/* +----------------------------------------------------------------------+ | PHP Version 7 | +----------------------------------------------------------------------+ | Copyright (c) 1997-2018 The PHP Group | +----------------------------------------------------------------------+ | This source file is subject to version 3.01 of the PHP license, | | that is bundled with this package in the file LICENSE, and is | | available through the world-wide-web at the following url: | | http://www.php.net/license/3_01.txt | | If you did not receive a copy of the PHP license and are unable to | | obtain it through the world-wide-web, please send a note to | | license@php.net so we can mail you a copy immediately. | +----------------------------------------------------------------------+ | Authors: Rasmus Lerdorf <rasmus@php.net> | | Zeev Suraski <zeev@zend.com> | | Pedro Melo <melo@ip.pt> | | Sterling Hughes <sterling@php.net> | | | | Based on code from: Richard J. Wagner <rjwagner@writeme.com> | | Makoto Matsumoto <matumoto@math.keio.ac.jp> | | Takuji Nishimura | | Shawn Cokus <Cokus@math.washington.edu> | +----------------------------------------------------------------------+ */ /* $Id$ */ #include "php.h" #include "php_rand.h" #include "php_mt_rand.h" /* MT RAND FUNCTIONS */ /* The following php_mt_...() functions are based on a C++ class MTRand by Richard J. Wagner. For more information see the web page at http://www-personal.engin.umich.edu/~wagnerr/MersenneTwister.html Mersenne Twister random number generator -- a C++ class MTRand Based on code by Makoto Matsumoto, Takuji Nishimura, and Shawn Cokus Richard J. Wagner v1.0 15 May 2003 rjwagner@writeme.com The Mersenne Twister is an algorithm for generating random numbers. It was designed with consideration of the flaws in various other generators. The period, 2^19937-1, and the order of equidistribution, 623 dimensions, are far greater. The generator is also fast; it avoids multiplication and division, and it benefits from caches and pipelines. For more information see the inventors' web page at http://www.math.keio.ac.jp/~matumoto/emt.html Reference M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-Dimensionally Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3-30. Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, Copyright (C) 2000 - 2003, Richard J. Wagner All rights reserved. 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. The names of its contributors may not 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. */ #define N MT_N /* length of state vector */ #define M (397) /* a period parameter */ #define hiBit(u) ((u) & 0x80000000U) /* mask all but highest bit of u */ #define loBit(u) ((u) & 0x00000001U) /* mask all but lowest bit of u */ #define loBits(u) ((u) & 0x7FFFFFFFU) /* mask the highest bit of u */ #define mixBits(u, v) (hiBit(u)|loBits(v)) /* move hi bit of u to hi bit of v */ #define twist(m,u,v) (m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(int32_t)(loBit(v))) & 0x9908b0dfU)) #define twist_php(m,u,v) (m ^ (mixBits(u,v)>>1) ^ ((uint32_t)(-(int32_t)(loBit(u))) & 0x9908b0dfU)) /* {{{ php_mt_initialize */ static inline void php_mt_initialize(uint32_t seed, uint32_t *state) { /* Initialize generator state with seed See Knuth TAOCP Vol 2, 3rd Ed, p.106 for multiplier. In previous versions, most significant bits (MSBs) of the seed affect only MSBs of the state array. Modified 9 Jan 2002 by Makoto Matsumoto. */ register uint32_t *s = state; register uint32_t *r = state; register int i = 1; *s++ = seed & 0xffffffffU; for( ; i < N; ++i ) { *s++ = ( 1812433253U * ( *r ^ (*r >> 30) ) + i ) & 0xffffffffU; r++; } } /* }}} */ /* {{{ php_mt_reload */ static inline void php_mt_reload(void) { /* Generate N new values in state Made clearer and faster by Matthew Bellew (matthew.bellew@home.com) */ register uint32_t *state = BG(state); register uint32_t *p = state; register int i; if (BG(mt_rand_mode) == MT_RAND_MT19937) { for (i = N - M; i--; ++p) *p = twist(p[M], p[0], p[1]); for (i = M; --i; ++p) *p = twist(p[M-N], p[0], p[1]); *p = twist(p[M-N], p[0], state[0]); } else { for (i = N - M; i--; ++p) *p = twist_php(p[M], p[0], p[1]); for (i = M; --i; ++p) *p = twist_php(p[M-N], p[0], p[1]); *p = twist_php(p[M-N], p[0], state[0]); } BG(left) = N; BG(next) = state; } /* }}} */ /* {{{ php_mt_srand */ PHPAPI void php_mt_srand(uint32_t seed) { /* Seed the generator with a simple uint32 */ php_mt_initialize(seed, BG(state)); php_mt_reload(); /* Seed only once */ BG(mt_rand_is_seeded) = 1; } /* }}} */ /* {{{ php_mt_rand */ PHPAPI uint32_t php_mt_rand(void) { /* Pull a 32-bit integer from the generator state Every other access function simply transforms the numbers extracted here */ register uint32_t s1; if (UNEXPECTED(!BG(mt_rand_is_seeded))) { php_mt_srand(GENERATE_SEED()); } if (BG(left) == 0) { php_mt_reload(); } --BG(left); s1 = *BG(next)++; s1 ^= (s1 >> 11); s1 ^= (s1 << 7) & 0x9d2c5680U; s1 ^= (s1 << 15) & 0xefc60000U; return ( s1 ^ (s1 >> 18) ); } /* }}} */ /* {{{ proto void mt_srand([int seed]) Seeds Mersenne Twister random number generator */ PHP_FUNCTION(mt_srand) { zend_long seed = 0; zend_long mode = MT_RAND_MT19937; if (zend_parse_parameters(ZEND_NUM_ARGS(), "|ll", &seed, &mode) == FAILURE) return; if (ZEND_NUM_ARGS() == 0) seed = GENERATE_SEED(); switch (mode) { case MT_RAND_PHP: BG(mt_rand_mode) = MT_RAND_PHP; break; default: BG(mt_rand_mode) = MT_RAND_MT19937; } php_mt_srand(seed); } /* }}} */ /* {{{ php_mt_rand_range */ PHPAPI zend_long php_mt_rand_range(zend_long min, zend_long max) { zend_ulong umax = max - min; zend_ulong limit; zend_ulong result; result = php_mt_rand(); #if ZEND_ULONG_MAX > UINT32_MAX if (umax > UINT32_MAX) { result = (result << 32) | php_mt_rand(); } #endif /* Special case where no modulus is required */ if (UNEXPECTED(umax == ZEND_ULONG_MAX)) { return (zend_long)result; } /* Increment the max so the range is inclusive of max */ umax++; /* Powers of two are not biased */ if (EXPECTED((umax & (umax - 1)) != 0)) { /* Ceiling under which ZEND_LONG_MAX % max == 0 */ limit = ZEND_ULONG_MAX - (ZEND_ULONG_MAX % umax) - 1; /* Discard numbers over the limit to avoid modulo bias */ while (UNEXPECTED(result > limit)) { #if ZEND_ULONG_MAX > UINT32_MAX if (umax > UINT32_MAX) { result = (result << 32) | php_mt_rand(); } else { result = php_mt_rand(); } #else result = php_mt_rand(); #endif } } return (zend_long)((result % umax) + min); } /* }}} */ /* {{{ php_mt_rand_common * rand() allows min > max, mt_rand does not */ PHPAPI zend_long php_mt_rand_common(zend_long min, zend_long max) { int64_t n; if (BG(mt_rand_mode) == MT_RAND_MT19937) { return php_mt_rand_range(min, max); } /* Legacy mode deliberately not inside php_mt_rand_range() * to prevent other functions being affected */ n = (int64_t)php_mt_rand() >> 1; RAND_RANGE_BADSCALING(n, min, max, PHP_MT_RAND_MAX); return n; } /* }}} */ /* {{{ proto int mt_rand([int min, int max]) Returns a random number from Mersenne Twister */ PHP_FUNCTION(mt_rand) { zend_long min; zend_long max; int argc = ZEND_NUM_ARGS(); if (argc == 0) { // genrand_int31 in mt19937ar.c performs a right shift RETURN_LONG(php_mt_rand() >> 1); } if (zend_parse_parameters(argc, "ll", &min, &max) == FAILURE) { return; } if (UNEXPECTED(max < min)) { php_error_docref(NULL, E_WARNING, "max(" ZEND_LONG_FMT ") is smaller than min(" ZEND_LONG_FMT ")", max, min); RETURN_FALSE; } RETURN_LONG(php_mt_rand_common(min, max)); } /* }}} */ /* {{{ proto int mt_getrandmax(void) Returns the maximum value a random number from Mersenne Twister can have */ PHP_FUNCTION(mt_getrandmax) { if (zend_parse_parameters_none() == FAILURE) { return; } /* * Melo: it could be 2^^32 but we only use 2^^31 to maintain * compatibility with the previous php_rand */ RETURN_LONG(PHP_MT_RAND_MAX); /* 2^^31 */ } /* }}} */ PHP_MINIT_FUNCTION(mt_rand) { REGISTER_LONG_CONSTANT("MT_RAND_MT19937", MT_RAND_MT19937, CONST_CS | CONST_PERSISTENT); REGISTER_LONG_CONSTANT("MT_RAND_PHP", MT_RAND_PHP, CONST_CS | CONST_PERSISTENT); return SUCCESS; } /* * Local variables: * tab-width: 4 * c-basic-offset: 4 * End: * vim600: noet sw=4 ts=4 fdm=marker * vim<600: noet sw=4 ts=4 */