1 //===- Cloning.h - Clone various parts of LLVM programs ---------*- C++ -*-===// 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 defines various functions that are used to clone chunks of LLVM 11 // code for various purposes. This varies from copying whole modules into new 12 // modules, to cloning functions with different arguments, to inlining 13 // functions, to copying basic blocks to support loop unrolling or superblock 14 // formation, etc. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #ifndef LLVM_TRANSFORMS_UTILS_CLONING_H 19 #define LLVM_TRANSFORMS_UTILS_CLONING_H 20 21 #include "llvm/ADT/ValueMap.h" 22 #include "llvm/ADT/SmallVector.h" 23 #include "llvm/ADT/Twine.h" 24 #include "llvm/Support/ValueHandle.h" 25 #include "llvm/Transforms/Utils/ValueMapper.h" 26 27 namespace llvm { 28 29 class Module; 30 class Function; 31 class Instruction; 32 class Pass; 33 class LPPassManager; 34 class BasicBlock; 35 class Value; 36 class CallInst; 37 class InvokeInst; 38 class ReturnInst; 39 class CallSite; 40 class Trace; 41 class CallGraph; 42 class TargetData; 43 class Loop; 44 class LoopInfo; 45 class AllocaInst; 46 47 /// CloneModule - Return an exact copy of the specified module 48 /// 49 Module *CloneModule(const Module *M); 50 Module *CloneModule(const Module *M, ValueToValueMapTy &VMap); 51 52 /// ClonedCodeInfo - This struct can be used to capture information about code 53 /// being cloned, while it is being cloned. 54 struct ClonedCodeInfo { 55 /// ContainsCalls - This is set to true if the cloned code contains a normal 56 /// call instruction. 57 bool ContainsCalls; 58 59 /// ContainsDynamicAllocas - This is set to true if the cloned code contains 60 /// a 'dynamic' alloca. Dynamic allocas are allocas that are either not in 61 /// the entry block or they are in the entry block but are not a constant 62 /// size. 63 bool ContainsDynamicAllocas; 64 65 ClonedCodeInfo() : ContainsCalls(false), ContainsDynamicAllocas(false) {} 66 }; 67 68 69 /// CloneBasicBlock - Return a copy of the specified basic block, but without 70 /// embedding the block into a particular function. The block returned is an 71 /// exact copy of the specified basic block, without any remapping having been 72 /// performed. Because of this, this is only suitable for applications where 73 /// the basic block will be inserted into the same function that it was cloned 74 /// from (loop unrolling would use this, for example). 75 /// 76 /// Also, note that this function makes a direct copy of the basic block, and 77 /// can thus produce illegal LLVM code. In particular, it will copy any PHI 78 /// nodes from the original block, even though there are no predecessors for the 79 /// newly cloned block (thus, phi nodes will have to be updated). Also, this 80 /// block will branch to the old successors of the original block: these 81 /// successors will have to have any PHI nodes updated to account for the new 82 /// incoming edges. 83 /// 84 /// The correlation between instructions in the source and result basic blocks 85 /// is recorded in the VMap map. 86 /// 87 /// If you have a particular suffix you'd like to use to add to any cloned 88 /// names, specify it as the optional third parameter. 89 /// 90 /// If you would like the basic block to be auto-inserted into the end of a 91 /// function, you can specify it as the optional fourth parameter. 92 /// 93 /// If you would like to collect additional information about the cloned 94 /// function, you can specify a ClonedCodeInfo object with the optional fifth 95 /// parameter. 96 /// 97 BasicBlock *CloneBasicBlock(const BasicBlock *BB, 98 ValueToValueMapTy &VMap, 99 const Twine &NameSuffix = "", Function *F = 0, 100 ClonedCodeInfo *CodeInfo = 0); 101 102 /// CloneFunction - Return a copy of the specified function, but without 103 /// embedding the function into another module. Also, any references specified 104 /// in the VMap are changed to refer to their mapped value instead of the 105 /// original one. If any of the arguments to the function are in the VMap, 106 /// the arguments are deleted from the resultant function. The VMap is 107 /// updated to include mappings from all of the instructions and basicblocks in 108 /// the function from their old to new values. The final argument captures 109 /// information about the cloned code if non-null. 110 /// 111 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue 112 /// mappings. 113 /// 114 Function *CloneFunction(const Function *F, 115 ValueToValueMapTy &VMap, 116 bool ModuleLevelChanges, 117 ClonedCodeInfo *CodeInfo = 0); 118 119 /// CloneFunction - Version of the function that doesn't need the VMap. 120 /// 121 inline Function *CloneFunction(const Function *F, ClonedCodeInfo *CodeInfo = 0){ 122 ValueToValueMapTy VMap; 123 return CloneFunction(F, VMap, CodeInfo); 124 } 125 126 /// Clone OldFunc into NewFunc, transforming the old arguments into references 127 /// to VMap values. Note that if NewFunc already has basic blocks, the ones 128 /// cloned into it will be added to the end of the function. This function 129 /// fills in a list of return instructions, and can optionally remap types 130 /// and/or append the specified suffix to all values cloned. 131 /// 132 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue 133 /// mappings. 134 /// 135 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc, 136 ValueToValueMapTy &VMap, 137 bool ModuleLevelChanges, 138 SmallVectorImpl<ReturnInst*> &Returns, 139 const char *NameSuffix = "", 140 ClonedCodeInfo *CodeInfo = 0, 141 ValueMapTypeRemapper *TypeMapper = 0); 142 143 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto, 144 /// except that it does some simple constant prop and DCE on the fly. The 145 /// effect of this is to copy significantly less code in cases where (for 146 /// example) a function call with constant arguments is inlined, and those 147 /// constant arguments cause a significant amount of code in the callee to be 148 /// dead. Since this doesn't produce an exactly copy of the input, it can't be 149 /// used for things like CloneFunction or CloneModule. 150 /// 151 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue 152 /// mappings. 153 /// 154 void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, 155 ValueToValueMapTy &VMap, 156 bool ModuleLevelChanges, 157 SmallVectorImpl<ReturnInst*> &Returns, 158 const char *NameSuffix = "", 159 ClonedCodeInfo *CodeInfo = 0, 160 const TargetData *TD = 0, 161 Instruction *TheCall = 0); 162 163 164 /// InlineFunctionInfo - This class captures the data input to the 165 /// InlineFunction call, and records the auxiliary results produced by it. 166 class InlineFunctionInfo { 167 public: 168 explicit InlineFunctionInfo(CallGraph *cg = 0, const TargetData *td = 0) 169 : CG(cg), TD(td) {} 170 171 /// CG - If non-null, InlineFunction will update the callgraph to reflect the 172 /// changes it makes. 173 CallGraph *CG; 174 const TargetData *TD; 175 176 /// StaticAllocas - InlineFunction fills this in with all static allocas that 177 /// get copied into the caller. 178 SmallVector<AllocaInst*, 4> StaticAllocas; 179 180 /// InlinedCalls - InlineFunction fills this in with callsites that were 181 /// inlined from the callee. This is only filled in if CG is non-null. 182 SmallVector<WeakVH, 8> InlinedCalls; 183 184 void reset() { 185 StaticAllocas.clear(); 186 InlinedCalls.clear(); 187 } 188 }; 189 190 /// InlineFunction - This function inlines the called function into the basic 191 /// block of the caller. This returns false if it is not possible to inline 192 /// this call. The program is still in a well defined state if this occurs 193 /// though. 194 /// 195 /// Note that this only does one level of inlining. For example, if the 196 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now 197 /// exists in the instruction stream. Similarly this will inline a recursive 198 /// function by one level. 199 /// 200 bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI, bool InsertLifetime = true); 201 bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI, bool InsertLifetime = true); 202 bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI, bool InsertLifetime = true); 203 204 } // End llvm namespace 205 206 #endif 207
