--- /dev/null
+/*
+ +----------------------------------------------------------------------+
+ | PHP version 4.0 |
+ +----------------------------------------------------------------------+
+ | Copyright (c) 1997-2001 The PHP Group |
+ +----------------------------------------------------------------------+
+ | This source file is subject to version 2.02 of the PHP license, |
+ | that is bundled with this package in the file LICENSE, and is |
+ | available at through the world-wide-web at |
+ | http://www.php.net/license/2_02.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@lerdorf.on.ca> |
+ | Zeev Suraski <zeev@zend.com> |
+ | Pedro Melo <melo@ip.pt> |
+ | Jeroen van Wolffelaar <jeroen@php.net> |
+ | |
+ | Based on code from: Shawn Cokus <Cokus@math.washington.edu> |
+ +----------------------------------------------------------------------+
+ */
+/* $Id$ */
+
+#include <stdlib.h>
+
+#include "php.h"
+#include "php_rand.h"
+
+#include "basic_functions.h"
+
+/*
+ This is the ``Mersenne Twister'' random number generator MT19937, which
+ generates pseudorandom integers uniformly distributed in 0..(2^32 - 1)
+ starting from any odd seed in 0..(2^32 - 1). This version is a recode
+ by Shawn Cokus (Cokus@math.washington.edu) on March 8, 1998 of a version by
+ Takuji Nishimura (who had suggestions from Topher Cooper and Marc Rieffel in
+ July-August 1997).
+
+ Effectiveness of the recoding (on Goedel2.math.washington.edu, a DEC Alpha
+ running OSF/1) using GCC -O3 as a compiler: before recoding: 51.6 sec. to
+ generate 300 million random numbers; after recoding: 24.0 sec. for the same
+ (i.e., 46.5% of original time), so speed is now about 12.5 million random
+ number generations per second on this machine.
+
+ According to the URL <http://www.math.keio.ac.jp/~matumoto/emt.html>
+ (and paraphrasing a bit in places), the Mersenne Twister is ``designed
+ with consideration of the flaws of various existing generators,'' has
+ a period of 2^19937 - 1, gives a sequence that is 623-dimensionally
+ equidistributed, and ``has passed many stringent tests, including the
+ die-hard test of G. Marsaglia and the load test of P. Hellekalek and
+ S. Wegenkittl.'' It is efficient in memory usage (typically using 2506
+ to 5012 bytes of static data, depending on data type sizes, and the code
+ is quite short as well). It generates random numbers in batches of 624
+ at a time, so the caching and pipelining of modern systems is exploited.
+ It is also divide- and mod-free.
+
+ This library is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Library General Public License as published by
+ the Free Software Foundation (either version 2 of the License or, at your
+ option, any later version). This library is distributed in the hope that
+ it will be useful, but WITHOUT ANY WARRANTY, without even the implied
+ warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ the GNU Library General Public License for more details. You should have
+ received a copy of the GNU Library General Public License along with this
+ library; if not, write to the Free Software Foundation, Inc., 59 Temple
+ Place, Suite 330, Boston, MA 02111-1307, USA.
+
+ The code as Shawn received it included the following notice:
+
+ Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura. When
+ you use this, send an e-mail to <matumoto@math.keio.ac.jp> with
+ an appropriate reference to your work.
+
+ It would be nice to CC: <Cokus@math.washington.edu> when you write.
+
+
+
+ php_uint32 must be an unsigned integer type capable of holding at least 32
+ bits; exactly 32 should be fastest, but 64 is better on an Alpha with
+ GCC at -O3 optimization so try your options and see what's best for you
+
+ Melo: we should put some ifdefs here to catch those alphas...
+*/
+
+static void _php_srand_mt(long seed TSRMLS_DC);
+static inline long _php_rand_mt_reload(TSRMLS_D);
+static long _php_rand_mt(void);
+/*
+ * Melo: it could be 2^^32 but we only use 2^^31 to maintain
+ * compatibility with the previous php_rand
+ */
+#define PHP_RANDMAX_MT ((long)(0x7FFFFFFF)) /* 2^^31 - 1 */
+
+PHP_MINIT_FUNCTION(rand_mt)
+{
+ PHP_RANDGEN_ENTRY(PHP_RAND_MT,
+ _php_srand_mt, /* void srand(long seed) */
+ _php_rand_mt, /* long rand(void) */
+ PHP_RANDMAX_MT, /* long randmax */
+ "mt" /* char *ini_str */
+ );
+}
+
+#define N MT_N /* length of state vector */
+#define M (397) /* a period parameter */
+#define K (0x9908B0DFU) /* a magic constant */
+#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 MIX_AND_RETURN(var) { \
+ (var) ^= ((var) >> 11); \
+ (var) ^= ((var) << 7) & 0x9D2C5680U; \
+ (var) ^= ((var) << 15) & 0xEFC60000U; \
+ (var) ^= ((var) >> 18); \
+ /*
+ * Melo: hmms.. these are 32 random bits...
+ * Yet, the previous php_rand only returns 31 at most.
+ * So I put a right shift to loose the lsb. It *seems*
+ * better than clearing the msb.
+ * Update:
+ * I talked with Cokus via email and it won't ruin the algorithm
+ *
+ * Jeroen: moved this to end of php_rand_mt and php_rand_mt_reload
+ */ \
+ return (long)((var) >> 1); \
+}
+
+/* {{{ void _php_srand_mt(long seed)
+ */
+static void _php_srand_mt(long seed TSRMLS_DC)
+{
+ /*
+ We initialize state[0..(N-1)] via the generator
+
+ x_new = (69069 * x_old) mod 2^32
+
+ from Line 15 of Table 1, p. 106, Sec. 3.3.4 of Knuth's
+ _The Art of Computer Programming_, Volume 2, 3rd ed.
+
+ Notes (SJC): I do not know what the initial state requirements
+ of the Mersenne Twister are, but it seems this seeding generator
+ could be better. It achieves the maximum period for its modulus
+ (2^30) iff x_initial is odd (p. 20-21, Sec. 3.2.1.2, Knuth); if
+ x_initial can be even, you have sequences like 0, 0, 0, ...;
+ 2^31, 2^31, 2^31, ...; 2^30, 2^30, 2^30, ...; 2^29, 2^29 + 2^31,
+ 2^29, 2^29 + 2^31, ..., etc. so I force seed to be odd below.
+
+ Even if x_initial is odd, if x_initial is 1 mod 4 then
+
+ the lowest bit of x is always 1,
+ the next-to-lowest bit of x is always 0,
+ the 2nd-from-lowest bit of x alternates ... 0 1 0 1 0 1 0 1 ... ,
+ the 3rd-from-lowest bit of x 4-cycles ... 0 1 1 0 0 1 1 0 ... ,
+ the 4th-from-lowest bit of x has the 8-cycle ... 0 0 0 1 1 1 1 0 ... ,
+ ...
+
+ and if x_initial is 3 mod 4 then
+
+ the lowest bit of x is always 1,
+ the next-to-lowest bit of x is always 1,
+ the 2nd-from-lowest bit of x alternates ... 0 1 0 1 0 1 0 1 ... ,
+ the 3rd-from-lowest bit of x 4-cycles ... 0 0 1 1 0 0 1 1 ... ,
+ the 4th-from-lowest bit of x has the 8-cycle ... 0 0 1 1 1 1 0 0 ... ,
+ ...
+
+ The generator's potency (min. s>=0 with (69069-1)^s = 0 mod 2^32) is
+ 16, which seems to be alright by p. 25, Sec. 3.2.1.3 of Knuth. It
+ also does well in the dimension 2..5 spectral tests, but it could be
+ better in dimension 6 (Line 15, Table 1, p. 106, Sec. 3.3.4, Knuth).
+
+ Note that the random number user does not see the values generated
+ here directly since reloadMT() will always munge them first, so maybe
+ none of all of this matters. In fact, the seed values made here could
+ even be extra-special desirable if the Mersenne Twister theory says
+ so-- that's why the only change I made is to restrict to odd seeds.
+ */
+
+ register php_uint32 x = ((php_uint32)seed | 1U) & 0xFFFFFFFFU, *s = BG(state);
+ register int j;
+
+ for(BG(left)=0, *s++=x, j=N; --j;
+ *s++ = (x*=69069U) & 0xFFFFFFFFU);
+}
+/* }}} */
+
+/* {{{ long _php_rand_mt_reload(void) [internal function]
+ * Generates a new batch of random numbers, and returns the first of it */
+static inline long _php_rand_mt_reload(TSRMLS_D)
+{
+ register php_uint32 *p0=BG(state), *p2=BG(state)+2, *pM=BG(state)+M, s0, s1;
+ register int j;
+
+ if(BG(left) < -1)
+ _php_srand_mt(4357U TSRMLS_CC);
+
+ BG(left)=N-1, BG(next)=BG(state)+1;
+
+ for(s0=BG(state)[0], s1=BG(state)[1], j=N-M+1; --j; s0=s1, s1=*p2++)
+ *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+ for(pM=BG(state), j=M; --j; s0=s1, s1=*p2++)
+ *p0++ = *pM++ ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+
+ s1=BG(state)[0], *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
+ MIX_AND_RETURN(s1);
+}
+/*}}}*/
+
+/* {{{ long _php_rand_mt(void) */
+static long _php_rand_mt(void)
+{
+ php_uint32 y;
+ TSRMLS_FETCH();
+
+ if(--BG(left) < 0)
+ return(_php_rand_mt_reload(TSRMLS_C));
+
+ y = *BG(next)++;
+ MIX_AND_RETURN(y);
+}
+/* }}} */
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ * vim600: sw=4 ts=4 tw=78 fdm=marker
+ * vim<600: sw=4 ts=4 tw=78
+ */
--- /dev/null
+/*
+ +----------------------------------------------------------------------+
+ | PHP version 4.0 |
+ +----------------------------------------------------------------------+
+ | Copyright (c) 1997-2001 The PHP Group |
+ +----------------------------------------------------------------------+
+ | This source file is subject to version 2.02 of the PHP license, |
+ | that is bundled with this package in the file LICENSE, and is |
+ | available at through the world-wide-web at |
+ | http://www.php.net/license/2_02.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@lerdorf.on.ca> |
+ | Zeev Suraski <zeev@zend.com> |
+ | Jeroen van Wolffelaar <jeroen@php.net> |
+ +----------------------------------------------------------------------+
+ */
+/* $Id$ */
+
+#include <stdlib.h>
+
+#include "php.h"
+#include "php_rand.h"
+
+#include "basic_functions.h"
+
+
+/* rand() & co (thread safe this time!): */
+static void _php_srand_sys(long seed)
+{
+ BG(rand_sys_seed) = (unsigned int) seed;
+}
+
+static long _php_rand_sys(void)
+{
+ return (long) rand_r(&BG(rand_sys_seed));
+}
+
+PHP_MINIT_FUNCTION(rand_sys)
+{
+#ifndef RAND_MAX
+#define RAND_MAX (1<<15)
+#endif
+ PHP_RANDGEN_ENTRY(PHP_RAND_SYS,
+ _php_srand_sys, /* void srand(long seed) */
+ _php_rand_sys, /* long rand(void) */
+ (long)RAND_MAX, /* long randmax */
+ "system" /* char *ini_str */
+ );
+
+ /* random() is left away, no manual page on my system, no bigger range than
+ * rand()
+ * --jeroen
+ */
+
+ /* lrand48 (_not_ TS) */
+#if HAVE_LRAND48
+ PHP_RANDGEN_ENTRY(PHP_RAND_LRAND48,
+ srand48, /* void srand(long seed) */
+ lrand48, /* long rand(void) */
+ 2147483647L, /* long randmax */
+ "lrand48" /* char *ini_str */
+ );
+#else
+ php_randgen_entries[PHP_RAND_LRAND48] = NULL;
+#endif
+
+}
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ * vim600: sw=4 ts=4 tw=78 fdm=marker
+ * vim: sw=4 ts=4 tw=78
+ */
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