fzy

terminal fuzzy finder picker
theft_mt.c

(4973B)
      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. */
     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. */
     81 void theft_mt_free(struct theft_mt *mt) {
     82     free(mt);
     83 }
     84 
     85 /* initializes mt[NN] with a 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. */
     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. */
    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 */
    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 }