/Users/buildslave/jenkins/sharedspace/clang-stage2-coverage-R@2/llvm/include/llvm/Transforms/Utils/Cloning.h
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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/Analysis/AliasAnalysis.h" |
24 | | #include "llvm/Analysis/AssumptionCache.h" |
25 | | #include "llvm/IR/CallSite.h" |
26 | | #include "llvm/IR/ValueHandle.h" |
27 | | #include "llvm/Transforms/Utils/ValueMapper.h" |
28 | | #include <functional> |
29 | | #include <memory> |
30 | | #include <vector> |
31 | | |
32 | | namespace llvm { |
33 | | |
34 | | class AllocaInst; |
35 | | class BasicBlock; |
36 | | class BlockFrequencyInfo; |
37 | | class CallInst; |
38 | | class CallGraph; |
39 | | class DebugInfoFinder; |
40 | | class DominatorTree; |
41 | | class Function; |
42 | | class Instruction; |
43 | | class InvokeInst; |
44 | | class Loop; |
45 | | class LoopInfo; |
46 | | class Module; |
47 | | class ProfileSummaryInfo; |
48 | | class ReturnInst; |
49 | | |
50 | | /// Return an exact copy of the specified module |
51 | | /// |
52 | | std::unique_ptr<Module> CloneModule(const Module *M); |
53 | | std::unique_ptr<Module> CloneModule(const Module *M, ValueToValueMapTy &VMap); |
54 | | |
55 | | /// Return a copy of the specified module. The ShouldCloneDefinition function |
56 | | /// controls whether a specific GlobalValue's definition is cloned. If the |
57 | | /// function returns false, the module copy will contain an external reference |
58 | | /// in place of the global definition. |
59 | | std::unique_ptr<Module> |
60 | | CloneModule(const Module *M, ValueToValueMapTy &VMap, |
61 | | function_ref<bool(const GlobalValue *)> ShouldCloneDefinition); |
62 | | |
63 | | /// ClonedCodeInfo - This struct can be used to capture information about code |
64 | | /// being cloned, while it is being cloned. |
65 | | struct ClonedCodeInfo { |
66 | | /// ContainsCalls - This is set to true if the cloned code contains a normal |
67 | | /// call instruction. |
68 | | bool ContainsCalls = false; |
69 | | |
70 | | /// ContainsDynamicAllocas - This is set to true if the cloned code contains |
71 | | /// a 'dynamic' alloca. Dynamic allocas are allocas that are either not in |
72 | | /// the entry block or they are in the entry block but are not a constant |
73 | | /// size. |
74 | | bool ContainsDynamicAllocas = false; |
75 | | |
76 | | /// All cloned call sites that have operand bundles attached are appended to |
77 | | /// this vector. This vector may contain nulls or undefs if some of the |
78 | | /// originally inserted callsites were DCE'ed after they were cloned. |
79 | | std::vector<WeakTrackingVH> OperandBundleCallSites; |
80 | | |
81 | 251k | ClonedCodeInfo() = default; |
82 | | }; |
83 | | |
84 | | /// CloneBasicBlock - Return a copy of the specified basic block, but without |
85 | | /// embedding the block into a particular function. The block returned is an |
86 | | /// exact copy of the specified basic block, without any remapping having been |
87 | | /// performed. Because of this, this is only suitable for applications where |
88 | | /// the basic block will be inserted into the same function that it was cloned |
89 | | /// from (loop unrolling would use this, for example). |
90 | | /// |
91 | | /// Also, note that this function makes a direct copy of the basic block, and |
92 | | /// can thus produce illegal LLVM code. In particular, it will copy any PHI |
93 | | /// nodes from the original block, even though there are no predecessors for the |
94 | | /// newly cloned block (thus, phi nodes will have to be updated). Also, this |
95 | | /// block will branch to the old successors of the original block: these |
96 | | /// successors will have to have any PHI nodes updated to account for the new |
97 | | /// incoming edges. |
98 | | /// |
99 | | /// The correlation between instructions in the source and result basic blocks |
100 | | /// is recorded in the VMap map. |
101 | | /// |
102 | | /// If you have a particular suffix you'd like to use to add to any cloned |
103 | | /// names, specify it as the optional third parameter. |
104 | | /// |
105 | | /// If you would like the basic block to be auto-inserted into the end of a |
106 | | /// function, you can specify it as the optional fourth parameter. |
107 | | /// |
108 | | /// If you would like to collect additional information about the cloned |
109 | | /// function, you can specify a ClonedCodeInfo object with the optional fifth |
110 | | /// parameter. |
111 | | /// |
112 | | BasicBlock *CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap, |
113 | | const Twine &NameSuffix = "", Function *F = nullptr, |
114 | | ClonedCodeInfo *CodeInfo = nullptr, |
115 | | DebugInfoFinder *DIFinder = nullptr); |
116 | | |
117 | | /// CloneFunction - Return a copy of the specified function and add it to that |
118 | | /// function's module. Also, any references specified in the VMap are changed |
119 | | /// to refer to their mapped value instead of the original one. If any of the |
120 | | /// arguments to the function are in the VMap, the arguments are deleted from |
121 | | /// the resultant function. The VMap is updated to include mappings from all of |
122 | | /// the instructions and basicblocks in the function from their old to new |
123 | | /// values. The final argument captures information about the cloned code if |
124 | | /// non-null. |
125 | | /// |
126 | | /// VMap contains no non-identity GlobalValue mappings and debug info metadata |
127 | | /// will not be cloned. |
128 | | /// |
129 | | Function *CloneFunction(Function *F, ValueToValueMapTy &VMap, |
130 | | ClonedCodeInfo *CodeInfo = nullptr); |
131 | | |
132 | | /// Clone OldFunc into NewFunc, transforming the old arguments into references |
133 | | /// to VMap values. Note that if NewFunc already has basic blocks, the ones |
134 | | /// cloned into it will be added to the end of the function. This function |
135 | | /// fills in a list of return instructions, and can optionally remap types |
136 | | /// and/or append the specified suffix to all values cloned. |
137 | | /// |
138 | | /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue |
139 | | /// mappings. |
140 | | /// |
141 | | void CloneFunctionInto(Function *NewFunc, const Function *OldFunc, |
142 | | ValueToValueMapTy &VMap, bool ModuleLevelChanges, |
143 | | SmallVectorImpl<ReturnInst*> &Returns, |
144 | | const char *NameSuffix = "", |
145 | | ClonedCodeInfo *CodeInfo = nullptr, |
146 | | ValueMapTypeRemapper *TypeMapper = nullptr, |
147 | | ValueMaterializer *Materializer = nullptr); |
148 | | |
149 | | void CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc, |
150 | | const Instruction *StartingInst, |
151 | | ValueToValueMapTy &VMap, bool ModuleLevelChanges, |
152 | | SmallVectorImpl<ReturnInst *> &Returns, |
153 | | const char *NameSuffix = "", |
154 | | ClonedCodeInfo *CodeInfo = nullptr); |
155 | | |
156 | | /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto, |
157 | | /// except that it does some simple constant prop and DCE on the fly. The |
158 | | /// effect of this is to copy significantly less code in cases where (for |
159 | | /// example) a function call with constant arguments is inlined, and those |
160 | | /// constant arguments cause a significant amount of code in the callee to be |
161 | | /// dead. Since this doesn't produce an exactly copy of the input, it can't be |
162 | | /// used for things like CloneFunction or CloneModule. |
163 | | /// |
164 | | /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue |
165 | | /// mappings. |
166 | | /// |
167 | | void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, |
168 | | ValueToValueMapTy &VMap, bool ModuleLevelChanges, |
169 | | SmallVectorImpl<ReturnInst*> &Returns, |
170 | | const char *NameSuffix = "", |
171 | | ClonedCodeInfo *CodeInfo = nullptr, |
172 | | Instruction *TheCall = nullptr); |
173 | | |
174 | | /// InlineFunctionInfo - This class captures the data input to the |
175 | | /// InlineFunction call, and records the auxiliary results produced by it. |
176 | | class InlineFunctionInfo { |
177 | | public: |
178 | | explicit InlineFunctionInfo(CallGraph *cg = nullptr, |
179 | | std::function<AssumptionCache &(Function &)> |
180 | | *GetAssumptionCache = nullptr, |
181 | | ProfileSummaryInfo *PSI = nullptr, |
182 | | BlockFrequencyInfo *CallerBFI = nullptr, |
183 | | BlockFrequencyInfo *CalleeBFI = nullptr) |
184 | | : CG(cg), GetAssumptionCache(GetAssumptionCache), PSI(PSI), |
185 | 344k | CallerBFI(CallerBFI), CalleeBFI(CalleeBFI) {} |
186 | | |
187 | | /// CG - If non-null, InlineFunction will update the callgraph to reflect the |
188 | | /// changes it makes. |
189 | | CallGraph *CG; |
190 | | std::function<AssumptionCache &(Function &)> *GetAssumptionCache; |
191 | | ProfileSummaryInfo *PSI; |
192 | | BlockFrequencyInfo *CallerBFI, *CalleeBFI; |
193 | | |
194 | | /// StaticAllocas - InlineFunction fills this in with all static allocas that |
195 | | /// get copied into the caller. |
196 | | SmallVector<AllocaInst *, 4> StaticAllocas; |
197 | | |
198 | | /// InlinedCalls - InlineFunction fills this in with callsites that were |
199 | | /// inlined from the callee. This is only filled in if CG is non-null. |
200 | | SmallVector<WeakTrackingVH, 8> InlinedCalls; |
201 | | |
202 | | /// All of the new call sites inlined into the caller. |
203 | | /// |
204 | | /// 'InlineFunction' fills this in by scanning the inlined instructions, and |
205 | | /// only if CG is null. If CG is non-null, instead the value handle |
206 | | /// `InlinedCalls` above is used. |
207 | | SmallVector<CallSite, 8> InlinedCallSites; |
208 | | |
209 | 255k | void reset() { |
210 | 255k | StaticAllocas.clear(); |
211 | 255k | InlinedCalls.clear(); |
212 | 255k | InlinedCallSites.clear(); |
213 | 255k | } |
214 | | }; |
215 | | |
216 | | /// InlineFunction - This function inlines the called function into the basic |
217 | | /// block of the caller. This returns false if it is not possible to inline |
218 | | /// this call. The program is still in a well defined state if this occurs |
219 | | /// though. |
220 | | /// |
221 | | /// Note that this only does one level of inlining. For example, if the |
222 | | /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now |
223 | | /// exists in the instruction stream. Similarly this will inline a recursive |
224 | | /// function by one level. |
225 | | /// |
226 | | /// Note that while this routine is allowed to cleanup and optimize the |
227 | | /// *inlined* code to minimize the actual inserted code, it must not delete |
228 | | /// code in the caller as users of this routine may have pointers to |
229 | | /// instructions in the caller that need to remain stable. |
230 | | bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI, |
231 | | AAResults *CalleeAAR = nullptr, bool InsertLifetime = true); |
232 | | bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI, |
233 | | AAResults *CalleeAAR = nullptr, bool InsertLifetime = true); |
234 | | bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI, |
235 | | AAResults *CalleeAAR = nullptr, bool InsertLifetime = true); |
236 | | |
237 | | /// \brief Clones a loop \p OrigLoop. Returns the loop and the blocks in \p |
238 | | /// Blocks. |
239 | | /// |
240 | | /// Updates LoopInfo and DominatorTree assuming the loop is dominated by block |
241 | | /// \p LoopDomBB. Insert the new blocks before block specified in \p Before. |
242 | | /// Note: Only innermost loops are supported. |
243 | | Loop *cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB, |
244 | | Loop *OrigLoop, ValueToValueMapTy &VMap, |
245 | | const Twine &NameSuffix, LoopInfo *LI, |
246 | | DominatorTree *DT, |
247 | | SmallVectorImpl<BasicBlock *> &Blocks); |
248 | | |
249 | | /// \brief Remaps instructions in \p Blocks using the mapping in \p VMap. |
250 | | void remapInstructionsInBlocks(const SmallVectorImpl<BasicBlock *> &Blocks, |
251 | | ValueToValueMapTy &VMap); |
252 | | |
253 | | /// Split edge between BB and PredBB and duplicate all non-Phi instructions |
254 | | /// from BB between its beginning and the StopAt instruction into the split |
255 | | /// block. Phi nodes are not duplicated, but their uses are handled correctly: |
256 | | /// we replace them with the uses of corresponding Phi inputs. ValueMapping |
257 | | /// is used to map the original instructions from BB to their newly-created |
258 | | /// copies. Returns the split block. |
259 | | BasicBlock * |
260 | | DuplicateInstructionsInSplitBetween(BasicBlock *BB, BasicBlock *PredBB, |
261 | | Instruction *StopAt, |
262 | | ValueToValueMapTy &ValueMapping); |
263 | | } // end namespace llvm |
264 | | |
265 | | #endif // LLVM_TRANSFORMS_UTILS_CLONING_H |