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Diffstat (limited to 'nuttx/libc/stdlib/lib_rand.c')
| -rw-r--r-- | nuttx/libc/stdlib/lib_rand.c | 277 |
1 files changed, 0 insertions, 277 deletions
diff --git a/nuttx/libc/stdlib/lib_rand.c b/nuttx/libc/stdlib/lib_rand.c deleted file mode 100644 index 453a4537a..000000000 --- a/nuttx/libc/stdlib/lib_rand.c +++ /dev/null @@ -1,277 +0,0 @@ -/**************************************************************************** - * libc/stdlib/lib_rand.c - * - * Copyright (C) 2007, 2011 Gregory Nutt. All rights reserved. - * Author: Gregory Nutt <gnutt@nuttx.org> - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * 3. Neither the name NuttX nor the names of its contributors may be - * used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN - * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - * - ****************************************************************************/ - -/**************************************************************************** - * Included Files - ****************************************************************************/ - -#include <sys/types.h> -#include <stdlib.h> - -/**************************************************************************** - * Pre-processor Definitions - ****************************************************************************/ -/* First, second, and thired order congruential generators are supported */ - -#ifndef CONFIG_LIB_RAND_ORDER -# define CONFIG_LIB_RAND_ORDER 1 -#endif - -#if CONFIG_LIB_RAND_ORDER > 3 -# undef CONFIG_LIB_RAND_ORDER -# define CONFIG_LIB_RAND_ORDER 3 -#endif - -/* Values needed by the random number generator */ - -#define RND1_CONSTK 470001 -#define RND1_CONSTP 999563 -#define RND2_CONSTK1 366528 -#define RND2_CONSTK2 508531 -#define RND2_CONSTP 998917 -#define RND3_CONSTK1 360137 -#define RND3_CONSTK2 519815 -#define RND3_CONSTK3 616087 -#define RND3_CONSTP 997783 - -/**************************************************************************** - * Private Function Prototypes - ****************************************************************************/ - -static unsigned int nrand(unsigned int nLimit); - -/* First order congruential generators */ - -static inline unsigned long fgenerate1(void); -#if (CONFIG_LIB_RAND_ORDER == 1) -static double_t frand1(void); -#endif - -/* Second order congruential generators */ - -#if (CONFIG_LIB_RAND_ORDER > 1) -static inline unsigned long fgenerate2(void); -#if (CONFIG_LIB_RAND_ORDER == 2) -static double_t frand2(void); -#endif - -/* Third order congruential generators */ - -#if (CONFIG_LIB_RAND_ORDER > 2) -static inline unsigned long fgenerate3(void); -static double_t frand3(void); -#endif -#endif - -/**************************************************************************** - * Private Data - ****************************************************************************/ - -static unsigned long g_randint1; -#if (CONFIG_LIB_RAND_ORDER > 1) -static unsigned long g_randint2; -#if (CONFIG_LIB_RAND_ORDER > 2) -static unsigned long g_randint3; -#endif -#endif - -/**************************************************************************** - * Private Functions - ****************************************************************************/ - -static unsigned int nrand(unsigned int nLimit) -{ - unsigned long result; - double_t ratio; - - /* Loop to be sure a legal random number is generated */ - - do - { - /* Get a random integer in the requested range */ - -#if (CONFIG_LIB_RAND_ORDER == 1) - ratio = frand1(); -#elif (CONFIG_LIB_RAND_ORDER == 2) - ratio = frand2(); -#else /* if (CONFIG_LIB_RAND_ORDER > 2) */ - ratio = frand3(); -#endif - - /* Then, produce the return-able value */ - - result = (unsigned long)(((double_t)nLimit) * ratio); - } - while (result >= (unsigned long)nLimit); - - return (unsigned int)result; -} - -/* First order congruential generators */ - -static inline unsigned long fgenerate1(void) -{ - unsigned long randint; - - /* First order congruential generator. One may be added to the result of the - * generated value to avoid the value zero. This would be fatal for the - * first order random number generator. - */ - - randint = (RND1_CONSTK * g_randint1) % RND1_CONSTP; - g_randint1 = (randint == 0 ? 1 : randint); - return randint; -} - -#if (CONFIG_LIB_RAND_ORDER == 1) -static double_t frand1(void) -{ - /* First order congruential generator. */ - - unsigned long randint = fgenerate1(); - - /* Construct an floating point value in the range from 0.0 up to 1.0 */ - - return ((double_t)randint) / ((double_t)RND1_CONSTP); -} -#endif - -/* Second order congruential generators */ - -#if (CONFIG_LIB_RAND_ORDER > 1) -static inline unsigned long fgenerate2(void) -{ - unsigned long randint; - - /* Second order congruential generator. */ - - randint = (RND2_CONSTK1 * g_randint1 + - RND2_CONSTK2 * g_randint2) % RND2_CONSTP; - - g_randint2 = g_randint1; - g_randint1 = randint; - - /* We cannot permit both values to become zero. That would be fatal for the - * second order random number generator. - */ - - if (g_randint2 == 0 && g_randint1 == 0) - { - g_randint2 = 1; - } - - return randint; -} - -#if (CONFIG_LIB_RAND_ORDER == 2) -static double_t frand2(void) -{ - /* Second order congruential generator */ - - unsigned long randint = fgenerate2(); - - /* Construct an floating point value in the range from 0.0 up to 1.0 */ - - return ((double_t)randint) / ((double_t)RND2_CONSTP); -} -#endif - -/* Third order congruential generators */ - -#if (CONFIG_LIB_RAND_ORDER > 2) -static inline unsigned long fgenerate3(void) -{ - unsigned long randint; - - /* Third order congruential generator. */ - - randint = (RND3_CONSTK1 * g_randint1 + - RND3_CONSTK2 * g_randint2 + - RND3_CONSTK2 * g_randint3) % RND3_CONSTP; - - g_randint3 = g_randint2; - g_randint2 = g_randint1; - g_randint1 = randint; - - /* We cannot permit all three values to become zero. That would be fatal for the - * third order random number generator. - */ - - if (g_randint3 == 0 && g_randint2 == 0 && g_randint1 == 0) - { - g_randint3 = 1; - } - - return randint; -} - -static double_t frand3(void) -{ - /* Third order congruential generator */ - - unsigned long randint = fgenerate3(); - - /* Construct an floating point value in the range from 0.0 up to 1.0 */ - - return ((double_t)randint) / ((double_t)RND3_CONSTP); -} -#endif -#endif - -/**************************************************************************** - * Public Functions - ****************************************************************************/ - -/**************************************************************************** - * Function: srand, rand - ****************************************************************************/ - -void srand(unsigned int seed) -{ - g_randint1 = seed; -#if (CONFIG_LIB_RAND_ORDER > 1) - g_randint2 = seed; - (void)fgenerate1(); -#if (CONFIG_LIB_RAND_ORDER > 2) - g_randint3 = seed; - (void)fgenerate2(); -#endif -#endif -} - -int rand(void) -{ - return (int)nrand(32768); -} |