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/DerivedTypes.h"
29 #include "llvm/IR/OperandTraits.h"
40 struct ConstantExprKeyType;
41 template <class ConstantClass> struct ConstantAggrKeyType;
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 void anchor() override;
49 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
50 ConstantInt(const ConstantInt &) LLVM_DELETED_FUNCTION;
51 ConstantInt(IntegerType *Ty, const APInt& V);
54 // allocate space for exactly zero operands
55 void *operator new(size_t s) {
56 return User::operator new(s, 0);
59 static ConstantInt *getTrue(LLVMContext &Context);
60 static ConstantInt *getFalse(LLVMContext &Context);
61 static Constant *getTrue(Type *Ty);
62 static Constant *getFalse(Type *Ty);
64 /// If Ty is a vector type, return a Constant with a splat of the given
65 /// value. Otherwise return a ConstantInt for the given value.
66 static Constant *get(Type *Ty, uint64_t V, bool isSigned = false);
68 /// Return a ConstantInt with the specified integer value for the specified
69 /// type. If the type is wider than 64 bits, the value will be zero-extended
70 /// to fit the type, unless isSigned is true, in which case the value will
71 /// be interpreted as a 64-bit signed integer and sign-extended to fit
73 /// @brief Get a ConstantInt for a specific value.
74 static ConstantInt *get(IntegerType *Ty, uint64_t V,
75 bool isSigned = false);
77 /// Return a ConstantInt with the specified value for the specified type. The
78 /// value V will be canonicalized to a an unsigned APInt. Accessing it with
79 /// either getSExtValue() or getZExtValue() will yield a correctly sized and
80 /// signed value for the type Ty.
81 /// @brief Get a ConstantInt for a specific signed value.
82 static ConstantInt *getSigned(IntegerType *Ty, int64_t V);
83 static Constant *getSigned(Type *Ty, int64_t V);
85 /// Return a ConstantInt with the specified value and an implied Type. The
86 /// type is the integer type that corresponds to the bit width of the value.
87 static ConstantInt *get(LLVMContext &Context, const APInt &V);
89 /// Return a ConstantInt constructed from the string strStart with the given
91 static ConstantInt *get(IntegerType *Ty, StringRef Str,
94 /// If Ty is a vector type, return a Constant with a splat of the given
95 /// value. Otherwise return a ConstantInt for the given value.
96 static Constant *get(Type* Ty, const APInt& V);
98 /// Return the constant as an APInt value reference. This allows clients to
99 /// obtain a copy of the value, with all its precision in tact.
100 /// @brief Return the constant's value.
101 inline const APInt &getValue() const {
105 /// getBitWidth - Return the bitwidth of this constant.
106 unsigned getBitWidth() const { return Val.getBitWidth(); }
108 /// Return the constant as a 64-bit unsigned integer value after it
109 /// has been zero extended as appropriate for the type of this constant. Note
110 /// that this method can assert if the value does not fit in 64 bits.
111 /// @brief Return the zero extended value.
112 inline uint64_t getZExtValue() const {
113 return Val.getZExtValue();
116 /// Return the constant as a 64-bit integer value after it has been sign
117 /// extended as appropriate for the type of this constant. Note that
118 /// this method can assert if the value does not fit in 64 bits.
119 /// @brief Return the sign extended value.
120 inline int64_t getSExtValue() const {
121 return Val.getSExtValue();
124 /// A helper method that can be used to determine if the constant contained
125 /// within is equal to a constant. This only works for very small values,
126 /// because this is all that can be represented with all types.
127 /// @brief Determine if this constant's value is same as an unsigned char.
128 bool equalsInt(uint64_t V) const {
132 /// getType - Specialize the getType() method to always return an IntegerType,
133 /// which reduces the amount of casting needed in parts of the compiler.
135 inline IntegerType *getType() const {
136 return cast<IntegerType>(Value::getType());
139 /// This static method returns true if the type Ty is big enough to
140 /// represent the value V. This can be used to avoid having the get method
141 /// assert when V is larger than Ty can represent. Note that there are two
142 /// versions of this method, one for unsigned and one for signed integers.
143 /// Although ConstantInt canonicalizes everything to an unsigned integer,
144 /// the signed version avoids callers having to convert a signed quantity
145 /// to the appropriate unsigned type before calling the method.
146 /// @returns true if V is a valid value for type Ty
147 /// @brief Determine if the value is in range for the given type.
148 static bool isValueValidForType(Type *Ty, uint64_t V);
149 static bool isValueValidForType(Type *Ty, int64_t V);
151 bool isNegative() const { return Val.isNegative(); }
153 /// This is just a convenience method to make client code smaller for a
154 /// common code. It also correctly performs the comparison without the
155 /// potential for an assertion from getZExtValue().
156 bool isZero() const {
160 /// This is just a convenience method to make client code smaller for a
161 /// common case. It also correctly performs the comparison without the
162 /// potential for an assertion from getZExtValue().
163 /// @brief Determine if the value is one.
168 /// This function will return true iff every bit in this constant is set
170 /// @returns true iff this constant's bits are all set to true.
171 /// @brief Determine if the value is all ones.
172 bool isMinusOne() const {
173 return Val.isAllOnesValue();
176 /// This function will return true iff this constant represents the largest
177 /// value that may be represented by the constant's type.
178 /// @returns true iff this is the largest value that may be represented
180 /// @brief Determine if the value is maximal.
181 bool isMaxValue(bool isSigned) const {
183 return Val.isMaxSignedValue();
185 return Val.isMaxValue();
188 /// This function will return true iff this constant represents the smallest
189 /// value that may be represented by this constant's type.
190 /// @returns true if this is the smallest value that may be represented by
192 /// @brief Determine if the value is minimal.
193 bool isMinValue(bool isSigned) const {
195 return Val.isMinSignedValue();
197 return Val.isMinValue();
200 /// This function will return true iff this constant represents a value with
201 /// active bits bigger than 64 bits or a value greater than the given uint64_t
203 /// @returns true iff this constant is greater or equal to the given number.
204 /// @brief Determine if the value is greater or equal to the given number.
205 bool uge(uint64_t Num) const {
206 return Val.getActiveBits() > 64 || Val.getZExtValue() >= Num;
209 /// getLimitedValue - If the value is smaller than the specified limit,
210 /// return it, otherwise return the limit value. This causes the value
211 /// to saturate to the limit.
212 /// @returns the min of the value of the constant and the specified value
213 /// @brief Get the constant's value with a saturation limit
214 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
215 return Val.getLimitedValue(Limit);
218 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
219 static bool classof(const Value *V) {
220 return V->getValueID() == ConstantIntVal;
225 //===----------------------------------------------------------------------===//
226 /// ConstantFP - Floating Point Values [float, double]
228 class ConstantFP : public Constant {
230 void anchor() override;
231 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
232 ConstantFP(const ConstantFP &) LLVM_DELETED_FUNCTION;
233 friend class LLVMContextImpl;
235 ConstantFP(Type *Ty, const APFloat& V);
237 // allocate space for exactly zero operands
238 void *operator new(size_t s) {
239 return User::operator new(s, 0);
242 /// Floating point negation must be implemented with f(x) = -0.0 - x. This
243 /// method returns the negative zero constant for floating point or vector
244 /// floating point types; for all other types, it returns the null value.
245 static Constant *getZeroValueForNegation(Type *Ty);
247 /// get() - This returns a ConstantFP, or a vector containing a splat of a
248 /// ConstantFP, for the specified value in the specified type. This should
249 /// only be used for simple constant values like 2.0/1.0 etc, that are
250 /// known-valid both as host double and as the target format.
251 static Constant *get(Type* Ty, double V);
252 static Constant *get(Type* Ty, StringRef Str);
253 static ConstantFP *get(LLVMContext &Context, const APFloat &V);
254 static Constant *getNegativeZero(Type *Ty);
255 static Constant *getInfinity(Type *Ty, bool Negative = false);
257 /// isValueValidForType - return true if Ty is big enough to represent V.
258 static bool isValueValidForType(Type *Ty, const APFloat &V);
259 inline const APFloat &getValueAPF() const { return Val; }
261 /// isZero - Return true if the value is positive or negative zero.
262 bool isZero() const { return Val.isZero(); }
264 /// isNegative - Return true if the sign bit is set.
265 bool isNegative() const { return Val.isNegative(); }
267 /// isNaN - Return true if the value is a NaN.
268 bool isNaN() const { return Val.isNaN(); }
270 /// isExactlyValue - We don't rely on operator== working on double values, as
271 /// it returns true for things that are clearly not equal, like -0.0 and 0.0.
272 /// As such, this method can be used to do an exact bit-for-bit comparison of
273 /// two floating point values. The version with a double operand is retained
274 /// because it's so convenient to write isExactlyValue(2.0), but please use
275 /// it only for simple constants.
276 bool isExactlyValue(const APFloat &V) const;
278 bool isExactlyValue(double V) const {
281 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
282 return isExactlyValue(FV);
284 /// Methods for support type inquiry through isa, cast, and dyn_cast:
285 static bool classof(const Value *V) {
286 return V->getValueID() == ConstantFPVal;
290 //===----------------------------------------------------------------------===//
291 /// ConstantAggregateZero - All zero aggregate value
293 class ConstantAggregateZero : public Constant {
294 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
295 ConstantAggregateZero(const ConstantAggregateZero &) LLVM_DELETED_FUNCTION;
297 explicit ConstantAggregateZero(Type *ty)
298 : Constant(ty, ConstantAggregateZeroVal, nullptr, 0) {}
300 // allocate space for exactly zero operands
301 void *operator new(size_t s) {
302 return User::operator new(s, 0);
305 static ConstantAggregateZero *get(Type *Ty);
307 void destroyConstant() override;
309 /// getSequentialElement - If this CAZ has array or vector type, return a zero
310 /// with the right element type.
311 Constant *getSequentialElement() const;
313 /// getStructElement - If this CAZ has struct type, return a zero with the
314 /// right element type for the specified element.
315 Constant *getStructElement(unsigned Elt) const;
317 /// getElementValue - Return a zero of the right value for the specified GEP
319 Constant *getElementValue(Constant *C) const;
321 /// getElementValue - Return a zero of the right value for the specified GEP
323 Constant *getElementValue(unsigned Idx) const;
325 /// Methods for support type inquiry through isa, cast, and dyn_cast:
327 static bool classof(const Value *V) {
328 return V->getValueID() == ConstantAggregateZeroVal;
333 //===----------------------------------------------------------------------===//
334 /// ConstantArray - Constant Array Declarations
336 class ConstantArray : public Constant {
337 friend struct ConstantAggrKeyType<ConstantArray>;
338 ConstantArray(const ConstantArray &) LLVM_DELETED_FUNCTION;
340 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val);
342 // ConstantArray accessors
343 static Constant *get(ArrayType *T, ArrayRef<Constant*> V);
346 static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V);
349 /// Transparently provide more efficient getOperand methods.
350 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
352 /// getType - Specialize the getType() method to always return an ArrayType,
353 /// which reduces the amount of casting needed in parts of the compiler.
355 inline ArrayType *getType() const {
356 return cast<ArrayType>(Value::getType());
359 void destroyConstant() override;
360 void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) override;
362 /// Methods for support type inquiry through isa, cast, and dyn_cast:
363 static bool classof(const Value *V) {
364 return V->getValueID() == ConstantArrayVal;
369 struct OperandTraits<ConstantArray> :
370 public VariadicOperandTraits<ConstantArray> {
373 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantArray, Constant)
375 //===----------------------------------------------------------------------===//
376 // ConstantStruct - Constant Struct Declarations
378 class ConstantStruct : public Constant {
379 friend struct ConstantAggrKeyType<ConstantStruct>;
380 ConstantStruct(const ConstantStruct &) LLVM_DELETED_FUNCTION;
382 ConstantStruct(StructType *T, ArrayRef<Constant *> Val);
384 // ConstantStruct accessors
385 static Constant *get(StructType *T, ArrayRef<Constant*> V);
386 static Constant *get(StructType *T, ...) END_WITH_NULL;
388 /// getAnon - Return an anonymous struct that has the specified
389 /// elements. If the struct is possibly empty, then you must specify a
391 static Constant *getAnon(ArrayRef<Constant*> V, bool Packed = false) {
392 return get(getTypeForElements(V, Packed), V);
394 static Constant *getAnon(LLVMContext &Ctx,
395 ArrayRef<Constant*> V, bool Packed = false) {
396 return get(getTypeForElements(Ctx, V, Packed), V);
399 /// getTypeForElements - Return an anonymous struct type to use for a constant
400 /// with the specified set of elements. The list must not be empty.
401 static StructType *getTypeForElements(ArrayRef<Constant*> V,
402 bool Packed = false);
403 /// getTypeForElements - This version of the method allows an empty list.
404 static StructType *getTypeForElements(LLVMContext &Ctx,
405 ArrayRef<Constant*> V,
406 bool Packed = false);
408 /// Transparently provide more efficient getOperand methods.
409 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
411 /// getType() specialization - Reduce amount of casting...
413 inline StructType *getType() const {
414 return cast<StructType>(Value::getType());
417 void destroyConstant() override;
418 void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) override;
420 /// Methods for support type inquiry through isa, cast, and dyn_cast:
421 static bool classof(const Value *V) {
422 return V->getValueID() == ConstantStructVal;
427 struct OperandTraits<ConstantStruct> :
428 public VariadicOperandTraits<ConstantStruct> {
431 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantStruct, Constant)
434 //===----------------------------------------------------------------------===//
435 /// ConstantVector - Constant Vector Declarations
437 class ConstantVector : public Constant {
438 friend struct ConstantAggrKeyType<ConstantVector>;
439 ConstantVector(const ConstantVector &) LLVM_DELETED_FUNCTION;
441 ConstantVector(VectorType *T, ArrayRef<Constant *> Val);
443 // ConstantVector accessors
444 static Constant *get(ArrayRef<Constant*> V);
447 static Constant *getImpl(ArrayRef<Constant *> V);
450 /// getSplat - Return a ConstantVector with the specified constant in each
452 static Constant *getSplat(unsigned NumElts, Constant *Elt);
454 /// Transparently provide more efficient getOperand methods.
455 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
457 /// getType - Specialize the getType() method to always return a VectorType,
458 /// which reduces the amount of casting needed in parts of the compiler.
460 inline VectorType *getType() const {
461 return cast<VectorType>(Value::getType());
464 /// getSplatValue - If this is a splat constant, meaning that all of the
465 /// elements have the same value, return that value. Otherwise return NULL.
466 Constant *getSplatValue() const;
468 void destroyConstant() override;
469 void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) override;
471 /// Methods for support type inquiry through isa, cast, and dyn_cast:
472 static bool classof(const Value *V) {
473 return V->getValueID() == ConstantVectorVal;
478 struct OperandTraits<ConstantVector> :
479 public VariadicOperandTraits<ConstantVector> {
482 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantVector, Constant)
484 //===----------------------------------------------------------------------===//
485 /// ConstantPointerNull - a constant pointer value that points to null
487 class ConstantPointerNull : public Constant {
488 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
489 ConstantPointerNull(const ConstantPointerNull &) LLVM_DELETED_FUNCTION;
491 explicit ConstantPointerNull(PointerType *T)
493 Value::ConstantPointerNullVal, nullptr, 0) {}
496 // allocate space for exactly zero operands
497 void *operator new(size_t s) {
498 return User::operator new(s, 0);
501 /// get() - Static factory methods - Return objects of the specified value
502 static ConstantPointerNull *get(PointerType *T);
504 void destroyConstant() override;
506 /// getType - Specialize the getType() method to always return an PointerType,
507 /// which reduces the amount of casting needed in parts of the compiler.
509 inline PointerType *getType() const {
510 return cast<PointerType>(Value::getType());
513 /// Methods for support type inquiry through isa, cast, and dyn_cast:
514 static bool classof(const Value *V) {
515 return V->getValueID() == ConstantPointerNullVal;
519 //===----------------------------------------------------------------------===//
520 /// ConstantDataSequential - A vector or array constant whose element type is a
521 /// simple 1/2/4/8-byte integer or float/double, and whose elements are just
522 /// simple data values (i.e. ConstantInt/ConstantFP). This Constant node has no
523 /// operands because it stores all of the elements of the constant as densely
524 /// packed data, instead of as Value*'s.
526 /// This is the common base class of ConstantDataArray and ConstantDataVector.
528 class ConstantDataSequential : public Constant {
529 friend class LLVMContextImpl;
530 /// DataElements - A pointer to the bytes underlying this constant (which is
531 /// owned by the uniquing StringMap).
532 const char *DataElements;
534 /// Next - This forms a link list of ConstantDataSequential nodes that have
535 /// the same value but different type. For example, 0,0,0,1 could be a 4
536 /// element array of i8, or a 1-element array of i32. They'll both end up in
537 /// the same StringMap bucket, linked up.
538 ConstantDataSequential *Next;
539 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
540 ConstantDataSequential(const ConstantDataSequential &) LLVM_DELETED_FUNCTION;
542 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
543 : Constant(ty, VT, nullptr, 0), DataElements(Data), Next(nullptr) {}
544 ~ConstantDataSequential() { delete Next; }
546 static Constant *getImpl(StringRef Bytes, Type *Ty);
549 // allocate space for exactly zero operands.
550 void *operator new(size_t s) {
551 return User::operator new(s, 0);
555 /// isElementTypeCompatible - Return true if a ConstantDataSequential can be
556 /// formed with a vector or array of the specified element type.
557 /// ConstantDataArray only works with normal float and int types that are
558 /// stored densely in memory, not with things like i42 or x86_f80.
559 static bool isElementTypeCompatible(const Type *Ty);
561 /// getElementAsInteger - If this is a sequential container of integers (of
562 /// any size), return the specified element in the low bits of a uint64_t.
563 uint64_t getElementAsInteger(unsigned i) const;
565 /// getElementAsAPFloat - If this is a sequential container of floating point
566 /// type, return the specified element as an APFloat.
567 APFloat getElementAsAPFloat(unsigned i) const;
569 /// getElementAsFloat - If this is an sequential container of floats, return
570 /// the specified element as a float.
571 float getElementAsFloat(unsigned i) const;
573 /// getElementAsDouble - If this is an sequential container of doubles, return
574 /// the specified element as a double.
575 double getElementAsDouble(unsigned i) const;
577 /// getElementAsConstant - Return a Constant for a specified index's element.
578 /// Note that this has to compute a new constant to return, so it isn't as
579 /// efficient as getElementAsInteger/Float/Double.
580 Constant *getElementAsConstant(unsigned i) const;
582 /// getType - Specialize the getType() method to always return a
583 /// SequentialType, which reduces the amount of casting needed in parts of the
585 inline SequentialType *getType() const {
586 return cast<SequentialType>(Value::getType());
589 /// getElementType - Return the element type of the array/vector.
590 Type *getElementType() const;
592 /// getNumElements - Return the number of elements in the array or vector.
593 unsigned getNumElements() const;
595 /// getElementByteSize - Return the size (in bytes) of each element in the
596 /// array/vector. The size of the elements is known to be a multiple of one
598 uint64_t getElementByteSize() const;
601 /// isString - This method returns true if this is an array of i8.
602 bool isString() const;
604 /// isCString - This method returns true if the array "isString", ends with a
605 /// nul byte, and does not contains any other nul bytes.
606 bool isCString() const;
608 /// getAsString - If this array is isString(), then this method returns the
609 /// array as a StringRef. Otherwise, it asserts out.
611 StringRef getAsString() const {
612 assert(isString() && "Not a string");
613 return getRawDataValues();
616 /// getAsCString - If this array is isCString(), then this method returns the
617 /// array (without the trailing null byte) as a StringRef. Otherwise, it
620 StringRef getAsCString() const {
621 assert(isCString() && "Isn't a C string");
622 StringRef Str = getAsString();
623 return Str.substr(0, Str.size()-1);
626 /// getRawDataValues - Return the raw, underlying, bytes of this data. Note
627 /// that this is an extremely tricky thing to work with, as it exposes the
628 /// host endianness of the data elements.
629 StringRef getRawDataValues() const;
631 void destroyConstant() override;
633 /// Methods for support type inquiry through isa, cast, and dyn_cast:
635 static bool classof(const Value *V) {
636 return V->getValueID() == ConstantDataArrayVal ||
637 V->getValueID() == ConstantDataVectorVal;
640 const char *getElementPointer(unsigned Elt) const;
643 //===----------------------------------------------------------------------===//
644 /// ConstantDataArray - An array constant whose element type is a simple
645 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
646 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
647 /// operands because it stores all of the elements of the constant as densely
648 /// packed data, instead of as Value*'s.
649 class ConstantDataArray : public ConstantDataSequential {
650 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
651 ConstantDataArray(const ConstantDataArray &) LLVM_DELETED_FUNCTION;
652 void anchor() override;
653 friend class ConstantDataSequential;
654 explicit ConstantDataArray(Type *ty, const char *Data)
655 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
657 // allocate space for exactly zero operands.
658 void *operator new(size_t s) {
659 return User::operator new(s, 0);
663 /// get() constructors - Return a constant with array type with an element
664 /// count and element type matching the ArrayRef passed in. Note that this
665 /// can return a ConstantAggregateZero object.
666 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
667 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
668 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
669 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
670 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
671 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
673 /// getString - This method constructs a CDS and initializes it with a text
674 /// string. The default behavior (AddNull==true) causes a null terminator to
675 /// be placed at the end of the array (increasing the length of the string by
676 /// one more than the StringRef would normally indicate. Pass AddNull=false
677 /// to disable this behavior.
678 static Constant *getString(LLVMContext &Context, StringRef Initializer,
679 bool AddNull = true);
681 /// getType - Specialize the getType() method to always return an ArrayType,
682 /// which reduces the amount of casting needed in parts of the compiler.
684 inline ArrayType *getType() const {
685 return cast<ArrayType>(Value::getType());
688 /// Methods for support type inquiry through isa, cast, and dyn_cast:
690 static bool classof(const Value *V) {
691 return V->getValueID() == ConstantDataArrayVal;
695 //===----------------------------------------------------------------------===//
696 /// ConstantDataVector - A vector constant whose element type is a simple
697 /// 1/2/4/8-byte integer or float/double, and whose elements are just simple
698 /// data values (i.e. ConstantInt/ConstantFP). This Constant node has no
699 /// operands because it stores all of the elements of the constant as densely
700 /// packed data, instead of as Value*'s.
701 class ConstantDataVector : public ConstantDataSequential {
702 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
703 ConstantDataVector(const ConstantDataVector &) LLVM_DELETED_FUNCTION;
704 void anchor() override;
705 friend class ConstantDataSequential;
706 explicit ConstantDataVector(Type *ty, const char *Data)
707 : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}
709 // allocate space for exactly zero operands.
710 void *operator new(size_t s) {
711 return User::operator new(s, 0);
715 /// get() constructors - Return a constant with vector type with an element
716 /// count and element type matching the ArrayRef passed in. Note that this
717 /// can return a ConstantAggregateZero object.
718 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
719 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
720 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
721 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
722 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
723 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
725 /// getSplat - Return a ConstantVector with the specified constant in each
726 /// element. The specified constant has to be a of a compatible type (i8/i16/
727 /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.
728 static Constant *getSplat(unsigned NumElts, Constant *Elt);
730 /// getSplatValue - If this is a splat constant, meaning that all of the
731 /// elements have the same value, return that value. Otherwise return NULL.
732 Constant *getSplatValue() const;
734 /// getType - Specialize the getType() method to always return a VectorType,
735 /// which reduces the amount of casting needed in parts of the compiler.
737 inline VectorType *getType() const {
738 return cast<VectorType>(Value::getType());
741 /// Methods for support type inquiry through isa, cast, and dyn_cast:
743 static bool classof(const Value *V) {
744 return V->getValueID() == ConstantDataVectorVal;
750 /// BlockAddress - The address of a basic block.
752 class BlockAddress : public Constant {
753 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
754 void *operator new(size_t s) { return User::operator new(s, 2); }
755 BlockAddress(Function *F, BasicBlock *BB);
757 /// get - Return a BlockAddress for the specified function and basic block.
758 static BlockAddress *get(Function *F, BasicBlock *BB);
760 /// get - Return a BlockAddress for the specified basic block. The basic
761 /// block must be embedded into a function.
762 static BlockAddress *get(BasicBlock *BB);
764 /// \brief Lookup an existing \c BlockAddress constant for the given
767 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.
768 static BlockAddress *lookup(const BasicBlock *BB);
770 /// Transparently provide more efficient getOperand methods.
771 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
773 Function *getFunction() const { return (Function*)Op<0>().get(); }
774 BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }
776 void destroyConstant() override;
777 void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) override;
779 /// Methods for support type inquiry through isa, cast, and dyn_cast:
780 static inline bool classof(const Value *V) {
781 return V->getValueID() == BlockAddressVal;
786 struct OperandTraits<BlockAddress> :
787 public FixedNumOperandTraits<BlockAddress, 2> {
790 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)
793 //===----------------------------------------------------------------------===//
794 /// ConstantExpr - a constant value that is initialized with an expression using
795 /// other constant values.
797 /// This class uses the standard Instruction opcodes to define the various
798 /// constant expressions. The Opcode field for the ConstantExpr class is
799 /// maintained in the Value::SubclassData field.
800 class ConstantExpr : public Constant {
801 friend struct ConstantExprKeyType;
804 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
805 : Constant(ty, ConstantExprVal, Ops, NumOps) {
806 // Operation type (an Instruction opcode) is stored as the SubclassData.
807 setValueSubclassData(Opcode);
811 // Static methods to construct a ConstantExpr of different kinds. Note that
812 // these methods may return a object that is not an instance of the
813 // ConstantExpr class, because they will attempt to fold the constant
814 // expression into something simpler if possible.
816 /// getAlignOf constant expr - computes the alignment of a type in a target
817 /// independent way (Note: the return type is an i64).
818 static Constant *getAlignOf(Type *Ty);
820 /// getSizeOf constant expr - computes the (alloc) size of a type (in
821 /// address-units, not bits) in a target independent way (Note: the return
824 static Constant *getSizeOf(Type *Ty);
826 /// getOffsetOf constant expr - computes the offset of a struct field in a
827 /// target independent way (Note: the return type is an i64).
829 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);
831 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
832 /// which supports any aggregate type, and any Constant index.
834 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);
836 static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);
837 static Constant *getFNeg(Constant *C);
838 static Constant *getNot(Constant *C);
839 static Constant *getAdd(Constant *C1, Constant *C2,
840 bool HasNUW = false, bool HasNSW = false);
841 static Constant *getFAdd(Constant *C1, Constant *C2);
842 static Constant *getSub(Constant *C1, Constant *C2,
843 bool HasNUW = false, bool HasNSW = false);
844 static Constant *getFSub(Constant *C1, Constant *C2);
845 static Constant *getMul(Constant *C1, Constant *C2,
846 bool HasNUW = false, bool HasNSW = false);
847 static Constant *getFMul(Constant *C1, Constant *C2);
848 static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);
849 static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);
850 static Constant *getFDiv(Constant *C1, Constant *C2);
851 static Constant *getURem(Constant *C1, Constant *C2);
852 static Constant *getSRem(Constant *C1, Constant *C2);
853 static Constant *getFRem(Constant *C1, Constant *C2);
854 static Constant *getAnd(Constant *C1, Constant *C2);
855 static Constant *getOr(Constant *C1, Constant *C2);
856 static Constant *getXor(Constant *C1, Constant *C2);
857 static Constant *getShl(Constant *C1, Constant *C2,
858 bool HasNUW = false, bool HasNSW = false);
859 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);
860 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);
861 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);
862 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
863 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
864 static Constant *getFPTrunc(Constant *C, Type *Ty,
865 bool OnlyIfReduced = false);
866 static Constant *getFPExtend(Constant *C, Type *Ty,
867 bool OnlyIfReduced = false);
868 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
869 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
870 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
871 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
872 static Constant *getPtrToInt(Constant *C, Type *Ty,
873 bool OnlyIfReduced = false);
874 static Constant *getIntToPtr(Constant *C, Type *Ty,
875 bool OnlyIfReduced = false);
876 static Constant *getBitCast(Constant *C, Type *Ty,
877 bool OnlyIfReduced = false);
878 static Constant *getAddrSpaceCast(Constant *C, Type *Ty,
879 bool OnlyIfReduced = false);
881 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }
882 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }
883 static Constant *getNSWAdd(Constant *C1, Constant *C2) {
884 return getAdd(C1, C2, false, true);
886 static Constant *getNUWAdd(Constant *C1, Constant *C2) {
887 return getAdd(C1, C2, true, false);
889 static Constant *getNSWSub(Constant *C1, Constant *C2) {
890 return getSub(C1, C2, false, true);
892 static Constant *getNUWSub(Constant *C1, Constant *C2) {
893 return getSub(C1, C2, true, false);
895 static Constant *getNSWMul(Constant *C1, Constant *C2) {
896 return getMul(C1, C2, false, true);
898 static Constant *getNUWMul(Constant *C1, Constant *C2) {
899 return getMul(C1, C2, true, false);
901 static Constant *getNSWShl(Constant *C1, Constant *C2) {
902 return getShl(C1, C2, false, true);
904 static Constant *getNUWShl(Constant *C1, Constant *C2) {
905 return getShl(C1, C2, true, false);
907 static Constant *getExactSDiv(Constant *C1, Constant *C2) {
908 return getSDiv(C1, C2, true);
910 static Constant *getExactUDiv(Constant *C1, Constant *C2) {
911 return getUDiv(C1, C2, true);
913 static Constant *getExactAShr(Constant *C1, Constant *C2) {
914 return getAShr(C1, C2, true);
916 static Constant *getExactLShr(Constant *C1, Constant *C2) {
917 return getLShr(C1, C2, true);
920 /// getBinOpIdentity - Return the identity for the given binary operation,
921 /// i.e. a constant C such that X op C = X and C op X = X for every X. It
922 /// returns null if the operator doesn't have an identity.
923 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty);
925 /// getBinOpAbsorber - Return the absorbing element for the given binary
926 /// operation, i.e. a constant C such that X op C = C and C op X = C for
927 /// every X. For example, this returns zero for integer multiplication.
928 /// It returns null if the operator doesn't have an absorbing element.
929 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
931 /// Transparently provide more efficient getOperand methods.
932 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
934 /// \brief Convenience function for getting a Cast operation.
936 /// \param ops The opcode for the conversion
937 /// \param C The constant to be converted
938 /// \param Ty The type to which the constant is converted
939 /// \param OnlyIfReduced see \a getWithOperands() docs.
940 static Constant *getCast(unsigned ops, Constant *C, Type *Ty,
941 bool OnlyIfReduced = false);
943 // @brief Create a ZExt or BitCast cast constant expression
944 static Constant *getZExtOrBitCast(
945 Constant *C, ///< The constant to zext or bitcast
946 Type *Ty ///< The type to zext or bitcast C to
949 // @brief Create a SExt or BitCast cast constant expression
950 static Constant *getSExtOrBitCast(
951 Constant *C, ///< The constant to sext or bitcast
952 Type *Ty ///< The type to sext or bitcast C to
955 // @brief Create a Trunc or BitCast cast constant expression
956 static Constant *getTruncOrBitCast(
957 Constant *C, ///< The constant to trunc or bitcast
958 Type *Ty ///< The type to trunc or bitcast C to
961 /// @brief Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant
963 static Constant *getPointerCast(
964 Constant *C, ///< The pointer value to be casted (operand 0)
965 Type *Ty ///< The type to which cast should be made
968 /// @brief Create a BitCast or AddrSpaceCast for a pointer type depending on
969 /// the address space.
970 static Constant *getPointerBitCastOrAddrSpaceCast(
971 Constant *C, ///< The constant to addrspacecast or bitcast
972 Type *Ty ///< The type to bitcast or addrspacecast C to
975 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
976 static Constant *getIntegerCast(
977 Constant *C, ///< The integer constant to be casted
978 Type *Ty, ///< The integer type to cast to
979 bool isSigned ///< Whether C should be treated as signed or not
982 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
983 static Constant *getFPCast(
984 Constant *C, ///< The integer constant to be casted
985 Type *Ty ///< The integer type to cast to
988 /// @brief Return true if this is a convert constant expression
991 /// @brief Return true if this is a compare constant expression
992 bool isCompare() const;
994 /// @brief Return true if this is an insertvalue or extractvalue expression,
995 /// and the getIndices() method may be used.
996 bool hasIndices() const;
998 /// @brief Return true if this is a getelementptr expression and all
999 /// the index operands are compile-time known integers within the
1000 /// corresponding notional static array extents. Note that this is
1001 /// not equivalant to, a subset of, or a superset of the "inbounds"
1003 bool isGEPWithNoNotionalOverIndexing() const;
1005 /// Select constant expr
1007 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1008 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2,
1009 Type *OnlyIfReducedTy = nullptr);
1011 /// get - Return a binary or shift operator constant expression,
1012 /// folding if possible.
1014 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1015 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
1016 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr);
1018 /// \brief Return an ICmp or FCmp comparison operator constant expression.
1020 /// \param OnlyIfReduced see \a getWithOperands() docs.
1021 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2,
1022 bool OnlyIfReduced = false);
1024 /// get* - Return some common constants without having to
1025 /// specify the full Instruction::OPCODE identifier.
1027 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS,
1028 bool OnlyIfReduced = false);
1029 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS,
1030 bool OnlyIfReduced = false);
1032 /// Getelementptr form. Value* is only accepted for convenience;
1033 /// all elements must be Constant's.
1035 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1036 static Constant *getGetElementPtr(Constant *C, ArrayRef<Constant *> IdxList,
1037 bool InBounds = false,
1038 Type *OnlyIfReducedTy = nullptr) {
1039 return getGetElementPtr(
1040 C, makeArrayRef((Value * const *)IdxList.data(), IdxList.size()),
1041 InBounds, OnlyIfReducedTy);
1043 static Constant *getGetElementPtr(Constant *C, Constant *Idx,
1044 bool InBounds = false,
1045 Type *OnlyIfReducedTy = nullptr) {
1046 // This form of the function only exists to avoid ambiguous overload
1047 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1048 // ArrayRef<Value *>.
1049 return getGetElementPtr(C, cast<Value>(Idx), InBounds, OnlyIfReducedTy);
1051 static Constant *getGetElementPtr(Constant *C, ArrayRef<Value *> IdxList,
1052 bool InBounds = false,
1053 Type *OnlyIfReducedTy = nullptr);
1055 /// Create an "inbounds" getelementptr. See the documentation for the
1056 /// "inbounds" flag in LangRef.html for details.
1057 static Constant *getInBoundsGetElementPtr(Constant *C,
1058 ArrayRef<Constant *> IdxList) {
1059 return getGetElementPtr(C, IdxList, true);
1061 static Constant *getInBoundsGetElementPtr(Constant *C,
1063 // This form of the function only exists to avoid ambiguous overload
1064 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1065 // ArrayRef<Value *>.
1066 return getGetElementPtr(C, Idx, true);
1068 static Constant *getInBoundsGetElementPtr(Constant *C,
1069 ArrayRef<Value *> IdxList) {
1070 return getGetElementPtr(C, IdxList, true);
1073 static Constant *getExtractElement(Constant *Vec, Constant *Idx,
1074 Type *OnlyIfReducedTy = nullptr);
1075 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx,
1076 Type *OnlyIfReducedTy = nullptr);
1077 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask,
1078 Type *OnlyIfReducedTy = nullptr);
1079 static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
1080 Type *OnlyIfReducedTy = nullptr);
1081 static Constant *getInsertValue(Constant *Agg, Constant *Val,
1082 ArrayRef<unsigned> Idxs,
1083 Type *OnlyIfReducedTy = nullptr);
1085 /// getOpcode - Return the opcode at the root of this constant expression
1086 unsigned getOpcode() const { return getSubclassDataFromValue(); }
1088 /// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
1089 /// not an ICMP or FCMP constant expression.
1090 unsigned getPredicate() const;
1092 /// getIndices - Assert that this is an insertvalue or exactvalue
1093 /// expression and return the list of indices.
1094 ArrayRef<unsigned> getIndices() const;
1096 /// getOpcodeName - Return a string representation for an opcode.
1097 const char *getOpcodeName() const;
1099 /// getWithOperandReplaced - Return a constant expression identical to this
1100 /// one, but with the specified operand set to the specified value.
1101 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
1103 /// getWithOperands - This returns the current constant expression with the
1104 /// operands replaced with the specified values. The specified array must
1105 /// have the same number of operands as our current one.
1106 Constant *getWithOperands(ArrayRef<Constant*> Ops) const {
1107 return getWithOperands(Ops, getType());
1110 /// \brief Get the current expression with the operands replaced.
1112 /// Return the current constant expression with the operands replaced with \c
1113 /// Ops and the type with \c Ty. The new operands must have the same number
1114 /// as the current ones.
1116 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something
1117 /// gets constant-folded, the type changes, or the expression is otherwise
1118 /// canonicalized. This parameter should almost always be \c false.
1119 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1120 bool OnlyIfReduced = false) const;
1122 /// getAsInstruction - Returns an Instruction which implements the same operation
1123 /// as this ConstantExpr. The instruction is not linked to any basic block.
1125 /// A better approach to this could be to have a constructor for Instruction
1126 /// which would take a ConstantExpr parameter, but that would have spread
1127 /// implementation details of ConstantExpr outside of Constants.cpp, which
1128 /// would make it harder to remove ConstantExprs altogether.
1129 Instruction *getAsInstruction();
1131 void destroyConstant() override;
1132 void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U) override;
1134 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1135 static inline bool classof(const Value *V) {
1136 return V->getValueID() == ConstantExprVal;
1140 // Shadow Value::setValueSubclassData with a private forwarding method so that
1141 // subclasses cannot accidentally use it.
1142 void setValueSubclassData(unsigned short D) {
1143 Value::setValueSubclassData(D);
1148 struct OperandTraits<ConstantExpr> :
1149 public VariadicOperandTraits<ConstantExpr, 1> {
1152 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant)
1154 //===----------------------------------------------------------------------===//
1155 /// UndefValue - 'undef' values are things that do not have specified contents.
1156 /// These are used for a variety of purposes, including global variable
1157 /// initializers and operands to instructions. 'undef' values can occur with
1158 /// any first-class type.
1160 /// Undef values aren't exactly constants; if they have multiple uses, they
1161 /// can appear to have different bit patterns at each use. See
1162 /// LangRef.html#undefvalues for details.
1164 class UndefValue : public Constant {
1165 void *operator new(size_t, unsigned) LLVM_DELETED_FUNCTION;
1166 UndefValue(const UndefValue &) LLVM_DELETED_FUNCTION;
1168 explicit UndefValue(Type *T) : Constant(T, UndefValueVal, nullptr, 0) {}
1170 // allocate space for exactly zero operands
1171 void *operator new(size_t s) {
1172 return User::operator new(s, 0);
1175 /// get() - Static factory methods - Return an 'undef' object of the specified
1178 static UndefValue *get(Type *T);
1180 /// getSequentialElement - If this Undef has array or vector type, return a
1181 /// undef with the right element type.
1182 UndefValue *getSequentialElement() const;
1184 /// getStructElement - If this undef has struct type, return a undef with the
1185 /// right element type for the specified element.
1186 UndefValue *getStructElement(unsigned Elt) const;
1188 /// getElementValue - Return an undef of the right value for the specified GEP
1190 UndefValue *getElementValue(Constant *C) const;
1192 /// getElementValue - Return an undef of the right value for the specified GEP
1194 UndefValue *getElementValue(unsigned Idx) const;
1196 void destroyConstant() override;
1198 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1199 static bool classof(const Value *V) {
1200 return V->getValueID() == UndefValueVal;
1204 } // End llvm namespace