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. Constants 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/ADT/None.h"
28 #include "llvm/ADT/Optional.h"
29 #include "llvm/ADT/STLExtras.h"
30 #include "llvm/ADT/StringRef.h"
31 #include "llvm/IR/Constant.h"
32 #include "llvm/IR/DerivedTypes.h"
33 #include "llvm/IR/OperandTraits.h"
34 #include "llvm/IR/User.h"
35 #include "llvm/IR/Value.h"
36 #include "llvm/Support/Casting.h"
37 #include "llvm/Support/Compiler.h"
38 #include "llvm/Support/ErrorHandling.h"
51 template <class ConstantClass> struct ConstantAggrKeyType;
53 /// Base class for constants with no operands.
55 /// These constants have no operands; they represent their data directly.
56 /// Since they can be in use by unrelated modules (and are never based on
57 /// GlobalValues), it never makes sense to RAUW them.
58 class ConstantData : public Constant {
59 friend class Constant;
61 Value *handleOperandChangeImpl(Value *From, Value *To) {
62 llvm_unreachable("Constant data does not have operands!");
66 explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {}
68 void *operator new(size_t s) { return User::operator new(s, 0); }
71 ConstantData(const ConstantData &) = delete;
73 /// Methods to support type inquiry through isa, cast, and dyn_cast.
74 static bool classof(const Value *V) {
75 return V->getValueID() >= ConstantDataFirstVal &&
76 V->getValueID() <= ConstantDataLastVal;
80 //===----------------------------------------------------------------------===//
81 /// This is the shared class of boolean and integer constants. This class
82 /// represents both boolean and integral constants.
83 /// @brief Class for constant integers.
84 class ConstantInt final : public ConstantData {
85 friend class Constant;
89 ConstantInt(IntegerType *Ty, const APInt& V);
91 void destroyConstantImpl();
94 ConstantInt(const ConstantInt &) = delete;
96 static ConstantInt *getTrue(LLVMContext &Context);
97 static ConstantInt *getFalse(LLVMContext &Context);
98 static Constant *getTrue(Type *Ty);
99 static Constant *getFalse(Type *Ty);
101 /// If Ty is a vector type, return a Constant with a splat of the given
102 /// value. Otherwise return a ConstantInt for the given value.
103 static Constant *get(Type *Ty, uint64_t V, bool isSigned = false);
105 /// Return a ConstantInt with the specified integer value for the specified
106 /// type. If the type is wider than 64 bits, the value will be zero-extended
107 /// to fit the type, unless isSigned is true, in which case the value will
108 /// be interpreted as a 64-bit signed integer and sign-extended to fit
110 /// @brief Get a ConstantInt for a specific value.
111 static ConstantInt *get(IntegerType *Ty, uint64_t V,
112 bool isSigned = false);
114 /// Return a ConstantInt with the specified value for the specified type. The
115 /// value V will be canonicalized to a an unsigned APInt. Accessing it with
116 /// either getSExtValue() or getZExtValue() will yield a correctly sized and
117 /// signed value for the type Ty.
118 /// @brief Get a ConstantInt for a specific signed value.
119 static ConstantInt *getSigned(IntegerType *Ty, int64_t V);
120 static Constant *getSigned(Type *Ty, int64_t V);
122 /// Return a ConstantInt with the specified value and an implied Type. The
123 /// type is the integer type that corresponds to the bit width of the value.
124 static ConstantInt *get(LLVMContext &Context, const APInt &V);
126 /// Return a ConstantInt constructed from the string strStart with the given
128 static ConstantInt *get(IntegerType *Ty, StringRef Str,
131 /// If Ty is a vector type, return a Constant with a splat of the given
132 /// value. Otherwise return a ConstantInt for the given value.
133 static Constant *get(Type* Ty, const APInt& V);
135 /// Return the constant as an APInt value reference. This allows clients to
136 /// obtain a full-precision copy of the value.
137 /// @brief Return the constant's value.
138 inline const APInt &getValue() const {
142 /// getBitWidth - Return the bitwidth of this constant.
143 unsigned getBitWidth() const { return Val.getBitWidth(); }
145 /// Return the constant as a 64-bit unsigned integer value after it
146 /// has been zero extended as appropriate for the type of this constant. Note
147 /// that this method can assert if the value does not fit in 64 bits.
148 /// @brief Return the zero extended value.
149 inline uint64_t getZExtValue() const {
150 return Val.getZExtValue();
153 /// Return the constant as a 64-bit integer value after it has been sign
154 /// extended as appropriate for the type of this constant. Note that
155 /// this method can assert if the value does not fit in 64 bits.
156 /// @brief Return the sign extended value.
157 inline int64_t getSExtValue() const {
158 return Val.getSExtValue();
161 /// A helper method that can be used to determine if the constant contained
162 /// within is equal to a constant. This only works for very small values,
163 /// because this is all that can be represented with all types.
164 /// @brief Determine if this constant's value is same as an unsigned char.
165 bool equalsInt(uint64_t V) const {
169 /// getType - Specialize the getType() method to always return an IntegerType,
170 /// which reduces the amount of casting needed in parts of the compiler.
172 inline IntegerType *getType() const {
173 return cast<IntegerType>(Value::getType());
176 /// This static method returns true if the type Ty is big enough to
177 /// represent the value V. This can be used to avoid having the get method
178 /// assert when V is larger than Ty can represent. Note that there are two
179 /// versions of this method, one for unsigned and one for signed integers.
180 /// Although ConstantInt canonicalizes everything to an unsigned integer,
181 /// the signed version avoids callers having to convert a signed quantity
182 /// to the appropriate unsigned type before calling the method.
183 /// @returns true if V is a valid value for type Ty
184 /// @brief Determine if the value is in range for the given type.
185 static bool isValueValidForType(Type *Ty, uint64_t V);
186 static bool isValueValidForType(Type *Ty, int64_t V);
188 bool isNegative() const { return Val.isNegative(); }
190 /// This is just a convenience method to make client code smaller for a
191 /// common code. It also correctly performs the comparison without the
192 /// potential for an assertion from getZExtValue().
193 bool isZero() const {
194 return Val.isNullValue();
197 /// This is just a convenience method to make client code smaller for a
198 /// common case. It also correctly performs the comparison without the
199 /// potential for an assertion from getZExtValue().
200 /// @brief Determine if the value is one.
202 return Val.isOneValue();
205 /// This function will return true iff every bit in this constant is set
207 /// @returns true iff this constant's bits are all set to true.
208 /// @brief Determine if the value is all ones.
209 bool isMinusOne() const {
210 return Val.isAllOnesValue();
213 /// This function will return true iff this constant represents the largest
214 /// value that may be represented by the constant's type.
215 /// @returns true iff this is the largest value that may be represented
217 /// @brief Determine if the value is maximal.
218 bool isMaxValue(bool isSigned) const {
220 return Val.isMaxSignedValue();
222 return Val.isMaxValue();
225 /// This function will return true iff this constant represents the smallest
226 /// value that may be represented by this constant's type.
227 /// @returns true if this is the smallest value that may be represented by
229 /// @brief Determine if the value is minimal.
230 bool isMinValue(bool isSigned) const {
232 return Val.isMinSignedValue();
234 return Val.isMinValue();
237 /// This function will return true iff this constant represents a value with
238 /// active bits bigger than 64 bits or a value greater than the given uint64_t
240 /// @returns true iff this constant is greater or equal to the given number.
241 /// @brief Determine if the value is greater or equal to the given number.
242 bool uge(uint64_t Num) const {
246 /// getLimitedValue - If the value is smaller than the specified limit,
247 /// return it, otherwise return the limit value. This causes the value
248 /// to saturate to the limit.
249 /// @returns the min of the value of the constant and the specified value
250 /// @brief Get the constant's value with a saturation limit
251 uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
252 return Val.getLimitedValue(Limit);
255 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
256 static bool classof(const Value *V) {
257 return V->getValueID() == ConstantIntVal;
261 //===----------------------------------------------------------------------===//
262 /// ConstantFP - Floating Point Values [float, double]
264 class ConstantFP final : public ConstantData {
265 friend class Constant;
269 ConstantFP(Type *Ty, const APFloat& V);
271 void destroyConstantImpl();
274 ConstantFP(const ConstantFP &) = delete;
276 /// Floating point negation must be implemented with f(x) = -0.0 - x. This
277 /// method returns the negative zero constant for floating point or vector
278 /// floating point types; for all other types, it returns the null value.
279 static Constant *getZeroValueForNegation(Type *Ty);
281 /// This returns a ConstantFP, or a vector containing a splat of a ConstantFP,
282 /// for the specified value in the specified type. This should only be used
283 /// for simple constant values like 2.0/1.0 etc, that are known-valid both as
284 /// host double and as the target format.
285 static Constant *get(Type* Ty, double V);
286 static Constant *get(Type* Ty, StringRef Str);
287 static ConstantFP *get(LLVMContext &Context, const APFloat &V);
288 static Constant *getNaN(Type *Ty, bool Negative = false, unsigned type = 0);
289 static Constant *getNegativeZero(Type *Ty);
290 static Constant *getInfinity(Type *Ty, bool Negative = false);
292 /// Return true if Ty is big enough to represent V.
293 static bool isValueValidForType(Type *Ty, const APFloat &V);
294 inline const APFloat &getValueAPF() const { return Val; }
296 /// Return true if the value is positive or negative zero.
297 bool isZero() const { return Val.isZero(); }
299 /// Return true if the sign bit is set.
300 bool isNegative() const { return Val.isNegative(); }
302 /// Return true if the value is infinity
303 bool isInfinity() const { return Val.isInfinity(); }
305 /// Return true if the value is a NaN.
306 bool isNaN() const { return Val.isNaN(); }
308 /// We don't rely on operator== working on double values, as it returns true
309 /// for things that are clearly not equal, like -0.0 and 0.0.
310 /// As such, this method can be used to do an exact bit-for-bit comparison of
311 /// two floating point values. The version with a double operand is retained
312 /// because it's so convenient to write isExactlyValue(2.0), but please use
313 /// it only for simple constants.
314 bool isExactlyValue(const APFloat &V) const;
316 bool isExactlyValue(double V) const {
319 FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
320 return isExactlyValue(FV);
323 /// Methods for support type inquiry through isa, cast, and dyn_cast:
324 static bool classof(const Value *V) {
325 return V->getValueID() == ConstantFPVal;
329 //===----------------------------------------------------------------------===//
330 /// All zero aggregate value
332 class ConstantAggregateZero final : public ConstantData {
333 friend class Constant;
335 explicit ConstantAggregateZero(Type *Ty)
336 : ConstantData(Ty, ConstantAggregateZeroVal) {}
338 void destroyConstantImpl();
341 ConstantAggregateZero(const ConstantAggregateZero &) = delete;
343 static ConstantAggregateZero *get(Type *Ty);
345 /// If this CAZ has array or vector type, return a zero with the right element
347 Constant *getSequentialElement() const;
349 /// If this CAZ has struct type, return a zero with the right element type for
350 /// the specified element.
351 Constant *getStructElement(unsigned Elt) const;
353 /// Return a zero of the right value for the specified GEP index if we can,
354 /// otherwise return null (e.g. if C is a ConstantExpr).
355 Constant *getElementValue(Constant *C) const;
357 /// Return a zero of the right value for the specified GEP index.
358 Constant *getElementValue(unsigned Idx) const;
360 /// Return the number of elements in the array, vector, or struct.
361 unsigned getNumElements() const;
363 /// Methods for support type inquiry through isa, cast, and dyn_cast:
365 static bool classof(const Value *V) {
366 return V->getValueID() == ConstantAggregateZeroVal;
370 /// Base class for aggregate constants (with operands).
372 /// These constants are aggregates of other constants, which are stored as
375 /// Subclasses are \a ConstantStruct, \a ConstantArray, and \a
378 /// \note Some subclasses of \a ConstantData are semantically aggregates --
379 /// such as \a ConstantDataArray -- but are not subclasses of this because they
381 class ConstantAggregate : public Constant {
383 ConstantAggregate(CompositeType *T, ValueTy VT, ArrayRef<Constant *> V);
386 /// Transparently provide more efficient getOperand methods.
387 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
389 /// Methods for support type inquiry through isa, cast, and dyn_cast:
390 static bool classof(const Value *V) {
391 return V->getValueID() >= ConstantAggregateFirstVal &&
392 V->getValueID() <= ConstantAggregateLastVal;
397 struct OperandTraits<ConstantAggregate>
398 : public VariadicOperandTraits<ConstantAggregate> {};
400 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant)
402 //===----------------------------------------------------------------------===//
403 /// ConstantArray - Constant Array Declarations
405 class ConstantArray final : public ConstantAggregate {
406 friend struct ConstantAggrKeyType<ConstantArray>;
407 friend class Constant;
409 ConstantArray(ArrayType *T, ArrayRef<Constant *> Val);
411 void destroyConstantImpl();
412 Value *handleOperandChangeImpl(Value *From, Value *To);
415 // ConstantArray accessors
416 static Constant *get(ArrayType *T, ArrayRef<Constant*> V);
419 static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V);
422 /// Specialize the getType() method to always return an ArrayType,
423 /// which reduces the amount of casting needed in parts of the compiler.
424 inline ArrayType *getType() const {
425 return cast<ArrayType>(Value::getType());
428 /// Methods for support type inquiry through isa, cast, and dyn_cast:
429 static bool classof(const Value *V) {
430 return V->getValueID() == ConstantArrayVal;
434 //===----------------------------------------------------------------------===//
435 // Constant Struct Declarations
437 class ConstantStruct final : public ConstantAggregate {
438 friend struct ConstantAggrKeyType<ConstantStruct>;
439 friend class Constant;
441 ConstantStruct(StructType *T, ArrayRef<Constant *> Val);
443 void destroyConstantImpl();
444 Value *handleOperandChangeImpl(Value *From, Value *To);
447 // ConstantStruct accessors
448 static Constant *get(StructType *T, ArrayRef<Constant*> V);
450 template <typename... Csts>
451 static typename std::enable_if<are_base_of<Constant, Csts...>::value,
453 get(StructType *T, Csts *... Vs) {
454 SmallVector<Constant *, 8> Values({Vs...});
455 return get(T, Values);
458 /// Return an anonymous struct that has the specified elements.
459 /// If the struct is possibly empty, then you must specify a context.
460 static Constant *getAnon(ArrayRef<Constant*> V, bool Packed = false) {
461 return get(getTypeForElements(V, Packed), V);
463 static Constant *getAnon(LLVMContext &Ctx,
464 ArrayRef<Constant*> V, bool Packed = false) {
465 return get(getTypeForElements(Ctx, V, Packed), V);
468 /// Return an anonymous struct type to use for a constant with the specified
469 /// set of elements. The list must not be empty.
470 static StructType *getTypeForElements(ArrayRef<Constant*> V,
471 bool Packed = false);
472 /// This version of the method allows an empty list.
473 static StructType *getTypeForElements(LLVMContext &Ctx,
474 ArrayRef<Constant*> V,
475 bool Packed = false);
477 /// Specialization - reduce amount of casting.
478 inline StructType *getType() const {
479 return cast<StructType>(Value::getType());
482 /// Methods for support type inquiry through isa, cast, and dyn_cast:
483 static bool classof(const Value *V) {
484 return V->getValueID() == ConstantStructVal;
488 //===----------------------------------------------------------------------===//
489 /// Constant Vector Declarations
491 class ConstantVector final : public ConstantAggregate {
492 friend struct ConstantAggrKeyType<ConstantVector>;
493 friend class Constant;
495 ConstantVector(VectorType *T, ArrayRef<Constant *> Val);
497 void destroyConstantImpl();
498 Value *handleOperandChangeImpl(Value *From, Value *To);
501 // ConstantVector accessors
502 static Constant *get(ArrayRef<Constant*> V);
505 static Constant *getImpl(ArrayRef<Constant *> V);
508 /// Return a ConstantVector with the specified constant in each element.
509 static Constant *getSplat(unsigned NumElts, Constant *Elt);
511 /// Specialize the getType() method to always return a VectorType,
512 /// which reduces the amount of casting needed in parts of the compiler.
513 inline VectorType *getType() const {
514 return cast<VectorType>(Value::getType());
517 /// If this is a splat constant, meaning that all of the elements have the
518 /// same value, return that value. Otherwise return NULL.
519 Constant *getSplatValue() const;
521 /// Methods for support type inquiry through isa, cast, and dyn_cast:
522 static bool classof(const Value *V) {
523 return V->getValueID() == ConstantVectorVal;
527 //===----------------------------------------------------------------------===//
528 /// A constant pointer value that points to null
530 class ConstantPointerNull final : public ConstantData {
531 friend class Constant;
533 explicit ConstantPointerNull(PointerType *T)
534 : ConstantData(T, Value::ConstantPointerNullVal) {}
536 void destroyConstantImpl();
539 ConstantPointerNull(const ConstantPointerNull &) = delete;
541 /// Static factory methods - Return objects of the specified value
542 static ConstantPointerNull *get(PointerType *T);
544 /// Specialize the getType() method to always return an PointerType,
545 /// which reduces the amount of casting needed in parts of the compiler.
546 inline PointerType *getType() const {
547 return cast<PointerType>(Value::getType());
550 /// Methods for support type inquiry through isa, cast, and dyn_cast:
551 static bool classof(const Value *V) {
552 return V->getValueID() == ConstantPointerNullVal;
556 //===----------------------------------------------------------------------===//
557 /// ConstantDataSequential - A vector or array constant whose element type is a
558 /// simple 1/2/4/8-byte integer or float/double, and whose elements are just
559 /// simple data values (i.e. ConstantInt/ConstantFP). This Constant node has no
560 /// operands because it stores all of the elements of the constant as densely
561 /// packed data, instead of as Value*'s.
563 /// This is the common base class of ConstantDataArray and ConstantDataVector.
565 class ConstantDataSequential : public ConstantData {
566 friend class LLVMContextImpl;
567 friend class Constant;
569 /// A pointer to the bytes underlying this constant (which is owned by the
570 /// uniquing StringMap).
571 const char *DataElements;
573 /// This forms a link list of ConstantDataSequential nodes that have
574 /// the same value but different type. For example, 0,0,0,1 could be a 4
575 /// element array of i8, or a 1-element array of i32. They'll both end up in
576 /// the same StringMap bucket, linked up.
577 ConstantDataSequential *Next;
579 void destroyConstantImpl();
582 explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
583 : ConstantData(ty, VT), DataElements(Data), Next(nullptr) {}
584 ~ConstantDataSequential() { delete Next; }
586 static Constant *getImpl(StringRef Bytes, Type *Ty);
589 ConstantDataSequential(const ConstantDataSequential &) = delete;
591 /// Return true if a ConstantDataSequential can be formed with a vector or
592 /// array of the specified element type.
593 /// ConstantDataArray only works with normal float and int types that are
594 /// stored densely in memory, not with things like i42 or x86_f80.
595 static bool isElementTypeCompatible(Type *Ty);
597 /// If this is a sequential container of integers (of any size), return the
598 /// specified element in the low bits of a uint64_t.
599 uint64_t getElementAsInteger(unsigned i) const;
601 /// If this is a sequential container of floating point type, return the
602 /// specified element as an APFloat.
603 APFloat getElementAsAPFloat(unsigned i) const;
605 /// If this is an sequential container of floats, return the specified element
607 float getElementAsFloat(unsigned i) const;
609 /// If this is an sequential container of doubles, return the specified
610 /// element as a double.
611 double getElementAsDouble(unsigned i) const;
613 /// Return a Constant for a specified index's element.
614 /// Note that this has to compute a new constant to return, so it isn't as
615 /// efficient as getElementAsInteger/Float/Double.
616 Constant *getElementAsConstant(unsigned i) const;
618 /// Specialize the getType() method to always return a SequentialType, which
619 /// reduces the amount of casting needed in parts of the compiler.
620 inline SequentialType *getType() const {
621 return cast<SequentialType>(Value::getType());
624 /// Return the element type of the array/vector.
625 Type *getElementType() const;
627 /// Return the number of elements in the array or vector.
628 unsigned getNumElements() const;
630 /// Return the size (in bytes) of each element in the array/vector.
631 /// The size of the elements is known to be a multiple of one byte.
632 uint64_t getElementByteSize() const;
634 /// This method returns true if this is an array of \p CharSize integers.
635 bool isString(unsigned CharSize = 8) const;
637 /// This method returns true if the array "isString", ends with a null byte,
638 /// and does not contains any other null bytes.
639 bool isCString() const;
641 /// If this array is isString(), then this method returns the array as a
642 /// StringRef. Otherwise, it asserts out.
643 StringRef getAsString() const {
644 assert(isString() && "Not a string");
645 return getRawDataValues();
648 /// If this array is isCString(), then this method returns the array (without
649 /// the trailing null byte) as a StringRef. Otherwise, it asserts out.
650 StringRef getAsCString() const {
651 assert(isCString() && "Isn't a C string");
652 StringRef Str = getAsString();
653 return Str.substr(0, Str.size()-1);
656 /// Return the raw, underlying, bytes of this data. Note that this is an
657 /// extremely tricky thing to work with, as it exposes the host endianness of
658 /// the data elements.
659 StringRef getRawDataValues() const;
661 /// Methods for support type inquiry through isa, cast, and dyn_cast:
662 static bool classof(const Value *V) {
663 return V->getValueID() == ConstantDataArrayVal ||
664 V->getValueID() == ConstantDataVectorVal;
668 const char *getElementPointer(unsigned Elt) const;
671 //===----------------------------------------------------------------------===//
672 /// An array constant whose element type is a simple 1/2/4/8-byte integer or
673 /// float/double, and whose elements are just simple data values
674 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
675 /// stores all of the elements of the constant as densely packed data, instead
677 class ConstantDataArray final : public ConstantDataSequential {
678 friend class ConstantDataSequential;
680 explicit ConstantDataArray(Type *ty, const char *Data)
681 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
683 /// Allocate space for exactly zero operands.
684 void *operator new(size_t s) {
685 return User::operator new(s, 0);
689 ConstantDataArray(const ConstantDataArray &) = delete;
691 /// get() constructors - Return a constant with array type with an element
692 /// count and element type matching the ArrayRef passed in. Note that this
693 /// can return a ConstantAggregateZero object.
694 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
695 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
696 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
697 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
698 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
699 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
701 /// getFP() constructors - Return a constant with array type with an element
702 /// count and element type of float with precision matching the number of
703 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
704 /// double for 64bits) Note that this can return a ConstantAggregateZero
706 static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
707 static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
708 static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
710 /// This method constructs a CDS and initializes it with a text string.
711 /// The default behavior (AddNull==true) causes a null terminator to
712 /// be placed at the end of the array (increasing the length of the string by
713 /// one more than the StringRef would normally indicate. Pass AddNull=false
714 /// to disable this behavior.
715 static Constant *getString(LLVMContext &Context, StringRef Initializer,
716 bool AddNull = true);
718 /// Specialize the getType() method to always return an ArrayType,
719 /// which reduces the amount of casting needed in parts of the compiler.
720 inline ArrayType *getType() const {
721 return cast<ArrayType>(Value::getType());
724 /// Methods for support type inquiry through isa, cast, and dyn_cast:
725 static bool classof(const Value *V) {
726 return V->getValueID() == ConstantDataArrayVal;
730 //===----------------------------------------------------------------------===//
731 /// A vector constant whose element type is a simple 1/2/4/8-byte integer or
732 /// float/double, and whose elements are just simple data values
733 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
734 /// stores all of the elements of the constant as densely packed data, instead
736 class ConstantDataVector final : public ConstantDataSequential {
737 friend class ConstantDataSequential;
739 explicit ConstantDataVector(Type *ty, const char *Data)
740 : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}
742 // allocate space for exactly zero operands.
743 void *operator new(size_t s) {
744 return User::operator new(s, 0);
748 ConstantDataVector(const ConstantDataVector &) = delete;
750 /// get() constructors - Return a constant with vector type with an element
751 /// count and element type matching the ArrayRef passed in. Note that this
752 /// can return a ConstantAggregateZero object.
753 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
754 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
755 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
756 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
757 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
758 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
760 /// getFP() constructors - Return a constant with vector type with an element
761 /// count and element type of float with the precision matching the number of
762 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
763 /// double for 64bits) Note that this can return a ConstantAggregateZero
765 static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
766 static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
767 static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
769 /// Return a ConstantVector with the specified constant in each element.
770 /// The specified constant has to be a of a compatible type (i8/i16/
771 /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.
772 static Constant *getSplat(unsigned NumElts, Constant *Elt);
774 /// If this is a splat constant, meaning that all of the elements have the
775 /// same value, return that value. Otherwise return NULL.
776 Constant *getSplatValue() const;
778 /// Specialize the getType() method to always return a VectorType,
779 /// which reduces the amount of casting needed in parts of the compiler.
780 inline VectorType *getType() const {
781 return cast<VectorType>(Value::getType());
784 /// Methods for support type inquiry through isa, cast, and dyn_cast:
785 static bool classof(const Value *V) {
786 return V->getValueID() == ConstantDataVectorVal;
790 //===----------------------------------------------------------------------===//
791 /// A constant token which is empty
793 class ConstantTokenNone final : public ConstantData {
794 friend class Constant;
796 explicit ConstantTokenNone(LLVMContext &Context)
797 : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {}
799 void destroyConstantImpl();
802 ConstantTokenNone(const ConstantTokenNone &) = delete;
804 /// Return the ConstantTokenNone.
805 static ConstantTokenNone *get(LLVMContext &Context);
807 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
808 static bool classof(const Value *V) {
809 return V->getValueID() == ConstantTokenNoneVal;
813 /// The address of a basic block.
815 class BlockAddress final : public Constant {
816 friend class Constant;
818 BlockAddress(Function *F, BasicBlock *BB);
820 void *operator new(size_t s) { return User::operator new(s, 2); }
822 void destroyConstantImpl();
823 Value *handleOperandChangeImpl(Value *From, Value *To);
826 /// Return a BlockAddress for the specified function and basic block.
827 static BlockAddress *get(Function *F, BasicBlock *BB);
829 /// Return a BlockAddress for the specified basic block. The basic
830 /// block must be embedded into a function.
831 static BlockAddress *get(BasicBlock *BB);
833 /// Lookup an existing \c BlockAddress constant for the given BasicBlock.
835 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.
836 static BlockAddress *lookup(const BasicBlock *BB);
838 /// Transparently provide more efficient getOperand methods.
839 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
841 Function *getFunction() const { return (Function*)Op<0>().get(); }
842 BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }
844 /// Methods for support type inquiry through isa, cast, and dyn_cast:
845 static bool classof(const Value *V) {
846 return V->getValueID() == BlockAddressVal;
851 struct OperandTraits<BlockAddress> :
852 public FixedNumOperandTraits<BlockAddress, 2> {
855 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)
857 //===----------------------------------------------------------------------===//
858 /// A constant value that is initialized with an expression using
859 /// other constant values.
861 /// This class uses the standard Instruction opcodes to define the various
862 /// constant expressions. The Opcode field for the ConstantExpr class is
863 /// maintained in the Value::SubclassData field.
864 class ConstantExpr : public Constant {
865 friend struct ConstantExprKeyType;
866 friend class Constant;
868 void destroyConstantImpl();
869 Value *handleOperandChangeImpl(Value *From, Value *To);
872 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
873 : Constant(ty, ConstantExprVal, Ops, NumOps) {
874 // Operation type (an Instruction opcode) is stored as the SubclassData.
875 setValueSubclassData(Opcode);
879 // Static methods to construct a ConstantExpr of different kinds. Note that
880 // these methods may return a object that is not an instance of the
881 // ConstantExpr class, because they will attempt to fold the constant
882 // expression into something simpler if possible.
884 /// getAlignOf constant expr - computes the alignment of a type in a target
885 /// independent way (Note: the return type is an i64).
886 static Constant *getAlignOf(Type *Ty);
888 /// getSizeOf constant expr - computes the (alloc) size of a type (in
889 /// address-units, not bits) in a target independent way (Note: the return
892 static Constant *getSizeOf(Type *Ty);
894 /// getOffsetOf constant expr - computes the offset of a struct field in a
895 /// target independent way (Note: the return type is an i64).
897 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);
899 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
900 /// which supports any aggregate type, and any Constant index.
902 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);
904 static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);
905 static Constant *getFNeg(Constant *C);
906 static Constant *getNot(Constant *C);
907 static Constant *getAdd(Constant *C1, Constant *C2,
908 bool HasNUW = false, bool HasNSW = false);
909 static Constant *getFAdd(Constant *C1, Constant *C2);
910 static Constant *getSub(Constant *C1, Constant *C2,
911 bool HasNUW = false, bool HasNSW = false);
912 static Constant *getFSub(Constant *C1, Constant *C2);
913 static Constant *getMul(Constant *C1, Constant *C2,
914 bool HasNUW = false, bool HasNSW = false);
915 static Constant *getFMul(Constant *C1, Constant *C2);
916 static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);
917 static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);
918 static Constant *getFDiv(Constant *C1, Constant *C2);
919 static Constant *getURem(Constant *C1, Constant *C2);
920 static Constant *getSRem(Constant *C1, Constant *C2);
921 static Constant *getFRem(Constant *C1, Constant *C2);
922 static Constant *getAnd(Constant *C1, Constant *C2);
923 static Constant *getOr(Constant *C1, Constant *C2);
924 static Constant *getXor(Constant *C1, Constant *C2);
925 static Constant *getShl(Constant *C1, Constant *C2,
926 bool HasNUW = false, bool HasNSW = false);
927 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);
928 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);
929 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);
930 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
931 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
932 static Constant *getFPTrunc(Constant *C, Type *Ty,
933 bool OnlyIfReduced = false);
934 static Constant *getFPExtend(Constant *C, Type *Ty,
935 bool OnlyIfReduced = false);
936 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
937 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
938 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
939 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
940 static Constant *getPtrToInt(Constant *C, Type *Ty,
941 bool OnlyIfReduced = false);
942 static Constant *getIntToPtr(Constant *C, Type *Ty,
943 bool OnlyIfReduced = false);
944 static Constant *getBitCast(Constant *C, Type *Ty,
945 bool OnlyIfReduced = false);
946 static Constant *getAddrSpaceCast(Constant *C, Type *Ty,
947 bool OnlyIfReduced = false);
949 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }
950 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }
952 static Constant *getNSWAdd(Constant *C1, Constant *C2) {
953 return getAdd(C1, C2, false, true);
956 static Constant *getNUWAdd(Constant *C1, Constant *C2) {
957 return getAdd(C1, C2, true, false);
960 static Constant *getNSWSub(Constant *C1, Constant *C2) {
961 return getSub(C1, C2, false, true);
964 static Constant *getNUWSub(Constant *C1, Constant *C2) {
965 return getSub(C1, C2, true, false);
968 static Constant *getNSWMul(Constant *C1, Constant *C2) {
969 return getMul(C1, C2, false, true);
972 static Constant *getNUWMul(Constant *C1, Constant *C2) {
973 return getMul(C1, C2, true, false);
976 static Constant *getNSWShl(Constant *C1, Constant *C2) {
977 return getShl(C1, C2, false, true);
980 static Constant *getNUWShl(Constant *C1, Constant *C2) {
981 return getShl(C1, C2, true, false);
984 static Constant *getExactSDiv(Constant *C1, Constant *C2) {
985 return getSDiv(C1, C2, true);
988 static Constant *getExactUDiv(Constant *C1, Constant *C2) {
989 return getUDiv(C1, C2, true);
992 static Constant *getExactAShr(Constant *C1, Constant *C2) {
993 return getAShr(C1, C2, true);
996 static Constant *getExactLShr(Constant *C1, Constant *C2) {
997 return getLShr(C1, C2, true);
1000 /// Return the identity for the given binary operation,
1001 /// i.e. a constant C such that X op C = X and C op X = X for every X. It
1002 /// returns null if the operator doesn't have an identity.
1003 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty);
1005 /// Return the absorbing element for the given binary
1006 /// operation, i.e. a constant C such that X op C = C and C op X = C for
1007 /// every X. For example, this returns zero for integer multiplication.
1008 /// It returns null if the operator doesn't have an absorbing element.
1009 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
1011 /// Transparently provide more efficient getOperand methods.
1012 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
1014 /// \brief Convenience function for getting a Cast operation.
1016 /// \param ops The opcode for the conversion
1017 /// \param C The constant to be converted
1018 /// \param Ty The type to which the constant is converted
1019 /// \param OnlyIfReduced see \a getWithOperands() docs.
1020 static Constant *getCast(unsigned ops, Constant *C, Type *Ty,
1021 bool OnlyIfReduced = false);
1023 // @brief Create a ZExt or BitCast cast constant expression
1024 static Constant *getZExtOrBitCast(
1025 Constant *C, ///< The constant to zext or bitcast
1026 Type *Ty ///< The type to zext or bitcast C to
1029 // @brief Create a SExt or BitCast cast constant expression
1030 static Constant *getSExtOrBitCast(
1031 Constant *C, ///< The constant to sext or bitcast
1032 Type *Ty ///< The type to sext or bitcast C to
1035 // @brief Create a Trunc or BitCast cast constant expression
1036 static Constant *getTruncOrBitCast(
1037 Constant *C, ///< The constant to trunc or bitcast
1038 Type *Ty ///< The type to trunc or bitcast C to
1041 /// @brief Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant
1043 static Constant *getPointerCast(
1044 Constant *C, ///< The pointer value to be casted (operand 0)
1045 Type *Ty ///< The type to which cast should be made
1048 /// @brief Create a BitCast or AddrSpaceCast for a pointer type depending on
1049 /// the address space.
1050 static Constant *getPointerBitCastOrAddrSpaceCast(
1051 Constant *C, ///< The constant to addrspacecast or bitcast
1052 Type *Ty ///< The type to bitcast or addrspacecast C to
1055 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
1056 static Constant *getIntegerCast(
1057 Constant *C, ///< The integer constant to be casted
1058 Type *Ty, ///< The integer type to cast to
1059 bool isSigned ///< Whether C should be treated as signed or not
1062 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
1063 static Constant *getFPCast(
1064 Constant *C, ///< The integer constant to be casted
1065 Type *Ty ///< The integer type to cast to
1068 /// @brief Return true if this is a convert constant expression
1069 bool isCast() const;
1071 /// @brief Return true if this is a compare constant expression
1072 bool isCompare() const;
1074 /// @brief Return true if this is an insertvalue or extractvalue expression,
1075 /// and the getIndices() method may be used.
1076 bool hasIndices() const;
1078 /// @brief Return true if this is a getelementptr expression and all
1079 /// the index operands are compile-time known integers within the
1080 /// corresponding notional static array extents. Note that this is
1081 /// not equivalant to, a subset of, or a superset of the "inbounds"
1083 bool isGEPWithNoNotionalOverIndexing() const;
1085 /// Select constant expr
1087 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1088 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2,
1089 Type *OnlyIfReducedTy = nullptr);
1091 /// get - Return a binary or shift operator constant expression,
1092 /// folding if possible.
1094 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1095 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
1096 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr);
1098 /// \brief Return an ICmp or FCmp comparison operator constant expression.
1100 /// \param OnlyIfReduced see \a getWithOperands() docs.
1101 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2,
1102 bool OnlyIfReduced = false);
1104 /// get* - Return some common constants without having to
1105 /// specify the full Instruction::OPCODE identifier.
1107 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS,
1108 bool OnlyIfReduced = false);
1109 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS,
1110 bool OnlyIfReduced = false);
1112 /// Getelementptr form. Value* is only accepted for convenience;
1113 /// all elements must be Constants.
1115 /// \param InRangeIndex the inrange index if present or None.
1116 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1117 static Constant *getGetElementPtr(Type *Ty, Constant *C,
1118 ArrayRef<Constant *> IdxList,
1119 bool InBounds = false,
1120 Optional<unsigned> InRangeIndex = None,
1121 Type *OnlyIfReducedTy = nullptr) {
1122 return getGetElementPtr(
1123 Ty, C, makeArrayRef((Value * const *)IdxList.data(), IdxList.size()),
1124 InBounds, InRangeIndex, OnlyIfReducedTy);
1126 static Constant *getGetElementPtr(Type *Ty, Constant *C, Constant *Idx,
1127 bool InBounds = false,
1128 Optional<unsigned> InRangeIndex = None,
1129 Type *OnlyIfReducedTy = nullptr) {
1130 // This form of the function only exists to avoid ambiguous overload
1131 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1132 // ArrayRef<Value *>.
1133 return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, InRangeIndex,
1136 static Constant *getGetElementPtr(Type *Ty, Constant *C,
1137 ArrayRef<Value *> IdxList,
1138 bool InBounds = false,
1139 Optional<unsigned> InRangeIndex = None,
1140 Type *OnlyIfReducedTy = nullptr);
1142 /// Create an "inbounds" getelementptr. See the documentation for the
1143 /// "inbounds" flag in LangRef.html for details.
1144 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1145 ArrayRef<Constant *> IdxList) {
1146 return getGetElementPtr(Ty, C, IdxList, true);
1148 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1150 // This form of the function only exists to avoid ambiguous overload
1151 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1152 // ArrayRef<Value *>.
1153 return getGetElementPtr(Ty, C, Idx, true);
1155 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1156 ArrayRef<Value *> IdxList) {
1157 return getGetElementPtr(Ty, C, IdxList, true);
1160 static Constant *getExtractElement(Constant *Vec, Constant *Idx,
1161 Type *OnlyIfReducedTy = nullptr);
1162 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx,
1163 Type *OnlyIfReducedTy = nullptr);
1164 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask,
1165 Type *OnlyIfReducedTy = nullptr);
1166 static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
1167 Type *OnlyIfReducedTy = nullptr);
1168 static Constant *getInsertValue(Constant *Agg, Constant *Val,
1169 ArrayRef<unsigned> Idxs,
1170 Type *OnlyIfReducedTy = nullptr);
1172 /// Return the opcode at the root of this constant expression
1173 unsigned getOpcode() const { return getSubclassDataFromValue(); }
1175 /// Return the ICMP or FCMP predicate value. Assert if this is not an ICMP or
1176 /// FCMP constant expression.
1177 unsigned getPredicate() const;
1179 /// Assert that this is an insertvalue or exactvalue
1180 /// expression and return the list of indices.
1181 ArrayRef<unsigned> getIndices() const;
1183 /// Return a string representation for an opcode.
1184 const char *getOpcodeName() const;
1186 /// Return a constant expression identical to this one, but with the specified
1187 /// operand set to the specified value.
1188 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
1190 /// This returns the current constant expression with the operands replaced
1191 /// with the specified values. The specified array must have the same number
1192 /// of operands as our current one.
1193 Constant *getWithOperands(ArrayRef<Constant*> Ops) const {
1194 return getWithOperands(Ops, getType());
1197 /// Get the current expression with the operands replaced.
1199 /// Return the current constant expression with the operands replaced with \c
1200 /// Ops and the type with \c Ty. The new operands must have the same number
1201 /// as the current ones.
1203 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something
1204 /// gets constant-folded, the type changes, or the expression is otherwise
1205 /// canonicalized. This parameter should almost always be \c false.
1206 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1207 bool OnlyIfReduced = false,
1208 Type *SrcTy = nullptr) const;
1210 /// Returns an Instruction which implements the same operation as this
1211 /// ConstantExpr. The instruction is not linked to any basic block.
1213 /// A better approach to this could be to have a constructor for Instruction
1214 /// which would take a ConstantExpr parameter, but that would have spread
1215 /// implementation details of ConstantExpr outside of Constants.cpp, which
1216 /// would make it harder to remove ConstantExprs altogether.
1217 Instruction *getAsInstruction();
1219 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1220 static bool classof(const Value *V) {
1221 return V->getValueID() == ConstantExprVal;
1225 // Shadow Value::setValueSubclassData with a private forwarding method so that
1226 // subclasses cannot accidentally use it.
1227 void setValueSubclassData(unsigned short D) {
1228 Value::setValueSubclassData(D);
1233 struct OperandTraits<ConstantExpr> :
1234 public VariadicOperandTraits<ConstantExpr, 1> {
1237 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant)
1239 //===----------------------------------------------------------------------===//
1240 /// 'undef' values are things that do not have specified contents.
1241 /// These are used for a variety of purposes, including global variable
1242 /// initializers and operands to instructions. 'undef' values can occur with
1243 /// any first-class type.
1245 /// Undef values aren't exactly constants; if they have multiple uses, they
1246 /// can appear to have different bit patterns at each use. See
1247 /// LangRef.html#undefvalues for details.
1249 class UndefValue final : public ConstantData {
1250 friend class Constant;
1252 explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {}
1254 void destroyConstantImpl();
1257 UndefValue(const UndefValue &) = delete;
1259 /// Static factory methods - Return an 'undef' object of the specified type.
1260 static UndefValue *get(Type *T);
1262 /// If this Undef has array or vector type, return a undef with the right
1264 UndefValue *getSequentialElement() const;
1266 /// If this undef has struct type, return a undef with the right element type
1267 /// for the specified element.
1268 UndefValue *getStructElement(unsigned Elt) const;
1270 /// Return an undef of the right value for the specified GEP index if we can,
1271 /// otherwise return null (e.g. if C is a ConstantExpr).
1272 UndefValue *getElementValue(Constant *C) const;
1274 /// Return an undef of the right value for the specified GEP index.
1275 UndefValue *getElementValue(unsigned Idx) const;
1277 /// Return the number of elements in the array, vector, or struct.
1278 unsigned getNumElements() const;
1280 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1281 static bool classof(const Value *V) {
1282 return V->getValueID() == UndefValueVal;
1286 } // end namespace llvm
1288 #endif // LLVM_IR_CONSTANTS_H