llvm-6502/include/llvm/Support/ConstantRange.h
2003-11-11 22:41:34 +00:00

133 lines
4.3 KiB
C++

//===-- llvm/Support/ConstantRange.h - Represent a range --------*- 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.
//
//===----------------------------------------------------------------------===//
//
// Represent a range of possible values that may occur when the program is run
// for an integral value. This keeps track of a lower and upper bound for the
// constant, which MAY wrap around the end of the numeric range. To do this, it
// keeps track of a [lower, upper) bound, which specifies an interval just like
// STL iterators. When used with boolean values, the following are important
// ranges (other integral ranges use min/max values for special range values):
//
// [F, F) = {} = Empty set
// [T, F) = {T}
// [F, T) = {F}
// [T, T) = {F, T} = Full set
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_CONSTANT_RANGE_H
#define LLVM_SUPPORT_CONSTANT_RANGE_H
#include "Support/DataTypes.h"
#include <iosfwd>
namespace llvm {
class ConstantIntegral;
class Type;
class ConstantRange {
ConstantIntegral *Lower, *Upper;
public:
/// Initialize a full (the default) or empty set for the specified type.
///
ConstantRange(const Type *Ty, bool isFullSet = true);
/// Initialize a range of values explicitly... this will assert out if
/// Lower==Upper and Lower != Min or Max for its type (or if the two constants
/// have different types)
///
ConstantRange(ConstantIntegral *Lower, ConstantIntegral *Upper);
/// Initialize a set of values that all satisfy the condition with C.
///
ConstantRange(unsigned SetCCOpcode, ConstantIntegral *C);
/// getLower - Return the lower value for this range...
///
ConstantIntegral *getLower() const { return Lower; }
/// getUpper - Return the upper value for this range...
///
ConstantIntegral *getUpper() const { return Upper; }
/// getType - Return the LLVM data type of this range.
///
const Type *getType() const;
/// isFullSet - Return true if this set contains all of the elements possible
/// for this data-type
///
bool isFullSet() const;
/// isEmptySet - Return true if this set contains no members.
///
bool isEmptySet() const;
/// isWrappedSet - Return true if this set wraps around the top of the range,
/// for example: [100, 8)
///
bool isWrappedSet() const;
/// getSingleElement - If this set contains a single element, return it,
/// otherwise return null.
///
ConstantIntegral *getSingleElement() const;
/// isSingleElement - Return true if this set contains exactly one member.
///
bool isSingleElement() const { return getSingleElement() != 0; }
/// getSetSize - Return the number of elements in this set.
///
uint64_t getSetSize() const;
/// operator== - Return true if this range is equal to another range.
///
bool operator==(const ConstantRange &CR) const {
return Lower == CR.Lower && Upper == CR.Upper;
}
bool operator!=(const ConstantRange &CR) const {
return !operator==(CR);
}
/// intersect - Return the range that results from the intersection of this
/// range with another range. The resultant range is pruned as much as
/// possible, but there may be cases where elements are included that are in
/// one of the sets but not the other. For example: [100, 8) intersect [3,
/// 120) yields [3, 120)
///
ConstantRange intersectWith(const ConstantRange &CR) const;
/// union - Return the range that results from the union of this range with
/// another range. The resultant range is guaranteed to include the elements
/// of both sets, but may contain more. For example, [3, 9) union [12,15) is
/// [3, 15), which includes 9, 10, and 11, which were not included in either
/// set before.
///
ConstantRange unionWith(const ConstantRange &CR) const;
/// print - Print out the bounds to a stream...
///
void print(std::ostream &OS) const;
/// dump - Allow printing from a debugger easily...
///
void dump() const;
};
inline std::ostream &operator<<(std::ostream &OS, const ConstantRange &CR) {
CR.print(OS);
return OS;
}
} // End llvm namespace
#endif