1 //===-- TransformInternals.h - Shared functions for Transforms ---*- C++ -*--=//
3 // This header file declares shared functions used by the different components
4 // of the Transforms library.
6 //===----------------------------------------------------------------------===//
8 #ifndef TRANSFORM_INTERNALS_H
9 #define TRANSFORM_INTERNALS_H
11 #include "llvm/BasicBlock.h"
12 #include "llvm/Target/TargetData.h"
13 #include "llvm/DerivedTypes.h"
14 #include "llvm/Constants.h"
18 // TargetData Hack: Eventually we will have annotations given to us by the
19 // backend so that we know stuff about type size and alignments. For now
20 // though, just use this, because it happens to match the model that GCC uses.
22 // FIXME: This should use annotations
24 extern const TargetData TD;
26 static inline int64_t getConstantValue(const ConstantInt *CPI) {
27 if (const ConstantSInt *CSI = dyn_cast<ConstantSInt>(CPI))
28 return CSI->getValue();
29 return (int64_t)cast<ConstantUInt>(CPI)->getValue();
33 // getPointedToComposite - If the argument is a pointer type, and the pointed to
34 // value is a composite type, return the composite type, else return null.
36 static inline const CompositeType *getPointedToComposite(const Type *Ty) {
37 const PointerType *PT = dyn_cast<PointerType>(Ty);
38 return PT ? dyn_cast<CompositeType>(PT->getElementType()) : 0;
41 // ConvertableToGEP - This function returns true if the specified value V is
42 // a valid index into a pointer of type Ty. If it is valid, Idx is filled in
43 // with the values that would be appropriate to make this a getelementptr
44 // instruction. The type returned is the root type that the GEP would point
45 // to if it were synthesized with this operands.
47 // If BI is nonnull, cast instructions are inserted as appropriate for the
48 // arguments of the getelementptr.
50 const Type *ConvertableToGEP(const Type *Ty, Value *V,
51 std::vector<Value*> &Indices,
52 BasicBlock::iterator *BI = 0);
55 //===----------------------------------------------------------------------===//
56 // ValueHandle Class - Smart pointer that occupies a slot on the users USE list
57 // that prevents it from being destroyed. This "looks" like an Instruction
58 // with Opcode UserOp1.
61 class ValueHandle : public Instruction {
64 ValueHandle(ValueMapCache &VMC, Value *V);
65 ValueHandle(const ValueHandle &);
68 virtual Instruction *clone() const { abort(); return 0; }
70 virtual const char *getOpcodeName() const {
74 inline bool operator<(const ValueHandle &VH) const {
75 return getOperand(0) < VH.getOperand(0);
78 // Methods for support type inquiry through isa, cast, and dyn_cast:
79 static inline bool classof(const ValueHandle *) { return true; }
80 static inline bool classof(const Instruction *I) {
81 return (I->getOpcode() == Instruction::UserOp1);
83 static inline bool classof(const Value *V) {
84 return isa<Instruction>(V) && classof(cast<Instruction>(V));
89 // ------------- Expression Conversion ---------------------
91 typedef std::map<const Value*, const Type*> ValueTypeCache;
93 struct ValueMapCache {
94 // Operands mapped - Contains an entry if the first value (the user) has had
95 // the second value (the operand) mapped already.
97 std::set<const User*> OperandsMapped;
99 // Expression Map - Contains an entry from the old value to the new value of
100 // an expression that has been converted over.
102 std::map<const Value *, Value *> ExprMap;
103 typedef std::map<const Value *, Value *> ExprMapTy;
105 // Cast Map - Cast instructions can have their source and destination values
106 // changed independantly for each part. Because of this, our old naive
107 // implementation would create a TWO new cast instructions, which would cause
108 // all kinds of problems. Here we keep track of the newly allocated casts, so
109 // that we only create one for a particular instruction.
111 std::set<ValueHandle> NewCasts;
115 bool ExpressionConvertableToType(Value *V, const Type *Ty, ValueTypeCache &Map);
116 Value *ConvertExpressionToType(Value *V, const Type *Ty, ValueMapCache &VMC);
118 // ValueConvertableToType - Return true if it is possible
119 bool ValueConvertableToType(Value *V, const Type *Ty,
120 ValueTypeCache &ConvertedTypes);
122 void ConvertValueToNewType(Value *V, Value *NewVal, ValueMapCache &VMC);
125 // getStructOffsetType - Return a vector of offsets that are to be used to index
126 // into the specified struct type to get as close as possible to index as we
127 // can. Note that it is possible that we cannot get exactly to Offset, in which
128 // case we update offset to be the offset we actually obtained. The resultant
129 // leaf type is returned.
131 // If StopEarly is set to true (the default), the first object with the
132 // specified type is returned, even if it is a struct type itself. In this
133 // case, this routine will not drill down to the leaf type. Set StopEarly to
134 // false if you want a leaf
136 const Type *getStructOffsetType(const Type *Ty, unsigned &Offset,
137 std::vector<Value*> &Offsets,
138 bool StopEarly = true);