- //===- NoFolder.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 NoFolder class, a helper for IRBuilder.  It provides 
- // IRBuilder with a set of methods for creating unfolded constants.  This is 
- // useful for learners trying to understand how LLVM IR works, and who don't 
- // want details to be hidden by the constant folder.  For general constant 
- // creation and folding, use ConstantExpr and the routines in 
- // llvm/Analysis/ConstantFolding.h. 
- // 
- // Note: since it is not actually possible to create unfolded constants, this 
- // class returns instructions rather than constants. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_IR_NOFOLDER_H 
- #define LLVM_IR_NOFOLDER_H 
-   
- #include "llvm/ADT/ArrayRef.h" 
- #include "llvm/IR/Constants.h" 
- #include "llvm/IR/FMF.h" 
- #include "llvm/IR/IRBuilderFolder.h" 
- #include "llvm/IR/InstrTypes.h" 
- #include "llvm/IR/Instruction.h" 
- #include "llvm/IR/Instructions.h" 
-   
- namespace llvm { 
-   
- /// NoFolder - Create "constants" (actually, instructions) with no folding. 
- class NoFolder final : public IRBuilderFolder { 
-   virtual void anchor(); 
-   
- public: 
-   explicit NoFolder() = default; 
-   
-   //===--------------------------------------------------------------------===// 
-   // 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 { 
-     return nullptr; 
-   } 
-   
-   Value *FoldExactBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, 
-                         bool IsExact) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldNoWrapBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, 
-                          bool HasNUW, bool HasNSW) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldBinOpFMF(Instruction::BinaryOps Opc, Value *LHS, Value *RHS, 
-                       FastMathFlags FMF) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldUnOpFMF(Instruction::UnaryOps Opc, Value *V, 
-                      FastMathFlags FMF) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList, 
-                  bool IsInBounds = false) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldSelect(Value *C, Value *True, Value *False) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldExtractValue(Value *Agg, 
-                           ArrayRef<unsigned> IdxList) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldInsertValue(Value *Agg, Value *Val, 
-                          ArrayRef<unsigned> IdxList) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldExtractElement(Value *Vec, Value *Idx) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldInsertElement(Value *Vec, Value *NewElt, 
-                            Value *Idx) const override { 
-     return nullptr; 
-   } 
-   
-   Value *FoldShuffleVector(Value *V1, Value *V2, 
-                            ArrayRef<int> Mask) const override { 
-     return nullptr; 
-   } 
-   
-   //===--------------------------------------------------------------------===// 
-   // Cast/Conversion Operators 
-   //===--------------------------------------------------------------------===// 
-   
-   Instruction *CreateCast(Instruction::CastOps Op, Constant *C, 
-                           Type *DestTy) const override { 
-     return CastInst::Create(Op, C, DestTy); 
-   } 
-   
-   Instruction *CreatePointerCast(Constant *C, Type *DestTy) const override { 
-     return CastInst::CreatePointerCast(C, DestTy); 
-   } 
-   
-   Instruction *CreatePointerBitCastOrAddrSpaceCast( 
-       Constant *C, Type *DestTy) const override { 
-     return CastInst::CreatePointerBitCastOrAddrSpaceCast(C, DestTy); 
-   } 
-   
-   Instruction *CreateIntCast(Constant *C, Type *DestTy, 
-                              bool isSigned) const override { 
-     return CastInst::CreateIntegerCast(C, DestTy, isSigned); 
-   } 
-   
-   Instruction *CreateFPCast(Constant *C, Type *DestTy) const override { 
-     return CastInst::CreateFPCast(C, DestTy); 
-   } 
-   
-   Instruction *CreateBitCast(Constant *C, Type *DestTy) const override { 
-     return CreateCast(Instruction::BitCast, C, DestTy); 
-   } 
-   
-   Instruction *CreateIntToPtr(Constant *C, Type *DestTy) const override { 
-     return CreateCast(Instruction::IntToPtr, C, DestTy); 
-   } 
-   
-   Instruction *CreatePtrToInt(Constant *C, Type *DestTy) const override { 
-     return CreateCast(Instruction::PtrToInt, C, DestTy); 
-   } 
-   
-   Instruction *CreateZExtOrBitCast(Constant *C, Type *DestTy) const override { 
-     return CastInst::CreateZExtOrBitCast(C, DestTy); 
-   } 
-   
-   Instruction *CreateSExtOrBitCast(Constant *C, Type *DestTy) const override { 
-     return CastInst::CreateSExtOrBitCast(C, DestTy); 
-   } 
-   
-   Instruction *CreateTruncOrBitCast(Constant *C, Type *DestTy) const override { 
-     return CastInst::CreateTruncOrBitCast(C, DestTy); 
-   } 
-   
-   //===--------------------------------------------------------------------===// 
-   // Compare Instructions 
-   //===--------------------------------------------------------------------===// 
-   
-   Instruction *CreateFCmp(CmpInst::Predicate P, 
-                           Constant *LHS, Constant *RHS) const override { 
-     return new FCmpInst(P, LHS, RHS); 
-   } 
- }; 
-   
- } // end namespace llvm 
-   
- #endif // LLVM_IR_NOFOLDER_H 
-