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
348 ConstantStruct(const StructType *T, const std::vector<Constant*> &Val);
350 /// get() - Static factory methods - Return objects of the specified value
352 static Constant *get(const StructType *T, const std::vector<Constant*> &V);
354 /// Transparently provide more efficient getOperand methods.
355 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
357 /// getType() specialization - Reduce amount of casting...
359 inline const StructType *getType() const {
360 return reinterpret_cast<const StructType*>(Value::getType());
363 /// isNullValue - Return true if this is the value that would be returned by
364 /// getNullValue. This always returns false because zero structs are always
365 /// created as ConstantAggregateZero objects.
366 virtual bool isNullValue() const {
370 virtual void destroyConstant();
371 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
373 /// Methods for support type inquiry through isa, cast, and dyn_cast:
374 static inline bool classof(const ConstantStruct *) { return true; }
375 static bool classof(const Value *V) {
376 return V->getValueID() == ConstantStructVal;
381 struct OperandTraits<ConstantStruct> : VariadicOperandTraits<> {
384 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantStruct, Constant)
386 //===----------------------------------------------------------------------===//
387 /// ConstantVector - Constant Vector Declarations
389 class ConstantVector : public Constant {
390 friend struct ConstantCreator<ConstantVector, VectorType,
391 std::vector<Constant*> >;
392 ConstantVector(const ConstantVector &); // DO NOT IMPLEMENT
394 ConstantVector(const VectorType *T, const std::vector<Constant*> &Val);
396 /// get() - Static factory methods - Return objects of the specified value
397 static Constant *get(const VectorType *T, const std::vector<Constant*> &);
399 /// Transparently provide more efficient getOperand methods.
400 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
402 /// getType - Specialize the getType() method to always return a VectorType,
403 /// which reduces the amount of casting needed in parts of the compiler.
405 inline const VectorType *getType() const {
406 return reinterpret_cast<const VectorType*>(Value::getType());
409 /// isNullValue - Return true if this is the value that would be returned by
410 /// getNullValue. This always returns false because zero vectors are always
411 /// created as ConstantAggregateZero objects.
412 virtual bool isNullValue() const { return false; }
414 /// This function will return true iff every element in this vector constant
415 /// is set to all ones.
416 /// @returns true iff this constant's emements are all set to all ones.
417 /// @brief Determine if the value is all ones.
418 bool isAllOnesValue() const;
420 /// getSplatValue - If this is a splat constant, meaning that all of the
421 /// elements have the same value, return that value. Otherwise return NULL.
422 Constant *getSplatValue();
424 virtual void destroyConstant();
425 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
427 /// Methods for support type inquiry through isa, cast, and dyn_cast:
428 static inline bool classof(const ConstantVector *) { return true; }
429 static bool classof(const Value *V) {
430 return V->getValueID() == ConstantVectorVal;
435 struct OperandTraits<ConstantVector> : VariadicOperandTraits<> {
438 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantVector, Constant)
440 //===----------------------------------------------------------------------===//
441 /// ConstantPointerNull - a constant pointer value that points to null
443 class ConstantPointerNull : public Constant {
444 friend struct ConstantCreator<ConstantPointerNull, PointerType, char>;
445 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
446 ConstantPointerNull(const ConstantPointerNull &); // DO NOT IMPLEMENT
448 explicit ConstantPointerNull(const PointerType *T)
449 : Constant(reinterpret_cast<const Type*>(T),
450 Value::ConstantPointerNullVal, 0, 0) {}
453 // allocate space for exactly zero operands
454 void *operator new(size_t s) {
455 return User::operator new(s, 0);
458 /// get() - Static factory methods - Return objects of the specified value
459 static ConstantPointerNull *get(const PointerType *T);
461 /// isNullValue - Return true if this is the value that would be returned by
463 virtual bool isNullValue() const { return true; }
465 virtual void destroyConstant();
467 /// getType - Specialize the getType() method to always return an PointerType,
468 /// which reduces the amount of casting needed in parts of the compiler.
470 inline const PointerType *getType() const {
471 return reinterpret_cast<const PointerType*>(Value::getType());
474 /// Methods for support type inquiry through isa, cast, and dyn_cast:
475 static inline bool classof(const ConstantPointerNull *) { return true; }
476 static bool classof(const Value *V) {
477 return V->getValueID() == ConstantPointerNullVal;
482 /// ConstantExpr - a constant value that is initialized with an expression using
483 /// other constant values.
485 /// This class uses the standard Instruction opcodes to define the various
486 /// constant expressions. The Opcode field for the ConstantExpr class is
487 /// maintained in the Value::SubclassData field.
488 class ConstantExpr : public Constant {
489 friend struct ConstantCreator<ConstantExpr,Type,
490 std::pair<unsigned, std::vector<Constant*> > >;
491 friend struct ConvertConstantType<ConstantExpr, Type>;
494 ConstantExpr(const Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
495 : Constant(ty, ConstantExprVal, Ops, NumOps) {
496 // Operation type (an Instruction opcode) is stored as the SubclassData.
497 SubclassData = Opcode;
500 // These private methods are used by the type resolution code to create
501 // ConstantExprs in intermediate forms.
502 static Constant *getTy(const Type *Ty, unsigned Opcode,
503 Constant *C1, Constant *C2);
504 static Constant *getCompareTy(unsigned short pred, Constant *C1,
506 static Constant *getSelectTy(const Type *Ty,
507 Constant *C1, Constant *C2, Constant *C3);
508 static Constant *getGetElementPtrTy(const Type *Ty, Constant *C,
509 Value* const *Idxs, unsigned NumIdxs);
510 static Constant *getExtractElementTy(const Type *Ty, Constant *Val,
512 static Constant *getInsertElementTy(const Type *Ty, Constant *Val,
513 Constant *Elt, Constant *Idx);
514 static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1,
515 Constant *V2, Constant *Mask);
516 static Constant *getExtractValueTy(const Type *Ty, Constant *Agg,
517 const unsigned *Idxs, unsigned NumIdxs);
518 static Constant *getInsertValueTy(const Type *Ty, Constant *Agg,
520 const unsigned *Idxs, unsigned NumIdxs);
523 // Static methods to construct a ConstantExpr of different kinds. Note that
524 // these methods may return a object that is not an instance of the
525 // ConstantExpr class, because they will attempt to fold the constant
526 // expression into something simpler if possible.
528 /// Cast constant expr
530 static Constant *getTrunc (Constant *C, const Type *Ty);
531 static Constant *getSExt (Constant *C, const Type *Ty);
532 static Constant *getZExt (Constant *C, const Type *Ty);
533 static Constant *getFPTrunc (Constant *C, const Type *Ty);
534 static Constant *getFPExtend(Constant *C, const Type *Ty);
535 static Constant *getUIToFP (Constant *C, const Type *Ty);
536 static Constant *getSIToFP (Constant *C, const Type *Ty);
537 static Constant *getFPToUI (Constant *C, const Type *Ty);
538 static Constant *getFPToSI (Constant *C, const Type *Ty);
539 static Constant *getPtrToInt(Constant *C, const Type *Ty);
540 static Constant *getIntToPtr(Constant *C, const Type *Ty);
541 static Constant *getBitCast (Constant *C, const Type *Ty);
543 /// Transparently provide more efficient getOperand methods.
544 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
546 // @brief Convenience function for getting one of the casting operations
547 // using a CastOps opcode.
548 static Constant *getCast(
549 unsigned ops, ///< The opcode for the conversion
550 Constant *C, ///< The constant to be converted
551 const Type *Ty ///< The type to which the constant is converted
554 // @brief Create a ZExt or BitCast cast constant expression
555 static Constant *getZExtOrBitCast(
556 Constant *C, ///< The constant to zext or bitcast
557 const Type *Ty ///< The type to zext or bitcast C to
560 // @brief Create a SExt or BitCast cast constant expression
561 static Constant *getSExtOrBitCast(
562 Constant *C, ///< The constant to sext or bitcast
563 const Type *Ty ///< The type to sext or bitcast C to
566 // @brief Create a Trunc or BitCast cast constant expression
567 static Constant *getTruncOrBitCast(
568 Constant *C, ///< The constant to trunc or bitcast
569 const Type *Ty ///< The type to trunc or bitcast C to
572 /// @brief Create a BitCast or a PtrToInt cast constant expression
573 static Constant *getPointerCast(
574 Constant *C, ///< The pointer value to be casted (operand 0)
575 const Type *Ty ///< The type to which cast should be made
578 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
579 static Constant *getIntegerCast(
580 Constant *C, ///< The integer constant to be casted
581 const Type *Ty, ///< The integer type to cast to
582 bool isSigned ///< Whether C should be treated as signed or not
585 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
586 static Constant *getFPCast(
587 Constant *C, ///< The integer constant to be casted
588 const Type *Ty ///< The integer type to cast to
591 /// @brief Return true if this is a convert constant expression
594 /// @brief Return true if this is a compare constant expression
595 bool isCompare() const;
597 /// @brief Return true if this is an insertvalue or extractvalue expression,
598 /// and the getIndices() method may be used.
599 bool hasIndices() const;
601 /// Select constant expr
603 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) {
604 return getSelectTy(V1->getType(), C, V1, V2);
607 /// ConstantExpr::get - Return a binary or shift operator constant expression,
608 /// folding if possible.
610 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2);
612 /// @brief Return an ICmp or FCmp comparison operator constant expression.
613 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2);
615 /// ConstantExpr::get* - Return some common constants without having to
616 /// specify the full Instruction::OPCODE identifier.
618 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS);
619 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS);
621 /// Getelementptr form. std::vector<Value*> is only accepted for convenience:
622 /// all elements must be Constant's.
624 static Constant *getGetElementPtr(Constant *C,
625 Constant* const *IdxList, unsigned NumIdx);
626 static Constant *getGetElementPtr(Constant *C,
627 Value* const *IdxList, unsigned NumIdx);
629 static Constant *getExtractElement(Constant *Vec, Constant *Idx);
630 static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
631 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
632 static Constant *getExtractValue(Constant *Agg,
633 const unsigned *IdxList, unsigned NumIdx);
634 static Constant *getInsertValue(Constant *Agg, Constant *Val,
635 const unsigned *IdxList, unsigned NumIdx);
637 /// isNullValue - Return true if this is the value that would be returned by
639 virtual bool isNullValue() const { return false; }
641 /// getOpcode - Return the opcode at the root of this constant expression
642 unsigned getOpcode() const { return SubclassData; }
644 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
645 /// not an ICMP or FCMP constant expression.
646 unsigned getPredicate() const;
648 /// getIndices - Assert that this is an insertvalue or exactvalue
649 /// expression and return the list of indices.
650 const SmallVector<unsigned, 4> &getIndices() const;
652 /// getOpcodeName - Return a string representation for an opcode.
653 const char *getOpcodeName() const;
655 /// getWithOperandReplaced - Return a constant expression identical to this
656 /// one, but with the specified operand set to the specified value.
657 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
659 /// getWithOperands - This returns the current constant expression with the
660 /// operands replaced with the specified values. The specified operands must
661 /// match count and type with the existing ones.
662 Constant *getWithOperands(const std::vector<Constant*> &Ops) const {
663 return getWithOperands(&Ops[0], (unsigned)Ops.size());
665 Constant *getWithOperands(Constant* const *Ops, unsigned NumOps) const;
667 virtual void destroyConstant();
668 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
670 /// Methods for support type inquiry through isa, cast, and dyn_cast:
671 static inline bool classof(const ConstantExpr *) { return true; }
672 static inline bool classof(const Value *V) {
673 return V->getValueID() == ConstantExprVal;
678 struct OperandTraits<ConstantExpr> : VariadicOperandTraits<1> {
681 DEFINE_TRANSPARENT_CASTED_OPERAND_ACCESSORS(ConstantExpr, Constant)
683 //===----------------------------------------------------------------------===//
684 /// UndefValue - 'undef' values are things that do not have specified contents.
685 /// These are used for a variety of purposes, including global variable
686 /// initializers and operands to instructions. 'undef' values can occur with
689 class UndefValue : public Constant {
690 friend struct ConstantCreator<UndefValue, Type, char>;
691 void *operator new(size_t, unsigned); // DO NOT IMPLEMENT
692 UndefValue(const UndefValue &); // DO NOT IMPLEMENT
694 explicit UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {}
696 // allocate space for exactly zero operands
697 void *operator new(size_t s) {
698 return User::operator new(s, 0);
701 /// get() - Static factory methods - Return an 'undef' object of the specified
704 static UndefValue *get(const Type *T);
706 /// isNullValue - Return true if this is the value that would be returned by
708 virtual bool isNullValue() const { return false; }
710 virtual void destroyConstant();
712 /// Methods for support type inquiry through isa, cast, and dyn_cast:
713 static inline bool classof(const UndefValue *) { return true; }
714 static bool classof(const Value *V) {
715 return V->getValueID() == UndefValueVal;
718 } // End llvm namespace