1 //===-- InstructionSimplify.h - Fold instructions into simpler forms ------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file declares routines for folding instructions into simpler forms
11 // that do not require creating new instructions. This does constant folding
12 // ("add i32 1, 1" -> "2") but can also handle non-constant operands, either
13 // returning a constant ("and i32 %x, 0" -> "0") or an already existing value
14 // ("and i32 %x, %x" -> "%x"). If the simplification is also an instruction
15 // then it dominates the original instruction.
17 //===----------------------------------------------------------------------===//
19 #ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
20 #define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H
30 /// SimplifyAddInst - Given operands for an Add, see if we can
31 /// fold the result. If not, this returns null.
32 Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
33 const TargetData *TD = 0, const DominatorTree *DT = 0);
35 /// SimplifySubInst - Given operands for a Sub, see if we can
36 /// fold the result. If not, this returns null.
37 Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
38 const TargetData *TD = 0, const DominatorTree *DT = 0);
40 /// SimplifyMulInst - Given operands for a Mul, see if we can
41 /// fold the result. If not, this returns null.
42 Value *SimplifyMulInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
43 const DominatorTree *DT = 0);
45 /// SimplifySDivInst - Given operands for an SDiv, see if we can
46 /// fold the result. If not, this returns null.
47 Value *SimplifySDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
48 const DominatorTree *DT = 0);
50 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
51 /// fold the result. If not, this returns null.
52 Value *SimplifyUDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
53 const DominatorTree *DT = 0);
55 /// SimplifyFDivInst - Given operands for an FDiv, see if we can
56 /// fold the result. If not, this returns null.
57 Value *SimplifyFDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
58 const DominatorTree *DT = 0);
60 /// SimplifySRemInst - Given operands for an SRem, see if we can
61 /// fold the result. If not, this returns null.
62 Value *SimplifySRemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
63 const DominatorTree *DT = 0);
65 /// SimplifyURemInst - Given operands for a URem, see if we can
66 /// fold the result. If not, this returns null.
67 Value *SimplifyURemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
68 const DominatorTree *DT = 0);
70 /// SimplifyFRemInst - Given operands for an FRem, see if we can
71 /// fold the result. If not, this returns null.
72 Value *SimplifyFRemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
73 const DominatorTree *DT = 0);
75 /// SimplifyShlInst - Given operands for a Shl, see if we can
76 /// fold the result. If not, this returns null.
77 Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
78 const TargetData *TD = 0, const DominatorTree *DT = 0);
80 /// SimplifyLShrInst - Given operands for a LShr, see if we can
81 /// fold the result. If not, this returns null.
82 Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
83 const TargetData *TD = 0, const DominatorTree *DT=0);
85 /// SimplifyAShrInst - Given operands for a AShr, see if we can
86 /// fold the result. If not, this returns null.
87 Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
88 const TargetData *TD = 0,
89 const DominatorTree *DT = 0);
91 /// SimplifyAndInst - Given operands for an And, see if we can
92 /// fold the result. If not, this returns null.
93 Value *SimplifyAndInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
94 const DominatorTree *DT = 0);
96 /// SimplifyOrInst - Given operands for an Or, see if we can
97 /// fold the result. If not, this returns null.
98 Value *SimplifyOrInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
99 const DominatorTree *DT = 0);
101 /// SimplifyXorInst - Given operands for a Xor, see if we can
102 /// fold the result. If not, this returns null.
103 Value *SimplifyXorInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
104 const DominatorTree *DT = 0);
106 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
107 /// fold the result. If not, this returns null.
108 Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
109 const TargetData *TD = 0,
110 const DominatorTree *DT = 0);
112 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
113 /// fold the result. If not, this returns null.
114 Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
115 const TargetData *TD = 0,
116 const DominatorTree *DT = 0);
118 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
119 /// the result. If not, this returns null.
120 Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
121 const TargetData *TD = 0,
122 const DominatorTree *DT = 0);
124 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
125 /// fold the result. If not, this returns null.
126 Value *SimplifyGEPInst(ArrayRef<Value *> Ops,
127 const TargetData *TD = 0, const DominatorTree *DT = 0);
129 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
130 /// can fold the result. If not, this returns null.
131 Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
132 ArrayRef<unsigned> Idxs,
133 const TargetData *TD = 0,
134 const DominatorTree *DT = 0);
136 //=== Helper functions for higher up the class hierarchy.
139 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
140 /// fold the result. If not, this returns null.
141 Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
142 const TargetData *TD = 0, const DominatorTree *DT = 0);
144 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
145 /// fold the result. If not, this returns null.
146 Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
147 const TargetData *TD = 0, const DominatorTree *DT = 0);
149 /// SimplifyInstruction - See if we can compute a simplified version of this
150 /// instruction. If not, this returns null.
151 Value *SimplifyInstruction(Instruction *I, const TargetData *TD = 0,
152 const DominatorTree *DT = 0);
155 /// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then
156 /// delete the From instruction. In addition to a basic RAUW, this does a
157 /// recursive simplification of the updated instructions. This catches
158 /// things where one simplification exposes other opportunities. This only
159 /// simplifies and deletes scalar operations, it does not change the CFG.
161 void ReplaceAndSimplifyAllUses(Instruction *From, Value *To,
162 const TargetData *TD = 0,
163 const DominatorTree *DT = 0);
164 } // end namespace llvm