llvm-6502/include/llvm/Constants.h
Reid Spencer 56667123b7 Take a baby step towards getting rid of inferred casts. Provide methods on
CastInst and ConstantExpr that allow the signedness to be explicitly passed
in and reliance on signedness removed from getCastOpcode. These are
temporary measures useful during the conversion of inferred casts.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32164 91177308-0d34-0410-b5e6-96231b3b80d8
2006-12-04 02:43:42 +00:00

694 lines
28 KiB
C++

//===-- llvm/Constants.h - Constant class subclass definitions --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @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. Constant's are
/// created on demand as needed and never deleted: thus clients don't have to
/// worry about the lifetime of the objects.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CONSTANTS_H
#define LLVM_CONSTANTS_H
#include "llvm/Constant.h"
#include "llvm/Type.h"
namespace llvm {
class ArrayType;
class StructType;
class PointerType;
class PackedType;
template<class ConstantClass, class TypeClass, class ValType>
struct ConstantCreator;
template<class ConstantClass, class TypeClass>
struct ConvertConstantType;
//===----------------------------------------------------------------------===//
/// This is the shared superclass of boolean and integer constants. This class
/// just defines some common interfaces to be implemented by the subclasses.
/// @brief An abstract class for integer constants.
class ConstantIntegral : public Constant {
protected:
uint64_t Val;
ConstantIntegral(const Type *Ty, ValueTy VT, uint64_t V);
public:
/// ConstantIntegral::get - Return a bool or integer constant.
static ConstantIntegral *get(const Type *Ty, int64_t V);
/// Return the constant as a 64-bit unsigned integer value after it
/// has been zero extended as appropriate for the type of this constant.
/// @brief Return the zero extended value.
inline uint64_t getZExtValue() const {
return Val;
}
/// Return the constant as a 64-bit integer value after it has been sign
/// sign extended as appropriate for the type of this constant.
/// @brief Return the sign extended value.
inline int64_t getSExtValue() const {
unsigned Size = getType()->getPrimitiveSizeInBits();
return (int64_t(Val) << (64-Size)) >> (64-Size);
}
/// This function is implemented by subclasses and will return true iff this
/// constant represents the the "null" value that would be returned by the
/// getNullValue method.
/// @returns true if the constant's value is 0.
/// @brief Determine if the value is null.
virtual bool isNullValue() const = 0;
/// This function is implemented by sublcasses and will return true iff this
/// constant represents the the largest value that may be represented by this
/// constant's type.
/// @returns true if the constant's value is maximal.
/// @brief Determine if the value is maximal.
virtual bool isMaxValue() const = 0;
/// This function is implemented by subclasses and will return true iff this
/// constant represents the smallest value that may be represented by this
/// constant's type.
/// @returns true if the constant's value is minimal
/// @brief Determine if the value is minimal.
virtual bool isMinValue() const = 0;
/// This function is implemented by subclasses and will return true iff every
/// bit in this constant is set to true.
/// @returns true if all bits of the constant are ones.
/// @brief Determine if the value is all ones.
virtual bool isAllOnesValue() const = 0;
/// @returns the largest value for an integer constant of the given type
/// @brief Get the maximal value
static ConstantIntegral *getMaxValue(const Type *Ty);
/// @returns the smallest value for an integer constant of the given type
/// @brief Get the minimal value
static ConstantIntegral *getMinValue(const Type *Ty);
/// @returns the value for an integer constant of the given type that has all
/// its bits set to true.
/// @brief Get the all ones value
static ConstantIntegral *getAllOnesValue(const Type *Ty);
/// Methods to support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantIntegral *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantBoolVal ||
V->getValueType() == ConstantIntVal;
}
};
//===----------------------------------------------------------------------===//
/// This concrete class represents constant values of type BoolTy. There are
/// only two instances of this class constructed: the True and False static
/// members. The constructor is hidden to ensure this invariant.
/// @brief Constant Boolean class
class ConstantBool : public ConstantIntegral {
ConstantBool(bool V);
public:
/// getTrue/getFalse - Return the singleton true/false values.
static ConstantBool *getTrue();
static ConstantBool *getFalse();
/// This method is provided mostly for compatibility with the other
/// ConstantIntegral subclasses.
/// @brief Static factory method for getting a ConstantBool instance.
static ConstantBool *get(bool Value) { return Value ? getTrue() : getFalse();}
/// This method is provided mostly for compatibility with the other
/// ConstantIntegral subclasses.
/// @brief Static factory method for getting a ConstantBool instance.
static ConstantBool *get(const Type *Ty, bool Value) { return get(Value); }
/// Returns the opposite value of this ConstantBool value.
/// @brief Get inverse value.
inline ConstantBool *inverted() const {
return getValue() ? getFalse() : getTrue();
}
/// @returns the value of this ConstantBool
/// @brief return the boolean value of this constant.
inline bool getValue() const { return static_cast<bool>(getZExtValue()); }
/// @see ConstantIntegral for details
/// @brief Implement overrides
virtual bool isNullValue() const { return getValue() == false; }
virtual bool isMaxValue() const { return getValue() == true; }
virtual bool isMinValue() const { return getValue() == false; }
virtual bool isAllOnesValue() const { return getValue() == true; }
/// @brief Methods to support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantBool *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantBoolVal;
}
};
//===----------------------------------------------------------------------===//
/// This is concrete integer subclass of ConstantIntegral that represents
/// both signed and unsigned integral constants, other than boolean.
/// @brief Class for constant integers.
class ConstantInt : public ConstantIntegral {
protected:
ConstantInt(const ConstantInt &); // DO NOT IMPLEMENT
ConstantInt(const Type *Ty, uint64_t V);
ConstantInt(const Type *Ty, int64_t V);
friend struct ConstantCreator<ConstantInt, Type, uint64_t>;
public:
/// 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.
/// @brief Determine if this constant's value is same as an unsigned char.
bool equalsInt(unsigned char V) const {
assert(V <= 127 &&
"equalsInt: Can only be used with very small positive constants!");
return Val == V;
}
/// Return a ConstantInt with the specified value for the specified type. The
/// value V will be canonicalized to a uint64_t but accessing it with either
/// getSExtValue() or getZExtValue() (ConstantIntegral) will yield the correct
/// sized/signed value for the type Ty.
/// @brief Get a ConstantInt for a specific value.
static ConstantInt *get(const Type *Ty, int64_t V);
/// 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.
/// @returns true if V is a valid value for type Ty
/// @brief Determine if the value is in range for the given type.
static bool isValueValidForType(const Type *Ty, int64_t V);
/// @returns true if this is the null integer value.
/// @see ConstantIntegral for details
/// @brief Implement override.
virtual bool isNullValue() const { return Val == 0; }
/// @returns true iff this constant's bits are all set to true.
/// @see ConstantIntegral
/// @brief Override implementation
virtual bool isAllOnesValue() const { return getSExtValue() == -1; }
/// @returns true iff this is the largest value that may be represented
/// by this type.
/// @see ConstantIntegeral
/// @brief Override implementation
virtual bool isMaxValue() const {
if (getType()->isSigned()) {
int64_t V = getSExtValue();
if (V < 0) return false; // Be careful about wrap-around on 'long's
++V;
return !isValueValidForType(getType(), V) || V < 0;
}
return isAllOnesValue();
}
/// @returns true if this is the smallest value that may be represented by
/// this type.
/// @see ConstantIntegral
/// @brief Override implementation
virtual bool isMinValue() const {
if (getType()->isSigned()) {
int64_t V = getSExtValue();
if (V > 0) return false; // Be careful about wrap-around on 'long's
--V;
return !isValueValidForType(getType(), V) || V > 0;
}
return getZExtValue() == 0;
}
/// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
static inline bool classof(const ConstantInt *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantIntVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantFP - Floating Point Values [float, double]
///
class ConstantFP : public Constant {
double Val;
friend struct ConstantCreator<ConstantFP, Type, uint64_t>;
friend struct ConstantCreator<ConstantFP, Type, uint32_t>;
ConstantFP(const ConstantFP &); // DO NOT IMPLEMENT
protected:
ConstantFP(const Type *Ty, double V);
public:
/// get() - Static factory methods - Return objects of the specified value
static ConstantFP *get(const Type *Ty, double V);
/// isValueValidForType - return true if Ty is big enough to represent V.
static bool isValueValidForType(const Type *Ty, double V);
inline double getValue() const { return Val; }
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue. Don't depend on == for doubles to tell us it's zero, it
/// considers -0.0 to be null as well as 0.0. :(
virtual bool isNullValue() const;
/// isExactlyValue - 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.
bool isExactlyValue(double V) const;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantFP *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantFPVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantAggregateZero - All zero aggregate value
///
class ConstantAggregateZero : public Constant {
friend struct ConstantCreator<ConstantAggregateZero, Type, char>;
ConstantAggregateZero(const ConstantAggregateZero &); // DO NOT IMPLEMENT
protected:
ConstantAggregateZero(const Type *Ty)
: Constant(Ty, ConstantAggregateZeroVal, 0, 0) {}
public:
/// get() - static factory method for creating a null aggregate. It is
/// illegal to call this method with a non-aggregate type.
static Constant *get(const Type *Ty);
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
virtual bool isNullValue() const { return true; }
virtual void destroyConstant();
/// Methods for support type inquiry through isa, cast, and dyn_cast:
///
static bool classof(const ConstantAggregateZero *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantAggregateZeroVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantArray - Constant Array Declarations
///
class ConstantArray : public Constant {
friend struct ConstantCreator<ConstantArray, ArrayType,
std::vector<Constant*> >;
ConstantArray(const ConstantArray &); // DO NOT IMPLEMENT
protected:
ConstantArray(const ArrayType *T, const std::vector<Constant*> &Val);
~ConstantArray();
public:
/// get() - Static factory methods - Return objects of the specified value
static Constant *get(const ArrayType *T, const std::vector<Constant*> &);
/// This method constructs a ConstantArray 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. This effectively increases the length
/// of the array by one (you've been warned). However, in some situations
/// this is not desired so if AddNull==false then the string is copied without
/// null termination.
static Constant *get(const std::string &Initializer, bool AddNull = true);
/// getType - Specialize the getType() method to always return an ArrayType,
/// which reduces the amount of casting needed in parts of the compiler.
///
inline const ArrayType *getType() const {
return reinterpret_cast<const ArrayType*>(Value::getType());
}
/// isString - This method returns true if the array is an array of sbyte or
/// ubyte, and if the elements of the array are all ConstantInt's.
bool isString() const;
/// isCString - This method returns true if the array is a string (see
/// isString) and it ends in a null byte \0 and does not contains any other
/// null bytes except its terminator.
bool isCString() const;
/// getAsString - If this array is isString(), then this method converts the
/// array to an std::string and returns it. Otherwise, it asserts out.
///
std::string getAsString() const;
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue. This always returns false because zero arrays are always
/// created as ConstantAggregateZero objects.
virtual bool isNullValue() const { return false; }
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantArray *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantArrayVal;
}
};
//===----------------------------------------------------------------------===//
// ConstantStruct - Constant Struct Declarations
//
class ConstantStruct : public Constant {
friend struct ConstantCreator<ConstantStruct, StructType,
std::vector<Constant*> >;
ConstantStruct(const ConstantStruct &); // DO NOT IMPLEMENT
protected:
ConstantStruct(const StructType *T, const std::vector<Constant*> &Val);
~ConstantStruct();
public:
/// get() - Static factory methods - Return objects of the specified value
///
static Constant *get(const StructType *T, const std::vector<Constant*> &V);
static Constant *get(const std::vector<Constant*> &V);
/// getType() specialization - Reduce amount of casting...
///
inline const StructType *getType() const {
return reinterpret_cast<const StructType*>(Value::getType());
}
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue. This always returns false because zero structs are always
/// created as ConstantAggregateZero objects.
virtual bool isNullValue() const {
return false;
}
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantStruct *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantStructVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantPacked - Constant Packed Declarations
///
class ConstantPacked : public Constant {
friend struct ConstantCreator<ConstantPacked, PackedType,
std::vector<Constant*> >;
ConstantPacked(const ConstantPacked &); // DO NOT IMPLEMENT
protected:
ConstantPacked(const PackedType *T, const std::vector<Constant*> &Val);
~ConstantPacked();
public:
/// get() - Static factory methods - Return objects of the specified value
static Constant *get(const PackedType *T, const std::vector<Constant*> &);
static Constant *get(const std::vector<Constant*> &V);
/// getType - Specialize the getType() method to always return an PackedType,
/// which reduces the amount of casting needed in parts of the compiler.
///
inline const PackedType *getType() const {
return reinterpret_cast<const PackedType*>(Value::getType());
}
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue. This always returns false because zero arrays are always
/// created as ConstantAggregateZero objects.
virtual bool isNullValue() const { return false; }
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantPacked *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantPackedVal;
}
};
//===----------------------------------------------------------------------===//
/// ConstantPointerNull - a constant pointer value that points to null
///
class ConstantPointerNull : public Constant {
friend struct ConstantCreator<ConstantPointerNull, PointerType, char>;
ConstantPointerNull(const ConstantPointerNull &); // DO NOT IMPLEMENT
protected:
ConstantPointerNull(const PointerType *T)
: Constant(reinterpret_cast<const Type*>(T),
Value::ConstantPointerNullVal, 0, 0) {}
public:
/// get() - Static factory methods - Return objects of the specified value
static ConstantPointerNull *get(const PointerType *T);
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
virtual bool isNullValue() const { return true; }
virtual void destroyConstant();
/// getType - Specialize the getType() method to always return an PointerType,
/// which reduces the amount of casting needed in parts of the compiler.
///
inline const PointerType *getType() const {
return reinterpret_cast<const PointerType*>(Value::getType());
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantPointerNull *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == ConstantPointerNullVal;
}
};
/// ConstantExpr - 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 ConstantCreator<ConstantExpr,Type,
std::pair<unsigned, std::vector<Constant*> > >;
friend struct ConvertConstantType<ConstantExpr, Type>;
protected:
ConstantExpr(const Type *Ty, unsigned Opcode, Use *Ops, unsigned NumOps)
: Constant(Ty, ConstantExprVal, Ops, NumOps) {
// Operation type (an Instruction opcode) is stored as the SubclassData.
SubclassData = Opcode;
}
// These private methods are used by the type resolution code to create
// ConstantExprs in intermediate forms.
static Constant *getTy(const Type *Ty, unsigned Opcode,
Constant *C1, Constant *C2);
static Constant *getShiftTy(const Type *Ty,
unsigned Opcode, Constant *C1, Constant *C2);
static Constant *getSelectTy(const Type *Ty,
Constant *C1, Constant *C2, Constant *C3);
static Constant *getGetElementPtrTy(const Type *Ty, Constant *C,
const std::vector<Value*> &IdxList);
static Constant *getExtractElementTy(const Type *Ty, Constant *Val,
Constant *Idx);
static Constant *getInsertElementTy(const Type *Ty, Constant *Val,
Constant *Elt, Constant *Idx);
static Constant *getShuffleVectorTy(const Type *Ty, Constant *V1,
Constant *V2, Constant *Mask);
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.
/// Cast constant expr
///
static Constant *getTrunc (Constant *C, const Type *Ty);
static Constant *getSignExtend (Constant *C, const Type *Ty);
static Constant *getZeroExtend (Constant *C, const Type *Ty);
static Constant *getFPTrunc (Constant *C, const Type *Ty);
static Constant *getFPExtend (Constant *C, const Type *Ty);
static Constant *getUIToFP (Constant *C, const Type *Ty);
static Constant *getSIToFP (Constant *C, const Type *Ty);
static Constant *getFPToUI (Constant *C, const Type *Ty);
static Constant *getFPToSI (Constant *C, const Type *Ty);
static Constant *getPtrToInt (Constant *C, const Type *Ty);
static Constant *getIntToPtr (Constant *C, const Type *Ty);
static Constant *getBitCast (Constant *C, const Type *Ty);
// @brief Convenience function for getting one of the casting operations
// using a CastOps opcode.
static Constant *getCast(
unsigned ops, ///< The opcode for the conversion
Constant *C, ///< The constant to be converted
const Type *Ty ///< The type to which the constant is converted
);
// This method uses the CastInst::getCastOpcode method to infer the
// cast opcode to use.
// @brief Get a ConstantExpr Conversion operator that casts C to Ty
static Constant *getInferredCast(Constant *C, bool SrcIsSigned,
const Type *Ty, bool DestIsSigned);
static Constant *getCast(Constant *C, const Type *Ty) {
return getInferredCast(C, C->getType()->isSigned(), Ty, Ty->isSigned());
}
/// @brief Return true if this is a convert constant expression
bool isCast() const;
/// Select constant expr
///
static Constant *getSelect(Constant *C, Constant *V1, Constant *V2) {
return getSelectTy(V1->getType(), C, V1, V2);
}
/// getSizeOf constant expr - computes the size of a type in a target
/// independent way (Note: the return type is a ULong).
///
static Constant *getSizeOf(const Type *Ty);
/// getPtrPtrFromArrayPtr constant expr - given a pointer to a constant array,
/// return a pointer to a pointer of the array element type.
static Constant *getPtrPtrFromArrayPtr(Constant *C);
/// ConstantExpr::get - Return a binary or shift operator constant expression,
/// folding if possible.
///
static Constant *get(unsigned Opcode, Constant *C1, Constant *C2);
/// ConstantExpr::get* - Return some common constants without having to
/// specify the full Instruction::OPCODE identifier.
///
static Constant *getNeg(Constant *C);
static Constant *getNot(Constant *C);
static Constant *getAdd(Constant *C1, Constant *C2);
static Constant *getSub(Constant *C1, Constant *C2);
static Constant *getMul(Constant *C1, Constant *C2);
static Constant *getUDiv(Constant *C1, Constant *C2);
static Constant *getSDiv(Constant *C1, Constant *C2);
static Constant *getFDiv(Constant *C1, Constant *C2);
static Constant *getURem(Constant *C1, Constant *C2); // unsigned rem
static Constant *getSRem(Constant *C1, Constant *C2); // signed rem
static Constant *getFRem(Constant *C1, Constant *C2);
static Constant *getAnd(Constant *C1, Constant *C2);
static Constant *getOr(Constant *C1, Constant *C2);
static Constant *getXor(Constant *C1, Constant *C2);
static Constant *getSetEQ(Constant *C1, Constant *C2);
static Constant *getSetNE(Constant *C1, Constant *C2);
static Constant *getSetLT(Constant *C1, Constant *C2);
static Constant *getSetGT(Constant *C1, Constant *C2);
static Constant *getSetLE(Constant *C1, Constant *C2);
static Constant *getSetGE(Constant *C1, Constant *C2);
static Constant* getICmp(unsigned short pred, Constant* LHS, Constant* RHS);
static Constant* getFCmp(unsigned short pred, Constant* LHS, Constant* RHS);
static Constant *getShl(Constant *C1, Constant *C2);
static Constant *getLShr(Constant *C1, Constant *C2);
static Constant *getAShr(Constant *C1, Constant *C2);
/// Getelementptr form. std::vector<Value*> is only accepted for convenience:
/// all elements must be Constant's.
///
static Constant *getGetElementPtr(Constant *C,
const std::vector<Constant*> &IdxList);
static Constant *getGetElementPtr(Constant *C,
const std::vector<Value*> &IdxList);
static Constant *getExtractElement(Constant *Vec, Constant *Idx);
static Constant *getInsertElement(Constant *Vec, Constant *Elt,Constant *Idx);
static Constant *getShuffleVector(Constant *V1, Constant *V2, Constant *Mask);
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
virtual bool isNullValue() const { return false; }
/// getOpcode - Return the opcode at the root of this constant expression
unsigned getOpcode() const { return SubclassData; }
/// getPredicate - Return the ICMP or FCMP predicate value. Assert if this is
/// not an ICMP or FCMP constant expression.
unsigned getPredicate() const;
/// getOpcodeName - Return a string representation for an opcode.
const char *getOpcodeName() const;
/// getWithOperandReplaced - Return a constant expression identical to this
/// one, but with the specified operand set to the specified value.
Constant *getWithOperandReplaced(unsigned OpNo, Constant *Op) const;
/// getWithOperands - This returns the current constant expression with the
/// operands replaced with the specified values. The specified operands must
/// match count and type with the existing ones.
Constant *getWithOperands(const std::vector<Constant*> &Ops) const;
virtual void destroyConstant();
virtual void replaceUsesOfWithOnConstant(Value *From, Value *To, Use *U);
/// Override methods to provide more type information...
inline Constant *getOperand(unsigned i) {
return cast<Constant>(User::getOperand(i));
}
inline Constant *getOperand(unsigned i) const {
return const_cast<Constant*>(cast<Constant>(User::getOperand(i)));
}
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const ConstantExpr *) { return true; }
static inline bool classof(const Value *V) {
return V->getValueType() == ConstantExprVal;
}
};
//===----------------------------------------------------------------------===//
/// UndefValue - '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 type.
///
class UndefValue : public Constant {
friend struct ConstantCreator<UndefValue, Type, char>;
UndefValue(const UndefValue &); // DO NOT IMPLEMENT
protected:
UndefValue(const Type *T) : Constant(T, UndefValueVal, 0, 0) {}
public:
/// get() - Static factory methods - Return an 'undef' object of the specified
/// type.
///
static UndefValue *get(const Type *T);
/// isNullValue - Return true if this is the value that would be returned by
/// getNullValue.
virtual bool isNullValue() const { return false; }
virtual void destroyConstant();
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const UndefValue *) { return true; }
static bool classof(const Value *V) {
return V->getValueType() == UndefValueVal;
}
};
} // End llvm namespace
#endif