intrinsic::uadd_with_overflow: |
| Res = C0->uadd_ov(*C1, Overflow); |
| break; |
| case Intrinsic::ssub_with_overflow: |
| Res = C0->ssub_ov(*C1, Overflow); |
| break; |
| case Intrinsic::usub_with_overflow: |
| Res = C0->usub_ov(*C1, Overflow); |
| break; |
| case Intrinsic::smul_with_overflow: |
| Res = C0->smul_ov(*C1, Overflow); |
| break; |
| case Intrinsic::umul_with_overflow: |
| Res = C0->umul_ov(*C1, Overflow); |
| break; |
| } |
| Constant *Ops[] = { |
| ConstantInt::get(Ty->getContext(), Res), |
| ConstantInt::get(Type::getInt1Ty(Ty->getContext()), Overflow) |
| }; |
| return ConstantStruct::get(cast<StructType>(Ty), Ops); |
| } |
| case Intrinsic::uadd_sat: |
| case Intrinsic::sadd_sat: |
| if (!C0 && !C1) |
| return UndefValue::get(Ty); |
| if (!C0 || !C1) |
| return Constant::getAllOnesValue(Ty); |
| if (IntrinsicID == Intrinsic::uadd_sat) |
| return ConstantInt::get(Ty, C0->uadd_sat(*C1)); |
| else |
| return ConstantInt::get(Ty, C0->sadd_sat(*C1)); |
| case Intrinsic::usub_sat: |
| case Intrinsic::ssub_sat: |
| if (!C0 && !C1) |
|