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Cloning.h

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00001 //===- Cloning.h - Clone various parts of LLVM programs ---------*- C++ -*-===//
00002 // 
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by the LLVM research group and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 // 
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file defines various functions that are used to clone chunks of LLVM
00011 // code for various purposes.  This varies from copying whole modules into new
00012 // modules, to cloning functions with different arguments, to inlining
00013 // functions, to copying basic blocks to support loop unrolling or superblock
00014 // formation, etc.
00015 //
00016 //===----------------------------------------------------------------------===//
00017 
00018 #ifndef LLVM_TRANSFORMS_UTILS_CLONING_H
00019 #define LLVM_TRANSFORMS_UTILS_CLONING_H
00020 
00021 #include <vector>
00022 #include <map>
00023 
00024 namespace llvm {
00025 
00026 class Module;
00027 class Function;
00028 class BasicBlock;
00029 class Value;
00030 class CallInst;
00031 class InvokeInst;
00032 class ReturnInst;
00033 class CallSite;
00034 class Trace;
00035 
00036 /// CloneModule - Return an exact copy of the specified module
00037 ///
00038 Module *CloneModule(const Module *M);
00039 
00040 /// CloneBasicBlock - Return a copy of the specified basic block, but without
00041 /// embedding the block into a particular function.  The block returned is an
00042 /// exact copy of the specified basic block, without any remapping having been
00043 /// performed.  Because of this, this is only suitable for applications where
00044 /// the basic block will be inserted into the same function that it was cloned
00045 /// from (loop unrolling would use this, for example).
00046 ///
00047 /// Also, note that this function makes a direct copy of the basic block, and
00048 /// can thus produce illegal LLVM code.  In particular, it will copy any PHI
00049 /// nodes from the original block, even though there are no predecessors for the
00050 /// newly cloned block (thus, phi nodes will have to be updated).  Also, this
00051 /// block will branch to the old successors of the original block: these
00052 /// successors will have to have any PHI nodes updated to account for the new
00053 /// incoming edges.
00054 ///
00055 /// The correlation between instructions in the source and result basic blocks
00056 /// is recorded in the ValueMap map.
00057 ///
00058 /// If you have a particular suffix you'd like to use to add to any cloned
00059 /// names, specify it as the optional third parameter.
00060 ///
00061 /// If you would like the basic block to be auto-inserted into the end of a
00062 /// function, you can specify it as the optional fourth parameter.
00063 ///
00064 BasicBlock *CloneBasicBlock(const BasicBlock *BB,
00065                             std::map<const Value*, Value*> &ValueMap,
00066                             const char *NameSuffix = "", Function *F = 0);
00067 
00068 
00069 /// CloneFunction - Return a copy of the specified function, but without
00070 /// embedding the function into another module.  Also, any references specified
00071 /// in the ValueMap are changed to refer to their mapped value instead of the
00072 /// original one.  If any of the arguments to the function are in the ValueMap,
00073 /// the arguments are deleted from the resultant function.  The ValueMap is
00074 /// updated to include mappings from all of the instructions and basicblocks in
00075 /// the function from their old to new values.
00076 ///
00077 Function *CloneFunction(const Function *F,
00078                         std::map<const Value*, Value*> &ValueMap);
00079 
00080 /// CloneFunction - Version of the function that doesn't need the ValueMap.
00081 ///
00082 inline Function *CloneFunction(const Function *F) {
00083   std::map<const Value*, Value*> ValueMap;
00084   return CloneFunction(F, ValueMap);
00085 }
00086 
00087 /// Clone OldFunc into NewFunc, transforming the old arguments into references
00088 /// to ArgMap values.  Note that if NewFunc already has basic blocks, the ones
00089 /// cloned into it will be added to the end of the function.  This function
00090 /// fills in a list of return instructions, and can optionally append the
00091 /// specified suffix to all values cloned.
00092 ///
00093 void CloneFunctionInto(Function *NewFunc, const Function *OldFunc,
00094                        std::map<const Value*, Value*> &ValueMap,
00095                        std::vector<ReturnInst*> &Returns,
00096                        const char *NameSuffix = "");
00097 
00098 
00099 /// CloneTraceInto - Clone T into NewFunc. Original<->clone mapping is
00100 /// saved in ValueMap.
00101 ///
00102 void CloneTraceInto(Function *NewFunc, Trace &T,
00103                     std::map<const Value*, Value*> &ValueMap,
00104                     const char *NameSuffix);
00105 
00106 /// InlineFunction - This function inlines the called function into the basic
00107 /// block of the caller.  This returns false if it is not possible to inline
00108 /// this call.  The program is still in a well defined state if this occurs
00109 /// though.
00110 ///
00111 /// Note that this only does one level of inlining.  For example, if the 
00112 /// instruction 'call B' is inlined, and 'B' calls 'C', then the call to 'C' now
00113 /// exists in the instruction stream.  Similiarly this will inline a recursive
00114 /// function by one level.
00115 ///
00116 bool InlineFunction(CallInst *C);
00117 bool InlineFunction(InvokeInst *II);
00118 bool InlineFunction(CallSite CS);
00119 
00120 /// CloneTrace - Returns a copy of the specified trace. 
00121 /// It takes a vector of basic blocks clones the basic blocks, removes internal 
00122 /// phi nodes, adds it to the same function as the original (although there is 
00123 /// no jump to it) and returns the new vector of basic blocks.
00124 std::vector<BasicBlock *> CloneTrace(const std::vector<BasicBlock*> &origTrace);
00125 
00126 } // End llvm namespace
00127 
00128 #endif