1 //===- Cloning.h - Clone various parts of LLVM programs ---------*- C++ -*-===//
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 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
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_TRANSFORMS_UTILS_CLONING_H
19 #define LLVM_TRANSFORMS_UTILS_CLONING_H
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"
47 class AssumptionCacheTracker;
49 /// CloneModule - Return an exact copy of the specified module
51 Module *CloneModule(const Module *M);
52 Module *CloneModule(const Module *M, ValueToValueMapTy &VMap);
54 /// ClonedCodeInfo - This struct can be used to capture information about code
55 /// being cloned, while it is being cloned.
56 struct ClonedCodeInfo {
57 /// ContainsCalls - This is set to true if the cloned code contains a normal
61 /// ContainsDynamicAllocas - This is set to true if the cloned code contains
62 /// a 'dynamic' alloca. Dynamic allocas are allocas that are either not in
63 /// the entry block or they are in the entry block but are not a constant
65 bool ContainsDynamicAllocas;
67 ClonedCodeInfo() : ContainsCalls(false), ContainsDynamicAllocas(false) {}
70 /// CloneBasicBlock - Return a copy of the specified basic block, but without
71 /// embedding the block into a particular function. The block returned is an
72 /// exact copy of the specified basic block, without any remapping having been
73 /// performed. Because of this, this is only suitable for applications where
74 /// the basic block will be inserted into the same function that it was cloned
75 /// from (loop unrolling would use this, for example).
77 /// Also, note that this function makes a direct copy of the basic block, and
78 /// can thus produce illegal LLVM code. In particular, it will copy any PHI
79 /// nodes from the original block, even though there are no predecessors for the
80 /// newly cloned block (thus, phi nodes will have to be updated). Also, this
81 /// block will branch to the old successors of the original block: these
82 /// successors will have to have any PHI nodes updated to account for the new
85 /// The correlation between instructions in the source and result basic blocks
86 /// is recorded in the VMap map.
88 /// If you have a particular suffix you'd like to use to add to any cloned
89 /// names, specify it as the optional third parameter.
91 /// If you would like the basic block to be auto-inserted into the end of a
92 /// function, you can specify it as the optional fourth parameter.
94 /// If you would like to collect additional information about the cloned
95 /// function, you can specify a ClonedCodeInfo object with the optional fifth
98 BasicBlock *CloneBasicBlock(const BasicBlock *BB,
99 ValueToValueMapTy &VMap,
100 const Twine &NameSuffix = "", Function *F = nullptr,
101 ClonedCodeInfo *CodeInfo = nullptr);
103 /// CloneFunction - Return a copy of the specified function, but without
104 /// embedding the function into another module. Also, any references specified
105 /// in the VMap are changed to refer to their mapped value instead of the
106 /// original one. If any of the arguments to the function are in the VMap,
107 /// the arguments are deleted from the resultant function. The VMap is
108 /// updated to include mappings from all of the instructions and basicblocks in
109 /// the function from their old to new values. The final argument captures
110 /// information about the cloned code if non-null.
112 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
113 /// mappings, and debug info metadata will not be cloned.
115 Function *CloneFunction(const Function *F,
116 ValueToValueMapTy &VMap,
117 bool ModuleLevelChanges,
118 ClonedCodeInfo *CodeInfo = nullptr);
120 /// Clone OldFunc into NewFunc, transforming the old arguments into references
121 /// to VMap values. Note that if NewFunc already has basic blocks, the ones
122 /// cloned into it will be added to the end of the function. This function
123 /// fills in a list of return instructions, and can optionally remap types
124 /// and/or append the specified suffix to all values cloned.
126 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
129 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
130 ValueToValueMapTy &VMap,
131 bool ModuleLevelChanges,
132 SmallVectorImpl<ReturnInst*> &Returns,
133 const char *NameSuffix = "",
134 ClonedCodeInfo *CodeInfo = nullptr,
135 ValueMapTypeRemapper *TypeMapper = nullptr,
136 ValueMaterializer *Materializer = nullptr);
138 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
139 /// except that it does some simple constant prop and DCE on the fly. The
140 /// effect of this is to copy significantly less code in cases where (for
141 /// example) a function call with constant arguments is inlined, and those
142 /// constant arguments cause a significant amount of code in the callee to be
143 /// dead. Since this doesn't produce an exactly copy of the input, it can't be
144 /// used for things like CloneFunction or CloneModule.
146 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
149 void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
150 ValueToValueMapTy &VMap,
151 bool ModuleLevelChanges,
152 SmallVectorImpl<ReturnInst*> &Returns,
153 const char *NameSuffix = "",
154 ClonedCodeInfo *CodeInfo = nullptr,
155 const DataLayout *DL = nullptr,
156 Instruction *TheCall = nullptr);
158 /// InlineFunctionInfo - This class captures the data input to the
159 /// InlineFunction call, and records the auxiliary results produced by it.
160 class InlineFunctionInfo {
162 explicit InlineFunctionInfo(CallGraph *cg = nullptr,
163 const DataLayout *DL = nullptr,
164 AliasAnalysis *AA = nullptr,
165 AssumptionCacheTracker *ACT = nullptr)
166 : CG(cg), DL(DL), AA(AA), ACT(ACT) {}
168 /// CG - If non-null, InlineFunction will update the callgraph to reflect the
169 /// changes it makes.
171 const DataLayout *DL;
173 AssumptionCacheTracker *ACT;
175 /// StaticAllocas - InlineFunction fills this in with all static allocas that
176 /// get copied into the caller.
177 SmallVector<AllocaInst*, 4> StaticAllocas;
179 /// InlinedCalls - InlineFunction fills this in with callsites that were
180 /// inlined from the callee. This is only filled in if CG is non-null.
181 SmallVector<WeakVH, 8> InlinedCalls;
184 StaticAllocas.clear();
185 InlinedCalls.clear();
189 /// InlineFunction - This function inlines the called function into the basic
190 /// block of the caller. This returns false if it is not possible to inline
191 /// this call. The program is still in a well defined state if this occurs
194 /// Note that this only does one level of inlining. For example, if the
195 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
196 /// exists in the instruction stream. Similarly this will inline a recursive
197 /// function by one level.
199 bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI, bool InsertLifetime = true);
200 bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI, bool InsertLifetime = true);
201 bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI, bool InsertLifetime = true);
203 } // End llvm namespace