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 integers (of any size), return the
602 /// specified element as an APInt.
603 APInt getElementAsAPInt(unsigned i) const;
605 /// If this is a sequential container of floating point type, return the
606 /// specified element as an APFloat.
607 APFloat getElementAsAPFloat(unsigned i) const;
609 /// If this is an sequential container of floats, return the specified element
611 float getElementAsFloat(unsigned i) const;
613 /// If this is an sequential container of doubles, return the specified
614 /// element as a double.
615 double getElementAsDouble(unsigned i) const;
617 /// Return a Constant for a specified index's element.
618 /// Note that this has to compute a new constant to return, so it isn't as
619 /// efficient as getElementAsInteger/Float/Double.
620 Constant *getElementAsConstant(unsigned i) const;
622 /// Specialize the getType() method to always return a SequentialType, which
623 /// reduces the amount of casting needed in parts of the compiler.
624 inline SequentialType *getType() const {
625 return cast<SequentialType>(Value::getType());
628 /// Return the element type of the array/vector.
629 Type *getElementType() const;
631 /// Return the number of elements in the array or vector.
632 unsigned getNumElements() const;
634 /// Return the size (in bytes) of each element in the array/vector.
635 /// The size of the elements is known to be a multiple of one byte.
636 uint64_t getElementByteSize() const;
638 /// This method returns true if this is an array of \p CharSize integers.
639 bool isString(unsigned CharSize = 8) const;
641 /// This method returns true if the array "isString", ends with a null byte,
642 /// and does not contains any other null bytes.
643 bool isCString() const;
645 /// If this array is isString(), then this method returns the array as a
646 /// StringRef. Otherwise, it asserts out.
647 StringRef getAsString() const {
648 assert(isString() && "Not a string");
649 return getRawDataValues();
652 /// If this array is isCString(), then this method returns the array (without
653 /// the trailing null byte) as a StringRef. Otherwise, it asserts out.
654 StringRef getAsCString() const {
655 assert(isCString() && "Isn't a C string");
656 StringRef Str = getAsString();
657 return Str.substr(0, Str.size()-1);
660 /// Return the raw, underlying, bytes of this data. Note that this is an
661 /// extremely tricky thing to work with, as it exposes the host endianness of
662 /// the data elements.
663 StringRef getRawDataValues() const;
665 /// Methods for support type inquiry through isa, cast, and dyn_cast:
666 static bool classof(const Value *V) {
667 return V->getValueID() == ConstantDataArrayVal ||
668 V->getValueID() == ConstantDataVectorVal;
672 const char *getElementPointer(unsigned Elt) const;
675 //===----------------------------------------------------------------------===//
676 /// An array constant whose element type is a simple 1/2/4/8-byte integer or
677 /// float/double, and whose elements are just simple data values
678 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
679 /// stores all of the elements of the constant as densely packed data, instead
681 class ConstantDataArray final : public ConstantDataSequential {
682 friend class ConstantDataSequential;
684 explicit ConstantDataArray(Type *ty, const char *Data)
685 : ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
688 ConstantDataArray(const ConstantDataArray &) = delete;
690 /// get() constructors - Return a constant with array type with an element
691 /// count and element type matching the ArrayRef passed in. Note that this
692 /// can return a ConstantAggregateZero object.
693 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
694 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
695 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
696 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
697 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
698 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
700 /// getFP() constructors - Return a constant with array type with an element
701 /// count and element type of float with precision matching the number of
702 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
703 /// double for 64bits) Note that this can return a ConstantAggregateZero
705 static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
706 static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
707 static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
709 /// This method constructs a CDS and initializes it with a text string.
710 /// The default behavior (AddNull==true) causes a null terminator to
711 /// be placed at the end of the array (increasing the length of the string by
712 /// one more than the StringRef would normally indicate. Pass AddNull=false
713 /// to disable this behavior.
714 static Constant *getString(LLVMContext &Context, StringRef Initializer,
715 bool AddNull = true);
717 /// Specialize the getType() method to always return an ArrayType,
718 /// which reduces the amount of casting needed in parts of the compiler.
719 inline ArrayType *getType() const {
720 return cast<ArrayType>(Value::getType());
723 /// Methods for support type inquiry through isa, cast, and dyn_cast:
724 static bool classof(const Value *V) {
725 return V->getValueID() == ConstantDataArrayVal;
729 //===----------------------------------------------------------------------===//
730 /// A vector constant whose element type is a simple 1/2/4/8-byte integer or
731 /// float/double, and whose elements are just simple data values
732 /// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
733 /// stores all of the elements of the constant as densely packed data, instead
735 class ConstantDataVector final : public ConstantDataSequential {
736 friend class ConstantDataSequential;
738 explicit ConstantDataVector(Type *ty, const char *Data)
739 : ConstantDataSequential(ty, ConstantDataVectorVal, Data) {}
742 ConstantDataVector(const ConstantDataVector &) = delete;
744 /// get() constructors - Return a constant with vector type with an element
745 /// count and element type matching the ArrayRef passed in. Note that this
746 /// can return a ConstantAggregateZero object.
747 static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
748 static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
749 static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
750 static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
751 static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
752 static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
754 /// getFP() constructors - Return a constant with vector type with an element
755 /// count and element type of float with the precision matching the number of
756 /// bits in the ArrayRef passed in. (i.e. half for 16bits, float for 32bits,
757 /// double for 64bits) Note that this can return a ConstantAggregateZero
759 static Constant *getFP(LLVMContext &Context, ArrayRef<uint16_t> Elts);
760 static Constant *getFP(LLVMContext &Context, ArrayRef<uint32_t> Elts);
761 static Constant *getFP(LLVMContext &Context, ArrayRef<uint64_t> Elts);
763 /// Return a ConstantVector with the specified constant in each element.
764 /// The specified constant has to be a of a compatible type (i8/i16/
765 /// i32/i64/float/double) and must be a ConstantFP or ConstantInt.
766 static Constant *getSplat(unsigned NumElts, Constant *Elt);
768 /// Returns true if this is a splat constant, meaning that all elements have
770 bool isSplat() const;
772 /// If this is a splat constant, meaning that all of the elements have the
773 /// same value, return that value. Otherwise return NULL.
774 Constant *getSplatValue() const;
776 /// Specialize the getType() method to always return a VectorType,
777 /// which reduces the amount of casting needed in parts of the compiler.
778 inline VectorType *getType() const {
779 return cast<VectorType>(Value::getType());
782 /// Methods for support type inquiry through isa, cast, and dyn_cast:
783 static bool classof(const Value *V) {
784 return V->getValueID() == ConstantDataVectorVal;
788 //===----------------------------------------------------------------------===//
789 /// A constant token which is empty
791 class ConstantTokenNone final : public ConstantData {
792 friend class Constant;
794 explicit ConstantTokenNone(LLVMContext &Context)
795 : ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {}
797 void destroyConstantImpl();
800 ConstantTokenNone(const ConstantTokenNone &) = delete;
802 /// Return the ConstantTokenNone.
803 static ConstantTokenNone *get(LLVMContext &Context);
805 /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
806 static bool classof(const Value *V) {
807 return V->getValueID() == ConstantTokenNoneVal;
811 /// The address of a basic block.
813 class BlockAddress final : public Constant {
814 friend class Constant;
816 BlockAddress(Function *F, BasicBlock *BB);
818 void *operator new(size_t s) { return User::operator new(s, 2); }
820 void destroyConstantImpl();
821 Value *handleOperandChangeImpl(Value *From, Value *To);
824 /// Return a BlockAddress for the specified function and basic block.
825 static BlockAddress *get(Function *F, BasicBlock *BB);
827 /// Return a BlockAddress for the specified basic block. The basic
828 /// block must be embedded into a function.
829 static BlockAddress *get(BasicBlock *BB);
831 /// Lookup an existing \c BlockAddress constant for the given BasicBlock.
833 /// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.
834 static BlockAddress *lookup(const BasicBlock *BB);
836 /// Transparently provide more efficient getOperand methods.
837 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
839 Function *getFunction() const { return (Function*)Op<0>().get(); }
840 BasicBlock *getBasicBlock() const { return (BasicBlock*)Op<1>().get(); }
842 /// Methods for support type inquiry through isa, cast, and dyn_cast:
843 static bool classof(const Value *V) {
844 return V->getValueID() == BlockAddressVal;
849 struct OperandTraits<BlockAddress> :
850 public FixedNumOperandTraits<BlockAddress, 2> {
853 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)
855 //===----------------------------------------------------------------------===//
856 /// A constant value that is initialized with an expression using
857 /// other constant values.
859 /// This class uses the standard Instruction opcodes to define the various
860 /// constant expressions. The Opcode field for the ConstantExpr class is
861 /// maintained in the Value::SubclassData field.
862 class ConstantExpr : public Constant {
863 friend struct ConstantExprKeyType;
864 friend class Constant;
866 void destroyConstantImpl();
867 Value *handleOperandChangeImpl(Value *From, Value *To);
870 ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
871 : Constant(ty, ConstantExprVal, Ops, NumOps) {
872 // Operation type (an Instruction opcode) is stored as the SubclassData.
873 setValueSubclassData(Opcode);
877 // Static methods to construct a ConstantExpr of different kinds. Note that
878 // these methods may return a object that is not an instance of the
879 // ConstantExpr class, because they will attempt to fold the constant
880 // expression into something simpler if possible.
882 /// getAlignOf constant expr - computes the alignment of a type in a target
883 /// independent way (Note: the return type is an i64).
884 static Constant *getAlignOf(Type *Ty);
886 /// getSizeOf constant expr - computes the (alloc) size of a type (in
887 /// address-units, not bits) in a target independent way (Note: the return
890 static Constant *getSizeOf(Type *Ty);
892 /// getOffsetOf constant expr - computes the offset of a struct field in a
893 /// target independent way (Note: the return type is an i64).
895 static Constant *getOffsetOf(StructType *STy, unsigned FieldNo);
897 /// getOffsetOf constant expr - This is a generalized form of getOffsetOf,
898 /// which supports any aggregate type, and any Constant index.
900 static Constant *getOffsetOf(Type *Ty, Constant *FieldNo);
902 static Constant *getNeg(Constant *C, bool HasNUW = false, bool HasNSW =false);
903 static Constant *getFNeg(Constant *C);
904 static Constant *getNot(Constant *C);
905 static Constant *getAdd(Constant *C1, Constant *C2,
906 bool HasNUW = false, bool HasNSW = false);
907 static Constant *getFAdd(Constant *C1, Constant *C2);
908 static Constant *getSub(Constant *C1, Constant *C2,
909 bool HasNUW = false, bool HasNSW = false);
910 static Constant *getFSub(Constant *C1, Constant *C2);
911 static Constant *getMul(Constant *C1, Constant *C2,
912 bool HasNUW = false, bool HasNSW = false);
913 static Constant *getFMul(Constant *C1, Constant *C2);
914 static Constant *getUDiv(Constant *C1, Constant *C2, bool isExact = false);
915 static Constant *getSDiv(Constant *C1, Constant *C2, bool isExact = false);
916 static Constant *getFDiv(Constant *C1, Constant *C2);
917 static Constant *getURem(Constant *C1, Constant *C2);
918 static Constant *getSRem(Constant *C1, Constant *C2);
919 static Constant *getFRem(Constant *C1, Constant *C2);
920 static Constant *getAnd(Constant *C1, Constant *C2);
921 static Constant *getOr(Constant *C1, Constant *C2);
922 static Constant *getXor(Constant *C1, Constant *C2);
923 static Constant *getShl(Constant *C1, Constant *C2,
924 bool HasNUW = false, bool HasNSW = false);
925 static Constant *getLShr(Constant *C1, Constant *C2, bool isExact = false);
926 static Constant *getAShr(Constant *C1, Constant *C2, bool isExact = false);
927 static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);
928 static Constant *getSExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
929 static Constant *getZExt(Constant *C, Type *Ty, bool OnlyIfReduced = false);
930 static Constant *getFPTrunc(Constant *C, Type *Ty,
931 bool OnlyIfReduced = false);
932 static Constant *getFPExtend(Constant *C, Type *Ty,
933 bool OnlyIfReduced = false);
934 static Constant *getUIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
935 static Constant *getSIToFP(Constant *C, Type *Ty, bool OnlyIfReduced = false);
936 static Constant *getFPToUI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
937 static Constant *getFPToSI(Constant *C, Type *Ty, bool OnlyIfReduced = false);
938 static Constant *getPtrToInt(Constant *C, Type *Ty,
939 bool OnlyIfReduced = false);
940 static Constant *getIntToPtr(Constant *C, Type *Ty,
941 bool OnlyIfReduced = false);
942 static Constant *getBitCast(Constant *C, Type *Ty,
943 bool OnlyIfReduced = false);
944 static Constant *getAddrSpaceCast(Constant *C, Type *Ty,
945 bool OnlyIfReduced = false);
947 static Constant *getNSWNeg(Constant *C) { return getNeg(C, false, true); }
948 static Constant *getNUWNeg(Constant *C) { return getNeg(C, true, false); }
950 static Constant *getNSWAdd(Constant *C1, Constant *C2) {
951 return getAdd(C1, C2, false, true);
954 static Constant *getNUWAdd(Constant *C1, Constant *C2) {
955 return getAdd(C1, C2, true, false);
958 static Constant *getNSWSub(Constant *C1, Constant *C2) {
959 return getSub(C1, C2, false, true);
962 static Constant *getNUWSub(Constant *C1, Constant *C2) {
963 return getSub(C1, C2, true, false);
966 static Constant *getNSWMul(Constant *C1, Constant *C2) {
967 return getMul(C1, C2, false, true);
970 static Constant *getNUWMul(Constant *C1, Constant *C2) {
971 return getMul(C1, C2, true, false);
974 static Constant *getNSWShl(Constant *C1, Constant *C2) {
975 return getShl(C1, C2, false, true);
978 static Constant *getNUWShl(Constant *C1, Constant *C2) {
979 return getShl(C1, C2, true, false);
982 static Constant *getExactSDiv(Constant *C1, Constant *C2) {
983 return getSDiv(C1, C2, true);
986 static Constant *getExactUDiv(Constant *C1, Constant *C2) {
987 return getUDiv(C1, C2, true);
990 static Constant *getExactAShr(Constant *C1, Constant *C2) {
991 return getAShr(C1, C2, true);
994 static Constant *getExactLShr(Constant *C1, Constant *C2) {
995 return getLShr(C1, C2, true);
998 /// Return the identity for the given binary operation,
999 /// i.e. a constant C such that X op C = X and C op X = X for every X. It
1000 /// returns null if the operator doesn't have an identity.
1001 static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty);
1003 /// Return the absorbing element for the given binary
1004 /// operation, i.e. a constant C such that X op C = C and C op X = C for
1005 /// every X. For example, this returns zero for integer multiplication.
1006 /// It returns null if the operator doesn't have an absorbing element.
1007 static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
1009 /// Transparently provide more efficient getOperand methods.
1010 DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
1012 /// \brief Convenience function for getting a Cast operation.
1014 /// \param ops The opcode for the conversion
1015 /// \param C The constant to be converted
1016 /// \param Ty The type to which the constant is converted
1017 /// \param OnlyIfReduced see \a getWithOperands() docs.
1018 static Constant *getCast(unsigned ops, Constant *C, Type *Ty,
1019 bool OnlyIfReduced = false);
1021 // @brief Create a ZExt or BitCast cast constant expression
1022 static Constant *getZExtOrBitCast(
1023 Constant *C, ///< The constant to zext or bitcast
1024 Type *Ty ///< The type to zext or bitcast C to
1027 // @brief Create a SExt or BitCast cast constant expression
1028 static Constant *getSExtOrBitCast(
1029 Constant *C, ///< The constant to sext or bitcast
1030 Type *Ty ///< The type to sext or bitcast C to
1033 // @brief Create a Trunc or BitCast cast constant expression
1034 static Constant *getTruncOrBitCast(
1035 Constant *C, ///< The constant to trunc or bitcast
1036 Type *Ty ///< The type to trunc or bitcast C to
1039 /// @brief Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant
1041 static Constant *getPointerCast(
1042 Constant *C, ///< The pointer value to be casted (operand 0)
1043 Type *Ty ///< The type to which cast should be made
1046 /// @brief Create a BitCast or AddrSpaceCast for a pointer type depending on
1047 /// the address space.
1048 static Constant *getPointerBitCastOrAddrSpaceCast(
1049 Constant *C, ///< The constant to addrspacecast or bitcast
1050 Type *Ty ///< The type to bitcast or addrspacecast C to
1053 /// @brief Create a ZExt, Bitcast or Trunc for integer -> integer casts
1054 static Constant *getIntegerCast(
1055 Constant *C, ///< The integer constant to be casted
1056 Type *Ty, ///< The integer type to cast to
1057 bool isSigned ///< Whether C should be treated as signed or not
1060 /// @brief Create a FPExt, Bitcast or FPTrunc for fp -> fp casts
1061 static Constant *getFPCast(
1062 Constant *C, ///< The integer constant to be casted
1063 Type *Ty ///< The integer type to cast to
1066 /// @brief Return true if this is a convert constant expression
1067 bool isCast() const;
1069 /// @brief Return true if this is a compare constant expression
1070 bool isCompare() const;
1072 /// @brief Return true if this is an insertvalue or extractvalue expression,
1073 /// and the getIndices() method may be used.
1074 bool hasIndices() const;
1076 /// @brief Return true if this is a getelementptr expression and all
1077 /// the index operands are compile-time known integers within the
1078 /// corresponding notional static array extents. Note that this is
1079 /// not equivalant to, a subset of, or a superset of the "inbounds"
1081 bool isGEPWithNoNotionalOverIndexing() const;
1083 /// Select constant expr
1085 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1086 static Constant *getSelect(Constant *C, Constant *V1, Constant *V2,
1087 Type *OnlyIfReducedTy = nullptr);
1089 /// get - Return a binary or shift operator constant expression,
1090 /// folding if possible.
1092 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1093 static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
1094 unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr);
1096 /// \brief Return an ICmp or FCmp comparison operator constant expression.
1098 /// \param OnlyIfReduced see \a getWithOperands() docs.
1099 static Constant *getCompare(unsigned short pred, Constant *C1, Constant *C2,
1100 bool OnlyIfReduced = false);
1102 /// get* - Return some common constants without having to
1103 /// specify the full Instruction::OPCODE identifier.
1105 static Constant *getICmp(unsigned short pred, Constant *LHS, Constant *RHS,
1106 bool OnlyIfReduced = false);
1107 static Constant *getFCmp(unsigned short pred, Constant *LHS, Constant *RHS,
1108 bool OnlyIfReduced = false);
1110 /// Getelementptr form. Value* is only accepted for convenience;
1111 /// all elements must be Constants.
1113 /// \param InRangeIndex the inrange index if present or None.
1114 /// \param OnlyIfReducedTy see \a getWithOperands() docs.
1115 static Constant *getGetElementPtr(Type *Ty, Constant *C,
1116 ArrayRef<Constant *> IdxList,
1117 bool InBounds = false,
1118 Optional<unsigned> InRangeIndex = None,
1119 Type *OnlyIfReducedTy = nullptr) {
1120 return getGetElementPtr(
1121 Ty, C, makeArrayRef((Value * const *)IdxList.data(), IdxList.size()),
1122 InBounds, InRangeIndex, OnlyIfReducedTy);
1124 static Constant *getGetElementPtr(Type *Ty, Constant *C, Constant *Idx,
1125 bool InBounds = false,
1126 Optional<unsigned> InRangeIndex = None,
1127 Type *OnlyIfReducedTy = nullptr) {
1128 // This form of the function only exists to avoid ambiguous overload
1129 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1130 // ArrayRef<Value *>.
1131 return getGetElementPtr(Ty, C, cast<Value>(Idx), InBounds, InRangeIndex,
1134 static Constant *getGetElementPtr(Type *Ty, Constant *C,
1135 ArrayRef<Value *> IdxList,
1136 bool InBounds = false,
1137 Optional<unsigned> InRangeIndex = None,
1138 Type *OnlyIfReducedTy = nullptr);
1140 /// Create an "inbounds" getelementptr. See the documentation for the
1141 /// "inbounds" flag in LangRef.html for details.
1142 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1143 ArrayRef<Constant *> IdxList) {
1144 return getGetElementPtr(Ty, C, IdxList, true);
1146 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1148 // This form of the function only exists to avoid ambiguous overload
1149 // warnings about whether to convert Idx to ArrayRef<Constant *> or
1150 // ArrayRef<Value *>.
1151 return getGetElementPtr(Ty, C, Idx, true);
1153 static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
1154 ArrayRef<Value *> IdxList) {
1155 return getGetElementPtr(Ty, C, IdxList, true);
1158 static Constant *getExtractElement(Constant *Vec, Constant *Idx,
1159 Type *OnlyIfReducedTy = nullptr);
1160 static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx,
1161 Type *OnlyIfReducedTy = nullptr);
1162 static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask,
1163 Type *OnlyIfReducedTy = nullptr);
1164 static Constant *getExtractValue(Constant *Agg, ArrayRef<unsigned> Idxs,
1165 Type *OnlyIfReducedTy = nullptr);
1166 static Constant *getInsertValue(Constant *Agg, Constant *Val,
1167 ArrayRef<unsigned> Idxs,
1168 Type *OnlyIfReducedTy = nullptr);
1170 /// Return the opcode at the root of this constant expression
1171 unsigned getOpcode() const { return getSubclassDataFromValue(); }
1173 /// Return the ICMP or FCMP predicate value. Assert if this is not an ICMP or
1174 /// FCMP constant expression.
1175 unsigned getPredicate() const;
1177 /// Assert that this is an insertvalue or exactvalue
1178 /// expression and return the list of indices.
1179 ArrayRef<unsigned> getIndices() const;
1181 /// Return a string representation for an opcode.
1182 const char *getOpcodeName() const;
1184 /// Return a constant expression identical to this one, but with the specified
1185 /// operand set to the specified value.
1186 Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
1188 /// This returns the current constant expression with the operands replaced
1189 /// with the specified values. The specified array must have the same number
1190 /// of operands as our current one.
1191 Constant *getWithOperands(ArrayRef<Constant*> Ops) const {
1192 return getWithOperands(Ops, getType());
1195 /// Get the current expression with the operands replaced.
1197 /// Return the current constant expression with the operands replaced with \c
1198 /// Ops and the type with \c Ty. The new operands must have the same number
1199 /// as the current ones.
1201 /// If \c OnlyIfReduced is \c true, nullptr will be returned unless something
1202 /// gets constant-folded, the type changes, or the expression is otherwise
1203 /// canonicalized. This parameter should almost always be \c false.
1204 Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
1205 bool OnlyIfReduced = false,
1206 Type *SrcTy = nullptr) const;
1208 /// Returns an Instruction which implements the same operation as this
1209 /// ConstantExpr. The instruction is not linked to any basic block.
1211 /// A better approach to this could be to have a constructor for Instruction
1212 /// which would take a ConstantExpr parameter, but that would have spread
1213 /// implementation details of ConstantExpr outside of Constants.cpp, which
1214 /// would make it harder to remove ConstantExprs altogether.
1215 Instruction *getAsInstruction();
1217 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1218 static bool classof(const Value *V) {
1219 return V->getValueID() == ConstantExprVal;
1223 // Shadow Value::setValueSubclassData with a private forwarding method so that
1224 // subclasses cannot accidentally use it.
1225 void setValueSubclassData(unsigned short D) {
1226 Value::setValueSubclassData(D);
1231 struct OperandTraits<ConstantExpr> :
1232 public VariadicOperandTraits<ConstantExpr, 1> {
1235 DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant)
1237 //===----------------------------------------------------------------------===//
1238 /// 'undef' values are things that do not have specified contents.
1239 /// These are used for a variety of purposes, including global variable
1240 /// initializers and operands to instructions. 'undef' values can occur with
1241 /// any first-class type.
1243 /// Undef values aren't exactly constants; if they have multiple uses, they
1244 /// can appear to have different bit patterns at each use. See
1245 /// LangRef.html#undefvalues for details.
1247 class UndefValue final : public ConstantData {
1248 friend class Constant;
1250 explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {}
1252 void destroyConstantImpl();
1255 UndefValue(const UndefValue &) = delete;
1257 /// Static factory methods - Return an 'undef' object of the specified type.
1258 static UndefValue *get(Type *T);
1260 /// If this Undef has array or vector type, return a undef with the right
1262 UndefValue *getSequentialElement() const;
1264 /// If this undef has struct type, return a undef with the right element type
1265 /// for the specified element.
1266 UndefValue *getStructElement(unsigned Elt) const;
1268 /// Return an undef of the right value for the specified GEP index if we can,
1269 /// otherwise return null (e.g. if C is a ConstantExpr).
1270 UndefValue *getElementValue(Constant *C) const;
1272 /// Return an undef of the right value for the specified GEP index.
1273 UndefValue *getElementValue(unsigned Idx) const;
1275 /// Return the number of elements in the array, vector, or struct.
1276 unsigned getNumElements() const;
1278 /// Methods for support type inquiry through isa, cast, and dyn_cast:
1279 static bool classof(const Value *V) {
1280 return V->getValueID() == UndefValueVal;
1284 } // end namespace llvm
1286 #endif // LLVM_IR_CONSTANTS_H