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
27 class TargetLibraryInfo;
31 /// SimplifyAddInst - Given operands for an Add, see if we can
32 /// fold the result. If not, this returns null.
33 Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
34 const TargetData *TD = 0,
35 const TargetLibraryInfo *TLI = 0,
36 const DominatorTree *DT = 0);
38 /// SimplifySubInst - Given operands for a Sub, see if we can
39 /// fold the result. If not, this returns null.
40 Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
41 const TargetData *TD = 0,
42 const TargetLibraryInfo *TLI = 0,
43 const DominatorTree *DT = 0);
45 /// SimplifyMulInst - Given operands for a Mul, see if we can
46 /// fold the result. If not, this returns null.
47 Value *SimplifyMulInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
48 const TargetLibraryInfo *TLI = 0,
49 const DominatorTree *DT = 0);
51 /// SimplifySDivInst - Given operands for an SDiv, see if we can
52 /// fold the result. If not, this returns null.
53 Value *SimplifySDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
54 const TargetLibraryInfo *TLI = 0,
55 const DominatorTree *DT = 0);
57 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
58 /// fold the result. If not, this returns null.
59 Value *SimplifyUDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
60 const TargetLibraryInfo *TLI = 0,
61 const DominatorTree *DT = 0);
63 /// SimplifyFDivInst - Given operands for an FDiv, see if we can
64 /// fold the result. If not, this returns null.
65 Value *SimplifyFDivInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
66 const TargetLibraryInfo *TLI = 0,
67 const DominatorTree *DT = 0);
69 /// SimplifySRemInst - Given operands for an SRem, see if we can
70 /// fold the result. If not, this returns null.
71 Value *SimplifySRemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
72 const TargetLibraryInfo *TLI = 0,
73 const DominatorTree *DT = 0);
75 /// SimplifyURemInst - Given operands for a URem, see if we can
76 /// fold the result. If not, this returns null.
77 Value *SimplifyURemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
78 const TargetLibraryInfo *TLI = 0,
79 const DominatorTree *DT = 0);
81 /// SimplifyFRemInst - Given operands for an FRem, see if we can
82 /// fold the result. If not, this returns null.
83 Value *SimplifyFRemInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
84 const TargetLibraryInfo *TLI = 0,
85 const DominatorTree *DT = 0);
87 /// SimplifyShlInst - Given operands for a Shl, see if we can
88 /// fold the result. If not, this returns null.
89 Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
90 const TargetData *TD = 0,
91 const TargetLibraryInfo *TLI = 0,
92 const DominatorTree *DT = 0);
94 /// SimplifyLShrInst - Given operands for a LShr, see if we can
95 /// fold the result. If not, this returns null.
96 Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
97 const TargetData *TD = 0,
98 const TargetLibraryInfo *TLI = 0,
99 const DominatorTree *DT = 0);
101 /// SimplifyAShrInst - Given operands for a AShr, see if we can
102 /// fold the result. If not, this returns null.
103 Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
104 const TargetData *TD = 0,
105 const TargetLibraryInfo *TLI = 0,
106 const DominatorTree *DT = 0);
108 /// SimplifyAndInst - Given operands for an And, see if we can
109 /// fold the result. If not, this returns null.
110 Value *SimplifyAndInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
111 const TargetLibraryInfo *TLI = 0,
112 const DominatorTree *DT = 0);
114 /// SimplifyOrInst - Given operands for an Or, see if we can
115 /// fold the result. If not, this returns null.
116 Value *SimplifyOrInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
117 const TargetLibraryInfo *TLI = 0,
118 const DominatorTree *DT = 0);
120 /// SimplifyXorInst - Given operands for a Xor, see if we can
121 /// fold the result. If not, this returns null.
122 Value *SimplifyXorInst(Value *LHS, Value *RHS, const TargetData *TD = 0,
123 const TargetLibraryInfo *TLI = 0,
124 const DominatorTree *DT = 0);
126 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
127 /// fold the result. If not, this returns null.
128 Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
129 const TargetData *TD = 0,
130 const TargetLibraryInfo *TLI = 0,
131 const DominatorTree *DT = 0);
133 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
134 /// fold the result. If not, this returns null.
135 Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
136 const TargetData *TD = 0,
137 const TargetLibraryInfo *TLI = 0,
138 const DominatorTree *DT = 0);
140 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
141 /// the result. If not, this returns null.
142 Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
143 const TargetData *TD = 0,
144 const DominatorTree *DT = 0);
146 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
147 /// fold the result. If not, this returns null.
148 Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const TargetData *TD = 0,
149 const DominatorTree *DT = 0);
151 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
152 /// can fold the result. If not, this returns null.
153 Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
154 ArrayRef<unsigned> Idxs,
155 const TargetData *TD = 0,
156 const DominatorTree *DT = 0);
158 //=== Helper functions for higher up the class hierarchy.
161 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
162 /// fold the result. If not, this returns null.
163 Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
164 const TargetData *TD = 0,
165 const TargetLibraryInfo *TLI = 0,
166 const DominatorTree *DT = 0);
168 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
169 /// fold the result. If not, this returns null.
170 Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
171 const TargetData *TD = 0,
172 const TargetLibraryInfo *TLI = 0,
173 const DominatorTree *DT = 0);
175 /// SimplifyInstruction - See if we can compute a simplified version of this
176 /// instruction. If not, this returns null.
177 Value *SimplifyInstruction(Instruction *I, const TargetData *TD = 0,
178 const TargetLibraryInfo *TLI = 0,
179 const DominatorTree *DT = 0);
182 /// ReplaceAndSimplifyAllUses - Perform From->replaceAllUsesWith(To) and then
183 /// delete the From instruction. In addition to a basic RAUW, this does a
184 /// recursive simplification of the updated instructions. This catches
185 /// things where one simplification exposes other opportunities. This only
186 /// simplifies and deletes scalar operations, it does not change the CFG.
188 void ReplaceAndSimplifyAllUses(Instruction *From, Value *To,
189 const TargetData *TD = 0,
190 const TargetLibraryInfo *TLI = 0,
191 const DominatorTree *DT = 0);
192 } // end namespace llvm