limits.hpp
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/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
* Main authors:
* Christian Schulte <schulte@gecode.org>
*
* Copyright:
* Christian Schulte, 2005
*
* This file is part of Gecode, the generic constraint
* development environment:
* http://www.gecode.org
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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namespace Gecode { namespace Int {
inline bool
Limits::valid(int n) {
return ((n >= min) && (n <= max));
}
inline bool
Limits::valid(long long int n) {
return ((n >= min) && (n <= max));
}
inline void
Limits::check(int n, const char* l) {
if ((n < min) || (n > max))
throw OutOfLimits(l);
}
inline void
Limits::check(long long int n, const char* l) {
if ((n < min) || (n > max))
throw OutOfLimits(l);
}
inline void
Limits::positive(int n, const char* l) {
if ((n <= 0) || (n > max))
throw OutOfLimits(l);
}
inline void
Limits::positive(long long int n, const char* l) {
if ((n <= 0.0) || (n > max))
throw OutOfLimits(l);
}
inline void
Limits::nonnegative(int n, const char* l) {
if ((n < 0) || (n > max))
throw OutOfLimits(l);
}
inline void
Limits::nonnegative(long long int n, const char* l) {
if ((n < 0.0) || (n > max))
throw OutOfLimits(l);
}
forceinline bool
Limits::overflow_add(int n, int m) {
long long int nm =
static_cast<long long int>(n) + static_cast<long long int>(m);
return (nm > INT_MAX) || (nm < INT_MIN+1);
}
forceinline bool
Limits::overflow_add(long long int n, long long int m) {
if (m < 0)
return n < LLONG_MIN + 1 - m;
else
return n > LLONG_MAX - m;
}
forceinline bool
Limits::overflow_sub(int n, int m) {
long long int nm =
static_cast<long long int>(n) - static_cast<long long int>(m);
return (nm > INT_MAX) || (nm < INT_MIN+1);
}
forceinline bool
Limits::overflow_sub(long long int n, long long int m) {
if (m < 0)
return n > LLONG_MAX + m;
else
return n < LLONG_MIN + 1 + m;
}
inline bool
Limits::overflow_mul(int n, int m) {
long long int nm =
static_cast<long long int>(n) * static_cast<long long int>(m);
return (nm > INT_MAX) || (nm < INT_MIN+1);
}
inline bool
Limits::overflow_mul(long long int n, long long int m) {
// Check whether we can at least change the sign
if ((n == LLONG_MIN) || (m == LLONG_MIN))
return false;
unsigned long long int un =
static_cast<unsigned long long int>(n < 0 ? -n : n);
unsigned long long int um =
static_cast<unsigned long long int>(m < 0 ? -m : m);
const unsigned int k = CHAR_BIT * sizeof(int);
unsigned long long int un_hi = un >> k;
unsigned long long int un_lo = un & ((1ULL << k) - 1ULL);
unsigned long long int um_hi = um >> k;
unsigned long long int um_lo = um & ((1ULL << k) - 1ULL);
// This would mean that there is something larger than 2^64
if ((un_hi != 0ULL) && (um_hi != 0ULL))
return true;
unsigned long long int unm_hi = 0ULL;
// Now, either un_hi or m_hi can be different from zero
if (un_hi != 0ULL)
unm_hi = un_hi * um_lo;
else if (um_hi != 0ULL)
unm_hi = um_hi * un_lo;
else
return false;
// Again, something larger than 2^64
if ((unm_hi >> k) != 0ULL)
return true;
unm_hi <<= k;
unsigned long long int unm_lo = un_lo * um_lo;
return unm_hi > static_cast<unsigned long long int>(LLONG_MAX) - unm_lo;
}
}}
// STATISTICS: int-var
Gecode::Int::OutOfLimits
Exception: Value out of limits
Definition exception.hpp:44
Gecode::Int::Limits::positive
void positive(int n, const char *l)
Check whether n is in range and strictly positive, otherwise throw out of limits with information l.
Definition limits.hpp:57
Gecode::Int::Limits::overflow_add
bool overflow_add(int n, int m)
Check whether adding n and m would overflow.
Definition limits.hpp:79
Gecode::Int::Limits::nonnegative
void nonnegative(int n, const char *l)
Check whether n is in range and nonnegative, otherwise throw out of limits with information l.
Definition limits.hpp:68
Gecode::Int::Limits::check
void check(int n, const char *l)
Check whether n is in range, otherwise throw out of limits with information l.
Definition limits.hpp:46
Gecode::Int::Limits::overflow_mul
bool overflow_mul(int n, int m)
Check whether multiplying n and m would overflow.
Definition limits.hpp:107
Gecode::Int::Limits::min
const int min
Smallest allowed integer value.
Definition int.hh:118
Gecode::Int::Limits::valid
bool valid(int n)
Return whether n is in range.
Definition limits.hpp:37
Gecode::Int::Limits::max
const int max
Largest allowed integer value.
Definition int.hh:116
Gecode::Int::Limits::overflow_sub
bool overflow_sub(int n, int m)
Check whether subtracting m from n would overflow.
Definition limits.hpp:93
Gecode::Int
Finite domain integers.
Gecode
Gecode toplevel namespace
forceinline
#define forceinline
Definition config.hpp:187