llvm-6502/include/llvm/Constants.h
Reid Spencer a009838674 Fix a comment to be accurate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31064 91177308-0d34-0410-b5e6-96231b3b80d8
2006-10-20 07:24:55 +00:00

647 lines
26 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:
/// 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;
/// 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 *getCast(Constant *C, const Type *Ty);
static Constant *getSignExtend(Constant *C, const Type *Ty);
static Constant *getZeroExtend(Constant *C, const Type *Ty);
/// 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 *getDiv(Constant *C1, Constant *C2);
static Constant *getRem(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 *getShl(Constant *C1, Constant *C2);
static Constant *getShr(Constant *C1, Constant *C2);
static Constant *getUShr(Constant *C1, Constant *C2); // unsigned shr
static Constant *getSShr(Constant *C1, Constant *C2); // signed shr
/// 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; }
/// 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