trunk/src/rng_mt.c

/* 
   A C-program for MT19937, with initialization improved 2002/1/26.
   Coded by Takuji Nishimura and Makoto Matsumoto.

   Before using, initialize the state by using init_genrand(seed)  
   or init_by_array(init_key, key_length).

   Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
   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.


   Any feedback is very welcome.
   http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
   email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)

   $Id$
*/

#include "stdinc.h"
#include "rng_mt.h"

/* Period parameters */  
#define N 624
#define M 397
#define MATRIX_A 0x9908b0dfU   /* constant vector a         */
#define UPPER_MASK 0x80000000U /* most significant w-r bits */
#define LOWER_MASK 0x7fffffffU /* least significant r bits  */

static uint32_t mt[N]; /* the array for the state vector  */
static int mti = N + 1; /* mti==N+1 means mt[N] is not initialized */

/* initializes mt[N] with a seed */
void
init_genrand(uint32_t s)
{
  mt[0] = s & 0xffffffffU;

  for (mti = 1; mti < N; mti++)
  {
    mt[mti] = (1812433253U * (mt[mti - 1] ^ (mt[mti - 1] >> 30)) + mti);
    /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
    /* In the previous versions, MSBs of the seed affect   */
    /* only MSBs of the array mt[].                        */
    /* 2002/01/09 modified by Makoto Matsumoto             */
    mt[mti] &= 0xffffffffU;
    /* for >32 bit machines */
  }
}

/* initialize by an array with array-length */
/* init_key is the array for initializing keys */
/* key_length is its length */
/* slight change for C++, 2004/2/26 */
void
init_by_array(uint32_t init_key[], int key_length)
{
  int i, j, k;

  init_genrand(19650218U);

  i = 1; j = 0;
  k = (N > key_length ? N : key_length);

  for (; k; k--)
  {
    mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525U))
          + init_key[j] + j; /* non linear */
    mt[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
    i++; j++;

    if (i >= N)
    {
      mt[0] = mt[N - 1];
      i = 1;
    }

    if (j >= key_length)
      j = 0;
  }

  for (k = N - 1; k; k--)
  {
    mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941U))
          - i; /* non linear */
    mt[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
    i++;

    if (i >= N)
    {
      mt[0] = mt[N - 1];
      i = 1;
    }
  }

  mt[0] = 0x80000000U; /* MSB is 1; assuring non-zero initial array */ 
}

/* generates a random number on [0,0xffffffff]-interval */
uint32_t
genrand_int32(void)
{
  uint32_t y;
  static uint32_t mag01[2]={ 0x0U, MATRIX_A };
  /* mag01[x] = x * MATRIX_A  for x=0,1 */

  if (mti >= N)
  { /* generate N words at one time */
    int kk;

    if (mti == N + 1)   /* if init_genrand() has not been called, */
      init_genrand(5489U); /* a default initial seed is used */

    for (kk = 0; kk < N - M; kk++)
    {
      y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
      mt[kk] = mt[kk + M] ^ (y >> 1) ^ mag01[y & 0x1U];
    }

    for (; kk < N - 1; kk++)
    {
      y = (mt[kk] & UPPER_MASK) | (mt[kk + 1] & LOWER_MASK);
      mt[kk] = mt[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1U];
    }

    y = (mt[N - 1] & UPPER_MASK) | (mt[0] & LOWER_MASK);
    mt[N - 1] = mt[M - 1] ^ (y >> 1) ^ mag01[y & 0x1U];

    mti = 0;
  }
  
  y = mt[mti++];

  /* Tempering */
  y ^= (y >> 11);
  y ^= (y <<  7) & 0x9d2c5680U;
  y ^= (y << 15) & 0xefc60000U;
  y ^= (y >> 18);

  return y;
}
Revision:	1592
Committed:	Sat Oct 27 21:02:32 2012 UTC (13 years, 8 months ago) by michael
Content type:	text/x-csrc
File size:	4950 byte(s)
Log Message:	- Second time's the charm? Moving svnroot/ircd-hybrid-8 to svnroot/ircd-hybrid/trunk
#	User	Rev	Content
1	michael	982	/*
2			A C-program for MT19937, with initialization improved 2002/1/26.
3			Coded by Takuji Nishimura and Makoto Matsumoto.
4
5			Before using, initialize the state by using init_genrand(seed)
6			or init_by_array(init_key, key_length).
7
8			Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
9			All rights reserved.
10
11			Redistribution and use in source and binary forms, with or without
12			modification, are permitted provided that the following conditions
13			are met:
14
15			1. Redistributions of source code must retain the above copyright
16			notice, this list of conditions and the following disclaimer.
17
18			2. Redistributions in binary form must reproduce the above copyright
19			notice, this list of conditions and the following disclaimer in the
20			documentation and/or other materials provided with the distribution.
21
22			3. The names of its contributors may not be used to endorse or promote
23			products derived from this software without specific prior written
24			permission.
25
26			THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27			"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28			LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
29			A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
30			CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31			EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32			PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33			PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34			LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35			NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36			SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37
38
39			Any feedback is very welcome.
40			http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
41			email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
42
43			$Id$
44			*/
45
46	michael	1343	#include "stdinc.h"
47	michael	982	#include "rng_mt.h"
48
49			/* Period parameters */
50			#define N 624
51			#define M 397
52	michael	1343	#define MATRIX_A 0x9908b0dfU /* constant vector a */
53			#define UPPER_MASK 0x80000000U /* most significant w-r bits */
54			#define LOWER_MASK 0x7fffffffU /* least significant r bits */
55	michael	982
56	michael	1343	static uint32_t mt[N]; /* the array for the state vector */
57	michael	982	static int mti = N + 1; /* mti==N+1 means mt[N] is not initialized */
58
59			/* initializes mt[N] with a seed */
60			void
61	michael	1343	init_genrand(uint32_t s)
62	michael	982	{
63	michael	1343	mt[0] = s & 0xffffffffU;
64	michael	982
65			for (mti = 1; mti < N; mti++)
66			{
67	michael	1343	mt[mti] = (1812433253U * (mt[mti - 1] ^ (mt[mti - 1] >> 30)) + mti);
68	michael	982	/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
69			/* In the previous versions, MSBs of the seed affect */
70			/* only MSBs of the array mt[]. */
71			/* 2002/01/09 modified by Makoto Matsumoto */
72	michael	1343	mt[mti] &= 0xffffffffU;
73	michael	982	/* for >32 bit machines */
74			}
75			}
76
77			/* initialize by an array with array-length */
78			/* init_key is the array for initializing keys */
79			/* key_length is its length */
80			/* slight change for C++, 2004/2/26 */
81			void
82	michael	1343	init_by_array(uint32_t init_key[], int key_length)
83	michael	982	{
84			int i, j, k;
85
86	michael	1343	init_genrand(19650218U);
87	michael	982
88			i = 1; j = 0;
89			k = (N > key_length ? N : key_length);
90
91			for (; k; k--)
92			{
93	michael	1343	mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1664525U))
94	michael	982	+ init_key[j] + j; /* non linear */
95	michael	1343	mt[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
96	michael	982	i++; j++;
97
98			if (i >= N)
99			{
100			mt[0] = mt[N - 1];
101			i = 1;
102			}
103
104			if (j >= key_length)
105			j = 0;
106			}
107
108			for (k = N - 1; k; k--)
109			{
110	michael	1343	mt[i] = (mt[i] ^ ((mt[i - 1] ^ (mt[i - 1] >> 30)) * 1566083941U))
111	michael	982	- i; /* non linear */
112	michael	1343	mt[i] &= 0xffffffffU; /* for WORDSIZE > 32 machines */
113	michael	982	i++;
114
115			if (i >= N)
116			{
117			mt[0] = mt[N - 1];
118			i = 1;
119			}
120			}
121
122	michael	1343	mt[0] = 0x80000000U; /* MSB is 1; assuring non-zero initial array */
123	michael	982	}
124
125			/* generates a random number on [0,0xffffffff]-interval */
126	michael	1343	uint32_t
127	michael	982	genrand_int32(void)
128			{
129	michael	1343	uint32_t y;
130			static uint32_t mag01[2]={ 0x0U, MATRIX_A };
131	michael	982	/* mag01[x] = x * MATRIX_A for x=0,1 */
132
133			if (mti >= N)
134			{ /* generate N words at one time */
135			int kk;
136
137			if (mti == N + 1) /* if init_genrand() has not been called, */
138	michael	1343	init_genrand(5489U); /* a default initial seed is used */
139	michael	982
140			for (kk = 0; kk < N - M; kk++)
141			{
142			y = (mt[kk] & UPPER_MASK) \| (mt[kk + 1] & LOWER_MASK);
143	michael	1343	mt[kk] = mt[kk + M] ^ (y >> 1) ^ mag01[y & 0x1U];
144	michael	982	}
145
146			for (; kk < N - 1; kk++)
147			{
148			y = (mt[kk] & UPPER_MASK) \| (mt[kk + 1] & LOWER_MASK);
149	michael	1343	mt[kk] = mt[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1U];
150	michael	982	}
151
152			y = (mt[N - 1] & UPPER_MASK) \| (mt[0] & LOWER_MASK);
153	michael	1343	mt[N - 1] = mt[M - 1] ^ (y >> 1) ^ mag01[y & 0x1U];
154	michael	982
155			mti = 0;
156			}
157
158			y = mt[mti++];
159
160			/* Tempering */
161			y ^= (y >> 11);
162	michael	1343	y ^= (y << 7) & 0x9d2c5680U;
163			y ^= (y << 15) & 0xefc60000U;
164	michael	982	y ^= (y >> 18);
165
166			return y;
167			}