Cloning.h revision a04e51f4c0dd981af9b8f6e8b219df495cccaa45 
1//===- Cloning.h - Clone various parts of LLVM programs ---------*- C++ -*-===//
2//
3// This file defines various functions that are used to clone chunks of LLVM
4// code for various purposes.  This varies from copying whole modules into new
5// modules, to cloning functions with different arguments, to inlining
6// functions, to copying basic blocks to support loop unrolling or superblock
7// formation, etc.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef LLVM_TRANSFORMS_UTILS_CLONING_H
12#define LLVM_TRANSFORMS_UTILS_CLONING_H
13
14#include <vector>
15#include <map>
16class Module;
17class Function;
18class BasicBlock;
19class Value;
20class CallInst;
21class InvokeInst;
22class ReturnInst;
23class CallSite;
24
25/// CloneModule - Return an exact copy of the specified module
26///
27Module *CloneModule(const Module *M);
28
29/// CloneBasicBlock - Return a copy of the specified basic block, but without
30/// embedding the block into a particular function.  The block returned is an
31/// exact copy of the specified basic block, without any remapping having been
32/// performed.  Because of this, this is only suitable for applications where
33/// the basic block will be inserted into the same function that it was cloned
34/// from (loop unrolling would use this, for example).
35///
36/// Also, note that this function makes a direct copy of the basic block, and
37/// can thus produce illegal LLVM code.  In particular, it will copy any PHI
38/// nodes from the original block, even though there are no predecessors for the
39/// newly cloned block (thus, phi nodes will have to be updated).  Also, this
40/// block will branch to the old successors of the original block: these
41/// successors will have to have any PHI nodes updated to account for the new
42/// incoming edges.
43///
44/// The correlation between instructions in the source and result basic blocks
45/// is recorded in the ValueMap map.
46///
47/// If you have a particular suffix you'd like to use to add to any cloned
48/// names, specify it as the optional second parameter.
49///
50BasicBlock *CloneBasicBlock(const BasicBlock *BB,
51                            std::map<const Value*, Value*> &ValueMap,
52                            const char *NameSuffix = "");
53
54
55/// CloneFunction - Return a copy of the specified function, but without
56/// embedding the function into another module.  Also, any references specified
57/// in the ValueMap are changed to refer to their mapped value instead of the
58/// original one.  If any of the arguments to the function are in the ValueMap,
59/// the arguments are deleted from the resultant function.  The ValueMap is
60/// updated to include mappings from all of the instructions and basicblocks in
61/// the function from their old to new values.
62///
63Function *CloneFunction(const Function *F,
64                        std::map<const Value*, Value*> &ValueMap);
65
66/// CloneFunction - Version of the function that doesn't need the ValueMap.
67///
68inline Function *CloneFunction(const Function *F) {
69  std::map<const Value*, Value*> ValueMap;
70  return CloneFunction(F, ValueMap);
71}
72
73/// Clone OldFunc into NewFunc, transforming the old arguments into references
74/// to ArgMap values.  Note that if NewFunc already has basic blocks, the ones
75/// cloned into it will be added to the end of the function.  This function
76/// fills in a list of return instructions, and can optionally append the
77/// specified suffix to all values cloned.
78///
79void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
80                       std::map<const Value*, Value*> &ValueMap,
81                       std::vector<ReturnInst*> &Returns,
82                       const char *NameSuffix = "");
83
84
85/// InlineFunction - This function inlines the called function into the basic
86/// block of the caller.  This returns false if it is not possible to inline
87/// this call.  The program is still in a well defined state if this occurs
88/// though.
89///
90/// Note that this only does one level of inlining.  For example, if the
91/// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
92/// exists in the instruction stream.  Similiarly this will inline a recursive
93/// function by one level.
94///
95bool InlineFunction(CallInst *C);
96bool InlineFunction(InvokeInst *II);
97bool InlineFunction(CallSite CS);
98
99/// CloneTrace - Returns a copy of the specified trace.
100/// It takes a vector of basic blocks clones the basic blocks, removes internal
101/// phi nodes, adds it to the same function as the original (although there is
102/// no jump to it) and returns the new vector of basic blocks.
103std::vector<BasicBlock *> CloneTrace(const std::vector<BasicBlock*> &origTrace);
104
105#endif
106