LLVM  4.0.0
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"
25 #include "llvm/IR/ValueHandle.h"
26 #include "llvm/IR/ValueMap.h"
28 #include <functional>
29 
30 namespace llvm {
31 
32 class Module;
33 class Function;
34 class Instruction;
35 class Pass;
36 class LPPassManager;
37 class BasicBlock;
38 class Value;
39 class CallInst;
40 class InvokeInst;
41 class ReturnInst;
42 class CallSite;
43 class Trace;
44 class CallGraph;
45 class DataLayout;
46 class Loop;
47 class LoopInfo;
48 class AllocaInst;
49 class AssumptionCacheTracker;
50 class DominatorTree;
51 
52 /// Return an exact copy of the specified module
53 ///
54 std::unique_ptr<Module> CloneModule(const Module *M);
55 std::unique_ptr<Module> CloneModule(const Module *M, ValueToValueMapTy &VMap);
56 
57 /// Return a copy of the specified module. The ShouldCloneDefinition function
58 /// controls whether a specific GlobalValue's definition is cloned. If the
59 /// function returns false, the module copy will contain an external reference
60 /// in place of the global definition.
61 std::unique_ptr<Module>
62 CloneModule(const Module *M, ValueToValueMapTy &VMap,
63  function_ref<bool(const GlobalValue *)> ShouldCloneDefinition);
64 
65 /// ClonedCodeInfo - This struct can be used to capture information about code
66 /// being cloned, while it is being cloned.
68  /// ContainsCalls - This is set to true if the cloned code contains a normal
69  /// call instruction.
71 
72  /// ContainsDynamicAllocas - This is set to true if the cloned code contains
73  /// a 'dynamic' alloca. Dynamic allocas are allocas that are either not in
74  /// the entry block or they are in the entry block but are not a constant
75  /// size.
77 
78  /// All cloned call sites that have operand bundles attached are appended to
79  /// this vector. This vector may contain nulls or undefs if some of the
80  /// originally inserted callsites were DCE'ed after they were cloned.
81  std::vector<WeakVH> OperandBundleCallSites;
82 
84 };
85 
86 /// CloneBasicBlock - Return a copy of the specified basic block, but without
87 /// embedding the block into a particular function. The block returned is an
88 /// exact copy of the specified basic block, without any remapping having been
89 /// performed. Because of this, this is only suitable for applications where
90 /// the basic block will be inserted into the same function that it was cloned
91 /// from (loop unrolling would use this, for example).
92 ///
93 /// Also, note that this function makes a direct copy of the basic block, and
94 /// can thus produce illegal LLVM code. In particular, it will copy any PHI
95 /// nodes from the original block, even though there are no predecessors for the
96 /// newly cloned block (thus, phi nodes will have to be updated). Also, this
97 /// block will branch to the old successors of the original block: these
98 /// successors will have to have any PHI nodes updated to account for the new
99 /// incoming edges.
100 ///
101 /// The correlation between instructions in the source and result basic blocks
102 /// is recorded in the VMap map.
103 ///
104 /// If you have a particular suffix you'd like to use to add to any cloned
105 /// names, specify it as the optional third parameter.
106 ///
107 /// If you would like the basic block to be auto-inserted into the end of a
108 /// function, you can specify it as the optional fourth parameter.
109 ///
110 /// If you would like to collect additional information about the cloned
111 /// function, you can specify a ClonedCodeInfo object with the optional fifth
112 /// parameter.
113 ///
115  const Twine &NameSuffix = "", Function *F = nullptr,
116  ClonedCodeInfo *CodeInfo = nullptr);
117 
118 /// CloneFunction - Return a copy of the specified function and add it to that
119 /// function's module. Also, any references specified in the VMap are changed
120 /// to refer to their mapped value instead of the original one. If any of the
121 /// arguments to the function are in the VMap, the arguments are deleted from
122 /// the resultant function. The VMap is updated to include mappings from all of
123 /// the instructions and basicblocks in the function from their old to new
124 /// values. The final argument captures information about the cloned code if
125 /// non-null.
126 ///
127 /// VMap contains no non-identity GlobalValue mappings and debug info metadata
128 /// will not be cloned.
129 ///
130 Function *CloneFunction(Function *F, ValueToValueMapTy &VMap,
131  ClonedCodeInfo *CodeInfo = nullptr);
132 
133 /// Clone OldFunc into NewFunc, transforming the old arguments into references
134 /// to VMap values. Note that if NewFunc already has basic blocks, the ones
135 /// cloned into it will be added to the end of the function. This function
136 /// fills in a list of return instructions, and can optionally remap types
137 /// and/or append the specified suffix to all values cloned.
138 ///
139 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
140 /// mappings.
141 ///
142 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
143  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
144  SmallVectorImpl<ReturnInst*> &Returns,
145  const char *NameSuffix = "",
146  ClonedCodeInfo *CodeInfo = nullptr,
147  ValueMapTypeRemapper *TypeMapper = nullptr,
148  ValueMaterializer *Materializer = nullptr);
149 
150 void CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
151  const Instruction *StartingInst,
152  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
153  SmallVectorImpl<ReturnInst *> &Returns,
154  const char *NameSuffix = "",
155  ClonedCodeInfo *CodeInfo = nullptr);
156 
157 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
158 /// except that it does some simple constant prop and DCE on the fly. The
159 /// effect of this is to copy significantly less code in cases where (for
160 /// example) a function call with constant arguments is inlined, and those
161 /// constant arguments cause a significant amount of code in the callee to be
162 /// dead. Since this doesn't produce an exactly copy of the input, it can't be
163 /// used for things like CloneFunction or CloneModule.
164 ///
165 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
166 /// mappings.
167 ///
168 void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
169  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
170  SmallVectorImpl<ReturnInst*> &Returns,
171  const char *NameSuffix = "",
172  ClonedCodeInfo *CodeInfo = nullptr,
173  Instruction *TheCall = nullptr);
174 
175 /// InlineFunctionInfo - This class captures the data input to the
176 /// InlineFunction call, and records the auxiliary results produced by it.
178 public:
179  explicit InlineFunctionInfo(CallGraph *cg = nullptr,
181  *GetAssumptionCache = nullptr)
183 
184  /// CG - If non-null, InlineFunction will update the callgraph to reflect the
185  /// changes it makes.
187  std::function<AssumptionCache &(Function &)> *GetAssumptionCache;
188 
189  /// StaticAllocas - InlineFunction fills this in with all static allocas that
190  /// get copied into the caller.
192 
193  /// InlinedCalls - InlineFunction fills this in with callsites that were
194  /// inlined from the callee. This is only filled in if CG is non-null.
196 
197  /// All of the new call sites inlined into the caller.
198  ///
199  /// 'InlineFunction' fills this in by scanning the inlined instructions, and
200  /// only if CG is null. If CG is non-null, instead the value handle
201  /// `InlinedCalls` above is used.
203 
204  void reset() {
205  StaticAllocas.clear();
206  InlinedCalls.clear();
207  InlinedCallSites.clear();
208  }
209 };
210 
211 /// InlineFunction - This function inlines the called function into the basic
212 /// block of the caller. This returns false if it is not possible to inline
213 /// this call. The program is still in a well defined state if this occurs
214 /// though.
215 ///
216 /// Note that this only does one level of inlining. For example, if the
217 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
218 /// exists in the instruction stream. Similarly this will inline a recursive
219 /// function by one level.
220 ///
221 /// Note that while this routine is allowed to cleanup and optimize the
222 /// *inlined* code to minimize the actual inserted code, it must not delete
223 /// code in the caller as users of this routine may have pointers to
224 /// instructions in the caller that need to remain stable.
225 bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI,
226  AAResults *CalleeAAR = nullptr, bool InsertLifetime = true);
227 bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
228  AAResults *CalleeAAR = nullptr, bool InsertLifetime = true);
229 bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
230  AAResults *CalleeAAR = nullptr, bool InsertLifetime = true);
231 
232 /// \brief Clones a loop \p OrigLoop. Returns the loop and the blocks in \p
233 /// Blocks.
234 ///
235 /// Updates LoopInfo and DominatorTree assuming the loop is dominated by block
236 /// \p LoopDomBB. Insert the new blocks before block specified in \p Before.
237 /// Note: Only innermost loops are supported.
238 Loop *cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
239  Loop *OrigLoop, ValueToValueMapTy &VMap,
240  const Twine &NameSuffix, LoopInfo *LI,
241  DominatorTree *DT,
242  SmallVectorImpl<BasicBlock *> &Blocks);
243 
244 /// \brief Remaps instructions in \p Blocks using the mapping in \p VMap.
245 void remapInstructionsInBlocks(const SmallVectorImpl<BasicBlock *> &Blocks,
246  ValueToValueMapTy &VMap);
247 
248 } // End llvm namespace
249 
250 #endif
CallGraph * CG
CG - If non-null, InlineFunction will update the callgraph to reflect the changes it makes...
Definition: Cloning.h:186
Various leaf nodes.
Definition: ISDOpcodes.h:60
aarch64 AArch64 CCMP Pass
std::function< AssumptionCache &(Function &)> * GetAssumptionCache
Definition: Cloning.h:187
Function * CloneFunction(Function *F, ValueToValueMapTy &VMap, ClonedCodeInfo *CodeInfo=nullptr)
CloneFunction - Return a copy of the specified function and add it to that function's module...
A cache of .assume calls within a function.
std::vector< WeakVH > OperandBundleCallSites
All cloned call sites that have operand bundles attached are appended to this vector.
Definition: Cloning.h:81
InlineFunctionInfo - This class captures the data input to the InlineFunction call, and records the auxiliary results produced by it.
Definition: Cloning.h:177
void remapInstructionsInBlocks(const SmallVectorImpl< BasicBlock * > &Blocks, ValueToValueMapTy &VMap)
Remaps instructions in Blocks using the mapping in VMap.
bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI, AAResults *CalleeAAR=nullptr, bool InsertLifetime=true)
InlineFunction - This function inlines the called function into the basic block of the caller...
void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc, ValueToValueMapTy &VMap, bool ModuleLevelChanges, SmallVectorImpl< ReturnInst * > &Returns, const char *NameSuffix="", ClonedCodeInfo *CodeInfo=nullptr, Instruction *TheCall=nullptr)
CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto, except that it does some simpl...
void CloneFunctionInto(Function *NewFunc, const Function *OldFunc, ValueToValueMapTy &VMap, bool ModuleLevelChanges, SmallVectorImpl< ReturnInst * > &Returns, const char *NameSuffix="", ClonedCodeInfo *CodeInfo=nullptr, ValueMapTypeRemapper *TypeMapper=nullptr, ValueMaterializer *Materializer=nullptr)
Clone OldFunc into NewFunc, transforming the old arguments into references to VMap values...
void CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc, const Instruction *StartingInst, ValueToValueMapTy &VMap, bool ModuleLevelChanges, SmallVectorImpl< ReturnInst * > &Returns, const char *NameSuffix="", ClonedCodeInfo *CodeInfo=nullptr)
This works like CloneAndPruneFunctionInto, except that it does not clone the entire function...
#define F(x, y, z)
Definition: MD5.cpp:51
Function Alias Analysis false
SmallVector< CallSite, 8 > InlinedCallSites
All of the new call sites inlined into the caller.
Definition: Cloning.h:202
SmallVector< WeakVH, 8 > InlinedCalls
InlinedCalls - InlineFunction fills this in with callsites that were inlined from the callee...
Definition: Cloning.h:195
ValueMap< const Value *, WeakVH > ValueToValueMapTy
Definition: ValueMapper.h:23
std::unique_ptr< Module > CloneModule(const Module *M)
Return an exact copy of the specified module.
Definition: CloneModule.cpp:27
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:843
static GCRegistry::Add< ShadowStackGC > C("shadow-stack","Very portable GC for uncooperative code generators")
Loop * cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB, Loop *OrigLoop, ValueToValueMapTy &VMap, const Twine &NameSuffix, LoopInfo *LI, DominatorTree *DT, SmallVectorImpl< BasicBlock * > &Blocks)
Clones a loop OrigLoop.
bool ContainsCalls
ContainsCalls - This is set to true if the cloned code contains a normal call instruction.
Definition: Cloning.h:70
SmallVector< AllocaInst *, 4 > StaticAllocas
StaticAllocas - InlineFunction fills this in with all static allocas that get copied into the caller...
Definition: Cloning.h:191
The basic data container for the call graph of a Module of IR.
Definition: CallGraph.h:76
ClonedCodeInfo - This struct can be used to capture information about code being cloned, while it is being cloned.
Definition: Cloning.h:67
bool ContainsDynamicAllocas
ContainsDynamicAllocas - This is set to true if the cloned code contains a 'dynamic' alloca...
Definition: Cloning.h:76
InlineFunctionInfo(CallGraph *cg=nullptr, std::function< AssumptionCache &(Function &)> *GetAssumptionCache=nullptr)
Definition: Cloning.h:179
print Print MemDeps of function
BasicBlock * CloneBasicBlock(const BasicBlock *BB, ValueToValueMapTy &VMap, const Twine &NameSuffix="", Function *F=nullptr, ClonedCodeInfo *CodeInfo=nullptr)
CloneBasicBlock - Return a copy of the specified basic block, but without embedding the block into a ...