My Project: jas_math.h Source File

My Project 2.0.17 |

jas_math.h
1 /*
2 * Copyright (c) 1999-2000 Image Power, Inc. and the University of
3 * British Columbia.
4 * Copyright (c) 2001-2002 Michael David Adams.
5 * All rights reserved.
6 */
7
8 /* __START_OF_JASPER_LICENSE__
9 *
10 * JasPer License Version 2.0
11 *
12 * Copyright (c) 2001-2006 Michael David Adams
13 * Copyright (c) 1999-2000 Image Power, Inc.
14 * Copyright (c) 1999-2000 The University of British Columbia
15 *
16 * All rights reserved.
17 *
18 * Permission is hereby granted, free of charge, to any person (the
19 * "User") obtaining a copy of this software and associated documentation
20 * files (the "Software"), to deal in the Software without restriction,
21 * including without limitation the rights to use, copy, modify, merge,
22 * publish, distribute, and/or sell copies of the Software, and to permit
23 * persons to whom the Software is furnished to do so, subject to the
24 * following conditions:
25 *
26 * 1. The above copyright notices and this permission notice (which
27 * includes the disclaimer below) shall be included in all copies or
28 * substantial portions of the Software.
29 *
30 * 2. The name of a copyright holder shall not be used to endorse or
31 * promote products derived from the Software without specific prior
32 * written permission.
33 *
34 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
35 * LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
36 * THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
37 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
38 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
39 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
40 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
41 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
42 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
43 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
44 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
45 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
46 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
47 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
48 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
49 * PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
50 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
51 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
52 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
53 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
54 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
55 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
56 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
57 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
58 * RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
59 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
60 *
61 * __END_OF_JASPER_LICENSE__
62 */
63
64 /*
65 * Math-Related Code
66 *
67 * $Id$
68 */
69
70 #ifndef JAS_MATH_H
71 #define JAS_MATH_H
72
73 /******************************************************************************\
74 * Includes
75 \******************************************************************************/
76
77 /* The configuration header file should be included first. */
78 #include <jasper/jas_config.h>
79
80 #include <jasper/jas_types.h>
81
82 #include <assert.h>
83 #include <stdio.h>
84 #include <string.h>
85 #include <stdint.h>
86 #include <limits.h>
87
88 #ifdef __cplusplus
89 extern "C" {
90 #endif
91
92 /******************************************************************************\
93 * Macros
94 \******************************************************************************/
95
96 #define JAS_KIBI JAS_CAST(size_t, 1024)
97 #define JAS_MEBI (JAS_KIBI * JAS_KIBI)
98
99 /* Compute the absolute value. */
100 #define JAS_ABS(x) \
101 (((x) >= 0) ? (x) : (-(x)))
102
103 /* Compute the minimum of two values. */
104 #define JAS_MIN(x, y) \
105 (((x) < (y)) ? (x) : (y))
106
107 /* Compute the maximum of two values. */
108 #define JAS_MAX(x, y) \
109 (((x) > (y)) ? (x) : (y))
110
111 /* Compute the remainder from division (where division is defined such
112 that the remainder is always nonnegative). */
113 #define JAS_MOD(x, y) \
114 (((x) < 0) ? (((-x) % (y)) ? ((y) - ((-(x)) % (y))) : (0)) : ((x) % (y)))
115
116 /* Compute the integer with the specified number of least significant bits
117 set to one. */
118 #define JAS_ONES(n) \
119 ((1 << (n)) - 1)
120
121 /******************************************************************************\
122 *
123 \******************************************************************************/
124
125 #ifdef __GNUC__
126 /* suppress clang warning "shifting a negative signed value is
127 undefined" in the assertions below */
128 #pragma GCC diagnostic push
129 #pragma GCC diagnostic ignored "-Wshift-negative-value"
130 #endif
131
132 JAS_ATTRIBUTE_CONST
133 JAS_ATTRIBUTE_DISABLE_USAN
134 inline static int jas_int_asr(int x, int n)
135 {
136 // Ensure that the shift of a negative value appears to behave as a
137 // signed arithmetic shift.
138 assert(((-1) >> 1) == -1);
139 assert(n >= 0);
140 // The behavior is undefined when x is negative. */
141 // We tacitly assume the behavior is equivalent to a signed
142 // arithmetic right shift.
143 return x >> n;
144 }
145
146 JAS_ATTRIBUTE_CONST
147 JAS_ATTRIBUTE_DISABLE_USAN
148 inline static int jas_int_asl(int x, int n)
149 {
150 // Ensure that the shift of a negative value appears to behave as a
151 // signed arithmetic shift.
152 assert(((-1) << 1) == -2);
153 assert(n >= 0);
154 // The behavior is undefined when x is negative. */
155 // We tacitly assume the behavior is equivalent to a signed
156 // arithmetic left shift.
157 return x << n;
158 }
159
160 JAS_ATTRIBUTE_CONST
161 JAS_ATTRIBUTE_DISABLE_USAN
162 inline static int jas_fast32_asr(int_fast32_t x, int n)
163 {
164 // Ensure that the shift of a negative value appears to behave as a
165 // signed arithmetic shift.
166 assert(((JAS_CAST(int_fast32_t, -1)) >> 1) == JAS_CAST(int_fast32_t, -1));
167 assert(n >= 0);
168 // The behavior is undefined when x is negative. */
169 // We tacitly assume the behavior is equivalent to a signed
170 // arithmetic right shift.
171 return x >> n;
172 }
173
174 JAS_ATTRIBUTE_CONST
175 JAS_ATTRIBUTE_DISABLE_USAN
176 inline static int jas_fast32_asl(int_fast32_t x, int n)
177 {
178 // Ensure that the shift of a negative value appears to behave as a
179 // signed arithmetic shift.
180 assert(((JAS_CAST(int_fast32_t, -1)) << 1) == JAS_CAST(int_fast32_t, -2));
181 assert(n >= 0);
182 // The behavior is undefined when x is negative. */
183 // We tacitly assume the behavior is equivalent to a signed
184 // arithmetic left shift.
185 return x << n;
186 }
187
188 #ifdef __GNUC__
189 #pragma GCC diagnostic pop
190 #endif
191
192 /******************************************************************************\
193 * Safe integer arithmetic (i.e., with overflow checking).
194 \******************************************************************************/
195
196 /* Compute the product of two size_t integers with overflow checking. */
197 inline static bool jas_safe_size_mul(size_t x, size_t y, size_t *result)
198 {
199 /* Check if overflow would occur */
200 if (x && y > SIZE_MAX / x) {
201 /* Overflow would occur. */
202 return false;
203 }
204 if (result) {
205 *result = x * y;
206 }
207 return true;
208 }
209
210 /* Compute the product of three size_t integers with overflow checking. */
211 inline static bool jas_safe_size_mul3(size_t a, size_t b, size_t c,
212 size_t *result)
213 {
214 size_t tmp;
215 if (!jas_safe_size_mul(a, b, &tmp) ||
216 !jas_safe_size_mul(tmp, c, &tmp)) {
217 return false;
218 }
219 if (result) {
220 *result = tmp;
221 }
222 return true;
223 }
224
225 /* Compute the sum of two size_t integers with overflow checking. */
226 inline static bool jas_safe_size_add(size_t x, size_t y, size_t *result)
227 {
228 if (y > SIZE_MAX - x) {
229 return false;
230 }
231 if (result) {
232 *result = x + y;
233 }
234 return true;
235 }
236
237 /* Compute the difference of two size_t integers with overflow checking. */
238 inline static bool jas_safe_size_sub(size_t x, size_t y, size_t *result)
239 {
240 if (y > x) {
241 return false;
242 }
243 if (result) {
244 *result = x - y;
245 }
246 return true;
247 }
248
249 /* Compute the product of two int_fast32_t integers with overflow checking. */
250 inline static bool jas_safe_intfast32_mul(int_fast32_t x, int_fast32_t y,
251 int_fast32_t *result)
252 {
253 if (x > 0) {
254 /* x is positive */
255 if (y > 0) {
256 /* x and y are positive */
257 if (x > INT_FAST32_MAX / y) {
258 return false;
259 }
260 } else {
261 /* x positive, y nonpositive */
262 if (y < INT_FAST32_MIN / x) {
263 return false;
264 }
265 }
266 } else {
267 /* x is nonpositive */
268 if (y > 0) {
269 /* x is nonpositive, y is positive */
270 if (x < INT_FAST32_MIN / y) {
271 return false;
272 }
273 } else { /* x and y are nonpositive */
274 if (x != 0 && y < INT_FAST32_MAX / x) {
275 return false;
276 }
277 }
278 }
279
280 if (result) {
281 *result = x * y;
282 }
283 return true;
284 }
285
286 /* Compute the product of three int_fast32_t integers with overflow checking. */
287 inline static bool jas_safe_intfast32_mul3(int_fast32_t a, int_fast32_t b,
288 int_fast32_t c, int_fast32_t *result)
289 {
290 int_fast32_t tmp;
291 if (!jas_safe_intfast32_mul(a, b, &tmp) ||
292 !jas_safe_intfast32_mul(tmp, c, &tmp)) {
293 return false;
294 }
295 if (result) {
296 *result = tmp;
297 }
298 return true;
299 }
300
301 /* Compute the sum of two int_fast32_t integers with overflow checking. */
302 inline static bool jas_safe_intfast32_add(int_fast32_t x, int_fast32_t y,
303 int_fast32_t *result)
304 {
305 if ((y > 0 && x > INT_FAST32_MAX - y) ||
306 (y < 0 && x < INT_FAST32_MIN - y)) {
307 return false;
308 }
309 if (result) {
310 *result = x + y;
311 }
312 return true;
313 }
314
315 #ifdef __cplusplus
316 }
317 #endif
318
319 #endif