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_IR_CONSTANTS_H
22 #define LLVM_IR_CONSTANTS_H
24 #include "llvm/ADT/APFloat.h"
25 #include "llvm/ADT/APInt.h"
26 #include "llvm/ADT/ArrayRef.h"
27 #include "llvm/IR/Constant.h"
28 #include "llvm/IR/OperandTraits.h"
39 template<class ConstantClass, class TypeClass, class ValType>
40 struct ConstantCreator;
41 template<class ConstantClass, class TypeClass>
42 struct ConstantArrayCreator;
43 template<class ConstantClass, class TypeClass>
44 struct ConvertConstantType;
46 //===----------------------------------------------------------------------===//
47 /// This is the shared class of boolean and integer constants. This class
48 /// represents both boolean and integral constants.
49 /// @brief Class for constant integers.
50 class ConstantInt : public Constant {
51 virtual void anchor();
52 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
53 ConstantInt(const ConstantInt &) LLVM_DELETED_FUNCTION;
54 ConstantInt(IntegerType *Ty, const APInt& V);
57 // allocate space for exactly zero operands
58 void *operator new(size_t s) {
59 return User::operator new(s, 0);
62 static ConstantInt *getTrue(LLVMContext &Context);
63 static ConstantInt *getFalse(LLVMContext &Context);
64 static Constant *getTrue(Type *Ty);
65 static Constant *getFalse(Type *Ty);
67 /// If Ty is a vector type, return a Constant with a splat of the given
68 /// value. Otherwise return a ConstantInt for the given value.
69 static Constant *get(Type *Ty, uint64_t V, bool isSigned = false);
71 /// Return a ConstantInt with the specified integer value for the specified
72 /// type. If the type is wider than 64 bits, the value will be zero-extended
73 /// to fit the type, unless isSigned is true, in which case the value will
74 /// be interpreted as a 64-bit signed integer and sign-extended to fit
76 /// @brief Get a ConstantInt for a specific value.
77 static ConstantInt *get(IntegerType *Ty, uint64_t V,
78 bool isSigned = false);
80 /// Return a ConstantInt with the specified value for the specified type. The
81 /// value V will be canonicalized to a an unsigned APInt. Accessing it with
82 /// either getSExtValue() or getZExtValue() will yield a correctly sized and
83 /// signed value for the type Ty.
84 /// @brief Get a ConstantInt for a specific signed value.
85 static ConstantInt *getSigned(IntegerType *Ty, int64_t V);
86 static Constant *getSigned(Type *Ty, int64_t V);
88 /// Return a ConstantInt with the specified value and an implied Type. The
89 /// type is the integer type that corresponds to the bit width of the value.
90 static ConstantInt *get(LLVMContext &Context, const APInt &V);
92 /// Return a ConstantInt constructed from the string strStart with the given
94 static ConstantInt *get(IntegerType *Ty, StringRef Str,
97 /// If Ty is a vector type, return a Constant with a splat of the given
98 /// value. Otherwise return a ConstantInt for the given value.
99 static Constant *get(Type* Ty, const APInt& V);
101 /// Return the constant as an APInt value reference. This allows clients to
102 /// obtain a copy of the value, with all its precision in tact.
103 /// @brief Return the constant's value.
104 inline const APInt &getValue() const {
108 /// getBitWidth - Return the bitwidth of this constant.
109 unsigned getBitWidth() const { return Val.getBitWidth(); }
111 /// Return the constant as a 64-bit unsigned integer value after it
112 /// has been zero extended as appropriate for the type of this constant. Note
113 /// that this method can assert if the value does not fit in 64 bits.
115 /// @brief Return the zero extended value.
116 inline uint64_t getZExtValue() const {
117 return Val.getZExtValue();
120 /// Return the constant as a 64-bit integer value after it has been sign
121 /// extended as appropriate for the type of this constant. Note that
122 /// this method can assert if the value does not fit in 64 bits.
124 /// @brief Return the sign extended value.
125 inline int64_t getSExtValue() const {
126 return Val.getSExtValue();
129 /// A helper method that can be used to determine if the constant contained
130 /// within is equal to a constant. This only works for very small values,
131 /// because this is all that can be represented with all types.
132 /// @brief Determine if this constant's value is same as an unsigned char.
133 bool equalsInt(uint64_t V) const {
137 /// getType - Specialize the getType() method to always return an IntegerType,
138 /// which reduces the amount of casting needed in parts of the compiler.
140 inline IntegerType *getType() const {
141 return reinterpret_cast<IntegerType*>(Value::getType());
144 /// This static method returns true if the type Ty is big enough to
145 /// represent the value V. This can be used to avoid having the get method
146 /// assert when V is larger than Ty can represent. Note that there are two
147 /// versions of this method, one for unsigned and one for signed integers.
148 /// Although ConstantInt canonicalizes everything to an unsigned integer,
149 /// the signed version avoids callers having to convert a signed quantity
150 /// to the appropriate unsigned type before calling the method.
151 /// @returns true if V is a valid value for type Ty
152 /// @brief Determine if the value is in range for the given type.
153 static bool isValueValidForType(Type *Ty, uint64_t V);
154 static bool isValueValidForType(Type *Ty, int64_t V);
156 bool isNegative() const { return Val.isNegative(); }
158 /// This is just a convenience method to make client code smaller for a
159 /// common code. It also correctly performs the comparison without the
160 /// potential for an assertion from getZExtValue().
161 bool isZero() const {
165 /// This is just a convenience method to make client code smaller for a
166 /// common case. It also correctly performs the comparison without the
167 /// potential for an assertion from getZExtValue().
168 /// @brief Determine if the value is one.
173 /// This function will return true iff every bit in this constant is set
175 /// @returns true iff this constant's bits are all set to true.
176 /// @brief Determine if the value is all ones.
177 bool isMinusOne() const {
178 return Val.isAllOnesValue();
181 /// This function will return true iff this constant represents the largest
182 /// value that may be represented by the constant's type.
183 /// @returns true iff this is the largest value that may be represented
185 /// @brief Determine if the value is maximal.
186 bool isMaxValue(bool isSigned) const {
188 return Val.isMaxSignedValue();
190 return Val.isMaxValue();
193 /// This function will return true iff this constant represents the smallest
194 /// value that may be represented by this constant's type.
195 /// @returns true if this is the smallest value that may be represented by
197 /// @brief Determine if the value is minimal.
198 bool isMinValue(bool isSigned) const {
200 return Val.isMinSignedValue();
202 return Val.isMinValue();
205 /// This function will return true iff this constant represents a value with
206 /// active bits bigger than 64 bits or a value greater than the given uint64_t
208 /// @returns true iff this constant is greater or equal to the given number.
209 /// @brief Determine if the value is greater or equal to the given number.
210 bool uge(uint64_t Num) const {
211 return Val.getActiveBits() > 64 || Val.getZExtValue() >= Num;
214 /// getLimitedValue - If the value is smaller than the specified limit,
215 /// return it, otherwise return the limit value. This causes the value
216 /// to saturate to the limit.
217 /// @returns the min of the value of the constant and the specified value
218 /// @brief Get the constant's value with a saturation limit
219 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
220 return Val.getLimitedValue(Limit);
223 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
224 static bool classof(const Value *V) {
225 return V->getValueID() == ConstantIntVal;
230 //===----------------------------------------------------------------------===//
231 /// ConstantFP - Floating Point Values [float, double]
233 class ConstantFP : public Constant {
235 virtual void anchor();
236 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
237 ConstantFP(const ConstantFP &) LLVM_DELETED_FUNCTION;
238 friend class LLVMContextImpl;
240 ConstantFP(Type *Ty, const APFloat& V);
242 // allocate space for exactly zero operands
243 void *operator new(size_t s) {
244 return User::operator new(s, 0);
247 /// Floating point negation must be implemented with f(x) = -0.0 - x. This
248 /// method returns the negative zero constant for floating point or vector
249 /// floating point types; for all other types, it returns the null value.
250 static Constant *getZeroValueForNegation(Type *Ty);
252 /// get() - This returns a ConstantFP, or a vector containing a splat of a
253 /// ConstantFP, for the specified value in the specified type. This should
254 /// only be used for simple constant values like 2.0/1.0 etc, that are
255 /// known-valid both as host double and as the target format.
256 static Constant *get(Type* Ty, double V);
257 static Constant *get(Type* Ty, StringRef Str);
258 static ConstantFP *get(LLVMContext &Context, const APFloat &V);
259 static ConstantFP *getNegativeZero(Type* Ty);
260 static ConstantFP *getInfinity(Type *Ty, bool Negative = false);
262 /// isValueValidForType - return true if Ty is big enough to represent V.
263 static bool isValueValidForType(Type *Ty, const APFloat &V);
264 inline const APFloat &getValueAPF() const { return Val; }
266 /// isZero - Return true if the value is positive or negative zero.
267 bool isZero() const { return Val.isZero(); }
269 /// isNegative - Return true if the sign bit is set.
270 bool isNegative() const { return Val.isNegative(); }
272 /// isNaN - Return true if the value is a NaN.
273 bool isNaN() const { return Val.isNaN(); }
275 /// isExactlyValue - We don't rely on operator== working on double values, as
276 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
277 /// As such, this method can be used to do an exact bit-for-bit comparison of
278 /// two floating point values. The version with a double operand is retained
279 /// because it's so convenient to write isExactlyValue(2.0), but please use
280 /// it only for simple constants.
281 bool isExactlyValue(const APFloat &V) const;
283 bool isExactlyValue(double V) const {
286 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
287 return isExactlyValue(FV);
289 /// Methods for support type inquiry through isa, cast, and dyn_cast:
290 static bool classof(const Value *V) {
291 return V->getValueID() == ConstantFPVal;
295 //===----------------------------------------------------------------------===//
296 /// ConstantAggregateZero - All zero aggregate value
298 class ConstantAggregateZero : public Constant {
299 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
300 ConstantAggregateZero(const ConstantAggregateZero &) LLVM_DELETED_FUNCTION;
302 explicit ConstantAggregateZero(Type *ty)
303 : Constant(ty, ConstantAggregateZeroVal, 0, 0) {}
305 // allocate space for exactly zero operands
306 void *operator new(size_t s) {
307 return User::operator new(s, 0);
310 static ConstantAggregateZero *get(Type *Ty);
312 virtual void destroyConstant();
314 /// getSequentialElement - If this CAZ has array or vector type, return a zero
315 /// with the right element type.
316 Constant *getSequentialElement() const;
318 /// getStructElement - If this CAZ has struct type, return a zero with the
319 /// right element type for the specified element.
320 Constant *getStructElement(unsigned Elt) const;
322 /// getElementValue - Return a zero of the right value for the specified GEP
324 Constant *getElementValue(Constant *C) const;
326 /// getElementValue - Return a zero of the right value for the specified GEP
328 Constant *getElementValue(unsigned Idx) const;
330 /// Methods for support type inquiry through isa, cast, and dyn_cast:
332 static bool classof(const Value *V) {
333 return V->getValueID() == ConstantAggregateZeroVal;
338 //===----------------------------------------------------------------------===//
339 /// ConstantArray - Constant Array Declarations
341 class ConstantArray : public Constant {
342 friend struct ConstantArrayCreator<ConstantArray, ArrayType>;
343 ConstantArray(const ConstantArray &) LLVM_DELETED_FUNCTION;
345 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val);
347 // ConstantArray accessors
348 static Constant *get(ArrayType *T, ArrayRef<Constant*> V);
350 /// Transparently provide more efficient getOperand methods.
351 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
353 /// getType - Specialize the getType() method to always return an ArrayType,
354 /// which reduces the amount of casting needed in parts of the compiler.
356 inline ArrayType *getType() const {
357 return reinterpret_cast<ArrayType*>(Value::getType());
360 virtual void destroyConstant();
361 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
363 /// Methods for support type inquiry through isa, cast, and dyn_cast:
364 static bool classof(const Value *V) {
365 return V->getValueID() == ConstantArrayVal;
370 struct OperandTraits<ConstantArray> :
371 public VariadicOperandTraits<ConstantArray> {
374 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantArray, Constant)
376 //===----------------------------------------------------------------------===//
377 // ConstantStruct - Constant Struct Declarations
379 class ConstantStruct : public Constant {
380 friend struct ConstantArrayCreator<ConstantStruct, StructType>;
381 ConstantStruct(const ConstantStruct &) LLVM_DELETED_FUNCTION;
383 ConstantStruct(StructType *T, ArrayRef<Constant *> Val);
385 // ConstantStruct accessors
386 static Constant *get(StructType *T, ArrayRef<Constant*> V);
387 static Constant *get(StructType *T, ...) END_WITH_NULL;
389 /// getAnon - Return an anonymous struct that has the specified
390 /// elements. If the struct is possibly empty, then you must specify a
392 static Constant *getAnon(ArrayRef<Constant*> V, bool Packed = false) {
393 return get(getTypeForElements(V, Packed), V);
395 static Constant *getAnon(LLVMContext &Ctx,
396 ArrayRef<Constant*> V, bool Packed = false) {
397 return get(getTypeForElements(Ctx, V, Packed), V);
400 /// getTypeForElements - Return an anonymous struct type to use for a constant
401 /// with the specified set of elements. The list must not be empty.
402 static StructType *getTypeForElements(ArrayRef<Constant*> V,
403 bool Packed = false);
404 /// getTypeForElements - This version of the method allows an empty list.
405 static StructType *getTypeForElements(LLVMContext &Ctx,
406 ArrayRef<Constant*> V,
407 bool Packed = false);
409 /// Transparently provide more efficient getOperand methods.
410 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
412 /// getType() specialization - Reduce amount of casting...
414 inline StructType *getType() const {
415 return reinterpret_cast<StructType*>(Value::getType());
418 virtual void destroyConstant();
419 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
421 /// Methods for support type inquiry through isa, cast, and dyn_cast:
422 static bool classof(const Value *V) {
423 return V->getValueID() == ConstantStructVal;
428 struct OperandTraits<ConstantStruct> :
429 public VariadicOperandTraits<ConstantStruct> {
432 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantStruct, Constant)
435 //===----------------------------------------------------------------------===//
436 /// ConstantVector - Constant Vector Declarations
438 class ConstantVector : public Constant {
439 friend struct ConstantArrayCreator<ConstantVector, VectorType>;
440 ConstantVector(const ConstantVector &) LLVM_DELETED_FUNCTION;
442 ConstantVector(VectorType *T, ArrayRef<Constant *> Val);
444 // ConstantVector accessors
445 static Constant *get(ArrayRef<Constant*> V);
447 /// getSplat - Return a ConstantVector with the specified constant in each
449 static Constant *getSplat(unsigned NumElts, Constant *Elt);
451 /// Transparently provide more efficient getOperand methods.
452 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
454 /// getType - Specialize the getType() method to always return a VectorType,
455 /// which reduces the amount of casting needed in parts of the compiler.
457 inline VectorType *getType() const {
458 return reinterpret_cast<VectorType*>(Value::getType());
461 /// getSplatValue - If this is a splat constant, meaning that all of the
462 /// elements have the same value, return that value. Otherwise return NULL.
463 Constant *getSplatValue() const;
465 virtual void destroyConstant();
466 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
468 /// Methods for support type inquiry through isa, cast, and dyn_cast:
469 static bool classof(const Value *V) {
470 return V->getValueID() == ConstantVectorVal;
475 struct OperandTraits<ConstantVector> :
476 public VariadicOperandTraits<ConstantVector> {
479 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantVector, Constant)
481 //===----------------------------------------------------------------------===//
482 /// ConstantPointerNull - a constant pointer value that points to null
484 class ConstantPointerNull : public Constant {
485 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
486 ConstantPointerNull(const ConstantPointerNull &) LLVM_DELETED_FUNCTION;
488 explicit ConstantPointerNull(PointerType *T)
489 : Constant(reinterpret_cast<Type*>(T),
490 Value::ConstantPointerNullVal, 0, 0) {}
493 // allocate space for exactly zero operands
494 void *operator new(size_t s) {
495 return User::operator new(s, 0);
498 /// get() - Static factory methods - Return objects of the specified value
499 static ConstantPointerNull *get(PointerType *T);
501 virtual void destroyConstant();
503 /// getType - Specialize the getType() method to always return an PointerType,
504 /// which reduces the amount of casting needed in parts of the compiler.
506 inline PointerType *getType() const {
507 return reinterpret_cast<PointerType*>(Value::getType());
510 /// Methods for support type inquiry through isa, cast, and dyn_cast:
511 static bool classof(const Value *V) {
512 return V->getValueID() == ConstantPointerNullVal;
516 //===----------------------------------------------------------------------===//
517 /// ConstantDataSequential - A vector or array constant whose element type is a
518 /// simple 1/2/4/8-byte integer or float/double, and whose elements are just
519 /// simple data values (i.e. ConstantInt/ConstantFP). This Constant node has no
520 /// operands because it stores all of the elements of the constant as densely
521 /// packed data, instead of as Value*'s.
523 /// This is the common base class of ConstantDataArray and ConstantDataVector.
525 class ConstantDataSequential : public Constant {
526 friend class LLVMContextImpl;
527 /// DataElements - A pointer to the bytes underlying this constant (which is
528 /// owned by the uniquing StringMap).
529 const char *DataElements;
531 /// Next - This forms a link list of ConstantDataSequential nodes that have
532 /// the same value but different type. For example, 0,0,0,1 could be a 4
533 /// element array of i8, or a 1-element array of i32. They'll both end up in
534 /// the same StringMap bucket, linked up.
535 ConstantDataSequential *Next;
536 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
537 ConstantDataSequential(const ConstantDataSequential &) LLVM_DELETED_FUNCTION;
539 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
540 : Constant(ty, VT, 0, 0), DataElements(Data), Next(0) {}
541 ~ConstantDataSequential() { delete Next; }
543 static Constant *getImpl(StringRef Bytes, Type *Ty);
546 // allocate space for exactly zero operands.
547 void *operator new(size_t s) {
548 return User::operator new(s, 0);
552 /// isElementTypeCompatible - Return true if a ConstantDataSequential can be
553 /// formed with a vector or array of the specified element type.
554 /// ConstantDataArray only works with normal float and int types that are
555 /// stored densely in memory, not with things like i42 or x86_f80.
556 static bool isElementTypeCompatible(const Type *Ty);
558 /// getElementAsInteger - If this is a sequential container of integers (of
559 /// any size), return the specified element in the low bits of a uint64_t.
560 uint64_t getElementAsInteger(unsigned i) const;
562 /// getElementAsAPFloat - If this is a sequential container of floating point
563 /// type, return the specified element as an APFloat.
564 APFloat getElementAsAPFloat(unsigned i) const;
566 /// getElementAsFloat - If this is an sequential container of floats, return
567 /// the specified element as a float.
568 float getElementAsFloat(unsigned i) const;
570 /// getElementAsDouble - If this is an sequential container of doubles, return
571 /// the specified element as a double.
572 double getElementAsDouble(unsigned i) const;
574 /// getElementAsConstant - Return a Constant for a specified index's element.
575 /// Note that this has to compute a new constant to return, so it isn't as
576 /// efficient as getElementAsInteger/Float/Double.
577 Constant *getElementAsConstant(unsigned i) const;
579 /// getType - Specialize the getType() method to always return a
580 /// SequentialType, which reduces the amount of casting needed in parts of the
582 inline SequentialType *getType() const {
583 return reinterpret_cast<SequentialType*>(Value::getType());
586 /// getElementType - Return the element type of the array/vector.
587 Type *getElementType() const;
589 /// getNumElements - Return the number of elements in the array or vector.
590 unsigned getNumElements() const;
592 /// getElementByteSize - Return the size (in bytes) of each element in the
593 /// array/vector. The size of the elements is known to be a multiple of one
595 uint64_t getElementByteSize() const;
598 /// isString - This method returns true if this is an array of i8.
599 bool isString() const;
601 /// isCString - This method returns true if the array "isString", ends with a
602 /// nul byte, and does not contains any other nul bytes.
603 bool isCString() const;
605 /// getAsString - If this array is isString(), then this method returns the
606 /// array as a StringRef. Otherwise, it asserts out.
608 StringRef getAsString() const {
609 assert(isString() && "Not a string");
610 return getRawDataValues();
613 /// getAsCString - If this array is isCString(), then this method returns the
614 /// array (without the trailing null byte) as a StringRef. Otherwise, it
617 StringRef getAsCString() const {
618 assert(isCString() && "Isn't a C string");
619 StringRef Str = getAsString();
620 return Str.substr(0, Str.size()-1);
623 /// getRawDataValues - Return the raw, underlying, bytes of this data. Note
624 /// that this is an extremely tricky thing to work with, as it exposes the
625 /// host endianness of the data elements.
626 StringRef getRawDataValues() const;
628 virtual void destroyConstant();
630 /// Methods for support type inquiry through isa, cast, and dyn_cast:
632 static bool classof(const Value *V) {
633 return V->getValueID() == ConstantDataArrayVal ||
634 V->getValueID() == ConstantDataVectorVal;
637 const char *getElementPointer(unsigned Elt) const;
640 //===----------------------------------------------------------------------===//
641 /// ConstantDataArray - An array constant whose element type is a simple
642 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
643 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
644 /// operands because it stores all of the elements of the constant as densely
645 /// packed data, instead of as Value*'s.
646 class ConstantDataArray : public ConstantDataSequential {
647 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
648 ConstantDataArray(const ConstantDataArray &) LLVM_DELETED_FUNCTION;
649 virtual void anchor();
650 friend class ConstantDataSequential;
651 explicit ConstantDataArray(Type *ty, const char *Data)
652 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
654 // allocate space for exactly zero operands.
655 void *operator new(size_t s) {
656 return User::operator new(s, 0);
660 /// get() constructors - Return a constant with array type with an element
661 /// count and element type matching the ArrayRef passed in. Note that this
662 /// can return a ConstantAggregateZero object.
663 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
664 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
665 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
666 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
667 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
668 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
670 /// getString - This method constructs a CDS and initializes it with a text
671 /// string. The default behavior (AddNull==true) causes a null terminator to
672 /// be placed at the end of the array (increasing the length of the string by
673 /// one more than the StringRef would normally indicate. Pass AddNull=false
674 /// to disable this behavior.
675 static Constant *getString(LLVMContext &Context, StringRef Initializer,
676 bool AddNull = true);
678 /// getType - Specialize the getType() method to always return an ArrayType,
679 /// which reduces the amount of casting needed in parts of the compiler.
681 inline ArrayType *getType() const {
682 return reinterpret_cast<ArrayType*>(Value::getType());
685 /// Methods for support type inquiry through isa, cast, and dyn_cast:
687 static bool classof(const Value *V) {
688 return V->getValueID() == ConstantDataArrayVal;
692 //===----------------------------------------------------------------------===//
693 /// ConstantDataVector - A vector constant whose element type is a simple
694 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
695 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
696 /// operands because it stores all of the elements of the constant as densely
697 /// packed data, instead of as Value*'s.
698 class ConstantDataVector : public ConstantDataSequential {
699 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
700 ConstantDataVector(const ConstantDataVector &) LLVM_DELETED_FUNCTION;
701 virtual void anchor();
702 friend class ConstantDataSequential;
703 explicit ConstantDataVector(Type *ty, const char *Data)
704 : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}
706 // allocate space for exactly zero operands.
707 void *operator new(size_t s) {
708 return User::operator new(s, 0);
712 /// get() constructors - Return a constant with vector type with an element
713 /// count and element type matching the ArrayRef passed in. Note that this
714 /// can return a ConstantAggregateZero object.
715 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
716 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
717 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
718 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
719 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
720 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
722 /// getSplat - Return a ConstantVector with the specified constant in each
723 /// element. The specified constant has to be a of a compatible type (i8/i16/
724 /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.
725 static Constant *getSplat(unsigned NumElts, Constant *Elt);
727 /// getSplatValue - If this is a splat constant, meaning that all of the
728 /// elements have the same value, return that value. Otherwise return NULL.
729 Constant *getSplatValue() const;
731 /// getType - Specialize the getType() method to always return a VectorType,
732 /// which reduces the amount of casting needed in parts of the compiler.
734 inline VectorType *getType() const {
735 return reinterpret_cast<VectorType*>(Value::getType());
738 /// Methods for support type inquiry through isa, cast, and dyn_cast:
740 static bool classof(const Value *V) {
741 return V->getValueID() == ConstantDataVectorVal;
747 /// BlockAddress - The address of a basic block.
749 class BlockAddress : public Constant {
750 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
751 void *operator new(size_t s) { return User::operator new(s, 2); }
752 BlockAddress(Function *F, BasicBlock *BB);
754 /// get - Return a BlockAddress for the specified function and basic block.
755 static BlockAddress *get(Function *F, BasicBlock *BB);
757 /// get - Return a BlockAddress for the specified basic block. The basic
758 /// block must be embedded into a function.
759 static BlockAddress *get(BasicBlock *BB);
761 /// Transparently provide more efficient getOperand methods.
762 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
764 Function *getFunction() const { return (Function*)Op<0>().get(); }
765 BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }
767 virtual void destroyConstant();
768 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
770 /// Methods for support type inquiry through isa, cast, and dyn_cast:
771 static inline bool classof(const Value *V) {
772 return V->getValueID() == BlockAddressVal;
777 struct OperandTraits<BlockAddress> :
778 public FixedNumOperandTraits<BlockAddress, 2> {
781 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)
784 //===----------------------------------------------------------------------===//
785 /// ConstantExpr - a constant value that is initialized with an expression using
786 /// other constant values.
788 /// This class uses the standard Instruction opcodes to define the various
789 /// constant expressions. The Opcode field for the ConstantExpr class is
790 /// maintained in the Value::SubclassData field.
791 class ConstantExpr : public Constant {
792 friend struct ConstantCreator<ConstantExpr,Type,
793 std::pair<unsigned, std::vector<Constant*> > >;
794 friend struct ConvertConstantType<ConstantExpr, Type>;
797 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
798 : Constant(ty, ConstantExprVal, Ops, NumOps) {
799 // Operation type (an Instruction opcode) is stored as the SubclassData.
800 setValueSubclassData(Opcode);
804 // Static methods to construct a ConstantExpr of different kinds. Note that
805 // these methods may return a object that is not an instance of the
806 // ConstantExpr class, because they will attempt to fold the constant
807 // expression into something simpler if possible.
809 /// getAlignOf constant expr - computes the alignment of a type in a target
810 /// independent way (Note: the return type is an i64).
811 static Constant *getAlignOf(Type *Ty);
813 /// getSizeOf constant expr - computes the (alloc) size of a type (in
814 /// address-units, not bits) in a target independent way (Note: the return
817 static Constant *getSizeOf(Type *Ty);
819 /// getOffsetOf constant expr - computes the offset of a struct field in a
820 /// target independent way (Note: the return type is an i64).
822 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);
824 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
825 /// which supports any aggregate type, and any Constant index.
827 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);
829 static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);
830 static Constant *getFNeg(Constant *C);
831 static Constant *getNot(Constant *C);
832 static Constant *getAdd(Constant *C1, Constant *C2,
833 bool HasNUW = false, bool HasNSW = false);
834 static Constant *getFAdd(Constant *C1, Constant *C2);
835 static Constant *getSub(Constant *C1, Constant *C2,
836 bool HasNUW = false, bool HasNSW = false);
837 static Constant *getFSub(Constant *C1, Constant *C2);
838 static Constant *getMul(Constant *C1, Constant *C2,
839 bool HasNUW = false, bool HasNSW = false);
840 static Constant *getFMul(Constant *C1, Constant *C2);
841 static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);
842 static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);
843 static Constant *getFDiv(Constant *C1, Constant *C2);
844 static Constant *getURem(Constant *C1, Constant *C2);
845 static Constant *getSRem(Constant *C1, Constant *C2);
846 static Constant *getFRem(Constant *C1, Constant *C2);
847 static Constant *getAnd(Constant *C1, Constant *C2);
848 static Constant *getOr(Constant *C1, Constant *C2);
849 static Constant *getXor(Constant *C1, Constant *C2);
850 static Constant *getShl(Constant *C1, Constant *C2,
851 bool HasNUW = false, bool HasNSW = false);
852 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);
853 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);
854 static Constant *getTrunc (Constant *C, Type *Ty);
855 static Constant *getSExt (Constant *C, Type *Ty);
856 static Constant *getZExt (Constant *C, Type *Ty);
857 static Constant *getFPTrunc (Constant *C, Type *Ty);
858 static Constant *getFPExtend(Constant *C, Type *Ty);
859 static Constant *getUIToFP (Constant *C, Type *Ty);
860 static Constant *getSIToFP (Constant *C, Type *Ty);
861 static Constant *getFPToUI (Constant *C, Type *Ty);
862 static Constant *getFPToSI (Constant *C, Type *Ty);
863 static Constant *getPtrToInt(Constant *C, Type *Ty);
864 static Constant *getIntToPtr(Constant *C, Type *Ty);
865 static Constant *getBitCast (Constant *C, Type *Ty);
867 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }
868 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }
869 static Constant *getNSWAdd(Constant *C1, Constant *C2) {
870 return getAdd(C1, C2, false, true);
872 static Constant *getNUWAdd(Constant *C1, Constant *C2) {
873 return getAdd(C1, C2, true, false);
875 static Constant *getNSWSub(Constant *C1, Constant *C2) {
876 return getSub(C1, C2, false, true);
878 static Constant *getNUWSub(Constant *C1, Constant *C2) {
879 return getSub(C1, C2, true, false);
881 static Constant *getNSWMul(Constant *C1, Constant *C2) {
882 return getMul(C1, C2, false, true);
884 static Constant *getNUWMul(Constant *C1, Constant *C2) {
885 return getMul(C1, C2, true, false);
887 static Constant *getNSWShl(Constant *C1, Constant *C2) {
888 return getShl(C1, C2, false, true);
890 static Constant *getNUWShl(Constant *C1, Constant *C2) {
891 return getShl(C1, C2, true, false);
893 static Constant *getExactSDiv(Constant *C1, Constant *C2) {
894 return getSDiv(C1, C2, true);
896 static Constant *getExactUDiv(Constant *C1, Constant *C2) {
897 return getUDiv(C1, C2, true);
899 static Constant *getExactAShr(Constant *C1, Constant *C2) {
900 return getAShr(C1, C2, true);
902 static Constant *getExactLShr(Constant *C1, Constant *C2) {
903 return getLShr(C1, C2, true);
906 /// getBinOpIdentity - Return the identity for the given binary operation,
907 /// i.e. a constant C such that X op C = X and C op X = X for every X. It
908 /// returns null if the operator doesn't have an identity.
909 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty);
911 /// getBinOpAbsorber - Return the absorbing element for the given binary
912 /// operation, i.e. a constant C such that X op C = C and C op X = C for
913 /// every X. For example, this returns zero for integer multiplication.
914 /// It returns null if the operator doesn't have an absorbing element.
915 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
917 /// Transparently provide more efficient getOperand methods.
918 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
920 // @brief Convenience function for getting one of the casting operations
921 // using a CastOps opcode.
922 static Constant *getCast(
923 unsigned ops, ///< The opcode for the conversion
924 Constant *C, ///< The constant to be converted
925 Type *Ty ///< The type to which the constant is converted
928 // @brief Create a ZExt or BitCast cast constant expression
929 static Constant *getZExtOrBitCast(
930 Constant *C, ///< The constant to zext or bitcast
931 Type *Ty ///< The type to zext or bitcast C to
934 // @brief Create a SExt or BitCast cast constant expression
935 static Constant *getSExtOrBitCast(
936 Constant *C, ///< The constant to sext or bitcast
937 Type *Ty ///< The type to sext or bitcast C to
940 // @brief Create a Trunc or BitCast cast constant expression
941 static Constant *getTruncOrBitCast(
942 Constant *C, ///< The constant to trunc or bitcast
943 Type *Ty ///< The type to trunc or bitcast C to
946 /// @brief Create a BitCast or a PtrToInt cast constant expression
947 static Constant *getPointerCast(
948 Constant *C, ///< The pointer value to be casted (operand 0)
949 Type *Ty ///< The type to which cast should be made
952 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
953 static Constant *getIntegerCast(
954 Constant *C, ///< The integer constant to be casted
955 Type *Ty, ///< The integer type to cast to
956 bool isSigned ///< Whether C should be treated as signed or not
959 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
960 static Constant *getFPCast(
961 Constant *C, ///< The integer constant to be casted
962 Type *Ty ///< The integer type to cast to
965 /// @brief Return true if this is a convert constant expression
968 /// @brief Return true if this is a compare constant expression
969 bool isCompare() const;
971 /// @brief Return true if this is an insertvalue or extractvalue expression,
972 /// and the getIndices() method may be used.
973 bool hasIndices() const;
975 /// @brief Return true if this is a getelementptr expression and all
976 /// the index operands are compile-time known integers within the
977 /// corresponding notional static array extents. Note that this is
978 /// not equivalant to, a subset of, or a superset of the "inbounds"
980 bool isGEPWithNoNotionalOverIndexing() const;
982 /// Select constant expr
984 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2);
986 /// get - Return a binary or shift operator constant expression,
987 /// folding if possible.
989 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
992 /// @brief Return an ICmp or FCmp comparison operator constant expression.
993 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2);
995 /// get* - Return some common constants without having to
996 /// specify the full Instruction::OPCODE identifier.
998 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS);
999 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS);
1001 /// Getelementptr form. Value* is only accepted for convenience;
1002 /// all elements must be Constant's.
1004 static Constant *getGetElementPtr(Constant *C,
1005 ArrayRef<Constant *> IdxList,
1006 bool InBounds = false) {
1007 return getGetElementPtr(C, makeArrayRef((Value * const *)IdxList.data(),
1011 static Constant *getGetElementPtr(Constant *C,
1013 bool InBounds = false) {
1014 // This form of the function only exists to avoid ambiguous overload
1015 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1016 // ArrayRef<Value *>.
1017 return getGetElementPtr(C, cast<Value>(Idx), InBounds);
1019 static Constant *getGetElementPtr(Constant *C,
1020 ArrayRef<Value *> IdxList,
1021 bool InBounds = false);
1023 /// Create an "inbounds" getelementptr. See the documentation for the
1024 /// "inbounds" flag in LangRef.html for details.
1025 static Constant *getInBoundsGetElementPtr(Constant *C,
1026 ArrayRef<Constant *> IdxList) {
1027 return getGetElementPtr(C, IdxList, true);
1029 static Constant *getInBoundsGetElementPtr(Constant *C,
1031 // This form of the function only exists to avoid ambiguous overload
1032 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1033 // ArrayRef<Value *>.
1034 return getGetElementPtr(C, Idx, true);
1036 static Constant *getInBoundsGetElementPtr(Constant *C,
1037 ArrayRef<Value *> IdxList) {
1038 return getGetElementPtr(C, IdxList, true);
1041 static Constant *getExtractElement(Constant *Vec, Constant *Idx);
1042 static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
1043 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
1044 static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs);
1045 static Constant *getInsertValue(Constant *Agg, Constant *Val,
1046 ArrayRef<unsigned> Idxs);
1048 /// getOpcode - Return the opcode at the root of this constant expression
1049 unsigned getOpcode() const { return getSubclassDataFromValue(); }
1051 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
1052 /// not an ICMP or FCMP constant expression.
1053 unsigned getPredicate() const;
1055 /// getIndices - Assert that this is an insertvalue or exactvalue
1056 /// expression and return the list of indices.
1057 ArrayRef<unsigned> getIndices() const;
1059 /// getOpcodeName - Return a string representation for an opcode.
1060 const char *getOpcodeName() const;
1062 /// getWithOperandReplaced - Return a constant expression identical to this
1063 /// one, but with the specified operand set to the specified value.
1064 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
1066 /// getWithOperands - This returns the current constant expression with the
1067 /// operands replaced with the specified values. The specified array must
1068 /// have the same number of operands as our current one.
1069 Constant *getWithOperands(ArrayRef<Constant*> Ops) const {
1070 return getWithOperands(Ops, getType());
1073 /// getWithOperands - This returns the current constant expression with the
1074 /// operands replaced with the specified values and with the specified result
1075 /// type. The specified array must have the same number of operands as our
1077 Constant *getWithOperands(ArrayRef<Constant*> Ops, Type *Ty) const;
1079 /// getAsInstruction - Returns an Instruction which implements the same operation
1080 /// as this ConstantExpr. The instruction is not linked to any basic block.
1082 /// A better approach to this could be to have a constructor for Instruction
1083 /// which would take a ConstantExpr parameter, but that would have spread
1084 /// implementation details of ConstantExpr outside of Constants.cpp, which
1085 /// would make it harder to remove ConstantExprs altogether.
1086 Instruction *getAsInstruction();
1088 virtual void destroyConstant();
1089 virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
1091 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1092 static inline bool classof(const Value *V) {
1093 return V->getValueID() == ConstantExprVal;
1097 // Shadow Value::setValueSubclassData with a private forwarding method so that
1098 // subclasses cannot accidentally use it.
1099 void setValueSubclassData(unsigned short D) {
1100 Value::setValueSubclassData(D);
1105 struct OperandTraits<ConstantExpr> :
1106 public VariadicOperandTraits<ConstantExpr, 1> {
1109 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant)
1111 //===----------------------------------------------------------------------===//
1112 /// UndefValue - 'undef' values are things that do not have specified contents.
1113 /// These are used for a variety of purposes, including global variable
1114 /// initializers and operands to instructions. 'undef' values can occur with
1115 /// any first-class type.
1117 /// Undef values aren't exactly constants; if they have multiple uses, they
1118 /// can appear to have different bit patterns at each use. See
1119 /// LangRef.html#undefvalues for details.
1121 class UndefValue : public Constant {
1122 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
1123 UndefValue(const UndefValue &) LLVM_DELETED_FUNCTION;
1125 explicit UndefValue(Type *T) : Constant(T, UndefValueVal, 0, 0) {}
1127 // allocate space for exactly zero operands
1128 void *operator new(size_t s) {
1129 return User::operator new(s, 0);
1132 /// get() - Static factory methods - Return an 'undef' object of the specified
1135 static UndefValue *get(Type *T);
1137 /// getSequentialElement - If this Undef has array or vector type, return a
1138 /// undef with the right element type.
1139 UndefValue *getSequentialElement() const;
1141 /// getStructElement - If this undef has struct type, return a undef with the
1142 /// right element type for the specified element.
1143 UndefValue *getStructElement(unsigned Elt) const;
1145 /// getElementValue - Return an undef of the right value for the specified GEP
1147 UndefValue *getElementValue(Constant *C) const;
1149 /// getElementValue - Return an undef of the right value for the specified GEP
1151 UndefValue *getElementValue(unsigned Idx) const;
1153 virtual void destroyConstant();
1155 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1156 static bool classof(const Value *V) {
1157 return V->getValueID() == UndefValueVal;
1161 } // End llvm namespace