1 /*!
2 \file
3 \brief Various routines for providing portable 32 and 64 bit random number
4 generators.
5
6 \date Started 5/17/2007
7 \author George
8 \version\verbatim $Id: random.c 11793 2012-04-04 21:03:02Z karypis $ \endverbatim
9 */
10
11 #include <GKlib.h>
12
13
14 /*************************************************************************/
15 /*! Create the various random number functions */
16 /*************************************************************************/
17 GK_MKRANDOM(gk_c, size_t, char)
18 GK_MKRANDOM(gk_i, size_t, int)
19 GK_MKRANDOM(gk_f, size_t, float)
20 GK_MKRANDOM(gk_d, size_t, double)
21 GK_MKRANDOM(gk_idx, size_t, gk_idx_t)
22 GK_MKRANDOM(gk_z, size_t, ssize_t)
23
24
25
26 /*************************************************************************/
27 /*! GKlib's built in random number generator for portability across
28 different architectures */
29 /*************************************************************************/
30 #ifdef USE_GKRAND
31 /*
32 A C-program for MT19937-64 (2004/9/29 version).
33 Coded by Takuji Nishimura and Makoto Matsumoto.
34
35 This is a 64-bit version of Mersenne Twister pseudorandom number
36 generator.
37
38 Before using, initialize the state by using init_genrand64(seed)
39 or init_by_array64(init_key, key_length).
40
41 Copyright (C) 2004, Makoto Matsumoto and Takuji Nishimura,
42 All rights reserved.
43
44 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
45 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
46 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
47 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
48 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
49 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
50 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
51 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
52 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
53 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
54 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
55 */
56
57 #define NN 312
58 #define MM 156
59 #define MATRIX_A 0xB5026F5AA96619E9ULL
60 #define UM 0xFFFFFFFF80000000ULL /* Most significant 33 bits */
61 #define LM 0x7FFFFFFFULL /* Least significant 31 bits */
62
63
64 /* The array for the state vector */
65 static uint64_t mt[NN];
66 /* mti==NN+1 means mt[NN] is not initialized */
67 static int mti=NN+1;
68 #endif /* USE_GKRAND */
69
70 /* initializes mt[NN] with a seed */
gk_randinit(uint64_t seed)71 void gk_randinit(uint64_t seed)
72 {
73 #ifdef USE_GKRAND
74 mt[0] = seed;
75 for (mti=1; mti<NN; mti++)
76 mt[mti] = (6364136223846793005ULL * (mt[mti-1] ^ (mt[mti-1] >> 62)) + mti);
77 #else
78 srand((unsigned int) seed);
79 #endif
80 }
81
82
83 /* generates a random number on [0, 2^64-1]-interval */
gk_randint64(void)84 uint64_t gk_randint64(void)
85 {
86 #ifdef USE_GKRAND
87 int i;
88 unsigned long long x;
89 static uint64_t mag01[2]={0ULL, MATRIX_A};
90
91 if (mti >= NN) { /* generate NN words at one time */
92 /* if init_genrand64() has not been called, */
93 /* a default initial seed is used */
94 if (mti == NN+1)
95 gk_randinit(5489ULL);
96
97 for (i=0; i<NN-MM; i++) {
98 x = (mt[i]&UM)|(mt[i+1]&LM);
99 mt[i] = mt[i+MM] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
100 }
101 for (; i<NN-1; i++) {
102 x = (mt[i]&UM)|(mt[i+1]&LM);
103 mt[i] = mt[i+(MM-NN)] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
104 }
105 x = (mt[NN-1]&UM)|(mt[0]&LM);
106 mt[NN-1] = mt[MM-1] ^ (x>>1) ^ mag01[(int)(x&1ULL)];
107
108 mti = 0;
109 }
110
111 x = mt[mti++];
112
113 x ^= (x >> 29) & 0x5555555555555555ULL;
114 x ^= (x << 17) & 0x71D67FFFEDA60000ULL;
115 x ^= (x << 37) & 0xFFF7EEE000000000ULL;
116 x ^= (x >> 43);
117
118 return x & 0x7FFFFFFFFFFFFFFF;
119 #else
120 return (uint64_t)(((uint64_t) rand()) << 32 | ((uint64_t) rand()));
121 #endif
122 }
123
124 /* generates a random number on [0, 2^32-1]-interval */
gk_randint32(void)125 uint32_t gk_randint32(void)
126 {
127 #ifdef USE_GKRAND
128 return (uint32_t)(gk_randint64() & 0x7FFFFFFF);
129 #else
130 return (uint32_t)rand();
131 #endif
132 }
133
134
135