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/* * Copyright (c) 1999-2000 Image Power, Inc. and the University of * British Columbia. * Copyright (c) 2001-2002 Michael David Adams. * All rights reserved. */ /* __START_OF_JASPER_LICENSE__ * * JasPer License Version 2.0 * * Copyright (c) 2001-2006 Michael David Adams * Copyright (c) 1999-2000 Image Power, Inc. * Copyright (c) 1999-2000 The University of British Columbia * * All rights reserved. * * Permission is hereby granted, free of charge, to any person (the * "User") 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, 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: * * 1. The above copyright notices and this permission notice (which * includes the disclaimer below) shall be included in all copies or * substantial portions of the Software. * * 2. The name of a copyright holder shall not be used to endorse or * promote products derived from the Software without specific prior * written permission. * * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS * LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER * THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS * "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 NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY. * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL * PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES, * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH, * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH * RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES. * * __END_OF_JASPER_LICENSE__ */ /* * Math-Related Code * * $Id$ */ #ifndef JAS_MATH_H #define JAS_MATH_H /******************************************************************************\ * Includes \******************************************************************************/ /* The configuration header file should be included first. */ #include <jasper/jas_config.h> #include <jasper/jas_types.h> #include <assert.h> #include <stdio.h> #include <string.h> #include <stdint.h> #ifdef __cplusplus extern "C" { #endif /******************************************************************************\ * Macros \******************************************************************************/ #define JAS_KIBI JAS_CAST(size_t, 1024) #define JAS_MEBI (JAS_KIBI * JAS_KIBI) /* Compute the absolute value. */ #define JAS_ABS(x) \ (((x) >= 0) ? (x) : (-(x))) /* Compute the minimum of two values. */ #define JAS_MIN(x, y) \ (((x) < (y)) ? (x) : (y)) /* Compute the maximum of two values. */ #define JAS_MAX(x, y) \ (((x) > (y)) ? (x) : (y)) /* Compute the remainder from division (where division is defined such that the remainder is always nonnegative). */ #define JAS_MOD(x, y) \ (((x) < 0) ? (((-x) % (y)) ? ((y) - ((-(x)) % (y))) : (0)) : ((x) % (y))) /* Compute the integer with the specified number of least significant bits set to one. */ #define JAS_ONES(n) \ ((1 << (n)) - 1) /******************************************************************************\ * \******************************************************************************/ JAS_ATTRIBUTE_DISABLE_USAN inline static int jas_int_asr(int x, int n) { // Ensure that the shift of a negative value appears to behave as a // signed arithmetic shift. assert(((-1) >> 1) == -1); assert(n >= 0); // The behavior is undefined when x is negative. */ // We tacitly assume the behavior is equivalent to a signed // arithmetic right shift. return x >> n; } JAS_ATTRIBUTE_DISABLE_USAN inline static int jas_int_asl(int x, int n) { // Ensure that the shift of a negative value appears to behave as a // signed arithmetic shift. assert(((-1) << 1) == -2); assert(n >= 0); // The behavior is undefined when x is negative. */ // We tacitly assume the behavior is equivalent to a signed // arithmetic left shift. return x << n; } JAS_ATTRIBUTE_DISABLE_USAN inline static int jas_fast32_asr(int_fast32_t x, int n) { // Ensure that the shift of a negative value appears to behave as a // signed arithmetic shift. assert(((JAS_CAST(int_fast32_t, -1)) >> 1) == JAS_CAST(int_fast32_t, -1)); assert(n >= 0); // The behavior is undefined when x is negative. */ // We tacitly assume the behavior is equivalent to a signed // arithmetic right shift. return x >> n; } JAS_ATTRIBUTE_DISABLE_USAN inline static int jas_fast32_asl(int_fast32_t x, int n) { // Ensure that the shift of a negative value appears to behave as a // signed arithmetic shift. assert(((JAS_CAST(int_fast32_t, -1)) << 1) == JAS_CAST(int_fast32_t, -2)); assert(n >= 0); // The behavior is undefined when x is negative. */ // We tacitly assume the behavior is equivalent to a signed // arithmetic left shift. return x << n; } /******************************************************************************\ * Safe integer arithmetic (i.e., with overflow checking). \******************************************************************************/ /* Compute the product of two size_t integers with overflow checking. */ inline static bool jas_safe_size_mul(size_t x, size_t y, size_t *result) { /* Check if overflow would occur */ if (x && y > SIZE_MAX / x) { /* Overflow would occur. */ return false; } if (result) { *result = x * y; } return true; } /* Compute the product of three size_t integers with overflow checking. */ inline static bool jas_safe_size_mul3(size_t a, size_t b, size_t c, size_t *result) { size_t tmp; if (!jas_safe_size_mul(a, b, &tmp) || !jas_safe_size_mul(tmp, c, &tmp)) { return false; } if (result) { *result = tmp; } return true; } /* Compute the sum of two size_t integers with overflow checking. */ inline static bool jas_safe_size_add(size_t x, size_t y, size_t *result) { if (y > SIZE_MAX - x) { return false; } if (result) { *result = x + y; } return true; } /* Compute the difference of two size_t integers with overflow checking. */ inline static bool jas_safe_size_sub(size_t x, size_t y, size_t *result) { if (y > x) { return false; } if (result) { *result = x - y; } return true; } /* Compute the product of two int_fast32_t integers with overflow checking. */ inline static bool jas_safe_intfast32_mul(int_fast32_t x, int_fast32_t y, int_fast32_t *result) { if (x > 0) { /* x is positive */ if (y > 0) { /* x and y are positive */ if (x > INT_FAST32_MAX / y) { return false; } } else { /* x positive, y nonpositive */ if (y < INT_FAST32_MIN / x) { return false; } } } else { /* x is nonpositive */ if (y > 0) { /* x is nonpositive, y is positive */ if (x < INT_FAST32_MIN / y) { return false; } } else { /* x and y are nonpositive */ if (x != 0 && y < INT_FAST32_MAX / x) { return false; } } } if (result) { *result = x * y; } return true; } /* Compute the product of three int_fast32_t integers with overflow checking. */ inline static bool jas_safe_intfast32_mul3(int_fast32_t a, int_fast32_t b, int_fast32_t c, int_fast32_t *result) { int_fast32_t tmp; if (!jas_safe_intfast32_mul(a, b, &tmp) || !jas_safe_intfast32_mul(tmp, c, &tmp)) { return false; } if (result) { *result = tmp; } return true; } /* Compute the sum of two int_fast32_t integers with overflow checking. */ inline static bool jas_safe_intfast32_add(int_fast32_t x, int_fast32_t y, int_fast32_t *result) { if ((y > 0 && x > INT_FAST32_MAX - y) || (y < 0 && x < INT_FAST32_MIN - y)) { return false; } if (result) { *result = x + y; } return true; } #ifdef __cplusplus } #endif #endif