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//===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// @file
/// This file contains the declarations for the subclasses of Constant,
/// which represent the different flavors of constant values that live in LLVM.
/// Note that Constants are immutable (once created they never change) and are
/// fully shared by structural equivalence. This means that two structurally
/// equivalent constants will always have the same address. Constants are
/// created on demand as needed and never deleted: thus clients don't have to
/// worry about the lifetime of the objects.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_CONSTANTS_H
#define LLVM_IR_CONSTANTS_H
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/GEPNoWrapFlags.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/OperandTraits.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <optional>
namespace llvm {
template <class ConstantClass> struct ConstantAggrKeyType;
/// Base class for constants with no operands.
///
/// These constants have no operands; they represent their data directly.
/// Since they can be in use by unrelated modules (and are never based on
/// GlobalValues), it never makes sense to RAUW them.
class ConstantData : public Constant {
friend class Constant;
Value *handleOperandChangeImpl(Value *From, Value *To) {
llvm_unreachable("Constant data does not have operands!");
}
protected:
explicit ConstantData(Type *Ty, ValueTy VT) : Constant(Ty, VT, nullptr, 0) {}
void *operator new(size_t S) { return User::operator new(S, 0); }
public:
void operator delete(void *Ptr) { User::operator delete(Ptr); }
ConstantData(const ConstantData &) = delete;
/// Methods to support type inquiry through isa, cast, and dyn_cast.
static bool classof(const Value *V) {
return V->getValueID() >= ConstantDataFirstVal &&
V->getValueID() <= ConstantDataLastVal;
}
};
//===----------------------------------------------------------------------===//
/// This is the shared class of boolean and integer constants. This class
/// represents both boolean and integral constants.
/// Class for constant integers.
class ConstantInt final : public ConstantData {
friend class Constant;
friend class ConstantVector;
APInt Val;
ConstantInt(Type *Ty, const APInt &V);
void destroyConstantImpl();
/// Return a ConstantInt with the specified value and an implied Type. The
/// type is the vector type whose integer element type corresponds to the bit
/// width of the value.
static ConstantInt *get(LLVMContext &Context, ElementCount EC,
const APInt &V);
public:
ConstantInt(const ConstantInt &) = delete;
static ConstantInt *getTrue(LLVMContext &Context);
static ConstantInt *getFalse(LLVMContext &Context);
static ConstantInt *getBool(LLVMContext &Context, bool V);
static Constant *getTrue(Type *Ty);
static Constant *getFalse(Type *Ty);
static Constant *getBool(Type *Ty, bool V);
/// If Ty is a vector type, return a Constant with a splat of the given
/// value. Otherwise return a ConstantInt for the given value.
static Constant *get(Type *Ty, uint64_t V, bool IsSigned = false);
/// Return a ConstantInt with the specified integer value for the specified
/// type. If the type is wider than 64 bits, the value will be zero-extended
/// to fit the type, unless IsSigned is true, in which case the value will
/// be interpreted as a 64-bit signed integer and sign-extended to fit
/// the type.
/// Get a ConstantInt for a specific value.
static ConstantInt *get(IntegerType *Ty, uint64_t V, bool IsSigned = false);
/// Return a ConstantInt with the specified value for the specified type. The
/// value V will be canonicalized to a an unsigned APInt. Accessing it with
/// either getSExtValue() or getZExtValue() will yield a correctly sized and
/// signed value for the type Ty.
/// Get a ConstantInt for a specific signed value.
static ConstantInt *getSigned(IntegerType *Ty, int64_t V) {
return get(Ty, V, true);
}
static Constant *getSigned(Type *Ty, int64_t V) {
return get(Ty, V, true);
}
/// Return a ConstantInt with the specified value and an implied Type. The
/// type is the integer type that corresponds to the bit width of the value.
static ConstantInt *get(LLVMContext &Context, const APInt &V);
/// Return a ConstantInt constructed from the string strStart with the given
/// radix.
static ConstantInt *get(IntegerType *Ty, StringRef Str, uint8_t Radix);
/// If Ty is a vector type, return a Constant with a splat of the given
/// value. Otherwise return a ConstantInt for the given value.
static Constant *get(Type *Ty, const APInt &V);
/// Return the constant as an APInt value reference. This allows clients to
/// obtain a full-precision copy of the value.
/// Return the constant's value.
inline const APInt &getValue() const { return Val; }
/// getBitWidth - Return the scalar bitwidth of this constant.
unsigned getBitWidth() const { return Val.getBitWidth(); }
/// Return the constant as a 64-bit unsigned integer value after it
/// has been zero extended as appropriate for the type of this constant. Note
/// that this method can assert if the value does not fit in 64 bits.
/// Return the zero extended value.
inline uint64_t getZExtValue() const { return Val.getZExtValue(); }
/// Return the constant as a 64-bit integer value after it has been sign
/// extended as appropriate for the type of this constant. Note that
/// this method can assert if the value does not fit in 64 bits.
/// Return the sign extended value.
inline int64_t getSExtValue() const { return Val.getSExtValue(); }
/// Return the constant as an llvm::MaybeAlign.
/// Note that this method can assert if the value does not fit in 64 bits or
/// is not a power of two.
inline MaybeAlign getMaybeAlignValue() const {
return MaybeAlign(getZExtValue());
}
/// Return the constant as an llvm::Align, interpreting `0` as `Align(1)`.
/// Note that this method can assert if the value does not fit in 64 bits or
/// is not a power of two.
inline Align getAlignValue() const {
return getMaybeAlignValue().valueOrOne();
}
/// A helper method that can be used to determine if the constant contained
/// within is equal to a constant. This only works for very small values,
/// because this is all that can be represented with all types.
/// Determine if this constant's value is same as an unsigned char.
bool equalsInt(uint64_t V) const { return Val == V; }
/// Variant of the getType() method to always return an IntegerType, which
/// reduces the amount of casting needed in parts of the compiler.
inline IntegerType *getIntegerType() const {
return cast<IntegerType>(Value::getType());
}
/// This static method returns true if the type Ty is big enough to
/// represent the value V. This can be used to avoid having the get method
/// assert when V is larger than Ty can represent. Note that there are two
/// versions of this method, one for unsigned and one for signed integers.
/// Although ConstantInt canonicalizes everything to an unsigned integer,
/// the signed version avoids callers having to convert a signed quantity
/// to the appropriate unsigned type before calling the method.
/// @returns true if V is a valid value for type Ty
/// Determine if the value is in range for the given type.
static bool isValueValidForType(Type *Ty, uint64_t V);
static bool isValueValidForType(Type *Ty, int64_t V);
bool isNegative() const { return Val.isNegative(); }
/// This is just a convenience method to make client code smaller for a
/// common code. It also correctly performs the comparison without the
/// potential for an assertion from getZExtValue().
bool isZero() const { return Val.isZero(); }
/// This is just a convenience method to make client code smaller for a
/// common case. It also correctly performs the comparison without the
/// potential for an assertion from getZExtValue().
/// Determine if the value is one.
bool isOne() const { return Val.isOne(); }
/// This function will return true iff every bit in this constant is set
/// to true.
/// @returns true iff this constant's bits are all set to true.
/// Determine if the value is all ones.
bool isMinusOne() const { return Val.isAllOnes(); }
/// This function will return true iff this constant represents the largest
/// value that may be represented by the constant's type.
/// @returns true iff this is the largest value that may be represented
/// by this type.
/// Determine if the value is maximal.
bool isMaxValue(bool IsSigned) const {
if (IsSigned)
return Val.isMaxSignedValue();
else
return Val.isMaxValue();
}
/// This function will return true iff this constant represents the smallest
/// value that may be represented by this constant's type.
/// @returns true if this is the smallest value that may be represented by
/// this type.
/// Determine if the value is minimal.
bool isMinValue(bool IsSigned) const {
if (IsSigned)
return Val.isMinSignedValue();
else
return Val.isMinValue();
}
/// This function will return true iff this constant represents a value with
/// active bits bigger than 64 bits or a value greater than the given uint64_t
/// value.
/// @returns true iff this constant is greater or equal to the given number.
/// Determine if the value is greater or equal to the given number.
bool uge(uint64_t Num) const { return Val.uge(Num); }
/// getLimitedValue - If the value is smaller than the specified limit,
/// return it, otherwise return the limit value. This causes the value
/// to saturate to the limit.
/// @returns the min of the value of the constant and the specified value
/// Get the constant's value with a saturation limit
uint64_t getLimitedValue(uint64_t Limit = ~0ULL) const {
return Val.getLimitedValue(Limit);
}
/// Methods to support type inquiry through isa, cast, and dyn_cast.
static bool classof(const Value *V) {
return V->getValueID() == ConstantIntVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantFP - Floating Point Values [float, double]
///
class ConstantFP final : public ConstantData {
friend class Constant;
friend class ConstantVector;
APFloat Val;
ConstantFP(Type *Ty, const APFloat &V);
void destroyConstantImpl();
/// Return a ConstantFP with the specified value and an implied Type. The
/// type is the vector type whose element type has the same floating point
/// semantics as the value.
static ConstantFP *get(LLVMContext &Context, ElementCount EC,
const APFloat &V);
public:
ConstantFP(const ConstantFP &) = delete;
/// This returns a ConstantFP, or a vector containing a splat of a ConstantFP,
/// for the specified value in the specified type. This should only be used
/// for simple constant values like 2.0/1.0 etc, that are known-valid both as
/// host double and as the target format.
static Constant *get(Type *Ty, double V);
/// If Ty is a vector type, return a Constant with a splat of the given
/// value. Otherwise return a ConstantFP for the given value.
static Constant *get(Type *Ty, const APFloat &V);
static Constant *get(Type *Ty, StringRef Str);
static ConstantFP *get(LLVMContext &Context, const APFloat &V);
static Constant *getNaN(Type *Ty, bool Negative = false,
uint64_t Payload = 0);
static Constant *getQNaN(Type *Ty, bool Negative = false,
APInt *Payload = nullptr);
static Constant *getSNaN(Type *Ty, bool Negative = false,
APInt *Payload = nullptr);
static Constant *getZero(Type *Ty, bool Negative = false);
static Constant *getNegativeZero(Type *Ty) { return getZero(Ty, true); }
static Constant *getInfinity(Type *Ty, bool Negative = false);
/// Return true if Ty is big enough to represent V.
static bool isValueValidForType(Type *Ty, const APFloat &V);
inline const APFloat &getValueAPF() const { return Val; }
inline const APFloat &getValue() const { return Val; }
/// Return true if the value is positive or negative zero.
bool isZero() const { return Val.isZero(); }
/// Return true if the sign bit is set.
bool isNegative() const { return Val.isNegative(); }
/// Return true if the value is infinity
bool isInfinity() const { return Val.isInfinity(); }
/// Return true if the value is a NaN.
bool isNaN() const { return Val.isNaN(); }
/// We don't rely on operator== working on double values, as it returns true
/// for things that are clearly not equal, like -0.0 and 0.0.
/// As such, this method can be used to do an exact bit-for-bit comparison of
/// two floating point values. The version with a double operand is retained
/// because it's so convenient to write isExactlyValue(2.0), but please use
/// it only for simple constants.
bool isExactlyValue(const APFloat &V) const;
bool isExactlyValue(double V) const {
bool ignored;
APFloat FV(V);
FV.convert(Val.getSemantics(), APFloat::rmNearestTiesToEven, &ignored);
return isExactlyValue(FV);
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantFPVal;
}
};
//===----------------------------------------------------------------------===//
/// All zero aggregate value
///
class ConstantAggregateZero final : public ConstantData {
friend class Constant;
explicit ConstantAggregateZero(Type *Ty)
: ConstantData(Ty, ConstantAggregateZeroVal) {}
void destroyConstantImpl();
public:
ConstantAggregateZero(const ConstantAggregateZero &) = delete;
static ConstantAggregateZero *get(Type *Ty);
/// If this CAZ has array or vector type, return a zero with the right element
/// type.
Constant *getSequentialElement() const;
/// If this CAZ has struct type, return a zero with the right element type for
/// the specified element.
Constant *getStructElement(unsigned Elt) const;
/// Return a zero of the right value for the specified GEP index if we can,
/// otherwise return null (e.g. if C is a ConstantExpr).
Constant *getElementValue(Constant *C) const;
/// Return a zero of the right value for the specified GEP index.
Constant *getElementValue(unsigned Idx) const;
/// Return the number of elements in the array, vector, or struct.
ElementCount getElementCount() const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
///
static bool classof(const Value *V) {
return V->getValueID() == ConstantAggregateZeroVal;
}
};
/// Base class for aggregate constants (with operands).
///
/// These constants are aggregates of other constants, which are stored as
/// operands.
///
/// Subclasses are \a ConstantStruct, \a ConstantArray, and \a
/// ConstantVector.
///
/// \note Some subclasses of \a ConstantData are semantically aggregates --
/// such as \a ConstantDataArray -- but are not subclasses of this because they
/// use operands.
class ConstantAggregate : public Constant {
protected:
ConstantAggregate(Type *T, ValueTy VT, ArrayRef<Constant *> V);
public:
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() >= ConstantAggregateFirstVal &&
V->getValueID() <= ConstantAggregateLastVal;
}
};
template <>
struct OperandTraits<ConstantAggregate>
: public VariadicOperandTraits<ConstantAggregate> {};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantAggregate, Constant)
//===----------------------------------------------------------------------===//
/// ConstantArray - Constant Array Declarations
///
class ConstantArray final : public ConstantAggregate {
friend struct ConstantAggrKeyType<ConstantArray>;
friend class Constant;
ConstantArray(ArrayType *T, ArrayRef<Constant *> Val);
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
// ConstantArray accessors
static Constant *get(ArrayType *T, ArrayRef<Constant *> V);
private:
static Constant *getImpl(ArrayType *T, ArrayRef<Constant *> V);
public:
/// Specialize the getType() method to always return an ArrayType,
/// which reduces the amount of casting needed in parts of the compiler.
inline ArrayType *getType() const {
return cast<ArrayType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantArrayVal;
}
};
//===----------------------------------------------------------------------===//
// Constant Struct Declarations
//
class ConstantStruct final : public ConstantAggregate {
friend struct ConstantAggrKeyType<ConstantStruct>;
friend class Constant;
ConstantStruct(StructType *T, ArrayRef<Constant *> Val);
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
// ConstantStruct accessors
static Constant *get(StructType *T, ArrayRef<Constant *> V);
template <typename... Csts>
static std::enable_if_t<are_base_of<Constant, Csts...>::value, Constant *>
get(StructType *T, Csts *...Vs) {
return get(T, ArrayRef<Constant *>({Vs...}));
}
/// Return an anonymous struct that has the specified elements.
/// If the struct is possibly empty, then you must specify a context.
static Constant *getAnon(ArrayRef<Constant *> V, bool Packed = false) {
return get(getTypeForElements(V, Packed), V);
}
static Constant *getAnon(LLVMContext &Ctx, ArrayRef<Constant *> V,
bool Packed = false) {
return get(getTypeForElements(Ctx, V, Packed), V);
}
/// Return an anonymous struct type to use for a constant with the specified
/// set of elements. The list must not be empty.
static StructType *getTypeForElements(ArrayRef<Constant *> V,
bool Packed = false);
/// This version of the method allows an empty list.
static StructType *getTypeForElements(LLVMContext &Ctx,
ArrayRef<Constant *> V,
bool Packed = false);
/// Specialization - reduce amount of casting.
inline StructType *getType() const {
return cast<StructType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantStructVal;
}
};
//===----------------------------------------------------------------------===//
/// Constant Vector Declarations
///
class ConstantVector final : public ConstantAggregate {
friend struct ConstantAggrKeyType<ConstantVector>;
friend class Constant;
ConstantVector(VectorType *T, ArrayRef<Constant *> Val);
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
// ConstantVector accessors
static Constant *get(ArrayRef<Constant *> V);
private:
static Constant *getImpl(ArrayRef<Constant *> V);
public:
/// Return a ConstantVector with the specified constant in each element.
/// Note that this might not return an instance of ConstantVector
static Constant *getSplat(ElementCount EC, Constant *Elt);
/// Specialize the getType() method to always return a FixedVectorType,
/// which reduces the amount of casting needed in parts of the compiler.
inline FixedVectorType *getType() const {
return cast<FixedVectorType>(Value::getType());
}
/// If all elements of the vector constant have the same value, return that
/// value. Otherwise, return nullptr. Ignore poison elements by setting
/// AllowPoison to true.
Constant *getSplatValue(bool AllowPoison = false) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantVectorVal;
}
};
//===----------------------------------------------------------------------===//
/// A constant pointer value that points to null
///
class ConstantPointerNull final : public ConstantData {
friend class Constant;
explicit ConstantPointerNull(PointerType *T)
: ConstantData(T, Value::ConstantPointerNullVal) {}
void destroyConstantImpl();
public:
ConstantPointerNull(const ConstantPointerNull &) = delete;
/// Static factory methods - Return objects of the specified value
static ConstantPointerNull *get(PointerType *T);
/// Specialize the getType() method to always return an PointerType,
/// which reduces the amount of casting needed in parts of the compiler.
inline PointerType *getType() const {
return cast<PointerType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantPointerNullVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantDataSequential - A vector or array constant whose element type is a
/// simple 1/2/4/8-byte integer or half/bfloat/float/double, and whose elements
/// are just simple data values (i.e. ConstantInt/ConstantFP). This Constant
/// node has no operands because it stores all of the elements of the constant
/// as densely packed data, instead of as Value*'s.
///
/// This is the common base class of ConstantDataArray and ConstantDataVector.
///
class ConstantDataSequential : public ConstantData {
friend class LLVMContextImpl;
friend class Constant;
/// A pointer to the bytes underlying this constant (which is owned by the
/// uniquing StringMap).
const char *DataElements;
/// This forms a link list of ConstantDataSequential nodes that have
/// the same value but different type. For example, 0,0,0,1 could be a 4
/// element array of i8, or a 1-element array of i32. They'll both end up in
/// the same StringMap bucket, linked up.
std::unique_ptr<ConstantDataSequential> Next;
void destroyConstantImpl();
protected:
explicit ConstantDataSequential(Type *ty, ValueTy VT, const char *Data)
: ConstantData(ty, VT), DataElements(Data) {}
static Constant *getImpl(StringRef Bytes, Type *Ty);
public:
ConstantDataSequential(const ConstantDataSequential &) = delete;
/// Return true if a ConstantDataSequential can be formed with a vector or
/// array of the specified element type.
/// ConstantDataArray only works with normal float and int types that are
/// stored densely in memory, not with things like i42 or x86_f80.
static bool isElementTypeCompatible(Type *Ty);
/// If this is a sequential container of integers (of any size), return the
/// specified element in the low bits of a uint64_t.
uint64_t getElementAsInteger(unsigned i) const;
/// If this is a sequential container of integers (of any size), return the
/// specified element as an APInt.
APInt getElementAsAPInt(unsigned i) const;
/// If this is a sequential container of floating point type, return the
/// specified element as an APFloat.
APFloat getElementAsAPFloat(unsigned i) const;
/// If this is an sequential container of floats, return the specified element
/// as a float.
float getElementAsFloat(unsigned i) const;
/// If this is an sequential container of doubles, return the specified
/// element as a double.
double getElementAsDouble(unsigned i) const;
/// Return a Constant for a specified index's element.
/// Note that this has to compute a new constant to return, so it isn't as
/// efficient as getElementAsInteger/Float/Double.
Constant *getElementAsConstant(unsigned i) const;
/// Return the element type of the array/vector.
Type *getElementType() const;
/// Return the number of elements in the array or vector.
unsigned getNumElements() const;
/// Return the size (in bytes) of each element in the array/vector.
/// The size of the elements is known to be a multiple of one byte.
uint64_t getElementByteSize() const;
/// This method returns true if this is an array of \p CharSize integers.
bool isString(unsigned CharSize = 8) const;
/// This method returns true if the array "isString", ends with a null byte,
/// and does not contains any other null bytes.
bool isCString() const;
/// If this array is isString(), then this method returns the array as a
/// StringRef. Otherwise, it asserts out.
StringRef getAsString() const {
assert(isString() && "Not a string");
return getRawDataValues();
}
/// If this array is isCString(), then this method returns the array (without
/// the trailing null byte) as a StringRef. Otherwise, it asserts out.
StringRef getAsCString() const {
assert(isCString() && "Isn't a C string");
StringRef Str = getAsString();
return Str.substr(0, Str.size() - 1);
}
/// Return the raw, underlying, bytes of this data. Note that this is an
/// extremely tricky thing to work with, as it exposes the host endianness of
/// the data elements.
StringRef getRawDataValues() const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantDataArrayVal ||
V->getValueID() == ConstantDataVectorVal;
}
private:
const char *getElementPointer(unsigned Elt) const;
};
//===----------------------------------------------------------------------===//
/// An array constant whose element type is a simple 1/2/4/8-byte integer or
/// float/double, and whose elements are just simple data values
/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
/// stores all of the elements of the constant as densely packed data, instead
/// of as Value*'s.
class ConstantDataArray final : public ConstantDataSequential {
friend class ConstantDataSequential;
explicit ConstantDataArray(Type *ty, const char *Data)
: ConstantDataSequential(ty, ConstantDataArrayVal, Data) {}
public:
ConstantDataArray(const ConstantDataArray &) = delete;
/// get() constructor - Return a constant with array type with an element
/// count and element type matching the ArrayRef passed in. Note that this
/// can return a ConstantAggregateZero object.
template <typename ElementTy>
static Constant *get(LLVMContext &Context, ArrayRef<ElementTy> Elts) {
const char *Data = reinterpret_cast<const char *>(Elts.data());
return getRaw(StringRef(Data, Elts.size() * sizeof(ElementTy)), Elts.size(),
Type::getScalarTy<ElementTy>(Context));
}
/// get() constructor - ArrayTy needs to be compatible with
/// ArrayRef<ElementTy>. Calls get(LLVMContext, ArrayRef<ElementTy>).
template <typename ArrayTy>
static Constant *get(LLVMContext &Context, ArrayTy &Elts) {
return ConstantDataArray::get(Context, ArrayRef(Elts));
}
/// getRaw() constructor - Return a constant with array type with an element
/// count and element type matching the NumElements and ElementTy parameters
/// passed in. Note that this can return a ConstantAggregateZero object.
/// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is
/// the buffer containing the elements. Be careful to make sure Data uses the
/// right endianness, the buffer will be used as-is.
static Constant *getRaw(StringRef Data, uint64_t NumElements,
Type *ElementTy) {
Type *Ty = ArrayType::get(ElementTy, NumElements);
return getImpl(Data, Ty);
}
/// getFP() constructors - Return a constant of array type with a float
/// element type taken from argument `ElementType', and count taken from
/// argument `Elts'. The amount of bits of the contained type must match the
/// number of bits of the type contained in the passed in ArrayRef.
/// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
/// that this can return a ConstantAggregateZero object.
static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts);
static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts);
static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts);
/// This method constructs a CDS and initializes it with a text string.
/// The default behavior (AddNull==true) causes a null terminator to
/// be placed at the end of the array (increasing the length of the string by
/// one more than the StringRef would normally indicate. Pass AddNull=false
/// to disable this behavior.
static Constant *getString(LLVMContext &Context, StringRef Initializer,
bool AddNull = true);
/// Specialize the getType() method to always return an ArrayType,
/// which reduces the amount of casting needed in parts of the compiler.
inline ArrayType *getType() const {
return cast<ArrayType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantDataArrayVal;
}
};
//===----------------------------------------------------------------------===//
/// A vector constant whose element type is a simple 1/2/4/8-byte integer or
/// float/double, and whose elements are just simple data values
/// (i.e. ConstantInt/ConstantFP). This Constant node has no operands because it
/// stores all of the elements of the constant as densely packed data, instead
/// of as Value*'s.
class ConstantDataVector final : public ConstantDataSequential {
friend class ConstantDataSequential;
explicit ConstantDataVector(Type *ty, const char *Data)
: ConstantDataSequential(ty, ConstantDataVectorVal, Data),
IsSplatSet(false) {}
// Cache whether or not the constant is a splat.
mutable bool IsSplatSet : 1;
mutable bool IsSplat : 1;
bool isSplatData() const;
public:
ConstantDataVector(const ConstantDataVector &) = delete;
/// get() constructors - Return a constant with vector type with an element
/// count and element type matching the ArrayRef passed in. Note that this
/// can return a ConstantAggregateZero object.
static Constant *get(LLVMContext &Context, ArrayRef<uint8_t> Elts);
static Constant *get(LLVMContext &Context, ArrayRef<uint16_t> Elts);
static Constant *get(LLVMContext &Context, ArrayRef<uint32_t> Elts);
static Constant *get(LLVMContext &Context, ArrayRef<uint64_t> Elts);
static Constant *get(LLVMContext &Context, ArrayRef<float> Elts);
static Constant *get(LLVMContext &Context, ArrayRef<double> Elts);
/// getRaw() constructor - Return a constant with vector type with an element
/// count and element type matching the NumElements and ElementTy parameters
/// passed in. Note that this can return a ConstantAggregateZero object.
/// ElementTy must be one of i8/i16/i32/i64/half/bfloat/float/double. Data is
/// the buffer containing the elements. Be careful to make sure Data uses the
/// right endianness, the buffer will be used as-is.
static Constant *getRaw(StringRef Data, uint64_t NumElements,
Type *ElementTy) {
Type *Ty = VectorType::get(ElementTy, ElementCount::getFixed(NumElements));
return getImpl(Data, Ty);
}
/// getFP() constructors - Return a constant of vector type with a float
/// element type taken from argument `ElementType', and count taken from
/// argument `Elts'. The amount of bits of the contained type must match the
/// number of bits of the type contained in the passed in ArrayRef.
/// (i.e. half or bfloat for 16bits, float for 32bits, double for 64bits) Note
/// that this can return a ConstantAggregateZero object.
static Constant *getFP(Type *ElementType, ArrayRef<uint16_t> Elts);
static Constant *getFP(Type *ElementType, ArrayRef<uint32_t> Elts);
static Constant *getFP(Type *ElementType, ArrayRef<uint64_t> Elts);
/// Return a ConstantVector with the specified constant in each element.
/// The specified constant has to be a of a compatible type (i8/i16/
/// i32/i64/half/bfloat/float/double) and must be a ConstantFP or ConstantInt.
static Constant *getSplat(unsigned NumElts, Constant *Elt);
/// Returns true if this is a splat constant, meaning that all elements have
/// the same value.
bool isSplat() const;
/// If this is a splat constant, meaning that all of the elements have the
/// same value, return that value. Otherwise return NULL.
Constant *getSplatValue() const;
/// Specialize the getType() method to always return a FixedVectorType,
/// which reduces the amount of casting needed in parts of the compiler.
inline FixedVectorType *getType() const {
return cast<FixedVectorType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantDataVectorVal;
}
};
//===----------------------------------------------------------------------===//
/// A constant token which is empty
///
class ConstantTokenNone final : public ConstantData {
friend class Constant;
explicit ConstantTokenNone(LLVMContext &Context)
: ConstantData(Type::getTokenTy(Context), ConstantTokenNoneVal) {}
void destroyConstantImpl();
public:
ConstantTokenNone(const ConstantTokenNone &) = delete;
/// Return the ConstantTokenNone.
static ConstantTokenNone *get(LLVMContext &Context);
/// Methods to support type inquiry through isa, cast, and dyn_cast.
static bool classof(const Value *V) {
return V->getValueID() == ConstantTokenNoneVal;
}
};
/// A constant target extension type default initializer
class ConstantTargetNone final : public ConstantData {
friend class Constant;
explicit ConstantTargetNone(TargetExtType *T)
: ConstantData(T, Value::ConstantTargetNoneVal) {}
void destroyConstantImpl();
public:
ConstantTargetNone(const ConstantTargetNone &) = delete;
/// Static factory methods - Return objects of the specified value.
static ConstantTargetNone *get(TargetExtType *T);
/// Specialize the getType() method to always return an TargetExtType,
/// which reduces the amount of casting needed in parts of the compiler.
inline TargetExtType *getType() const {
return cast<TargetExtType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast.
static bool classof(const Value *V) {
return V->getValueID() == ConstantTargetNoneVal;
}
};
/// The address of a basic block.
///
class BlockAddress final : public Constant {
friend class Constant;
BlockAddress(Function *F, BasicBlock *BB);
void *operator new(size_t S) { return User::operator new(S, 2); }
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
void operator delete(void *Ptr) { User::operator delete(Ptr); }
/// Return a BlockAddress for the specified function and basic block.
static BlockAddress *get(Function *F, BasicBlock *BB);
/// Return a BlockAddress for the specified basic block. The basic
/// block must be embedded into a function.
static BlockAddress *get(BasicBlock *BB);
/// Lookup an existing \c BlockAddress constant for the given BasicBlock.
///
/// \returns 0 if \c !BB->hasAddressTaken(), otherwise the \c BlockAddress.
static BlockAddress *lookup(const BasicBlock *BB);
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
Function *getFunction() const { return (Function *)Op<0>().get(); }
BasicBlock *getBasicBlock() const { return (BasicBlock *)Op<1>().get(); }
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == BlockAddressVal;
}
};
template <>
struct OperandTraits<BlockAddress>
: public FixedNumOperandTraits<BlockAddress, 2> {};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(BlockAddress, Value)
/// Wrapper for a function that represents a value that
/// functionally represents the original function. This can be a function,
/// global alias to a function, or an ifunc.
class DSOLocalEquivalent final : public Constant {
friend class Constant;
DSOLocalEquivalent(GlobalValue *GV);
void *operator new(size_t S) { return User::operator new(S, 1); }
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
void operator delete(void *Ptr) { User::operator delete(Ptr); }
/// Return a DSOLocalEquivalent for the specified global value.
static DSOLocalEquivalent *get(GlobalValue *GV);
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
GlobalValue *getGlobalValue() const {
return cast<GlobalValue>(Op<0>().get());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == DSOLocalEquivalentVal;
}
};
template <>
struct OperandTraits<DSOLocalEquivalent>
: public FixedNumOperandTraits<DSOLocalEquivalent, 1> {};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(DSOLocalEquivalent, Value)
/// Wrapper for a value that won't be replaced with a CFI jump table
/// pointer in LowerTypeTestsModule.
class NoCFIValue final : public Constant {
friend class Constant;
NoCFIValue(GlobalValue *GV);
void *operator new(size_t S) { return User::operator new(S, 1); }
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
/// Return a NoCFIValue for the specified function.
static NoCFIValue *get(GlobalValue *GV);
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
GlobalValue *getGlobalValue() const {
return cast<GlobalValue>(Op<0>().get());
}
/// NoCFIValue is always a pointer.
PointerType *getType() const {
return cast<PointerType>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == NoCFIValueVal;
}
};
template <>
struct OperandTraits<NoCFIValue> : public FixedNumOperandTraits<NoCFIValue, 1> {
};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(NoCFIValue, Value)
/// A signed pointer, in the ptrauth sense.
class ConstantPtrAuth final : public Constant {
friend struct ConstantPtrAuthKeyType;
friend class Constant;
ConstantPtrAuth(Constant *Ptr, ConstantInt *Key, ConstantInt *Disc,
Constant *AddrDisc);
void *operator new(size_t s) { return User::operator new(s, 4); }
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
public:
/// Return a pointer signed with the specified parameters.
static ConstantPtrAuth *get(Constant *Ptr, ConstantInt *Key,
ConstantInt *Disc, Constant *AddrDisc);
/// Produce a new ptrauth expression signing the given value using
/// the same schema as is stored in one.
ConstantPtrAuth *getWithSameSchema(Constant *Pointer) const;
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
/// The pointer that is signed in this ptrauth signed pointer.
Constant *getPointer() const { return cast<Constant>(Op<0>().get()); }
/// The Key ID, an i32 constant.
ConstantInt *getKey() const { return cast<ConstantInt>(Op<1>().get()); }
/// The integer discriminator, an i64 constant, or 0.
ConstantInt *getDiscriminator() const {
return cast<ConstantInt>(Op<2>().get());
}
/// The address discriminator if any, or the null constant.
/// If present, this must be a value equivalent to the storage location of
/// the only global-initializer user of the ptrauth signed pointer.
Constant *getAddrDiscriminator() const {
return cast<Constant>(Op<3>().get());
}
/// Whether there is any non-null address discriminator.
bool hasAddressDiscriminator() const {
return !getAddrDiscriminator()->isNullValue();
}
/// Check whether an authentication operation with key \p Key and (possibly
/// blended) discriminator \p Discriminator is known to be compatible with
/// this ptrauth signed pointer.
bool isKnownCompatibleWith(const Value *Key, const Value *Discriminator,
const DataLayout &DL) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantPtrAuthVal;
}
};
template <>
struct OperandTraits<ConstantPtrAuth>
: public FixedNumOperandTraits<ConstantPtrAuth, 4> {};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPtrAuth, Constant)
//===----------------------------------------------------------------------===//
/// A constant value that is initialized with an expression using
/// other constant values.
///
/// This class uses the standard Instruction opcodes to define the various
/// constant expressions. The Opcode field for the ConstantExpr class is
/// maintained in the Value::SubclassData field.
class ConstantExpr : public Constant {
friend struct ConstantExprKeyType;
friend class Constant;
void destroyConstantImpl();
Value *handleOperandChangeImpl(Value *From, Value *To);
protected:
ConstantExpr(Type *ty, unsigned Opcode, Use *Ops, unsigned NumOps)
: Constant(ty, ConstantExprVal, Ops, NumOps) {
// Operation type (an Instruction opcode) is stored as the SubclassData.
setValueSubclassData(Opcode);
}
~ConstantExpr() = default;
public:
// Static methods to construct a ConstantExpr of different kinds. Note that
// these methods may return a object that is not an instance of the
// ConstantExpr class, because they will attempt to fold the constant
// expression into something simpler if possible.
/// getAlignOf constant expr - computes the alignment of a type in a target
/// independent way (Note: the return type is an i64).
static Constant *getAlignOf(Type *Ty);
/// getSizeOf constant expr - computes the (alloc) size of a type (in
/// address-units, not bits) in a target independent way (Note: the return
/// type is an i64).
///
static Constant *getSizeOf(Type *Ty);
static Constant *getNeg(Constant *C, bool HasNSW = false);
static Constant *getNot(Constant *C);
static Constant *getAdd(Constant *C1, Constant *C2, bool HasNUW = false,
bool HasNSW = false);
static Constant *getSub(Constant *C1, Constant *C2, bool HasNUW = false,
bool HasNSW = false);
static Constant *getMul(Constant *C1, Constant *C2, bool HasNUW = false,
bool HasNSW = false);
static Constant *getXor(Constant *C1, Constant *C2);
static Constant *getTrunc(Constant *C, Type *Ty, bool OnlyIfReduced = false);
static Constant *getPtrToInt(Constant *C, Type *Ty,
bool OnlyIfReduced = false);
static Constant *getIntToPtr(Constant *C, Type *Ty,
bool OnlyIfReduced = false);
static Constant *getBitCast(Constant *C, Type *Ty,
bool OnlyIfReduced = false);
static Constant *getAddrSpaceCast(Constant *C, Type *Ty,
bool OnlyIfReduced = false);
static Constant *getNSWNeg(Constant *C) { return getNeg(C, /*HasNSW=*/true); }
static Constant *getNSWAdd(Constant *C1, Constant *C2) {
return getAdd(C1, C2, false, true);
}
static Constant *getNUWAdd(Constant *C1, Constant *C2) {
return getAdd(C1, C2, true, false);
}
static Constant *getNSWSub(Constant *C1, Constant *C2) {
return getSub(C1, C2, false, true);
}
static Constant *getNUWSub(Constant *C1, Constant *C2) {
return getSub(C1, C2, true, false);
}
static Constant *getNSWMul(Constant *C1, Constant *C2) {
return getMul(C1, C2, false, true);
}
static Constant *getNUWMul(Constant *C1, Constant *C2) {
return getMul(C1, C2, true, false);
}
/// If C is a scalar/fixed width vector of known powers of 2, then this
/// function returns a new scalar/fixed width vector obtained from logBase2
/// of C. Undef vector elements are set to zero.
/// Return a null pointer otherwise.
static Constant *getExactLogBase2(Constant *C);
/// Return the identity constant for a binary opcode.
/// If the binop is not commutative, callers can acquire the operand 1
/// identity constant by setting AllowRHSConstant to true. For example, any
/// shift has a zero identity constant for operand 1: X shift 0 = X. If this
/// is a fadd/fsub operation and we don't care about signed zeros, then
/// setting NSZ to true returns the identity +0.0 instead of -0.0. Return
/// nullptr if the operator does not have an identity constant.
static Constant *getBinOpIdentity(unsigned Opcode, Type *Ty,
bool AllowRHSConstant = false,
bool NSZ = false);
static Constant *getIntrinsicIdentity(Intrinsic::ID, Type *Ty);
/// Return the identity constant for a binary or intrinsic Instruction.
/// The identity constant C is defined as X op C = X and C op X = X where C
/// and X are the first two operands, and the operation is commutative.
static Constant *getIdentity(Instruction *I, Type *Ty,
bool AllowRHSConstant = false, bool NSZ = false);
/// Return the absorbing element for the given binary
/// operation, i.e. a constant C such that X op C = C and C op X = C for
/// every X. For example, this returns zero for integer multiplication.
/// It returns null if the operator doesn't have an absorbing element.
static Constant *getBinOpAbsorber(unsigned Opcode, Type *Ty);
/// Transparently provide more efficient getOperand methods.
DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Constant);
/// Convenience function for getting a Cast operation.
///
/// \param ops The opcode for the conversion
/// \param C The constant to be converted
/// \param Ty The type to which the constant is converted
/// \param OnlyIfReduced see \a getWithOperands() docs.
static Constant *getCast(unsigned ops, Constant *C, Type *Ty,
bool OnlyIfReduced = false);
// Create a Trunc or BitCast cast constant expression
static Constant *
getTruncOrBitCast(Constant *C, ///< The constant to trunc or bitcast
Type *Ty ///< The type to trunc or bitcast C to
);
/// Create a BitCast, AddrSpaceCast, or a PtrToInt cast constant
/// expression.
static Constant *
getPointerCast(Constant *C, ///< The pointer value to be casted (operand 0)
Type *Ty ///< The type to which cast should be made
);
/// Create a BitCast or AddrSpaceCast for a pointer type depending on
/// the address space.
static Constant *getPointerBitCastOrAddrSpaceCast(
Constant *C, ///< The constant to addrspacecast or bitcast
Type *Ty ///< The type to bitcast or addrspacecast C to
);
/// Return true if this is a convert constant expression
bool isCast() const;
/// get - Return a binary or shift operator constant expression,
/// folding if possible.
///
/// \param OnlyIfReducedTy see \a getWithOperands() docs.
static Constant *get(unsigned Opcode, Constant *C1, Constant *C2,
unsigned Flags = 0, Type *OnlyIfReducedTy = nullptr);
/// Getelementptr form. Value* is only accepted for convenience;
/// all elements must be Constants.
///
/// \param InRange the inrange range if present or std::nullopt.
/// \param OnlyIfReducedTy see \a getWithOperands() docs.
static Constant *
getGetElementPtr(Type *Ty, Constant *C, ArrayRef<Constant *> IdxList,
GEPNoWrapFlags NW = GEPNoWrapFlags::none(),
std::optional<ConstantRange> InRange = std::nullopt,
Type *OnlyIfReducedTy = nullptr) {
return getGetElementPtr(
Ty, C, ArrayRef((Value *const *)IdxList.data(), IdxList.size()), NW,
InRange, OnlyIfReducedTy);
}
static Constant *
getGetElementPtr(Type *Ty, Constant *C, Constant *Idx,
GEPNoWrapFlags NW = GEPNoWrapFlags::none(),
std::optional<ConstantRange> InRange = std::nullopt,
Type *OnlyIfReducedTy = nullptr) {
// This form of the function only exists to avoid ambiguous overload
// warnings about whether to convert Idx to ArrayRef<Constant *> or
// ArrayRef<Value *>.
return getGetElementPtr(Ty, C, cast<Value>(Idx), NW, InRange,
OnlyIfReducedTy);
}
static Constant *
getGetElementPtr(Type *Ty, Constant *C, ArrayRef<Value *> IdxList,
GEPNoWrapFlags NW = GEPNoWrapFlags::none(),
std::optional<ConstantRange> InRange = std::nullopt,
Type *OnlyIfReducedTy = nullptr);
/// Create an "inbounds" getelementptr. See the documentation for the
/// "inbounds" flag in LangRef.html for details.
static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
ArrayRef<Constant *> IdxList) {
return getGetElementPtr(Ty, C, IdxList, GEPNoWrapFlags::inBounds());
}
static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
Constant *Idx) {
// This form of the function only exists to avoid ambiguous overload
// warnings about whether to convert Idx to ArrayRef<Constant *> or
// ArrayRef<Value *>.
return getGetElementPtr(Ty, C, Idx, GEPNoWrapFlags::inBounds());
}
static Constant *getInBoundsGetElementPtr(Type *Ty, Constant *C,
ArrayRef<Value *> IdxList) {
return getGetElementPtr(Ty, C, IdxList, GEPNoWrapFlags::inBounds());
}
static Constant *getExtractElement(Constant *Vec, Constant *Idx,
Type *OnlyIfReducedTy = nullptr);
static Constant *getInsertElement(Constant *Vec, Constant *Elt, Constant *Idx,
Type *OnlyIfReducedTy = nullptr);
static Constant *getShuffleVector(Constant *V1, Constant *V2,
ArrayRef<int> Mask,
Type *OnlyIfReducedTy = nullptr);
/// Return the opcode at the root of this constant expression
unsigned getOpcode() const { return getSubclassDataFromValue(); }
/// Assert that this is a shufflevector and return the mask. See class
/// ShuffleVectorInst for a description of the mask representation.
ArrayRef<int> getShuffleMask() const;
/// Assert that this is a shufflevector and return the mask.
///
/// TODO: This is a temporary hack until we update the bitcode format for
/// shufflevector.
Constant *getShuffleMaskForBitcode() const;
/// Return a string representation for an opcode.
const char *getOpcodeName() const;
/// This returns the current constant expression with the operands replaced
/// with the specified values. The specified array must have the same number
/// of operands as our current one.
Constant *getWithOperands(ArrayRef<Constant *> Ops) const {
return getWithOperands(Ops, getType());
}
/// Get the current expression with the operands replaced.
///
/// Return the current constant expression with the operands replaced with \c
/// Ops and the type with \c Ty. The new operands must have the same number
/// as the current ones.
///
/// If \c OnlyIfReduced is \c true, nullptr will be returned unless something
/// gets constant-folded, the type changes, or the expression is otherwise
/// canonicalized. This parameter should almost always be \c false.
Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
bool OnlyIfReduced = false,
Type *SrcTy = nullptr) const;
/// Returns an Instruction which implements the same operation as this
/// ConstantExpr. It is not inserted into any basic block.
///
/// A better approach to this could be to have a constructor for Instruction
/// which would take a ConstantExpr parameter, but that would have spread
/// implementation details of ConstantExpr outside of Constants.cpp, which
/// would make it harder to remove ConstantExprs altogether.
Instruction *getAsInstruction() const;
/// Whether creating a constant expression for this binary operator is
/// desirable.
static bool isDesirableBinOp(unsigned Opcode);
/// Whether creating a constant expression for this binary operator is
/// supported.
static bool isSupportedBinOp(unsigned Opcode);
/// Whether creating a constant expression for this cast is desirable.
static bool isDesirableCastOp(unsigned Opcode);
/// Whether creating a constant expression for this cast is supported.
static bool isSupportedCastOp(unsigned Opcode);
/// Whether creating a constant expression for this getelementptr type is
/// supported.
static bool isSupportedGetElementPtr(const Type *SrcElemTy) {
return !SrcElemTy->isScalableTy();
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == ConstantExprVal;
}
private:
// Shadow Value::setValueSubclassData with a private forwarding method so that
// subclasses cannot accidentally use it.
void setValueSubclassData(unsigned short D) {
Value::setValueSubclassData(D);
}
};
template <>
struct OperandTraits<ConstantExpr>
: public VariadicOperandTraits<ConstantExpr, 1> {};
DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantExpr, Constant)
//===----------------------------------------------------------------------===//
/// 'undef' values are things that do not have specified contents.
/// These are used for a variety of purposes, including global variable
/// initializers and operands to instructions. 'undef' values can occur with
/// any first-class type.
///
/// Undef values aren't exactly constants; if they have multiple uses, they
/// can appear to have different bit patterns at each use. See
/// LangRef.html#undefvalues for details.
///
class UndefValue : public ConstantData {
friend class Constant;
explicit UndefValue(Type *T) : ConstantData(T, UndefValueVal) {}
void destroyConstantImpl();
protected:
explicit UndefValue(Type *T, ValueTy vty) : ConstantData(T, vty) {}
public:
UndefValue(const UndefValue &) = delete;
/// Static factory methods - Return an 'undef' object of the specified type.
static UndefValue *get(Type *T);
/// If this Undef has array or vector type, return a undef with the right
/// element type.
UndefValue *getSequentialElement() const;
/// If this undef has struct type, return a undef with the right element type
/// for the specified element.
UndefValue *getStructElement(unsigned Elt) const;
/// Return an undef of the right value for the specified GEP index if we can,
/// otherwise return null (e.g. if C is a ConstantExpr).
UndefValue *getElementValue(Constant *C) const;
/// Return an undef of the right value for the specified GEP index.
UndefValue *getElementValue(unsigned Idx) const;
/// Return the number of elements in the array, vector, or struct.
unsigned getNumElements() const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == UndefValueVal ||
V->getValueID() == PoisonValueVal;
}
};
//===----------------------------------------------------------------------===//
/// In order to facilitate speculative execution, many instructions do not
/// invoke immediate undefined behavior when provided with illegal operands,
/// and return a poison value instead.
///
/// see LangRef.html#poisonvalues for details.
///
class PoisonValue final : public UndefValue {
friend class Constant;
explicit PoisonValue(Type *T) : UndefValue(T, PoisonValueVal) {}
void destroyConstantImpl();
public:
PoisonValue(const PoisonValue &) = delete;
/// Static factory methods - Return an 'poison' object of the specified type.
static PoisonValue *get(Type *T);
/// If this poison has array or vector type, return a poison with the right
/// element type.
PoisonValue *getSequentialElement() const;
/// If this poison has struct type, return a poison with the right element
/// type for the specified element.
PoisonValue *getStructElement(unsigned Elt) const;
/// Return an poison of the right value for the specified GEP index if we can,
/// otherwise return null (e.g. if C is a ConstantExpr).
PoisonValue *getElementValue(Constant *C) const;
/// Return an poison of the right value for the specified GEP index.
PoisonValue *getElementValue(unsigned Idx) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == PoisonValueVal;
}
};
} // end namespace llvm
#endif // LLVM_IR_CONSTANTS_H
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