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
289 friend class LLVMContextImpl;
291 ConstantArray(const ArrayType *T, const std::vector<Constant*> &Val);
293 /// Transparently provide more efficient getOperand methods.
294 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
296 /// getType - Specialize the getType() method to always return an ArrayType,
297 /// which reduces the amount of casting needed in parts of the compiler.
299 inline const ArrayType *getType() const {
300 return reinterpret_cast<const ArrayType*>(Value::getType());
303 /// isString - This method returns true if the array is an array of i8 and
304 /// the elements of the array are all ConstantInt's.
305 bool isString() const;
307 /// isCString - This method returns true if the array is a string (see
309 /// isString) and it ends in a null byte \0 and does not contains any other
311 /// null bytes except its terminator.
312 bool isCString() const;
314 /// getAsString - If this array is isString(), then this method converts the
315 /// array to an std::string and returns it. Otherwise, it asserts out.
317 std::string getAsString() const;
319 /// isNullValue - Return true if this is the value that would be returned by
320 /// getNullValue. This always returns false because zero arrays are always
321 /// created as ConstantAggregateZero objects.
322 virtual bool isNullValue() const { return false; }
324 virtual void destroyConstant();
325 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
327 /// Methods for support type inquiry through isa, cast, and dyn_cast:
328 static inline bool classof(const ConstantArray *) { return true; }
329 static bool classof(const Value *V) {
330 return V->getValueID() == ConstantArrayVal;
335 struct OperandTraits<ConstantArray> : VariadicOperandTraits<> {
338 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantArray, Constant)
340 //===----------------------------------------------------------------------===//
341 // ConstantStruct - Constant Struct Declarations
343 class ConstantStruct : public Constant {
344 friend struct ConstantCreator<ConstantStruct, StructType,
345 std::vector<Constant*> >;
346 ConstantStruct(const ConstantStruct &); // DO NOT IMPLEMENT
347 friend class LLVMContextImpl;
349 ConstantStruct(const StructType *T, const std::vector<Constant*> &Val);
351 /// Transparently provide more efficient getOperand methods.
352 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
354 /// getType() specialization - Reduce amount of casting...
356 inline const StructType *getType() const {
357 return reinterpret_cast<const StructType*>(Value::getType());
360 /// isNullValue - Return true if this is the value that would be returned by
361 /// getNullValue. This always returns false because zero structs are always
362 /// created as ConstantAggregateZero objects.
363 virtual bool isNullValue() const {
367 virtual void destroyConstant();
368 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
370 /// Methods for support type inquiry through isa, cast, and dyn_cast:
371 static inline bool classof(const ConstantStruct *) { return true; }
372 static bool classof(const Value *V) {
373 return V->getValueID() == ConstantStructVal;
378 struct OperandTraits<ConstantStruct> : VariadicOperandTraits<> {
381 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantStruct, Constant)
383 //===----------------------------------------------------------------------===//
384 /// ConstantVector - Constant Vector Declarations
386 class ConstantVector : public Constant {
387 friend struct ConstantCreator<ConstantVector, VectorType,
388 std::vector<Constant*> >;
389 ConstantVector(const ConstantVector &); // DO NOT IMPLEMENT
391 ConstantVector(const VectorType *T, const std::vector<Constant*> &Val);
393 /// get() - Static factory methods - Return objects of the specified value
394 static Constant *get(const VectorType *T, const std::vector<Constant*> &);
396 /// Transparently provide more efficient getOperand methods.
397 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
399 /// getType - Specialize the getType() method to always return a VectorType,
400 /// which reduces the amount of casting needed in parts of the compiler.
402 inline const VectorType *getType() const {
403 return reinterpret_cast<const VectorType*>(Value::getType());
406 /// isNullValue - Return true if this is the value that would be returned by
407 /// getNullValue. This always returns false because zero vectors are always
408 /// created as ConstantAggregateZero objects.
409 virtual bool isNullValue() const { return false; }
411 /// This function will return true iff every element in this vector constant
412 /// is set to all ones.
413 /// @returns true iff this constant's emements are all set to all ones.
414 /// @brief Determine if the value is all ones.
415 bool isAllOnesValue() const;
417 /// getSplatValue - If this is a splat constant, meaning that all of the
418 /// elements have the same value, return that value. Otherwise return NULL.
419 Constant *getSplatValue();
421 virtual void destroyConstant();
422 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
424 /// Methods for support type inquiry through isa, cast, and dyn_cast:
425 static inline bool classof(const ConstantVector *) { return true; }
426 static bool classof(const Value *V) {
427 return V->getValueID() == ConstantVectorVal;
432 struct OperandTraits<ConstantVector> : VariadicOperandTraits<> {
435 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantVector, Constant)
437 //===----------------------------------------------------------------------===//
438 /// ConstantPointerNull - a constant pointer value that points to null
440 class ConstantPointerNull : public Constant {
441 friend struct ConstantCreator<ConstantPointerNull, PointerType, char>;
442 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
443 ConstantPointerNull(const ConstantPointerNull &); // DO NOT IMPLEMENT
445 explicit ConstantPointerNull(const PointerType *T)
446 : Constant(reinterpret_cast<const Type*>(T),
447 Value::ConstantPointerNullVal, 0, 0) {}
450 // allocate space for exactly zero operands
451 void *operator new(size_t s) {
452 return User::operator new(s, 0);
455 /// get() - Static factory methods - Return objects of the specified value
456 static ConstantPointerNull *get(const PointerType *T);
458 /// isNullValue - Return true if this is the value that would be returned by
460 virtual bool isNullValue() const { return true; }
462 virtual void destroyConstant();
464 /// getType - Specialize the getType() method to always return an PointerType,
465 /// which reduces the amount of casting needed in parts of the compiler.
467 inline const PointerType *getType() const {
468 return reinterpret_cast<const PointerType*>(Value::getType());
471 /// Methods for support type inquiry through isa, cast, and dyn_cast:
472 static inline bool classof(const ConstantPointerNull *) { return true; }
473 static bool classof(const Value *V) {
474 return V->getValueID() == ConstantPointerNullVal;
479 /// ConstantExpr - a constant value that is initialized with an expression using
480 /// other constant values.
482 /// This class uses the standard Instruction opcodes to define the various
483 /// constant expressions. The Opcode field for the ConstantExpr class is
484 /// maintained in the Value::SubclassData field.
485 class ConstantExpr : public Constant {
486 friend struct ConstantCreator<ConstantExpr,Type,
487 std::pair<unsigned, std::vector<Constant*> > >;
488 friend struct ConvertConstantType<ConstantExpr, Type>;
491 ConstantExpr(const Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
492 : Constant(ty, ConstantExprVal, Ops, NumOps) {
493 // Operation type (an Instruction opcode) is stored as the SubclassData.
494 SubclassData = Opcode;
497 // These private methods are used by the type resolution code to create
498 // ConstantExprs in intermediate forms.
499 static Constant *getTy(const Type *Ty, unsigned Opcode,
500 Constant *C1, Constant *C2);
501 static Constant *getCompareTy(unsigned short pred, Constant *C1,
503 static Constant *getSelectTy(const Type *Ty,
504 Constant *C1, Constant *C2, Constant *C3);
505 static Constant *getGetElementPtrTy(const Type *Ty, Constant *C,
506 Value* const *Idxs, unsigned NumIdxs);
507 static Constant *getExtractElementTy(const Type *Ty, Constant *Val,
509 static Constant *getInsertElementTy(const Type *Ty, Constant *Val,
510 Constant *Elt, Constant *Idx);
511 static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1,
512 Constant *V2, Constant *Mask);
513 static Constant *getExtractValueTy(const Type *Ty, Constant *Agg,
514 const unsigned *Idxs, unsigned NumIdxs);
515 static Constant *getInsertValueTy(const Type *Ty, Constant *Agg,
517 const unsigned *Idxs, unsigned NumIdxs);
520 // Static methods to construct a ConstantExpr of different kinds. Note that
521 // these methods may return a object that is not an instance of the
522 // ConstantExpr class, because they will attempt to fold the constant
523 // expression into something simpler if possible.
525 /// Cast constant expr
527 static Constant *getTrunc (Constant *C, const Type *Ty);
528 static Constant *getSExt (Constant *C, const Type *Ty);
529 static Constant *getZExt (Constant *C, const Type *Ty);
530 static Constant *getFPTrunc (Constant *C, const Type *Ty);
531 static Constant *getFPExtend(Constant *C, const Type *Ty);
532 static Constant *getUIToFP (Constant *C, const Type *Ty);
533 static Constant *getSIToFP (Constant *C, const Type *Ty);
534 static Constant *getFPToUI (Constant *C, const Type *Ty);
535 static Constant *getFPToSI (Constant *C, const Type *Ty);
536 static Constant *getPtrToInt(Constant *C, const Type *Ty);
537 static Constant *getIntToPtr(Constant *C, const Type *Ty);
538 static Constant *getBitCast (Constant *C, const Type *Ty);
540 /// Transparently provide more efficient getOperand methods.
541 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
543 // @brief Convenience function for getting one of the casting operations
544 // using a CastOps opcode.
545 static Constant *getCast(
546 unsigned ops, ///< The opcode for the conversion
547 Constant *C, ///< The constant to be converted
548 const Type *Ty ///< The type to which the constant is converted
551 // @brief Create a ZExt or BitCast cast constant expression
552 static Constant *getZExtOrBitCast(
553 Constant *C, ///< The constant to zext or bitcast
554 const Type *Ty ///< The type to zext or bitcast C to
557 // @brief Create a SExt or BitCast cast constant expression
558 static Constant *getSExtOrBitCast(
559 Constant *C, ///< The constant to sext or bitcast
560 const Type *Ty ///< The type to sext or bitcast C to
563 // @brief Create a Trunc or BitCast cast constant expression
564 static Constant *getTruncOrBitCast(
565 Constant *C, ///< The constant to trunc or bitcast
566 const Type *Ty ///< The type to trunc or bitcast C to
569 /// @brief Create a BitCast or a PtrToInt cast constant expression
570 static Constant *getPointerCast(
571 Constant *C, ///< The pointer value to be casted (operand 0)
572 const Type *Ty ///< The type to which cast should be made
575 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
576 static Constant *getIntegerCast(
577 Constant *C, ///< The integer constant to be casted
578 const Type *Ty, ///< The integer type to cast to
579 bool isSigned ///< Whether C should be treated as signed or not
582 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
583 static Constant *getFPCast(
584 Constant *C, ///< The integer constant to be casted
585 const Type *Ty ///< The integer type to cast to
588 /// @brief Return true if this is a convert constant expression
591 /// @brief Return true if this is a compare constant expression
592 bool isCompare() const;
594 /// @brief Return true if this is an insertvalue or extractvalue expression,
595 /// and the getIndices() method may be used.
596 bool hasIndices() const;
598 /// Select constant expr
600 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) {
601 return getSelectTy(V1->getType(), C, V1, V2);
604 /// ConstantExpr::get - Return a binary or shift operator constant expression,
605 /// folding if possible.
607 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2);
609 /// @brief Return an ICmp or FCmp comparison operator constant expression.
610 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2);
612 /// ConstantExpr::get* - Return some common constants without having to
613 /// specify the full Instruction::OPCODE identifier.
615 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS);
616 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS);
618 /// Getelementptr form. std::vector<Value*> is only accepted for convenience:
619 /// all elements must be Constant's.
621 static Constant *getGetElementPtr(Constant *C,
622 Constant* const *IdxList, unsigned NumIdx);
623 static Constant *getGetElementPtr(Constant *C,
624 Value* const *IdxList, unsigned NumIdx);
626 static Constant *getExtractElement(Constant *Vec, Constant *Idx);
627 static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
628 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
629 static Constant *getExtractValue(Constant *Agg,
630 const unsigned *IdxList, unsigned NumIdx);
631 static Constant *getInsertValue(Constant *Agg, Constant *Val,
632 const unsigned *IdxList, unsigned NumIdx);
634 /// isNullValue - Return true if this is the value that would be returned by
636 virtual bool isNullValue() const { return false; }
638 /// getOpcode - Return the opcode at the root of this constant expression
639 unsigned getOpcode() const { return SubclassData; }
641 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
642 /// not an ICMP or FCMP constant expression.
643 unsigned getPredicate() const;
645 /// getIndices - Assert that this is an insertvalue or exactvalue
646 /// expression and return the list of indices.
647 const SmallVector<unsigned, 4> &getIndices() const;
649 /// getOpcodeName - Return a string representation for an opcode.
650 const char *getOpcodeName() const;
652 /// getWithOperandReplaced - Return a constant expression identical to this
653 /// one, but with the specified operand set to the specified value.
654 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
656 /// getWithOperands - This returns the current constant expression with the
657 /// operands replaced with the specified values. The specified operands must
658 /// match count and type with the existing ones.
659 Constant *getWithOperands(const std::vector<Constant*> &Ops) const {
660 return getWithOperands(&Ops[0], (unsigned)Ops.size());
662 Constant *getWithOperands(Constant* const *Ops, unsigned NumOps) const;
664 virtual void destroyConstant();
665 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
667 /// Methods for support type inquiry through isa, cast, and dyn_cast:
668 static inline bool classof(const ConstantExpr *) { return true; }
669 static inline bool classof(const Value *V) {
670 return V->getValueID() == ConstantExprVal;
675 struct OperandTraits<ConstantExpr> : VariadicOperandTraits<1> {
678 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantExpr, Constant)
680 //===----------------------------------------------------------------------===//
681 /// UndefValue - 'undef' values are things that do not have specified contents.
682 /// These are used for a variety of purposes, including global variable
683 /// initializers and operands to instructions. 'undef' values can occur with
686 class UndefValue : public Constant {
687 friend struct ConstantCreator<UndefValue, Type, char>;
688 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
689 UndefValue(const UndefValue &); // DO NOT IMPLEMENT
691 explicit UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {}
693 // allocate space for exactly zero operands
694 void *operator new(size_t s) {
695 return User::operator new(s, 0);
698 /// get() - Static factory methods - Return an 'undef' object of the specified
701 static UndefValue *get(const Type *T);
703 /// isNullValue - Return true if this is the value that would be returned by
705 virtual bool isNullValue() const { return false; }
707 virtual void destroyConstant();
709 /// Methods for support type inquiry through isa, cast, and dyn_cast:
710 static inline bool classof(const UndefValue *) { return true; }
711 static bool classof(const Value *V) {
712 return V->getValueID() == UndefValueVal;
715 } // End llvm namespace