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
29 class TargetLibraryInfo;
33 /// SimplifyAddInst - Given operands for an Add, see if we can
34 /// fold the result. If not, this returns null.
35 Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
36 const DataLayout *TD = 0,
37 const TargetLibraryInfo *TLI = 0,
38 const DominatorTree *DT = 0);
40 /// SimplifySubInst - Given operands for a Sub, see if we can
41 /// fold the result. If not, this returns null.
42 Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
43 const DataLayout *TD = 0,
44 const TargetLibraryInfo *TLI = 0,
45 const DominatorTree *DT = 0);
47 /// Given operands for an FMul, see if we can fold the result. If not, this
49 Value *SimplifyFMulInst(Value *LHS, Value *RHS,
51 const DataLayout *TD = 0,
52 const TargetLibraryInfo *TLI = 0,
53 const DominatorTree *DT = 0);
55 /// SimplifyMulInst - Given operands for a Mul, see if we can
56 /// fold the result. If not, this returns null.
57 Value *SimplifyMulInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
58 const TargetLibraryInfo *TLI = 0,
59 const DominatorTree *DT = 0);
61 /// SimplifySDivInst - Given operands for an SDiv, see if we can
62 /// fold the result. If not, this returns null.
63 Value *SimplifySDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
64 const TargetLibraryInfo *TLI = 0,
65 const DominatorTree *DT = 0);
67 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
68 /// fold the result. If not, this returns null.
69 Value *SimplifyUDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
70 const TargetLibraryInfo *TLI = 0,
71 const DominatorTree *DT = 0);
73 /// SimplifyFDivInst - Given operands for an FDiv, see if we can
74 /// fold the result. If not, this returns null.
75 Value *SimplifyFDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
76 const TargetLibraryInfo *TLI = 0,
77 const DominatorTree *DT = 0);
79 /// SimplifySRemInst - Given operands for an SRem, see if we can
80 /// fold the result. If not, this returns null.
81 Value *SimplifySRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
82 const TargetLibraryInfo *TLI = 0,
83 const DominatorTree *DT = 0);
85 /// SimplifyURemInst - Given operands for a URem, see if we can
86 /// fold the result. If not, this returns null.
87 Value *SimplifyURemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
88 const TargetLibraryInfo *TLI = 0,
89 const DominatorTree *DT = 0);
91 /// SimplifyFRemInst - Given operands for an FRem, see if we can
92 /// fold the result. If not, this returns null.
93 Value *SimplifyFRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
94 const TargetLibraryInfo *TLI = 0,
95 const DominatorTree *DT = 0);
97 /// SimplifyShlInst - Given operands for a Shl, see if we can
98 /// fold the result. If not, this returns null.
99 Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
100 const DataLayout *TD = 0,
101 const TargetLibraryInfo *TLI = 0,
102 const DominatorTree *DT = 0);
104 /// SimplifyLShrInst - Given operands for a LShr, see if we can
105 /// fold the result. If not, this returns null.
106 Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
107 const DataLayout *TD = 0,
108 const TargetLibraryInfo *TLI = 0,
109 const DominatorTree *DT = 0);
111 /// SimplifyAShrInst - Given operands for a AShr, see if we can
112 /// fold the result. If not, this returns null.
113 Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
114 const DataLayout *TD = 0,
115 const TargetLibraryInfo *TLI = 0,
116 const DominatorTree *DT = 0);
118 /// SimplifyAndInst - Given operands for an And, see if we can
119 /// fold the result. If not, this returns null.
120 Value *SimplifyAndInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
121 const TargetLibraryInfo *TLI = 0,
122 const DominatorTree *DT = 0);
124 /// SimplifyOrInst - Given operands for an Or, see if we can
125 /// fold the result. If not, this returns null.
126 Value *SimplifyOrInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
127 const TargetLibraryInfo *TLI = 0,
128 const DominatorTree *DT = 0);
130 /// SimplifyXorInst - Given operands for a Xor, see if we can
131 /// fold the result. If not, this returns null.
132 Value *SimplifyXorInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
133 const TargetLibraryInfo *TLI = 0,
134 const DominatorTree *DT = 0);
136 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
137 /// fold the result. If not, this returns null.
138 Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
139 const DataLayout *TD = 0,
140 const TargetLibraryInfo *TLI = 0,
141 const DominatorTree *DT = 0);
143 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
144 /// fold the result. If not, this returns null.
145 Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
146 const DataLayout *TD = 0,
147 const TargetLibraryInfo *TLI = 0,
148 const DominatorTree *DT = 0);
150 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
151 /// the result. If not, this returns null.
152 Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
153 const DataLayout *TD = 0,
154 const TargetLibraryInfo *TLI = 0,
155 const DominatorTree *DT = 0);
157 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
158 /// fold the result. If not, this returns null.
159 Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD = 0,
160 const TargetLibraryInfo *TLI = 0,
161 const DominatorTree *DT = 0);
163 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
164 /// can fold the result. If not, this returns null.
165 Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
166 ArrayRef<unsigned> Idxs,
167 const DataLayout *TD = 0,
168 const TargetLibraryInfo *TLI = 0,
169 const DominatorTree *DT = 0);
171 /// SimplifyTruncInst - Given operands for an TruncInst, see if we can fold
172 /// the result. If not, this returns null.
173 Value *SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD = 0,
174 const TargetLibraryInfo *TLI = 0,
175 const DominatorTree *DT = 0);
177 //=== Helper functions for higher up the class hierarchy.
180 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
181 /// fold the result. If not, this returns null.
182 Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
183 const DataLayout *TD = 0,
184 const TargetLibraryInfo *TLI = 0,
185 const DominatorTree *DT = 0);
187 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
188 /// fold the result. If not, this returns null.
189 Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
190 const DataLayout *TD = 0,
191 const TargetLibraryInfo *TLI = 0,
192 const DominatorTree *DT = 0);
194 /// SimplifyInstruction - See if we can compute a simplified version of this
195 /// instruction. If not, this returns null.
196 Value *SimplifyInstruction(Instruction *I, const DataLayout *TD = 0,
197 const TargetLibraryInfo *TLI = 0,
198 const DominatorTree *DT = 0);
201 /// \brief Replace all uses of 'I' with 'SimpleV' and simplify the uses
204 /// This first performs a normal RAUW of I with SimpleV. It then recursively
205 /// attempts to simplify those users updated by the operation. The 'I'
206 /// instruction must not be equal to the simplified value 'SimpleV'.
208 /// The function returns true if any simplifications were performed.
209 bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
210 const DataLayout *TD = 0,
211 const TargetLibraryInfo *TLI = 0,
212 const DominatorTree *DT = 0);
214 /// \brief Recursively attempt to simplify an instruction.
216 /// This routine uses SimplifyInstruction to simplify 'I', and if successful
217 /// replaces uses of 'I' with the simplified value. It then recurses on each
218 /// of the users impacted. It returns true if any simplifications were
220 bool recursivelySimplifyInstruction(Instruction *I,
221 const DataLayout *TD = 0,
222 const TargetLibraryInfo *TLI = 0,
223 const DominatorTree *DT = 0);
224 } // end namespace llvm