LLVM  3.7.0
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"
23 #include "llvm/IR/ValueHandle.h"
24 #include "llvm/IR/ValueMap.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 DataLayout;
43 class Loop;
44 class LoopInfo;
45 class AllocaInst;
46 class AliasAnalysis;
47 class AssumptionCacheTracker;
48 class DominatorTree;
49 
50 /// CloneModule - Return an exact copy of the specified module
51 ///
52 Module *CloneModule(const Module *M);
53 Module *CloneModule(const Module *M, ValueToValueMapTy &VMap);
54 
55 /// ClonedCodeInfo - This struct can be used to capture information about code
56 /// being cloned, while it is being cloned.
58  /// ContainsCalls - This is set to true if the cloned code contains a normal
59  /// call instruction.
61 
62  /// ContainsDynamicAllocas - This is set to true if the cloned code contains
63  /// a 'dynamic' alloca. Dynamic allocas are allocas that are either not in
64  /// the entry block or they are in the entry block but are not a constant
65  /// size.
67 
69 };
70 
71 /// CloneBasicBlock - Return a copy of the specified basic block, but without
72 /// embedding the block into a particular function. The block returned is an
73 /// exact copy of the specified basic block, without any remapping having been
74 /// performed. Because of this, this is only suitable for applications where
75 /// the basic block will be inserted into the same function that it was cloned
76 /// from (loop unrolling would use this, for example).
77 ///
78 /// Also, note that this function makes a direct copy of the basic block, and
79 /// can thus produce illegal LLVM code. In particular, it will copy any PHI
80 /// nodes from the original block, even though there are no predecessors for the
81 /// newly cloned block (thus, phi nodes will have to be updated). Also, this
82 /// block will branch to the old successors of the original block: these
83 /// successors will have to have any PHI nodes updated to account for the new
84 /// incoming edges.
85 ///
86 /// The correlation between instructions in the source and result basic blocks
87 /// is recorded in the VMap map.
88 ///
89 /// If you have a particular suffix you'd like to use to add to any cloned
90 /// names, specify it as the optional third parameter.
91 ///
92 /// If you would like the basic block to be auto-inserted into the end of a
93 /// function, you can specify it as the optional fourth parameter.
94 ///
95 /// If you would like to collect additional information about the cloned
96 /// function, you can specify a ClonedCodeInfo object with the optional fifth
97 /// parameter.
98 ///
100  const Twine &NameSuffix = "", Function *F = nullptr,
101  ClonedCodeInfo *CodeInfo = nullptr);
102 
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.
111 ///
112 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
113 /// mappings, and debug info metadata will not be cloned.
114 ///
115 Function *CloneFunction(const Function *F, ValueToValueMapTy &VMap,
116  bool ModuleLevelChanges,
117  ClonedCodeInfo *CodeInfo = nullptr);
118 
119 /// Clone OldFunc into NewFunc, transforming the old arguments into references
120 /// to VMap values. Note that if NewFunc already has basic blocks, the ones
121 /// cloned into it will be added to the end of the function. This function
122 /// fills in a list of return instructions, and can optionally remap types
123 /// and/or append the specified suffix to all values cloned.
124 ///
125 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
126 /// mappings.
127 ///
128 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
129  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
130  SmallVectorImpl<ReturnInst*> &Returns,
131  const char *NameSuffix = "",
132  ClonedCodeInfo *CodeInfo = nullptr,
133  ValueMapTypeRemapper *TypeMapper = nullptr,
134  ValueMaterializer *Materializer = nullptr);
135 
136 /// A helper class used with CloneAndPruneIntoFromInst to change the default
137 /// behavior while instructions are being cloned.
139 public:
140  /// This enumeration describes the way CloneAndPruneIntoFromInst should
141  /// proceed after the CloningDirector has examined an instruction.
143  ///< Continue cloning the instruction (default behavior).
145  ///< Skip this instruction but continue cloning the current basic block.
147  ///< Skip this instruction and stop cloning the current basic block.
149  ///< Don't clone the terminator but clone the current block's successors.
151  };
152 
153  virtual ~CloningDirector() {}
154 
155  /// Subclasses must override this function to customize cloning behavior.
157  const Instruction *Inst,
158  BasicBlock *NewBB) = 0;
159 
160  virtual ValueMapTypeRemapper *getTypeRemapper() { return nullptr; }
161  virtual ValueMaterializer *getValueMaterializer() { return nullptr; }
162 };
163 
164 void CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc,
165  const Instruction *StartingInst,
166  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
167  SmallVectorImpl<ReturnInst*> &Returns,
168  const char *NameSuffix = "",
169  ClonedCodeInfo *CodeInfo = nullptr,
170  CloningDirector *Director = nullptr);
171 
172 
173 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,
174 /// except that it does some simple constant prop and DCE on the fly. The
175 /// effect of this is to copy significantly less code in cases where (for
176 /// example) a function call with constant arguments is inlined, and those
177 /// constant arguments cause a significant amount of code in the callee to be
178 /// dead. Since this doesn't produce an exactly copy of the input, it can't be
179 /// used for things like CloneFunction or CloneModule.
180 ///
181 /// If ModuleLevelChanges is false, VMap contains no non-identity GlobalValue
182 /// mappings.
183 ///
184 void CloneAndPruneFunctionInto(Function *NewFunc, const Function *OldFunc,
185  ValueToValueMapTy &VMap, bool ModuleLevelChanges,
186  SmallVectorImpl<ReturnInst*> &Returns,
187  const char *NameSuffix = "",
188  ClonedCodeInfo *CodeInfo = nullptr,
189  Instruction *TheCall = nullptr);
190 
191 /// InlineFunctionInfo - This class captures the data input to the
192 /// InlineFunction call, and records the auxiliary results produced by it.
194 public:
195  explicit InlineFunctionInfo(CallGraph *cg = nullptr,
196  AliasAnalysis *AA = nullptr,
197  AssumptionCacheTracker *ACT = nullptr)
198  : CG(cg), AA(AA), ACT(ACT) {}
199 
200  /// CG - If non-null, InlineFunction will update the callgraph to reflect the
201  /// changes it makes.
205 
206  /// StaticAllocas - InlineFunction fills this in with all static allocas that
207  /// get copied into the caller.
209 
210  /// InlinedCalls - InlineFunction fills this in with callsites that were
211  /// inlined from the callee. This is only filled in if CG is non-null.
213 
214  void reset() {
215  StaticAllocas.clear();
216  InlinedCalls.clear();
217  }
218 };
219 
220 /// InlineFunction - This function inlines the called function into the basic
221 /// block of the caller. This returns false if it is not possible to inline
222 /// this call. The program is still in a well defined state if this occurs
223 /// though.
224 ///
225 /// Note that this only does one level of inlining. For example, if the
226 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
227 /// exists in the instruction stream. Similarly this will inline a recursive
228 /// function by one level.
229 ///
230 bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI,
231  bool InsertLifetime = true);
232 bool InlineFunction(InvokeInst *II, InlineFunctionInfo &IFI,
233  bool InsertLifetime = true);
234 bool InlineFunction(CallSite CS, InlineFunctionInfo &IFI,
235  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 Loop *cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB,
243  Loop *OrigLoop, ValueToValueMapTy &VMap,
244  const Twine &NameSuffix, LoopInfo *LI,
245  DominatorTree *DT,
246  SmallVectorImpl<BasicBlock *> &Blocks);
247 
248 /// \brief Remaps instructions in \p Blocks using the mapping in \p VMap.
249 void remapInstructionsInBlocks(const SmallVectorImpl<BasicBlock *> &Blocks,
250  ValueToValueMapTy &VMap);
251 
252 } // End llvm namespace
253 
254 #endif
void CloneAndPruneIntoFromInst(Function *NewFunc, const Function *OldFunc, const Instruction *StartingInst, ValueToValueMapTy &VMap, bool ModuleLevelChanges, SmallVectorImpl< ReturnInst * > &Returns, const char *NameSuffix="", ClonedCodeInfo *CodeInfo=nullptr, CloningDirector *Director=nullptr)
This works like CloneAndPruneFunctionInto, except that it does not clone the entire function...
CallGraph * CG
CG - If non-null, InlineFunction will update the callgraph to reflect the changes it makes...
Definition: Cloning.h:202
Various leaf nodes.
Definition: ISDOpcodes.h:60
Module * CloneModule(const Module *M)
CloneModule - Return an exact copy of the specified module.
Definition: CloneModule.cpp:28
bool InlineFunction(CallInst *C, InlineFunctionInfo &IFI, bool InsertLifetime=true)
InlineFunction - This function inlines the called function into the basic block of the caller...
An immutable pass that tracks lazily created AssumptionCache objects.
F(f)
InlineFunctionInfo - This class captures the data input to the InlineFunction call, and records the auxiliary results produced by it.
Definition: Cloning.h:193
virtual ValueMaterializer * getValueMaterializer()
Definition: Cloning.h:161
void remapInstructionsInBlocks(const SmallVectorImpl< BasicBlock * > &Blocks, ValueToValueMapTy &VMap)
Remaps instructions in Blocks using the mapping in VMap.
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...
virtual CloningAction handleInstruction(ValueToValueMapTy &VMap, const Instruction *Inst, BasicBlock *NewBB)=0
Subclasses must override this function to customize cloning behavior.
#define false
Definition: ConvertUTF.c:65
virtual ValueMapTypeRemapper * getTypeRemapper()
Definition: Cloning.h:160
virtual ~CloningDirector()
Definition: Cloning.h:153
AliasAnalysis * AA
Definition: Cloning.h:203
A helper class used with CloneAndPruneIntoFromInst to change the default behavior while instructions ...
Definition: Cloning.h:138
ValueMaterializer - This is a class that can be implemented by clients to materialize Values on deman...
Definition: ValueMapper.h:39
LLVM Basic Block Representation.
Definition: BasicBlock.h:65
Continue cloning the instruction (default behavior).
Definition: Cloning.h:144
SmallVector< WeakVH, 8 > InlinedCalls
InlinedCalls - InlineFunction fills this in with callsites that were inlined from the callee...
Definition: Cloning.h:212
AssumptionCacheTracker * ACT
Definition: Cloning.h:204
ValueMap< const Value *, WeakVH > ValueToValueMapTy
Definition: ValueMapper.h:22
aarch64 type AArch64 Type Promotion Pass
InlineFunctionInfo(CallGraph *cg=nullptr, AliasAnalysis *AA=nullptr, AssumptionCacheTracker *ACT=nullptr)
Definition: Cloning.h:195
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:861
Skip this instruction and stop cloning the current basic block.
Definition: Cloning.h:146
Loop * cloneLoopWithPreheader(BasicBlock *Before, BasicBlock *LoopDomBB, Loop *OrigLoop, ValueToValueMapTy &VMap, const Twine &NameSuffix, LoopInfo *LI, DominatorTree *DT, SmallVectorImpl< BasicBlock * > &Blocks)
Clones a loop OrigLoop.
ValueMapTypeRemapper - This is a class that can be implemented by clients to remap types when cloning...
Definition: ValueMapper.h:27
Don't clone the terminator but clone the current block's successors.
Definition: Cloning.h:148
bool ContainsCalls
ContainsCalls - This is set to true if the cloned code contains a normal call instruction.
Definition: Cloning.h:60
SmallVector< AllocaInst *, 4 > StaticAllocas
StaticAllocas - InlineFunction fills this in with all static allocas that get copied into the caller...
Definition: Cloning.h:208
The basic data container for the call graph of a Module of IR.
Definition: CallGraph.h:75
ClonedCodeInfo - This struct can be used to capture information about code being cloned, while it is being cloned.
Definition: Cloning.h:57
CloningAction
This enumeration describes the way CloneAndPruneIntoFromInst should proceed after the CloningDirector...
Definition: Cloning.h:142
bool ContainsDynamicAllocas
ContainsDynamicAllocas - This is set to true if the cloned code contains a 'dynamic' alloca...
Definition: Cloning.h:66
Function * CloneFunction(const Function *F, ValueToValueMapTy &VMap, bool ModuleLevelChanges, ClonedCodeInfo *CodeInfo=nullptr)
CloneFunction - Return a copy of the specified function, but without embedding the function into anot...
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 ...