| //====- TargetFolder.h - Constant folding helper ---------------*- C++ -*-====// |
| // |
| // 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 the TargetFolder class, a helper for IRBuilder. |
| // It provides IRBuilder with a set of methods for creating constants with |
| // target dependent folding, in addition to the same target-independent |
| // folding that the ConstantFolder class provides. For general constant |
| // creation and folding, use ConstantExpr and the routines in |
| // llvm/Analysis/ConstantFolding.h. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ANALYSIS_TARGETFOLDER_H |
| #define LLVM_ANALYSIS_TARGETFOLDER_H |
| |
| #include "llvm/ADT/ArrayRef.h" |
| #include "llvm/Analysis/ConstantFolding.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/IRBuilderFolder.h" |
| #include "llvm/IR/Operator.h" |
| |
| namespace llvm { |
| |
| class Constant; |
| class DataLayout; |
| class Type; |
| |
| /// TargetFolder - Create constants with target dependent folding. |
| class TargetFolder final : public IRBuilderFolder { |
| const DataLayout &DL; |
| |
| /// Fold - Fold the constant using target specific information. |
| Constant *Fold(Constant *C) const { |
| return ConstantFoldConstant(C, DL); |
| } |
| |
| virtual void anchor(); |
| |
| public: |
| explicit TargetFolder(const DataLayout &DL) : DL(DL) {} |
| |
| //===--------------------------------------------------------------------===// |
| // Value-based folders. |
| // |
| // Return an existing value or a constant if the operation can be simplified. |
| // Otherwise return nullptr. |
| //===--------------------------------------------------------------------===// |
| |
| Value *FoldBinOp(Instruction::BinaryOps Opc, Value *LHS, |
| Value *RHS) const override { |
| auto *LC = dyn_cast<Constant>(LHS); |
| auto *RC = dyn_cast<Constant>(RHS); |
| if (LC && RC) { |
| if (ConstantExpr::isDesirableBinOp(Opc)) |
| return Fold(ConstantExpr::get(Opc, LC, RC)); |
| return ConstantFoldBinaryOpOperands(Opc, LC, RC, DL); |
| } |
| return nullptr; |
| } |
| |
| Value *FoldExactBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, |
| bool IsExact) const override { |
| auto *LC = dyn_cast<Constant>(LHS); |
| auto *RC = dyn_cast<Constant>(RHS); |
| if (LC && RC) { |
| if (ConstantExpr::isDesirableBinOp(Opc)) |
| return Fold(ConstantExpr::get( |
| Opc, LC, RC, IsExact ? PossiblyExactOperator::IsExact : 0)); |
| return ConstantFoldBinaryOpOperands(Opc, LC, RC, DL); |
| } |
| return nullptr; |
| } |
| |
| Value *FoldNoWrapBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, |
| bool HasNUW, bool HasNSW) const override { |
| auto *LC = dyn_cast<Constant>(LHS); |
| auto *RC = dyn_cast<Constant>(RHS); |
| if (LC && RC) { |
| if (ConstantExpr::isDesirableBinOp(Opc)) { |
| unsigned Flags = 0; |
| if (HasNUW) |
| Flags |= OverflowingBinaryOperator::NoUnsignedWrap; |
| if (HasNSW) |
| Flags |= OverflowingBinaryOperator::NoSignedWrap; |
| return Fold(ConstantExpr::get(Opc, LC, RC, Flags)); |
| } |
| return ConstantFoldBinaryOpOperands(Opc, LC, RC, DL); |
| } |
| return nullptr; |
| } |
| |
| Value *FoldBinOpFMF(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, |
| FastMathFlags FMF) const override { |
| return FoldBinOp(Opc, LHS, RHS); |
| } |
| |
| Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override { |
| auto *LC = dyn_cast<Constant>(LHS); |
| auto *RC = dyn_cast<Constant>(RHS); |
| if (LC && RC) |
| return Fold(ConstantExpr::getCompare(P, LC, RC)); |
| return nullptr; |
| } |
| |
| Value *FoldUnOpFMF(Instruction::UnaryOps Opc, Value *V, |
| FastMathFlags FMF) const override { |
| if (Constant *C = dyn_cast<Constant>(V)) |
| return ConstantFoldUnaryOpOperand(Opc, C, DL); |
| return nullptr; |
| } |
| |
| Value *FoldGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList, |
| bool IsInBounds = false) const override { |
| if (auto *PC = dyn_cast<Constant>(Ptr)) { |
| // Every index must be constant. |
| if (any_of(IdxList, [](Value *V) { return !isa<Constant>(V); })) |
| return nullptr; |
| if (IsInBounds) |
| return Fold(ConstantExpr::getInBoundsGetElementPtr(Ty, PC, IdxList)); |
| else |
| return Fold(ConstantExpr::getGetElementPtr(Ty, PC, IdxList)); |
| } |
| return nullptr; |
| } |
| |
| Value *FoldSelect(Value *C, Value *True, Value *False) const override { |
| auto *CC = dyn_cast<Constant>(C); |
| auto *TC = dyn_cast<Constant>(True); |
| auto *FC = dyn_cast<Constant>(False); |
| if (CC && TC && FC) |
| return Fold(ConstantExpr::getSelect(CC, TC, FC)); |
| |
| return nullptr; |
| } |
| |
| Value *FoldExtractValue(Value *Agg, |
| ArrayRef<unsigned> IdxList) const override { |
| if (auto *CAgg = dyn_cast<Constant>(Agg)) |
| return ConstantFoldExtractValueInstruction(CAgg, IdxList); |
| return nullptr; |
| }; |
| |
| Value *FoldInsertValue(Value *Agg, Value *Val, |
| ArrayRef<unsigned> IdxList) const override { |
| auto *CAgg = dyn_cast<Constant>(Agg); |
| auto *CVal = dyn_cast<Constant>(Val); |
| if (CAgg && CVal) |
| return ConstantFoldInsertValueInstruction(CAgg, CVal, IdxList); |
| return nullptr; |
| } |
| |
| Value *FoldExtractElement(Value *Vec, Value *Idx) const override { |
| auto *CVec = dyn_cast<Constant>(Vec); |
| auto *CIdx = dyn_cast<Constant>(Idx); |
| if (CVec && CIdx) |
| return Fold(ConstantExpr::getExtractElement(CVec, CIdx)); |
| return nullptr; |
| } |
| |
| Value *FoldInsertElement(Value *Vec, Value *NewElt, |
| Value *Idx) const override { |
| auto *CVec = dyn_cast<Constant>(Vec); |
| auto *CNewElt = dyn_cast<Constant>(NewElt); |
| auto *CIdx = dyn_cast<Constant>(Idx); |
| if (CVec && CNewElt && CIdx) |
| return Fold(ConstantExpr::getInsertElement(CVec, CNewElt, CIdx)); |
| return nullptr; |
| } |
| |
| Value *FoldShuffleVector(Value *V1, Value *V2, |
| ArrayRef<int> Mask) const override { |
| auto *C1 = dyn_cast<Constant>(V1); |
| auto *C2 = dyn_cast<Constant>(V2); |
| if (C1 && C2) |
| return Fold(ConstantExpr::getShuffleVector(C1, C2, Mask)); |
| return nullptr; |
| } |
| |
| //===--------------------------------------------------------------------===// |
| // Cast/Conversion Operators |
| //===--------------------------------------------------------------------===// |
| |
| Constant *CreateCast(Instruction::CastOps Op, Constant *C, |
| Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getCast(Op, C, DestTy)); |
| } |
| Constant *CreateIntCast(Constant *C, Type *DestTy, |
| bool isSigned) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getIntegerCast(C, DestTy, isSigned)); |
| } |
| Constant *CreatePointerCast(Constant *C, Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getPointerCast(C, DestTy)); |
| } |
| Constant *CreateFPCast(Constant *C, Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getFPCast(C, DestTy)); |
| } |
| Constant *CreateBitCast(Constant *C, Type *DestTy) const override { |
| return CreateCast(Instruction::BitCast, C, DestTy); |
| } |
| Constant *CreateIntToPtr(Constant *C, Type *DestTy) const override { |
| return CreateCast(Instruction::IntToPtr, C, DestTy); |
| } |
| Constant *CreatePtrToInt(Constant *C, Type *DestTy) const override { |
| return CreateCast(Instruction::PtrToInt, C, DestTy); |
| } |
| Constant *CreateZExtOrBitCast(Constant *C, Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getZExtOrBitCast(C, DestTy)); |
| } |
| Constant *CreateSExtOrBitCast(Constant *C, Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getSExtOrBitCast(C, DestTy)); |
| } |
| Constant *CreateTruncOrBitCast(Constant *C, Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getTruncOrBitCast(C, DestTy)); |
| } |
| |
| Constant *CreatePointerBitCastOrAddrSpaceCast(Constant *C, |
| Type *DestTy) const override { |
| if (C->getType() == DestTy) |
| return C; // avoid calling Fold |
| return Fold(ConstantExpr::getPointerBitCastOrAddrSpaceCast(C, DestTy)); |
| } |
| |
| //===--------------------------------------------------------------------===// |
| // Compare Instructions |
| //===--------------------------------------------------------------------===// |
| |
| Constant *CreateFCmp(CmpInst::Predicate P, Constant *LHS, |
| Constant *RHS) const override { |
| return Fold(ConstantExpr::getCompare(P, LHS, RHS)); |
| } |
| }; |
| |
| } |
| |
| #endif |