1//===- NoFolder.h - Constant folding helper ---------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the NoFolder class, a helper for IRBuilder. It provides
10// IRBuilder with a set of methods for creating unfolded constants. This is
11// useful for learners trying to understand how LLVM IR works, and who don't
12// want details to be hidden by the constant folder. For general constant
13// creation and folding, use ConstantExpr and the routines in
14// llvm/Analysis/ConstantFolding.h.
15//
16// Note: since it is not actually possible to create unfolded constants, this
17// class returns instructions rather than constants.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_IR_NOFOLDER_H
22#define LLVM_IR_NOFOLDER_H
23
24#include "llvm/ADT/ArrayRef.h"
25#include "llvm/IR/Constants.h"
26#include "llvm/IR/FMF.h"
27#include "llvm/IR/IRBuilderFolder.h"
28#include "llvm/IR/InstrTypes.h"
29#include "llvm/IR/Instruction.h"
30#include "llvm/IR/Instructions.h"
31
32namespace llvm {
33
34/// NoFolder - Create "constants" (actually, instructions) with no folding.
35class NoFolder final : public IRBuilderFolder {
36 virtual void anchor();
37
38public:
39 explicit NoFolder() = default;
40
41 //===--------------------------------------------------------------------===//
42 // Value-based folders.
43 //
44 // Return an existing value or a constant if the operation can be simplified.
45 // Otherwise return nullptr.
46 //===--------------------------------------------------------------------===//
47
48 Value *FoldBinOp(Instruction::BinaryOps Opc, Value *LHS,
49 Value *RHS) const override {
50 return nullptr;
51 }
52
53 Value *FoldExactBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS,
54 bool IsExact) const override {
55 return nullptr;
56 }
57
58 Value *FoldNoWrapBinOp(Instruction::BinaryOps Opc, Value *LHS, Value *RHS,
59 bool HasNUW, bool HasNSW) const override {
60 return nullptr;
61 }
62
63 Value *FoldBinOpFMF(Instruction::BinaryOps Opc, Value *LHS, Value *RHS,
64 FastMathFlags FMF) const override {
65 return nullptr;
66 }
67
68 Value *FoldUnOpFMF(Instruction::UnaryOps Opc, Value *V,
69 FastMathFlags FMF) const override {
70 return nullptr;
71 }
72
73 Value *FoldICmp(CmpInst::Predicate P, Value *LHS, Value *RHS) const override {
74 return nullptr;
75 }
76
77 Value *FoldGEP(Type *Ty, Value *Ptr, ArrayRef<Value *> IdxList,
78 bool IsInBounds = false) const override {
79 return nullptr;
80 }
81
82 Value *FoldSelect(Value *C, Value *True, Value *False) const override {
83 return nullptr;
84 }
85
86 Value *FoldExtractValue(Value *Agg,
87 ArrayRef<unsigned> IdxList) const override {
88 return nullptr;
89 }
90
91 Value *FoldInsertValue(Value *Agg, Value *Val,
92 ArrayRef<unsigned> IdxList) const override {
93 return nullptr;
94 }
95
96 Value *FoldExtractElement(Value *Vec, Value *Idx) const override {
97 return nullptr;
98 }
99
100 Value *FoldInsertElement(Value *Vec, Value *NewElt,
101 Value *Idx) const override {
102 return nullptr;
103 }
104
105 Value *FoldShuffleVector(Value *V1, Value *V2,
106 ArrayRef<int> Mask) const override {
107 return nullptr;
108 }
109
110 Value *FoldCast(Instruction::CastOps Op, Value *V,
111 Type *DestTy) const override {
112 return nullptr;
113 }
114
115 //===--------------------------------------------------------------------===//
116 // Cast/Conversion Operators
117 //===--------------------------------------------------------------------===//
118
119 Instruction *CreatePointerCast(Constant *C, Type *DestTy) const override {
120 return CastInst::CreatePointerCast(S: C, Ty: DestTy);
121 }
122
123 Instruction *CreatePointerBitCastOrAddrSpaceCast(
124 Constant *C, Type *DestTy) const override {
125 return CastInst::CreatePointerBitCastOrAddrSpaceCast(S: C, Ty: DestTy);
126 }
127
128 //===--------------------------------------------------------------------===//
129 // Compare Instructions
130 //===--------------------------------------------------------------------===//
131
132 Instruction *CreateFCmp(CmpInst::Predicate P,
133 Constant *LHS, Constant *RHS) const override {
134 return new FCmpInst(P, LHS, RHS);
135 }
136};
137
138} // end namespace llvm
139
140#endif // LLVM_IR_NOFOLDER_H
141

source code of llvm/include/llvm/IR/NoFolder.h