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"
50 //===----------------------------------------------------------------------===//
51 // Implement == and != directly...
52 //===----------------------------------------------------------------------===//
54 inline ConstantBool *operator==(const Constant &V1, const Constant &V2) {
55 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
56 return ConstantBool::get(&V1 == &V2);
59 inline ConstantBool *operator!=(const Constant &V1, const Constant &V2) {
60 return ConstantBool::get(&V1 != &V2);
63 //===----------------------------------------------------------------------===//
64 // Implement all other operators indirectly through TypeRules system
65 //===----------------------------------------------------------------------===//
67 class ConstRules : public Annotation {
69 inline ConstRules() : Annotation(AID) {} // Can only be subclassed...
71 static AnnotationID AID; // AnnotationID for this class
73 // Binary Operators...
74 virtual Constant *add(const Constant *V1, const Constant *V2) const = 0;
75 virtual Constant *sub(const Constant *V1, const Constant *V2) const = 0;
76 virtual Constant *mul(const Constant *V1, const Constant *V2) const = 0;
77 virtual Constant *div(const Constant *V1, const Constant *V2) const = 0;
78 virtual Constant *rem(const Constant *V1, const Constant *V2) const = 0;
79 virtual Constant *op_and(const Constant *V1, const Constant *V2) const = 0;
80 virtual Constant *op_or (const Constant *V1, const Constant *V2) const = 0;
81 virtual Constant *op_xor(const Constant *V1, const Constant *V2) const = 0;
82 virtual Constant *shl(const Constant *V1, const Constant *V2) const = 0;
83 virtual Constant *shr(const Constant *V1, const Constant *V2) const = 0;
85 virtual ConstantBool *lessthan(const Constant *V1,
86 const Constant *V2) const = 0;
88 // Casting operators. ick
89 virtual ConstantBool *castToBool (const Constant *V) const = 0;
90 virtual ConstantSInt *castToSByte (const Constant *V) const = 0;
91 virtual ConstantUInt *castToUByte (const Constant *V) const = 0;
92 virtual ConstantSInt *castToShort (const Constant *V) const = 0;
93 virtual ConstantUInt *castToUShort(const Constant *V) const = 0;
94 virtual ConstantSInt *castToInt (const Constant *V) const = 0;
95 virtual ConstantUInt *castToUInt (const Constant *V) const = 0;
96 virtual ConstantSInt *castToLong (const Constant *V) const = 0;
97 virtual ConstantUInt *castToULong (const Constant *V) const = 0;
98 virtual ConstantFP *castToFloat (const Constant *V) const = 0;
99 virtual ConstantFP *castToDouble(const Constant *V) const = 0;
100 virtual Constant *castToPointer(const Constant *V,
101 const PointerType *Ty) const = 0;
103 inline Constant *castTo(const Constant *V, const Type *Ty) const {
104 switch (Ty->getPrimitiveID()) {
105 case Type::BoolTyID: return castToBool(V);
106 case Type::UByteTyID: return castToUByte(V);
107 case Type::SByteTyID: return castToSByte(V);
108 case Type::UShortTyID: return castToUShort(V);
109 case Type::ShortTyID: return castToShort(V);
110 case Type::UIntTyID: return castToUInt(V);
111 case Type::IntTyID: return castToInt(V);
112 case Type::ULongTyID: return castToULong(V);
113 case Type::LongTyID: return castToLong(V);
114 case Type::FloatTyID: return castToFloat(V);
115 case Type::DoubleTyID: return castToDouble(V);
116 case Type::PointerTyID:
117 return castToPointer(V, reinterpret_cast<const PointerType*>(Ty));
122 // ConstRules::get - A type will cache its own type rules if one is needed...
123 // we just want to make sure to hit the cache instead of doing it indirectly,
126 static inline ConstRules *get(const Constant &V1, const Constant &V2) {
127 if (isa<ConstantExpr>(V1) || isa<ConstantExpr>(V2))
128 return getConstantExprRules();
129 return static_cast<ConstRules*>(V1.getType()->getOrCreateAnnotation(AID));
132 static ConstRules *getConstantExprRules();
133 static Annotation *find(AnnotationID AID, const Annotable *Ty, void *);
135 ConstRules(const ConstRules &); // Do not implement
136 ConstRules &operator=(const ConstRules &); // Do not implement
139 // Unary operators...
140 inline Constant *operator~(const Constant &V) {
141 assert(V.getType()->isIntegral() && "Cannot invert non-integral constant!");
142 return ConstRules::get(V, V)->op_xor(&V,
143 ConstantInt::getAllOnesValue(V.getType()));
146 inline Constant *operator-(const Constant &V) {
147 return ConstRules::get(V, V)->sub(Constant::getNullValue(V.getType()), &V);
150 // Standard binary operators...
151 inline Constant *operator+(const Constant &V1, const Constant &V2) {
152 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
153 return ConstRules::get(V1, V2)->add(&V1, &V2);
156 inline Constant *operator-(const Constant &V1, const Constant &V2) {
157 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
158 return ConstRules::get(V1, V2)->sub(&V1, &V2);
161 inline Constant *operator*(const Constant &V1, const Constant &V2) {
162 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
163 return ConstRules::get(V1, V2)->mul(&V1, &V2);
166 inline Constant *operator/(const Constant &V1, const Constant &V2) {
167 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
168 return ConstRules::get(V1, V2)->div(&V1, &V2);
171 inline Constant *operator%(const Constant &V1, const Constant &V2) {
172 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
173 return ConstRules::get(V1, V2)->rem(&V1, &V2);
176 // Logical Operators...
177 inline Constant *operator&(const Constant &V1, const Constant &V2) {
178 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
179 return ConstRules::get(V1, V2)->op_and(&V1, &V2);
182 inline Constant *operator|(const Constant &V1, const Constant &V2) {
183 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
184 return ConstRules::get(V1, V2)->op_or(&V1, &V2);
187 inline Constant *operator^(const Constant &V1, const Constant &V2) {
188 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
189 return ConstRules::get(V1, V2)->op_xor(&V1, &V2);
192 // Shift Instructions...
193 inline Constant *operator<<(const Constant &V1, const Constant &V2) {
194 assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy);
195 return ConstRules::get(V1, V2)->shl(&V1, &V2);
198 inline Constant *operator>>(const Constant &V1, const Constant &V2) {
199 assert(V1.getType()->isInteger() && V2.getType() == Type::UByteTy);
200 return ConstRules::get(V1, V2)->shr(&V1, &V2);
203 inline ConstantBool *operator<(const Constant &V1,
204 const Constant &V2) {
205 assert(V1.getType() == V2.getType() && "Constant types must be identical!");
206 return ConstRules::get(V1, V2)->lessthan(&V1, &V2);
210 //===----------------------------------------------------------------------===//
211 // Implement 'derived' operators based on what we already have...
212 //===----------------------------------------------------------------------===//
214 inline ConstantBool *operator>(const Constant &V1,
215 const Constant &V2) {
219 inline ConstantBool *operator>=(const Constant &V1,
220 const Constant &V2) {
221 if (ConstantBool *V = (V1 < V2))
222 return V->inverted(); // !(V1 < V2)
226 inline ConstantBool *operator<=(const Constant &V1,
227 const Constant &V2) {
228 if (ConstantBool *V = (V1 > V2))
229 return V->inverted(); // !(V1 > V2)
234 //===----------------------------------------------------------------------===//
235 // Implement higher level instruction folding type instructions
236 //===----------------------------------------------------------------------===//
238 // ConstantFoldInstruction - Attempt to constant fold the specified instruction.
239 // If successful, the constant result is returned, if not, null is returned.
241 Constant *ConstantFoldInstruction(Instruction *I);
243 // Constant fold various types of instruction...
244 Constant *ConstantFoldCastInstruction(const Constant *V, const Type *DestTy);
245 Constant *ConstantFoldBinaryInstruction(unsigned Opcode, const Constant *V1,
247 Constant *ConstantFoldShiftInstruction(unsigned Opcode, const Constant *V1,
249 Constant *ConstantFoldGetElementPtr(const Constant *C,
250 const std::vector<Constant*> &IdxList);
252 } // End llvm namespace