LLVM API Documentation

TransformInternals.h

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00001 //===-- TransformInternals.h - Shared functions for Transforms --*- 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 header file declares shared functions used by the different components
00011 //  of the Transforms library.
00012 //
00013 //===----------------------------------------------------------------------===//
00014 
00015 #ifndef TRANSFORM_INTERNALS_H
00016 #define TRANSFORM_INTERNALS_H
00017 
00018 #include "llvm/BasicBlock.h"
00019 #include "llvm/Target/TargetData.h"
00020 #include "llvm/DerivedTypes.h"
00021 #include "llvm/Constants.h"
00022 #include <map>
00023 #include <set>
00024 
00025 namespace llvm {
00026 
00027 static inline int64_t getConstantValue(const ConstantInt *CPI) {
00028   return (int64_t)cast<ConstantInt>(CPI)->getRawValue();
00029 }
00030 
00031 
00032 // getPointedToComposite - If the argument is a pointer type, and the pointed to
00033 // value is a composite type, return the composite type, else return null.
00034 //
00035 static inline const CompositeType *getPointedToComposite(const Type *Ty) {
00036   const PointerType *PT = dyn_cast<PointerType>(Ty);
00037   return PT ? dyn_cast<CompositeType>(PT->getElementType()) : 0;
00038 }
00039 
00040 
00041 //===----------------------------------------------------------------------===//
00042 //  ValueHandle Class - Smart pointer that occupies a slot on the users USE list
00043 //  that prevents it from being destroyed.  This "looks" like an Instruction
00044 //  with Opcode UserOp1.
00045 //
00046 class ValueMapCache;
00047 class ValueHandle : public Instruction {
00048   Use Op;
00049   ValueMapCache &Cache;
00050 public:
00051   ValueHandle(ValueMapCache &VMC, Value *V);
00052   ValueHandle(const ValueHandle &);
00053   ~ValueHandle();
00054 
00055   virtual Instruction *clone() const { abort(); return 0; }
00056 
00057   virtual const char *getOpcodeName() const {
00058     return "ValueHandle";
00059   }
00060 
00061   inline bool operator<(const ValueHandle &VH) const {
00062     return getOperand(0) < VH.getOperand(0);
00063   }
00064 
00065   // Methods for support type inquiry through isa, cast, and dyn_cast:
00066   static inline bool classof(const ValueHandle *) { return true; }
00067   static inline bool classof(const Instruction *I) {
00068     return (I->getOpcode() == Instruction::UserOp1);
00069   }
00070   static inline bool classof(const Value *V) {
00071     return isa<Instruction>(V) && classof(cast<Instruction>(V));
00072   }
00073 };
00074 
00075 
00076 // ------------- Expression Conversion ---------------------
00077 
00078 typedef std::map<const Value*, const Type*> ValueTypeCache;
00079 
00080 class ValueMapCache {
00081 public:
00082   // Operands mapped - Contains an entry if the first value (the user) has had
00083   // the second value (the operand) mapped already.
00084   //
00085   std::set<const User*> OperandsMapped;
00086 
00087   // Expression Map - Contains an entry from the old value to the new value of
00088   // an expression that has been converted over.
00089   //
00090   std::map<const Value *, Value *> ExprMap;
00091   typedef std::map<const Value *, Value *> ExprMapTy;
00092 
00093   // Cast Map - Cast instructions can have their source and destination values
00094   // changed independently for each part.  Because of this, our old naive
00095   // implementation would create a TWO new cast instructions, which would cause
00096   // all kinds of problems.  Here we keep track of the newly allocated casts, so
00097   // that we only create one for a particular instruction.
00098   //
00099   std::set<ValueHandle> NewCasts;
00100 };
00101 
00102 
00103 bool ExpressionConvertibleToType(Value *V, const Type *Ty, ValueTypeCache &Map,
00104                                  const TargetData &TD);
00105 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC,
00106                                const TargetData &TD);
00107 
00108 // ValueConvertibleToType - Return true if it is possible
00109 bool ValueConvertibleToType(Value *V, const Type *Ty,
00110                             ValueTypeCache &ConvertedTypes,
00111                             const TargetData &TD);
00112 
00113 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC,
00114                            const TargetData &TD);
00115 
00116 
00117 // getStructOffsetType - Return a vector of offsets that are to be used to index
00118 // into the specified struct type to get as close as possible to index as we
00119 // can.  Note that it is possible that we cannot get exactly to Offset, in which
00120 // case we update offset to be the offset we actually obtained.  The resultant
00121 // leaf type is returned.
00122 //
00123 // If StopEarly is set to true (the default), the first object with the
00124 // specified type is returned, even if it is a struct type itself.  In this
00125 // case, this routine will not drill down to the leaf type.  Set StopEarly to
00126 // false if you want a leaf
00127 //
00128 const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
00129                                 std::vector<Value*> &Offsets,
00130                                 const TargetData &TD, bool StopEarly = true);
00131 
00132 } // End llvm namespace
00133 
00134 #endif