Cloning.h revision 34695381d626485a560594f162701088079589df 
1//===- Cloning.h - Clone various parts of LLVM programs ---------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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 <vector>
22#include <map>
23
24namespace llvm {
25
26class Module;
27class Function;
28class BasicBlock;
29class Value;
30class CallInst;
31class InvokeInst;
32class ReturnInst;
33class CallSite;
34class Trace;
35
36/// CloneModule - Return an exact copy of the specified module
37///
38Module *CloneModule(const Module *M);
39
40/// CloneBasicBlock - Return a copy of the specified basic block, but without
41/// embedding the block into a particular function.  The block returned is an
42/// exact copy of the specified basic block, without any remapping having been
43/// performed.  Because of this, this is only suitable for applications where
44/// the basic block will be inserted into the same function that it was cloned
45/// from (loop unrolling would use this, for example).
46///
47/// Also, note that this function makes a direct copy of the basic block, and
48/// can thus produce illegal LLVM code.  In particular, it will copy any PHI
49/// nodes from the original block, even though there are no predecessors for the
50/// newly cloned block (thus, phi nodes will have to be updated).  Also, this
51/// block will branch to the old successors of the original block: these
52/// successors will have to have any PHI nodes updated to account for the new
53/// incoming edges.
54///
55/// The correlation between instructions in the source and result basic blocks
56/// is recorded in the ValueMap map.
57///
58/// If you have a particular suffix you'd like to use to add to any cloned
59/// names, specify it as the optional third parameter.
60///
61/// If you would like the basic block to be auto-inserted into the end of a
62/// function, you can specify it as the optional fourth parameter.
63///
64BasicBlock *CloneBasicBlock(const BasicBlock *BB,
65                            std::map<const Value*, Value*> &ValueMap,
66                            const char *NameSuffix = "", Function *F = 0);
67
68
69/// CloneFunction - Return a copy of the specified function, but without
70/// embedding the function into another module.  Also, any references specified
71/// in the ValueMap are changed to refer to their mapped value instead of the
72/// original one.  If any of the arguments to the function are in the ValueMap,
73/// the arguments are deleted from the resultant function.  The ValueMap is
74/// updated to include mappings from all of the instructions and basicblocks in
75/// the function from their old to new values.
76///
77Function *CloneFunction(const Function *F,
78                        std::map<const Value*, Value*> &ValueMap);
79
80/// CloneFunction - Version of the function that doesn't need the ValueMap.
81///
82inline Function *CloneFunction(const Function *F) {
83  std::map<const Value*, Value*> ValueMap;
84  return CloneFunction(F, ValueMap);
85}
86
87/// Clone OldFunc into NewFunc, transforming the old arguments into references
88/// to ArgMap values.  Note that if NewFunc already has basic blocks, the ones
89/// cloned into it will be added to the end of the function.  This function
90/// fills in a list of return instructions, and can optionally append the
91/// specified suffix to all values cloned.
92///
93void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
94                       std::map<const Value*, Value*> &ValueMap,
95                       std::vector<ReturnInst*> &Returns,
96                       const char *NameSuffix = "");
97
98
99/// CloneTraceInto - Clone T into NewFunc. Original<->clone mapping is
100/// saved in ValueMap.
101///
102void CloneTraceInto(Function *NewFunc, Trace &T,
103                    std::map<const Value*, Value*> &ValueMap,
104                    const char *NameSuffix);
105
106/// InlineFunction - This function inlines the called function into the basic
107/// block of the caller.  This returns false if it is not possible to inline
108/// this call.  The program is still in a well defined state if this occurs
109/// though.
110///
111/// Note that this only does one level of inlining.  For example, if the
112/// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
113/// exists in the instruction stream.  Similiarly this will inline a recursive
114/// function by one level.
115///
116bool InlineFunction(CallInst *C);
117bool InlineFunction(InvokeInst *II);
118bool InlineFunction(CallSite CS);
119
120/// CloneTrace - Returns a copy of the specified trace.
121/// It takes a vector of basic blocks clones the basic blocks, removes internal
122/// phi nodes, adds it to the same function as the original (although there is
123/// no jump to it) and returns the new vector of basic blocks.
124std::vector<BasicBlock *> CloneTrace(const std::vector<BasicBlock*> &origTrace);
125
126} // End llvm namespace
127
128#endif
129