1 //===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// This file contains the declarations for the subclasses of Constant,
12 /// which represent the different flavors of constant values that live in LLVM.
13 /// Note that Constants are immutable (once created they never change) and are
14 /// fully shared by structural equivalence. This means that two structurally
15 /// equivalent constants will always have the same address. Constant's are
16 /// created on demand as needed and never deleted: thus clients don't have to
17 /// worry about the lifetime of the objects.
19 //===----------------------------------------------------------------------===//
21 #ifndef LLVM_CONSTANTS_H
22 #define LLVM_CONSTANTS_H
24 #include "llvm/Constant.h"
25 #include "llvm/Type.h"
26 #include "llvm/OperandTraits.h"
27 #include "llvm/ADT/APInt.h"
28 #include "llvm/ADT/APFloat.h"
29 #include "llvm/ADT/SmallVector.h"
38 template<class ConstantClass, class TypeClass, class ValType>
39 struct ConstantCreator;
40 template<class ConstantClass, class TypeClass>
41 struct ConvertConstantType;
43 //===----------------------------------------------------------------------===//
44 /// This is the shared class of boolean and integer constants. This class
45 /// represents both boolean and integral constants.
46 /// @brief Class for constant integers.
47 class ConstantInt : public Constant {
48 static ConstantInt *TheTrueVal, *TheFalseVal;
49 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
50 ConstantInt(const ConstantInt &); // DO NOT IMPLEMENT
51 ConstantInt(const IntegerType *Ty, const APInt& V);
53 friend class LLVMContextImpl;
55 // allocate space for exactly zero operands
56 void *operator new(size_t s) {
57 return User::operator new(s, 0);
60 /// Return the constant as an APInt value reference. This allows clients to
61 /// obtain a copy of the value, with all its precision in tact.
62 /// @brief Return the constant's value.
63 inline const APInt& getValue() const {
67 /// getBitWidth - Return the bitwidth of this constant.
68 unsigned getBitWidth() const { return Val.getBitWidth(); }
70 /// Return the constant as a 64-bit unsigned integer value after it
71 /// has been zero extended as appropriate for the type of this constant. Note
72 /// that this method can assert if the value does not fit in 64 bits.
74 /// @brief Return the zero extended value.
75 inline uint64_t getZExtValue() const {
76 return Val.getZExtValue();
79 /// Return the constant as a 64-bit integer value after it has been sign
80 /// extended as appropriate for the type of this constant. Note that
81 /// this method can assert if the value does not fit in 64 bits.
83 /// @brief Return the sign extended value.
84 inline int64_t getSExtValue() const {
85 return Val.getSExtValue();
88 /// A helper method that can be used to determine if the constant contained
89 /// within is equal to a constant. This only works for very small values,
90 /// because this is all that can be represented with all types.
91 /// @brief Determine if this constant's value is same as an unsigned char.
92 bool equalsInt(uint64_t V) const {
96 /// getType - Specialize the getType() method to always return an IntegerType,
97 /// which reduces the amount of casting needed in parts of the compiler.
99 inline const IntegerType *getType() const {
100 return reinterpret_cast<const IntegerType*>(Value::getType());
103 /// This static method returns true if the type Ty is big enough to
104 /// represent the value V. This can be used to avoid having the get method
105 /// assert when V is larger than Ty can represent. Note that there are two
106 /// versions of this method, one for unsigned and one for signed integers.
107 /// Although ConstantInt canonicalizes everything to an unsigned integer,
108 /// the signed version avoids callers having to convert a signed quantity
109 /// to the appropriate unsigned type before calling the method.
110 /// @returns true if V is a valid value for type Ty
111 /// @brief Determine if the value is in range for the given type.
112 static bool isValueValidForType(const Type *Ty, uint64_t V);
113 static bool isValueValidForType(const Type *Ty, int64_t V);
115 /// This function will return true iff this constant represents the "null"
116 /// value that would be returned by the getNullValue method.
117 /// @returns true if this is the null integer value.
118 /// @brief Determine if the value is null.
119 virtual bool isNullValue() const {
123 /// This is just a convenience method to make client code smaller for a
124 /// common code. It also correctly performs the comparison without the
125 /// potential for an assertion from getZExtValue().
126 bool isZero() const {
130 /// This is just a convenience method to make client code smaller for a
131 /// common case. It also correctly performs the comparison without the
132 /// potential for an assertion from getZExtValue().
133 /// @brief Determine if the value is one.
138 /// This function will return true iff every bit in this constant is set
140 /// @returns true iff this constant's bits are all set to true.
141 /// @brief Determine if the value is all ones.
142 bool isAllOnesValue() const {
143 return Val.isAllOnesValue();
146 /// This function will return true iff this constant represents the largest
147 /// value that may be represented by the constant's type.
148 /// @returns true iff this is the largest value that may be represented
150 /// @brief Determine if the value is maximal.
151 bool isMaxValue(bool isSigned) const {
153 return Val.isMaxSignedValue();
155 return Val.isMaxValue();
158 /// This function will return true iff this constant represents the smallest
159 /// value that may be represented by this constant's type.
160 /// @returns true if this is the smallest value that may be represented by
162 /// @brief Determine if the value is minimal.
163 bool isMinValue(bool isSigned) const {
165 return Val.isMinSignedValue();
167 return Val.isMinValue();
170 /// This function will return true iff this constant represents a value with
171 /// active bits bigger than 64 bits or a value greater than the given uint64_t
173 /// @returns true iff this constant is greater or equal to the given number.
174 /// @brief Determine if the value is greater or equal to the given number.
175 bool uge(uint64_t Num) {
176 return Val.getActiveBits() > 64 || Val.getZExtValue() >= Num;
179 /// getLimitedValue - If the value is smaller than the specified limit,
180 /// return it, otherwise return the limit value. This causes the value
181 /// to saturate to the limit.
182 /// @returns the min of the value of the constant and the specified value
183 /// @brief Get the constant's value with a saturation limit
184 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
185 return Val.getLimitedValue(Limit);
188 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
189 static inline bool classof(const ConstantInt *) { return true; }
190 static bool classof(const Value *V) {
191 return V->getValueID() == ConstantIntVal;
196 //===----------------------------------------------------------------------===//
197 /// ConstantFP - Floating Point Values [float, double]
199 class ConstantFP : public Constant {
201 void *operator new(size_t, unsigned);// DO NOT IMPLEMENT
202 ConstantFP(const ConstantFP &); // DO NOT IMPLEMENT
203 friend class LLVMContextImpl;
205 ConstantFP(const Type *Ty, const APFloat& V);
207 // allocate space for exactly zero operands
208 void *operator new(size_t s) {
209 return User::operator new(s, 0);
212 /// isValueValidForType - return true if Ty is big enough to represent V.
213 static bool isValueValidForType(const Type *Ty, const APFloat& V);
214 inline const APFloat& getValueAPF() const { return Val; }
216 /// isNullValue - Return true if this is the value that would be returned by
217 /// getNullValue. Don't depend on == for doubles to tell us it's zero, it
218 /// considers -0.0 to be null as well as 0.0. :(
219 virtual bool isNullValue() const;
221 /// isNegativeZeroValue - Return true if the value is what would be returned
222 /// by getZeroValueForNegation.
223 virtual bool isNegativeZeroValue() const {
224 return Val.isZero() && Val.isNegative();
227 /// isExactlyValue - We don't rely on operator== working on double values, as
228 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
229 /// As such, this method can be used to do an exact bit-for-bit comparison of
230 /// two floating point values. The version with a double operand is retained
231 /// because it's so convenient to write isExactlyValue(2.0), but please use
232 /// it only for simple constants.
233 bool isExactlyValue(const APFloat& V) const;
235 bool isExactlyValue(double V) const {
237 // convert is not supported on this type
238 if (&Val.getSemantics() == &APFloat::PPCDoubleDouble)
241 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
242 return isExactlyValue(FV);
244 /// Methods for support type inquiry through isa, cast, and dyn_cast:
245 static inline bool classof(const ConstantFP *) { return true; }
246 static bool classof(const Value *V) {
247 return V->getValueID() == ConstantFPVal;
251 //===----------------------------------------------------------------------===//
252 /// ConstantAggregateZero - All zero aggregate value
254 class ConstantAggregateZero : public Constant {
255 friend struct ConstantCreator<ConstantAggregateZero, Type, char>;
256 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
257 ConstantAggregateZero(const ConstantAggregateZero &); // DO NOT IMPLEMENT
259 explicit ConstantAggregateZero(const Type *ty)
260 : Constant(ty, ConstantAggregateZeroVal, 0, 0) {}
262 // allocate space for exactly zero operands
263 void *operator new(size_t s) {
264 return User::operator new(s, 0);
267 /// isNullValue - Return true if this is the value that would be returned by
269 virtual bool isNullValue() const { return true; }
271 virtual void destroyConstant();
273 /// Methods for support type inquiry through isa, cast, and dyn_cast:
275 static bool classof(const ConstantAggregateZero *) { return true; }
276 static bool classof(const Value *V) {
277 return V->getValueID() == ConstantAggregateZeroVal;
282 //===----------------------------------------------------------------------===//
283 /// ConstantArray - Constant Array Declarations
285 class ConstantArray : public Constant {
286 friend struct ConstantCreator<ConstantArray, ArrayType,
287 std::vector<Constant*> >;
288 ConstantArray(const ConstantArray &); // DO NOT IMPLEMENT
290 ConstantArray(const ArrayType *T, const std::vector<Constant*> &Val);
292 /// get() - Static factory methods - Return objects of the specified value
293 static Constant *get(const ArrayType *T, const std::vector<Constant*> &);
295 /// Transparently provide more efficient getOperand methods.
296 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
298 /// getType - Specialize the getType() method to always return an ArrayType,
299 /// which reduces the amount of casting needed in parts of the compiler.
301 inline const ArrayType *getType() const {
302 return reinterpret_cast<const ArrayType*>(Value::getType());
305 /// isString - This method returns true if the array is an array of i8 and
306 /// the elements of the array are all ConstantInt's.
307 bool isString() const;
309 /// isCString - This method returns true if the array is a string (see
311 /// isString) and it ends in a null byte \0 and does not contains any other
313 /// null bytes except its terminator.
314 bool isCString() const;
316 /// getAsString - If this array is isString(), then this method converts the
317 /// array to an std::string and returns it. Otherwise, it asserts out.
319 std::string getAsString() const;
321 /// isNullValue - Return true if this is the value that would be returned by
322 /// getNullValue. This always returns false because zero arrays are always
323 /// created as ConstantAggregateZero objects.
324 virtual bool isNullValue() const { return false; }
326 virtual void destroyConstant();
327 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
329 /// Methods for support type inquiry through isa, cast, and dyn_cast:
330 static inline bool classof(const ConstantArray *) { return true; }
331 static bool classof(const Value *V) {
332 return V->getValueID() == ConstantArrayVal;
337 struct OperandTraits<ConstantArray> : VariadicOperandTraits<> {
340 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantArray, Constant)
342 //===----------------------------------------------------------------------===//
343 // ConstantStruct - Constant Struct Declarations
345 class ConstantStruct : public Constant {
346 friend struct ConstantCreator<ConstantStruct, StructType,
347 std::vector<Constant*> >;
348 ConstantStruct(const ConstantStruct &); // DO NOT IMPLEMENT
350 ConstantStruct(const StructType *T, const std::vector<Constant*> &Val);
352 /// get() - Static factory methods - Return objects of the specified value
354 static Constant *get(const StructType *T, const std::vector<Constant*> &V);
356 /// Transparently provide more efficient getOperand methods.
357 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
359 /// getType() specialization - Reduce amount of casting...
361 inline const StructType *getType() const {
362 return reinterpret_cast<const StructType*>(Value::getType());
365 /// isNullValue - Return true if this is the value that would be returned by
366 /// getNullValue. This always returns false because zero structs are always
367 /// created as ConstantAggregateZero objects.
368 virtual bool isNullValue() const {
372 virtual void destroyConstant();
373 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
375 /// Methods for support type inquiry through isa, cast, and dyn_cast:
376 static inline bool classof(const ConstantStruct *) { return true; }
377 static bool classof(const Value *V) {
378 return V->getValueID() == ConstantStructVal;
383 struct OperandTraits<ConstantStruct> : VariadicOperandTraits<> {
386 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantStruct, Constant)
388 //===----------------------------------------------------------------------===//
389 /// ConstantVector - Constant Vector Declarations
391 class ConstantVector : public Constant {
392 friend struct ConstantCreator<ConstantVector, VectorType,
393 std::vector<Constant*> >;
394 ConstantVector(const ConstantVector &); // DO NOT IMPLEMENT
396 ConstantVector(const VectorType *T, const std::vector<Constant*> &Val);
398 /// get() - Static factory methods - Return objects of the specified value
399 static Constant *get(const VectorType *T, const std::vector<Constant*> &);
401 /// Transparently provide more efficient getOperand methods.
402 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
404 /// getType - Specialize the getType() method to always return a VectorType,
405 /// which reduces the amount of casting needed in parts of the compiler.
407 inline const VectorType *getType() const {
408 return reinterpret_cast<const VectorType*>(Value::getType());
411 /// isNullValue - Return true if this is the value that would be returned by
412 /// getNullValue. This always returns false because zero vectors are always
413 /// created as ConstantAggregateZero objects.
414 virtual bool isNullValue() const { return false; }
416 /// This function will return true iff every element in this vector constant
417 /// is set to all ones.
418 /// @returns true iff this constant's emements are all set to all ones.
419 /// @brief Determine if the value is all ones.
420 bool isAllOnesValue() const;
422 /// getSplatValue - If this is a splat constant, meaning that all of the
423 /// elements have the same value, return that value. Otherwise return NULL.
424 Constant *getSplatValue();
426 virtual void destroyConstant();
427 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
429 /// Methods for support type inquiry through isa, cast, and dyn_cast:
430 static inline bool classof(const ConstantVector *) { return true; }
431 static bool classof(const Value *V) {
432 return V->getValueID() == ConstantVectorVal;
437 struct OperandTraits<ConstantVector> : VariadicOperandTraits<> {
440 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantVector, Constant)
442 //===----------------------------------------------------------------------===//
443 /// ConstantPointerNull - a constant pointer value that points to null
445 class ConstantPointerNull : public Constant {
446 friend struct ConstantCreator<ConstantPointerNull, PointerType, char>;
447 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
448 ConstantPointerNull(const ConstantPointerNull &); // DO NOT IMPLEMENT
450 explicit ConstantPointerNull(const PointerType *T)
451 : Constant(reinterpret_cast<const Type*>(T),
452 Value::ConstantPointerNullVal, 0, 0) {}
455 // allocate space for exactly zero operands
456 void *operator new(size_t s) {
457 return User::operator new(s, 0);
460 /// get() - Static factory methods - Return objects of the specified value
461 static ConstantPointerNull *get(const PointerType *T);
463 /// isNullValue - Return true if this is the value that would be returned by
465 virtual bool isNullValue() const { return true; }
467 virtual void destroyConstant();
469 /// getType - Specialize the getType() method to always return an PointerType,
470 /// which reduces the amount of casting needed in parts of the compiler.
472 inline const PointerType *getType() const {
473 return reinterpret_cast<const PointerType*>(Value::getType());
476 /// Methods for support type inquiry through isa, cast, and dyn_cast:
477 static inline bool classof(const ConstantPointerNull *) { return true; }
478 static bool classof(const Value *V) {
479 return V->getValueID() == ConstantPointerNullVal;
484 /// ConstantExpr - a constant value that is initialized with an expression using
485 /// other constant values.
487 /// This class uses the standard Instruction opcodes to define the various
488 /// constant expressions. The Opcode field for the ConstantExpr class is
489 /// maintained in the Value::SubclassData field.
490 class ConstantExpr : public Constant {
491 friend struct ConstantCreator<ConstantExpr,Type,
492 std::pair<unsigned, std::vector<Constant*> > >;
493 friend struct ConvertConstantType<ConstantExpr, Type>;
496 ConstantExpr(const Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
497 : Constant(ty, ConstantExprVal, Ops, NumOps) {
498 // Operation type (an Instruction opcode) is stored as the SubclassData.
499 SubclassData = Opcode;
502 // These private methods are used by the type resolution code to create
503 // ConstantExprs in intermediate forms.
504 static Constant *getTy(const Type *Ty, unsigned Opcode,
505 Constant *C1, Constant *C2);
506 static Constant *getCompareTy(unsigned short pred, Constant *C1,
508 static Constant *getSelectTy(const Type *Ty,
509 Constant *C1, Constant *C2, Constant *C3);
510 static Constant *getGetElementPtrTy(const Type *Ty, Constant *C,
511 Value* const *Idxs, unsigned NumIdxs);
512 static Constant *getExtractElementTy(const Type *Ty, Constant *Val,
514 static Constant *getInsertElementTy(const Type *Ty, Constant *Val,
515 Constant *Elt, Constant *Idx);
516 static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1,
517 Constant *V2, Constant *Mask);
518 static Constant *getExtractValueTy(const Type *Ty, Constant *Agg,
519 const unsigned *Idxs, unsigned NumIdxs);
520 static Constant *getInsertValueTy(const Type *Ty, Constant *Agg,
522 const unsigned *Idxs, unsigned NumIdxs);
525 // Static methods to construct a ConstantExpr of different kinds. Note that
526 // these methods may return a object that is not an instance of the
527 // ConstantExpr class, because they will attempt to fold the constant
528 // expression into something simpler if possible.
530 /// Cast constant expr
532 static Constant *getTrunc (Constant *C, const Type *Ty);
533 static Constant *getSExt (Constant *C, const Type *Ty);
534 static Constant *getZExt (Constant *C, const Type *Ty);
535 static Constant *getFPTrunc (Constant *C, const Type *Ty);
536 static Constant *getFPExtend(Constant *C, const Type *Ty);
537 static Constant *getUIToFP (Constant *C, const Type *Ty);
538 static Constant *getSIToFP (Constant *C, const Type *Ty);
539 static Constant *getFPToUI (Constant *C, const Type *Ty);
540 static Constant *getFPToSI (Constant *C, const Type *Ty);
541 static Constant *getPtrToInt(Constant *C, const Type *Ty);
542 static Constant *getIntToPtr(Constant *C, const Type *Ty);
543 static Constant *getBitCast (Constant *C, const Type *Ty);
545 /// Transparently provide more efficient getOperand methods.
546 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
548 // @brief Convenience function for getting one of the casting operations
549 // using a CastOps opcode.
550 static Constant *getCast(
551 unsigned ops, ///< The opcode for the conversion
552 Constant *C, ///< The constant to be converted
553 const Type *Ty ///< The type to which the constant is converted
556 // @brief Create a ZExt or BitCast cast constant expression
557 static Constant *getZExtOrBitCast(
558 Constant *C, ///< The constant to zext or bitcast
559 const Type *Ty ///< The type to zext or bitcast C to
562 // @brief Create a SExt or BitCast cast constant expression
563 static Constant *getSExtOrBitCast(
564 Constant *C, ///< The constant to sext or bitcast
565 const Type *Ty ///< The type to sext or bitcast C to
568 // @brief Create a Trunc or BitCast cast constant expression
569 static Constant *getTruncOrBitCast(
570 Constant *C, ///< The constant to trunc or bitcast
571 const Type *Ty ///< The type to trunc or bitcast C to
574 /// @brief Create a BitCast or a PtrToInt cast constant expression
575 static Constant *getPointerCast(
576 Constant *C, ///< The pointer value to be casted (operand 0)
577 const Type *Ty ///< The type to which cast should be made
580 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
581 static Constant *getIntegerCast(
582 Constant *C, ///< The integer constant to be casted
583 const Type *Ty, ///< The integer type to cast to
584 bool isSigned ///< Whether C should be treated as signed or not
587 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
588 static Constant *getFPCast(
589 Constant *C, ///< The integer constant to be casted
590 const Type *Ty ///< The integer type to cast to
593 /// @brief Return true if this is a convert constant expression
596 /// @brief Return true if this is a compare constant expression
597 bool isCompare() const;
599 /// @brief Return true if this is an insertvalue or extractvalue expression,
600 /// and the getIndices() method may be used.
601 bool hasIndices() const;
603 /// Select constant expr
605 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) {
606 return getSelectTy(V1->getType(), C, V1, V2);
609 /// ConstantExpr::get - Return a binary or shift operator constant expression,
610 /// folding if possible.
612 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2);
614 /// @brief Return an ICmp or FCmp comparison operator constant expression.
615 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2);
617 /// ConstantExpr::get* - Return some common constants without having to
618 /// specify the full Instruction::OPCODE identifier.
620 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS);
621 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS);
623 /// Getelementptr form. std::vector<Value*> is only accepted for convenience:
624 /// all elements must be Constant's.
626 static Constant *getGetElementPtr(Constant *C,
627 Constant* const *IdxList, unsigned NumIdx);
628 static Constant *getGetElementPtr(Constant *C,
629 Value* const *IdxList, unsigned NumIdx);
631 static Constant *getExtractElement(Constant *Vec, Constant *Idx);
632 static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
633 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
634 static Constant *getExtractValue(Constant *Agg,
635 const unsigned *IdxList, unsigned NumIdx);
636 static Constant *getInsertValue(Constant *Agg, Constant *Val,
637 const unsigned *IdxList, unsigned NumIdx);
639 /// isNullValue - Return true if this is the value that would be returned by
641 virtual bool isNullValue() const { return false; }
643 /// getOpcode - Return the opcode at the root of this constant expression
644 unsigned getOpcode() const { return SubclassData; }
646 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
647 /// not an ICMP or FCMP constant expression.
648 unsigned getPredicate() const;
650 /// getIndices - Assert that this is an insertvalue or exactvalue
651 /// expression and return the list of indices.
652 const SmallVector<unsigned, 4> &getIndices() const;
654 /// getOpcodeName - Return a string representation for an opcode.
655 const char *getOpcodeName() const;
657 /// getWithOperandReplaced - Return a constant expression identical to this
658 /// one, but with the specified operand set to the specified value.
659 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
661 /// getWithOperands - This returns the current constant expression with the
662 /// operands replaced with the specified values. The specified operands must
663 /// match count and type with the existing ones.
664 Constant *getWithOperands(const std::vector<Constant*> &Ops) const {
665 return getWithOperands(&Ops[0], (unsigned)Ops.size());
667 Constant *getWithOperands(Constant* const *Ops, unsigned NumOps) const;
669 virtual void destroyConstant();
670 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
672 /// Methods for support type inquiry through isa, cast, and dyn_cast:
673 static inline bool classof(const ConstantExpr *) { return true; }
674 static inline bool classof(const Value *V) {
675 return V->getValueID() == ConstantExprVal;
680 struct OperandTraits<ConstantExpr> : VariadicOperandTraits<1> {
683 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantExpr, Constant)
685 //===----------------------------------------------------------------------===//
686 /// UndefValue - 'undef' values are things that do not have specified contents.
687 /// These are used for a variety of purposes, including global variable
688 /// initializers and operands to instructions. 'undef' values can occur with
691 class UndefValue : public Constant {
692 friend struct ConstantCreator<UndefValue, Type, char>;
693 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
694 UndefValue(const UndefValue &); // DO NOT IMPLEMENT
696 explicit UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {}
698 // allocate space for exactly zero operands
699 void *operator new(size_t s) {
700 return User::operator new(s, 0);
703 /// get() - Static factory methods - Return an 'undef' object of the specified
706 static UndefValue *get(const Type *T);
708 /// isNullValue - Return true if this is the value that would be returned by
710 virtual bool isNullValue() const { return false; }
712 virtual void destroyConstant();
714 /// Methods for support type inquiry through isa, cast, and dyn_cast:
715 static inline bool classof(const UndefValue *) { return true; }
716 static bool classof(const Value *V) {
717 return V->getValueID() == UndefValueVal;
721 //===----------------------------------------------------------------------===//
722 /// MDString - a single uniqued string.
723 /// These are used to efficiently contain a byte sequence for metadata.
725 class MDString : public Constant {
726 MDString(const MDString &); // DO NOT IMPLEMENT
727 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
728 MDString(const char *begin, const char *end);
730 const char *StrBegin, *StrEnd;
731 friend class LLVMContextImpl;
733 // allocate space for exactly zero operands
734 void *operator new(size_t s) {
735 return User::operator new(s, 0);
738 /// size() - The length of this string.
740 intptr_t size() const { return StrEnd - StrBegin; }
742 /// begin() - Pointer to the first byte of the string.
744 const char *begin() const { return StrBegin; }
746 /// end() - Pointer to one byte past the end of the string.
748 const char *end() const { return StrEnd; }
750 /// getType() specialization - Type is always MetadataTy.
752 inline const Type *getType() const {
753 return Type::MetadataTy;
756 /// isNullValue - Return true if this is the value that would be returned by
757 /// getNullValue. This always returns false because getNullValue will never
758 /// produce metadata.
759 virtual bool isNullValue() const {
763 virtual void destroyConstant();
765 /// Methods for support type inquiry through isa, cast, and dyn_cast:
766 static inline bool classof(const MDString *) { return true; }
767 static bool classof(const Value *V) {
768 return V->getValueID() == MDStringVal;
772 } // End llvm namespace