1 /*
2 A C-program for MT19937-64 (2004/9/29 version).
3 Coded by Takuji Nishimura and Makoto Matsumoto.
4
5 This is a 64-bit version of Mersenne Twister pseudorandom number
6 generator.
7
8 Before using, initialize the state by using init_genrand64(seed)
9 or init_by_array64(init_key, key_length).
10
11 Copyright (C) 2004, Makoto Matsumoto and Takuji Nishimura,
12 All rights reserved.
13
14 Redistribution and use in source and binary forms, with or without
15 modification, are permitted provided that the following conditions
16 are met:
17
18 1. Redistributions of source code must retain the above copyright
19 notice, this list of conditions and the following disclaimer.
20
21 2. Redistributions in binary form must reproduce the above copyright
22 notice, this list of conditions and the following disclaimer in the
23 documentation and/or other materials provided with the distribution.
24
25 3. The names of its contributors may not be used to endorse or promote
26 products derived from this software without specific prior written
27 permission.
28
29 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
33 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
34 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
35 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
36 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
37 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
38 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
39 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40
41 References:
42 T. Nishimura, ``Tables of 64-bit Mersenne Twisters''
43 ACM Transactions on Modeling and
44 Computer Simulation 10. (2000) 348--357.
45 M. Matsumoto and T. Nishimura,
46 ``Mersenne Twister: a 623-dimensionally equidistributed
47 uniform pseudorandom number generator''
48 ACM Transactions on Modeling and
49 Computer Simulation 8. (Jan. 1998) 3--30.
50
51 Any feedback is very welcome.
52 http://www.math.hiroshima-u.ac.jp/~m-mat/MT/emt.html
53 email: m-mat @ math.sci.hiroshima-u.ac.jp (remove spaces)
54 */
55
56 /* The code has been modified to store internal state in heap/stack
57 * allocated memory, rather than statically allocated memory, to allow
58 * multiple instances running in the same address space. */
59
60 #include <stdlib.h>
61 #include <stdio.h>
62 #include "theft_mt.h"
63
64 #define NN THEFT_MT_PARAM_N
65 #define MM 156
66 #define MATRIX_A 0xB5026F5AA96619E9ULL
67 #define UM 0xFFFFFFFF80000000ULL /* Most significant 33 bits */
68 #define LM 0x7FFFFFFFULL /* Least significant 31 bits */
69
70 static uint64_t genrand64_int64(struct theft_mt *r);
71
72 /* Heap-allocate a mersenne twister struct. */
theft_mt_init(uint64_t seed)73 struct theft_mt *theft_mt_init(uint64_t seed) {
74 struct theft_mt *mt = malloc(sizeof(struct theft_mt));
75 if (mt == NULL) { return NULL; }
76 theft_mt_reset(mt, seed);
77 return mt;
78 }
79
80 /* Free a heap-allocated mersenne twister struct. */
theft_mt_free(struct theft_mt * mt)81 void theft_mt_free(struct theft_mt *mt) {
82 free(mt);
83 }
84
85 /* initializes mt[NN] with a seed */
theft_mt_reset(struct theft_mt * mt,uint64_t seed)86 void theft_mt_reset(struct theft_mt *mt, uint64_t seed)
87 {
88 mt->mt[0] = seed;
89 uint16_t mti = 0;
90 for (mti=1; mti<NN; mti++) {
91 mt->mt[mti] = (6364136223846793005ULL *
92 (mt->mt[mti-1] ^ (mt->mt[mti-1] >> 62)) + mti);
93 }
94 mt->mti = mti;
95 }
96
97 /* Get a 64-bit random number. */
theft_mt_random(struct theft_mt * mt)98 uint64_t theft_mt_random(struct theft_mt *mt) {
99 return genrand64_int64(mt);
100 }
101
102 /* Generate a random number on [0,1]-real-interval. */
theft_mt_random_double(struct theft_mt * mt)103 double theft_mt_random_double(struct theft_mt *mt)
104 {
105 return (genrand64_int64(mt) >> 11) * (1.0/9007199254740991.0);
106 }
107
108 /* generates a random number on [0, 2^64-1]-interval */
genrand64_int64(struct theft_mt * r)109 static uint64_t genrand64_int64(struct theft_mt *r)
110 {
111 int i;
112 uint64_t x;
113 static uint64_t mag01[2]={0ULL, MATRIX_A};
114
115 if (r->mti >= NN) { /* generate NN words at one time */
116
117 /* if init has not been called, */
118 /* a default initial seed is used */
119 if (r->mti == NN+1)
120 theft_mt_reset(r, 5489ULL);
121
122 for (i=0;i<NN-MM;i++) {
123 x = (r->mt[i]&UM)|(r->mt[i+1]&LM);
124 r->mt[i] = r->mt[i+MM] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
125 }
126 for (;i<NN-1;i++) {
127 x = (r->mt[i]&UM)|(r->mt[i+1]&LM);
128 r->mt[i] = r->mt[i+(MM-NN)] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
129 }
130 x = (r->mt[NN-1]&UM)|(r->mt[0]&LM);
131 r->mt[NN-1] = r->mt[MM-1] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
132
133 r->mti = 0;
134 }
135
136 x = r->mt[r->mti++];
137
138 x ^= (x >> 29) & 0x5555555555555555ULL;
139 x ^= (x << 17) & 0x71D67FFFEDA60000ULL;
140 x ^= (x << 37) & 0xFFF7EEE000000000ULL;
141 x ^= (x >> 43);
142
143 return x;
144 }
145