Generated on Thu Jan 16 2025 00:00:00 for Gecode by doxygen 1.14.0
limits.hpp
Go to the documentation of this file.
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2005
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34namespace Gecode { namespace Int {
35
36 inline bool
38 return ((n >= min) && (n <= max));
39 }
40 inline bool
41 Limits::valid(long long int n) {
42 return ((n >= min) && (n <= max));
43 }
44
45 inline void
46 Limits::check(int n, const char* l) {
47 if ((n < min) || (n > max))
48 throw OutOfLimits(l);
49 }
50 inline void
51 Limits::check(long long int n, const char* l) {
52 if ((n < min) || (n > max))
53 throw OutOfLimits(l);
54 }
55
56 inline void
57 Limits::positive(int n, const char* l) {
58 if ((n <= 0) || (n > max))
59 throw OutOfLimits(l);
60 }
61 inline void
62 Limits::positive(long long int n, const char* l) {
63 if ((n <= 0.0) || (n > max))
64 throw OutOfLimits(l);
65 }
66
67 inline void
68 Limits::nonnegative(int n, const char* l) {
69 if ((n < 0) || (n > max))
70 throw OutOfLimits(l);
71 }
72 inline void
73 Limits::nonnegative(long long int n, const char* l) {
74 if ((n < 0.0) || (n > max))
75 throw OutOfLimits(l);
76 }
77
78 forceinline bool
79 Limits::overflow_add(int n, int m) {
80 long long int nm =
81 static_cast<long long int>(n) + static_cast<long long int>(m);
82 return (nm > INT_MAX) || (nm < INT_MIN+1);
83 }
84 forceinline bool
85 Limits::overflow_add(long long int n, long long int m) {
86 if (m < 0)
87 return n < LLONG_MIN + 1 - m;
88 else
89 return n > LLONG_MAX - m;
90 }
91
92 forceinline bool
93 Limits::overflow_sub(int n, int m) {
94 long long int nm =
95 static_cast<long long int>(n) - static_cast<long long int>(m);
96 return (nm > INT_MAX) || (nm < INT_MIN+1);
97 }
98 forceinline bool
99 Limits::overflow_sub(long long int n, long long int m) {
100 if (m < 0)
101 return n > LLONG_MAX + m;
102 else
103 return n < LLONG_MIN + 1 + m;
104 }
105
106 inline bool
107 Limits::overflow_mul(int n, int m) {
108 long long int nm =
109 static_cast<long long int>(n) * static_cast<long long int>(m);
110 return (nm > INT_MAX) || (nm < INT_MIN+1);
111 }
112
113 inline bool
114 Limits::overflow_mul(long long int n, long long int m) {
115 // Check whether we can at least change the sign
116 if ((n == LLONG_MIN) || (m == LLONG_MIN))
117 return false;
118
119 unsigned long long int un =
120 static_cast<unsigned long long int>(n < 0 ? -n : n);
121 unsigned long long int um =
122 static_cast<unsigned long long int>(m < 0 ? -m : m);
123
124 const unsigned int k = CHAR_BIT * sizeof(int);
125
126 unsigned long long int un_hi = un >> k;
127 unsigned long long int un_lo = un & ((1ULL << k) - 1ULL);
128 unsigned long long int um_hi = um >> k;
129 unsigned long long int um_lo = um & ((1ULL << k) - 1ULL);
130
131 // This would mean that there is something larger than 2^64
132 if ((un_hi != 0ULL) && (um_hi != 0ULL))
133 return true;
134
135 unsigned long long int unm_hi = 0ULL;
136
137 // Now, either un_hi or m_hi can be different from zero
138 if (un_hi != 0ULL)
139 unm_hi = un_hi * um_lo;
140 else if (um_hi != 0ULL)
141 unm_hi = um_hi * un_lo;
142 else
143 return false;
144
145 // Again, something larger than 2^64
146 if ((unm_hi >> k) != 0ULL)
147 return true;
148 unm_hi <<= k;
149
150 unsigned long long int unm_lo = un_lo * um_lo;
151
152 return unm_hi > static_cast<unsigned long long int>(LLONG_MAX) - unm_lo;
153 }
154
155}}
156
157// STATISTICS: int-var
Exception: Value out of limits
Definition exception.hpp:44
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
bool overflow_add(int n, int m)
Check whether adding n and m would overflow.
Definition limits.hpp:79
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
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
bool overflow_mul(int n, int m)
Check whether multiplying n and m would overflow.
Definition limits.hpp:107
const int min
Smallest allowed integer value.
Definition int.hh:118
bool valid(int n)
Return whether n is in range.
Definition limits.hpp:37
const int max
Largest allowed integer value.
Definition int.hh:116
bool overflow_sub(int n, int m)
Check whether subtracting m from n would overflow.
Definition limits.hpp:93
Finite domain integers.
Gecode toplevel namespace
#define forceinline
Definition config.hpp:194