InstructionSimplify.h revision c98bd9f1a79adffe73acd337b6f7f9afa6bae078
1//===-- InstructionSimplify.h - Fold instructions into simpler forms ------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 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. 16// 17//===----------------------------------------------------------------------===// 18 19#ifndef LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H 20#define LLVM_ANALYSIS_INSTRUCTIONSIMPLIFY_H 21 22#include "llvm/User.h" 23 24namespace llvm { 25 template<typename T> 26 class ArrayRef; 27 class DominatorTree; 28 class Instruction; 29 class DataLayout; 30 class FastMathFlags; 31 class TargetLibraryInfo; 32 class Type; 33 class Value; 34 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); 41 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); 48 49 /// Given operands for an FAdd, see if we can fold the result. If not, this 50 /// returns null. 51 Value *SimplifyFAddInst(Value *LHS, Value *RHS, FastMathFlags FMF, 52 const DataLayout *TD = 0, 53 const TargetLibraryInfo *TLI = 0, 54 const DominatorTree *DT = 0); 55 56 /// Given operands for an FSub, see if we can fold the result. If not, this 57 /// returns null. 58 Value *SimplifyFSubInst(Value *LHS, Value *RHS, FastMathFlags FMF, 59 const DataLayout *TD = 0, 60 const TargetLibraryInfo *TLI = 0, 61 const DominatorTree *DT = 0); 62 63 /// Given operands for an FMul, see if we can fold the result. If not, this 64 /// returns null. 65 Value *SimplifyFMulInst(Value *LHS, Value *RHS, 66 FastMathFlags FMF, 67 const DataLayout *TD = 0, 68 const TargetLibraryInfo *TLI = 0, 69 const DominatorTree *DT = 0); 70 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); 76 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); 82 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); 88 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); 94 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); 100 101 /// 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); 106 107 /// 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); 112 113 /// 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); 119 120 /// 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); 126 127 /// 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); 133 134 /// 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); 139 140 /// 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); 145 146 /// 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); 151 152 /// 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); 158 159 /// 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); 165 166 /// 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); 172 173 /// 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); 178 179 /// 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); 186 187 /// 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); 192 193 //=== Helper functions for higher up the class hierarchy. 194 195 196 /// 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); 202 203 /// 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); 209 210 /// \brief Given a function and iterators over arguments, see if we can fold 211 /// the result. 212 /// 213 /// If this call could not be simplified returns null. 214 Value *SimplifyCall(Value *F, User::op_iterator ArgBegin, 215 User::op_iterator ArgEnd, const DataLayout *TD = 0, 216 const TargetLibraryInfo *TLI = 0, 217 const DominatorTree *DT = 0); 218 219 /// \brief Given a function and set of arguments, see if we can fold the 220 /// result. 221 /// 222 /// If this call could not be simplified returns null. 223 Value *SimplifyCall(Value *F, ArrayRef<Value *> Args, 224 const DataLayout *TD = 0, 225 const TargetLibraryInfo *TLI = 0, 226 const DominatorTree *DT = 0); 227 228 /// 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); 233 234 235 /// \brief Replace all uses of 'I' with 'SimpleV' and simplify the uses 236 /// recursively. 237 /// 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'. 241 /// 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); 247 248 /// \brief Recursively attempt to simplify an instruction. 249 /// 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 253 /// performed. 254 bool recursivelySimplifyInstruction(Instruction *I, 255 const DataLayout *TD = 0, 256 const TargetLibraryInfo *TLI = 0, 257 const DominatorTree *DT = 0); 258} // end namespace llvm 259 260#endif 261 262