1 //===-- ConstantHandling.h - Stuff for manipulating constants ---*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declarations of some cool operators that allow you
11 // to do natural things with constant pool values.
13 // Unfortunately we can't overload operators on pointer types (like this:)
15 // inline bool operator==(const Constant *V1, const Constant *V2)
17 // so we must make due with references, even though it leads to some butt ugly
18 // looking code downstream. *sigh* (ex: Constant *Result = *V1 + *v2; )
20 //===----------------------------------------------------------------------===//
22 // WARNING: These operators may return a null object if I don't know how to
23 // perform the specified operation on the specified constant types.
25 //===----------------------------------------------------------------------===//
27 // Implementation notes:
28 // This library is implemented this way for a reason: In most cases, we do
29 // not want to have to link the constant mucking code into an executable.
30 // We do, however want to tie some of this into the main type system, as an
31 // optional component. By using a mutable cache member in the Type class, we
32 // get exactly the kind of behavior we want.
34 // In the end, we get performance almost exactly the same as having a virtual
35 // function dispatch, but we don't have to put our virtual functions into the
36 // "Type" class, and we can implement functionality with templates. Good deal.
38 //===----------------------------------------------------------------------===//
40 #ifndef LLVM_CONSTANTHANDLING_H
41 #define LLVM_CONSTANTHANDLING_H
43 #include "llvm/Constants.h"
44 #include "llvm/Type.h"
47 //===----------------------------------------------------------------------===//
48 // Implement == and != directly...
49 //===----------------------------------------------------------------------===//
51 inline ConstantBool *operator==(const Constant &V1, const Constant &V2) {
52 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
53 return ConstantBool::get(&V1 == &V2);
56 inline ConstantBool *operator!=(const Constant &V1, const Constant &V2) {
57 return ConstantBool::get(&V1 != &V2);
60 //===----------------------------------------------------------------------===//
61 // Implement all other operators indirectly through TypeRules system
62 //===----------------------------------------------------------------------===//
64 class ConstRules : public Annotation {
66 inline ConstRules() : Annotation(AID) {} // Can only be subclassed...
68 static AnnotationID AID; // AnnotationID for this class
70 // Binary Operators...
71 virtual Constant *add(const Constant *V1, const Constant *V2) const = 0;
72 virtual Constant *sub(const Constant *V1, const Constant *V2) const = 0;
73 virtual Constant *mul(const Constant *V1, const Constant *V2) const = 0;
74 virtual Constant *div(const Constant *V1, const Constant *V2) const = 0;
75 virtual Constant *rem(const Constant *V1, const Constant *V2) const = 0;
76 virtual Constant *op_and(const Constant *V1, const Constant *V2) const = 0;
77 virtual Constant *op_or (const Constant *V1, const Constant *V2) const = 0;
78 virtual Constant *op_xor(const Constant *V1, const Constant *V2) const = 0;
79 virtual Constant *shl(const Constant *V1, const Constant *V2) const = 0;
80 virtual Constant *shr(const Constant *V1, const Constant *V2) const = 0;
82 virtual ConstantBool *lessthan(const Constant *V1,
83 const Constant *V2) const = 0;
85 // Casting operators. ick
86 virtual ConstantBool *castToBool (const Constant *V) const = 0;
87 virtual ConstantSInt *castToSByte (const Constant *V) const = 0;
88 virtual ConstantUInt *castToUByte (const Constant *V) const = 0;
89 virtual ConstantSInt *castToShort (const Constant *V) const = 0;
90 virtual ConstantUInt *castToUShort(const Constant *V) const = 0;
91 virtual ConstantSInt *castToInt (const Constant *V) const = 0;
92 virtual ConstantUInt *castToUInt (const Constant *V) const = 0;
93 virtual ConstantSInt *castToLong (const Constant *V) const = 0;
94 virtual ConstantUInt *castToULong (const Constant *V) const = 0;
95 virtual ConstantFP *castToFloat (const Constant *V) const = 0;
96 virtual ConstantFP *castToDouble(const Constant *V) const = 0;
97 virtual Constant *castToPointer(const Constant *V,
98 const PointerType *Ty) const = 0;
100 inline Constant *castTo(const Constant *V, const Type *Ty) const {
101 switch (Ty->getPrimitiveID()) {
102 case Type::BoolTyID: return castToBool(V);
103 case Type::UByteTyID: return castToUByte(V);
104 case Type::SByteTyID: return castToSByte(V);
105 case Type::UShortTyID: return castToUShort(V);
106 case Type::ShortTyID: return castToShort(V);
107 case Type::UIntTyID: return castToUInt(V);
108 case Type::IntTyID: return castToInt(V);
109 case Type::ULongTyID: return castToULong(V);
110 case Type::LongTyID: return castToLong(V);
111 case Type::FloatTyID: return castToFloat(V);
112 case Type::DoubleTyID: return castToDouble(V);
113 case Type::PointerTyID:return castToPointer(V, (PointerType*)Ty);
118 // ConstRules::get - A type will cache its own type rules if one is needed...
119 // we just want to make sure to hit the cache instead of doing it indirectly,
122 static inline ConstRules *get(const Constant &V1, const Constant &V2) {
123 if (isa<ConstantExpr>(V1) || isa<ConstantExpr>(V2))
124 return getConstantExprRules();
125 return (ConstRules*)V1.getType()->getOrCreateAnnotation(AID);
128 static ConstRules *getConstantExprRules();
129 static Annotation *find(AnnotationID AID, const Annotable *Ty, void *);
131 ConstRules(const ConstRules &); // Do not implement
132 ConstRules &operator=(const ConstRules &); // Do not implement
135 // Unary operators...
136 inline Constant *operator~(const Constant &V) {
137 assert(V.getType()->isIntegral() && "Cannot invert non-intergral constant!");
138 return ConstRules::get(V, V)->op_xor(&V,
139 ConstantInt::getAllOnesValue(V.getType()));
142 // Standard binary operators...
143 inline Constant *operator+(const Constant &V1, const Constant &V2) {
144 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
145 return ConstRules::get(V1, V2)->add(&V1, &V2);
148 inline Constant *operator-(const Constant &V1, const Constant &V2) {
149 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
150 return ConstRules::get(V1, V2)->sub(&V1, &V2);
153 inline Constant *operator*(const Constant &V1, const Constant &V2) {
154 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
155 return ConstRules::get(V1, V2)->mul(&V1, &V2);
158 inline Constant *operator/(const Constant &V1, const Constant &V2) {
159 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
160 return ConstRules::get(V1, V2)->div(&V1, &V2);
163 inline Constant *operator%(const Constant &V1, const Constant &V2) {
164 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
165 return ConstRules::get(V1, V2)->rem(&V1, &V2);
168 // Logical Operators...
169 inline Constant *operator&(const Constant &V1, const Constant &V2) {
170 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
171 return ConstRules::get(V1, V2)->op_and(&V1, &V2);
174 inline Constant *operator|(const Constant &V1, const Constant &V2) {
175 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
176 return ConstRules::get(V1, V2)->op_or(&V1, &V2);
179 inline Constant *operator^(const Constant &V1, const Constant &V2) {
180 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
181 return ConstRules::get(V1, V2)->op_xor(&V1, &V2);
184 // Shift Instructions...
185 inline Constant *operator<<(const Constant &V1, const Constant &V2) {
186 assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy);
187 return ConstRules::get(V1, V2)->shl(&V1, &V2);
190 inline Constant *operator>>(const Constant &V1, const Constant &V2) {
191 assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy);
192 return ConstRules::get(V1, V2)->shr(&V1, &V2);
195 inline ConstantBool *operator<(const Constant &V1,
196 const Constant &V2) {
197 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
198 return ConstRules::get(V1, V2)->lessthan(&V1, &V2);
202 //===----------------------------------------------------------------------===//
203 // Implement 'derived' operators based on what we already have...
204 //===----------------------------------------------------------------------===//
206 inline ConstantBool *operator>(const Constant &V1,
207 const Constant &V2) {
211 inline ConstantBool *operator>=(const Constant &V1,
212 const Constant &V2) {
213 if (ConstantBool *V = (V1 < V2))
214 return V->inverted(); // !(V1 < V2)
218 inline ConstantBool *operator<=(const Constant &V1,
219 const Constant &V2) {
220 if (ConstantBool *V = (V1 > V2))
221 return V->inverted(); // !(V1 > V2)
226 //===----------------------------------------------------------------------===//
227 // Implement higher level instruction folding type instructions
228 //===----------------------------------------------------------------------===//
230 // ConstantFoldInstruction - Attempt to constant fold the specified instruction.
231 // If successful, the constant result is returned, if not, null is returned.
233 Constant *ConstantFoldInstruction(Instruction *I);
235 // Constant fold various types of instruction...
236 Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy);
237 Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
239 Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1,
241 Constant *ConstantFoldGetElementPtr(const Constant *C,
242 const std::vector<Constant*> &IdxList);