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