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
22 #include "llvm/IR/User.h"
31 class TargetLibraryInfo;
35 /// SimplifyAddInst - Given operands for an Add, see if we can
36 /// fold the result. If not, this returns null.
37 Value *SimplifyAddInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
38 const DataLayout *TD = 0,
39 const TargetLibraryInfo *TLI = 0,
40 const DominatorTree *DT = 0);
42 /// SimplifySubInst - Given operands for a Sub, see if we can
43 /// fold the result. If not, this returns null.
44 Value *SimplifySubInst(Value *LHS, Value *RHS, bool isNSW, bool isNUW,
45 const DataLayout *TD = 0,
46 const TargetLibraryInfo *TLI = 0,
47 const DominatorTree *DT = 0);
49 /// Given operands for an FAdd, see if we can fold the result. If not, this
51 Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF,
52 const DataLayout *TD = 0,
53 const TargetLibraryInfo *TLI = 0,
54 const DominatorTree *DT = 0);
56 /// Given operands for an FSub, see if we can fold the result. If not, this
58 Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF,
59 const DataLayout *TD = 0,
60 const TargetLibraryInfo *TLI = 0,
61 const DominatorTree *DT = 0);
63 /// Given operands for an FMul, see if we can fold the result. If not, this
65 Value *SimplifyFMulInst(Value *LHS, Value *RHS,
67 const DataLayout *TD = 0,
68 const TargetLibraryInfo *TLI = 0,
69 const DominatorTree *DT = 0);
71 /// SimplifyMulInst - Given operands for a Mul, see if we can
72 /// fold the result. If not, this returns null.
73 Value *SimplifyMulInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
74 const TargetLibraryInfo *TLI = 0,
75 const DominatorTree *DT = 0);
77 /// SimplifySDivInst - Given operands for an SDiv, see if we can
78 /// fold the result. If not, this returns null.
79 Value *SimplifySDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
80 const TargetLibraryInfo *TLI = 0,
81 const DominatorTree *DT = 0);
83 /// SimplifyUDivInst - Given operands for a UDiv, see if we can
84 /// fold the result. If not, this returns null.
85 Value *SimplifyUDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
86 const TargetLibraryInfo *TLI = 0,
87 const DominatorTree *DT = 0);
89 /// SimplifyFDivInst - Given operands for an FDiv, see if we can
90 /// fold the result. If not, this returns null.
91 Value *SimplifyFDivInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
92 const TargetLibraryInfo *TLI = 0,
93 const DominatorTree *DT = 0);
95 /// SimplifySRemInst - Given operands for an SRem, see if we can
96 /// fold the result. If not, this returns null.
97 Value *SimplifySRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
98 const TargetLibraryInfo *TLI = 0,
99 const DominatorTree *DT = 0);
101 /// SimplifyURemInst - Given operands for a URem, see if we can
102 /// fold the result. If not, this returns null.
103 Value *SimplifyURemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
104 const TargetLibraryInfo *TLI = 0,
105 const DominatorTree *DT = 0);
107 /// SimplifyFRemInst - Given operands for an FRem, see if we can
108 /// fold the result. If not, this returns null.
109 Value *SimplifyFRemInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
110 const TargetLibraryInfo *TLI = 0,
111 const DominatorTree *DT = 0);
113 /// SimplifyShlInst - Given operands for a Shl, see if we can
114 /// fold the result. If not, this returns null.
115 Value *SimplifyShlInst(Value *Op0, Value *Op1, bool isNSW, bool isNUW,
116 const DataLayout *TD = 0,
117 const TargetLibraryInfo *TLI = 0,
118 const DominatorTree *DT = 0);
120 /// SimplifyLShrInst - Given operands for a LShr, see if we can
121 /// fold the result. If not, this returns null.
122 Value *SimplifyLShrInst(Value *Op0, Value *Op1, bool isExact,
123 const DataLayout *TD = 0,
124 const TargetLibraryInfo *TLI = 0,
125 const DominatorTree *DT = 0);
127 /// SimplifyAShrInst - Given operands for a AShr, see if we can
128 /// fold the result. If not, this returns null.
129 Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
130 const DataLayout *TD = 0,
131 const TargetLibraryInfo *TLI = 0,
132 const DominatorTree *DT = 0);
134 /// SimplifyAndInst - Given operands for an And, see if we can
135 /// fold the result. If not, this returns null.
136 Value *SimplifyAndInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
137 const TargetLibraryInfo *TLI = 0,
138 const DominatorTree *DT = 0);
140 /// SimplifyOrInst - Given operands for an Or, see if we can
141 /// fold the result. If not, this returns null.
142 Value *SimplifyOrInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
143 const TargetLibraryInfo *TLI = 0,
144 const DominatorTree *DT = 0);
146 /// SimplifyXorInst - Given operands for a Xor, see if we can
147 /// fold the result. If not, this returns null.
148 Value *SimplifyXorInst(Value *LHS, Value *RHS, const DataLayout *TD = 0,
149 const TargetLibraryInfo *TLI = 0,
150 const DominatorTree *DT = 0);
152 /// SimplifyICmpInst - Given operands for an ICmpInst, see if we can
153 /// fold the result. If not, this returns null.
154 Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
155 const DataLayout *TD = 0,
156 const TargetLibraryInfo *TLI = 0,
157 const DominatorTree *DT = 0);
159 /// SimplifyFCmpInst - Given operands for an FCmpInst, see if we can
160 /// fold the result. If not, this returns null.
161 Value *SimplifyFCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
162 const DataLayout *TD = 0,
163 const TargetLibraryInfo *TLI = 0,
164 const DominatorTree *DT = 0);
166 /// SimplifySelectInst - Given operands for a SelectInst, see if we can fold
167 /// the result. If not, this returns null.
168 Value *SimplifySelectInst(Value *Cond, Value *TrueVal, Value *FalseVal,
169 const DataLayout *TD = 0,
170 const TargetLibraryInfo *TLI = 0,
171 const DominatorTree *DT = 0);
173 /// SimplifyGEPInst - Given operands for an GetElementPtrInst, see if we can
174 /// fold the result. If not, this returns null.
175 Value *SimplifyGEPInst(ArrayRef<Value *> Ops, const DataLayout *TD = 0,
176 const TargetLibraryInfo *TLI = 0,
177 const DominatorTree *DT = 0);
179 /// SimplifyInsertValueInst - Given operands for an InsertValueInst, see if we
180 /// can fold the result. If not, this returns null.
181 Value *SimplifyInsertValueInst(Value *Agg, Value *Val,
182 ArrayRef<unsigned> Idxs,
183 const DataLayout *TD = 0,
184 const TargetLibraryInfo *TLI = 0,
185 const DominatorTree *DT = 0);
187 /// SimplifyTruncInst - Given operands for an TruncInst, see if we can fold
188 /// the result. If not, this returns null.
189 Value *SimplifyTruncInst(Value *Op, Type *Ty, const DataLayout *TD = 0,
190 const TargetLibraryInfo *TLI = 0,
191 const DominatorTree *DT = 0);
193 //=== Helper functions for higher up the class hierarchy.
196 /// SimplifyCmpInst - Given operands for a CmpInst, see if we can
197 /// fold the result. If not, this returns null.
198 Value *SimplifyCmpInst(unsigned Predicate, Value *LHS, Value *RHS,
199 const DataLayout *TD = 0,
200 const TargetLibraryInfo *TLI = 0,
201 const DominatorTree *DT = 0);
203 /// SimplifyBinOp - Given operands for a BinaryOperator, see if we can
204 /// fold the result. If not, this returns null.
205 Value *SimplifyBinOp(unsigned Opcode, Value *LHS, Value *RHS,
206 const DataLayout *TD = 0,
207 const TargetLibraryInfo *TLI = 0,
208 const DominatorTree *DT = 0);
210 /// \brief Given a function and iterators over arguments, see if we can fold
213 /// If this call could not be simplified returns null.
214 Value *SimplifyCall(Value *V, User::op_iterator ArgBegin,
215 User::op_iterator ArgEnd, const DataLayout *TD = 0,
216 const TargetLibraryInfo *TLI = 0,
217 const DominatorTree *DT = 0);
219 /// \brief Given a function and set of arguments, see if we can fold the
222 /// If this call could not be simplified returns null.
223 Value *SimplifyCall(Value *V, ArrayRef<Value *> Args,
224 const DataLayout *TD = 0,
225 const TargetLibraryInfo *TLI = 0,
226 const DominatorTree *DT = 0);
228 /// SimplifyInstruction - See if we can compute a simplified version of this
229 /// instruction. If not, this returns null.
230 Value *SimplifyInstruction(Instruction *I, const DataLayout *TD = 0,
231 const TargetLibraryInfo *TLI = 0,
232 const DominatorTree *DT = 0);
235 /// \brief Replace all uses of 'I' with 'SimpleV' and simplify the uses
238 /// This first performs a normal RAUW of I with SimpleV. It then recursively
239 /// attempts to simplify those users updated by the operation. The 'I'
240 /// instruction must not be equal to the simplified value 'SimpleV'.
242 /// The function returns true if any simplifications were performed.
243 bool replaceAndRecursivelySimplify(Instruction *I, Value *SimpleV,
244 const DataLayout *TD = 0,
245 const TargetLibraryInfo *TLI = 0,
246 const DominatorTree *DT = 0);
248 /// \brief Recursively attempt to simplify an instruction.
250 /// This routine uses SimplifyInstruction to simplify 'I', and if successful
251 /// replaces uses of 'I' with the simplified value. It then recurses on each
252 /// of the users impacted. It returns true if any simplifications were
254 bool recursivelySimplifyInstruction(Instruction *I,
255 const DataLayout *TD = 0,
256 const TargetLibraryInfo *TLI = 0,
257 const DominatorTree *DT = 0);
258 } // end namespace llvm