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Annotation of OpenXM_contrib/gmp/rand.c, Revision 1.1

1.1     ! maekawa     1: /* gmp_randinit (state, algorithm, ...) -- Initialize a random state.
        !             2:
        !             3: Copyright (C) 1999, 2000  Free Software Foundation, Inc.
        !             4:
        !             5: This file is part of the GNU MP Library.
        !             6:
        !             7: The GNU MP Library is free software; you can redistribute it and/or modify
        !             8: it under the terms of the GNU Lesser General Public License as published by
        !             9: the Free Software Foundation; either version 2.1 of the License, or (at your
        !            10: option) any later version.
        !            11:
        !            12: The GNU MP Library is distributed in the hope that it will be useful, but
        !            13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
        !            15: License for more details.
        !            16:
        !            17: You should have received a copy of the GNU Lesser General Public License
        !            18: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
        !            19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            20: MA 02111-1307, USA. */
        !            21:
        !            22: #include <stdio.h> /* for NULL */
        !            23: #if __STDC__
        !            24: # include <stdarg.h>
        !            25: #else
        !            26: # include <varargs.h>
        !            27: #endif
        !            28:
        !            29: #include "gmp.h"
        !            30: #include "gmp-impl.h"
        !            31:
        !            32: /* Array of CL-schemes, ordered in increasing order of the first
        !            33:    member (the 'm2exp' value).  The end of the array is indicated with
        !            34:    an entry containing all zeros.  */
        !            35:
        !            36: /* All multipliers are in the range 0.01*m and 0.99*m, and are
        !            37: congruent to 5 (mod 8).
        !            38: They all pass the spectral test with Vt >= 2^(30/t) and merit >= 1.
        !            39: (Up to and including 196 bits, merit is >= 3.)  */
        !            40:
        !            41: struct __gmp_rand_lc_scheme_struct
        !            42: {
        !            43:   unsigned long int m2exp;     /* Modulus is 2 ^ m2exp. */
        !            44:   char *astr;                  /* Multiplier in string form. */
        !            45:   unsigned long int c;         /* Adder. */
        !            46: };
        !            47:
        !            48: struct __gmp_rand_lc_scheme_struct __gmp_rand_lc_scheme[] =
        !            49: {
        !            50:   {32, "43840821",          1},
        !            51:   {33, "85943917",          1},
        !            52:   {34, "171799469",         1},
        !            53:   {35, "343825285",         1},
        !            54:   {36, "687285701",         1},
        !            55:   {37, "1374564613",        1},
        !            56:   {38, "2749193437",        1},
        !            57:   {39, "5497652029",        1},
        !            58:   {40, "10995212661",       1},
        !            59:   {56, "47988680294711517",  1},
        !            60:   {64, "13469374875402548381", 1},
        !            61:   {100, "203786806069096950756900463357", 1},
        !            62:   {128, "96573135900076068624591706046897650309", 1},
        !            63:   {156, "43051576988660538262511726153887323360449035333", 1},
        !            64:   {196, "1611627857640767981443524165616850972435303571524033586421", 1},
        !            65:   {200, "491824250216153841876046962368396460896019632211283945747141", 1},
        !            66:   {256, "79336254595106925775099152154558630917988041692672147726148065355845551082677", 1},
        !            67:   {0, NULL, 0}                 /* End of array. */
        !            68: };
        !            69:
        !            70: void
        !            71: #if __STDC__
        !            72: gmp_randinit (gmp_randstate_t rstate,
        !            73:              gmp_randalg_t alg,
        !            74:              ...)
        !            75: #else
        !            76: gmp_randinit (va_alist)
        !            77:      va_dcl
        !            78: #endif
        !            79: {
        !            80:   va_list ap;
        !            81: #if __STDC__
        !            82: #else
        !            83:   __gmp_randstate_struct *rstate;
        !            84:   gmp_randalg_t alg;
        !            85: #endif
        !            86:
        !            87: #if __STDC__
        !            88:   va_start (ap, alg);
        !            89: #else
        !            90:   va_start (ap);
        !            91:
        !            92:   rstate = va_arg (ap, __gmp_randstate_struct *);
        !            93:   alg = va_arg (ap, gmp_randalg_t);
        !            94: #endif
        !            95:
        !            96:   switch (alg)
        !            97:     {
        !            98:     case GMP_RAND_ALG_LC:      /* Linear congruential.  */
        !            99:       {
        !           100:        unsigned long int size;
        !           101:        struct __gmp_rand_lc_scheme_struct *sp;
        !           102:        mpz_t a;
        !           103:
        !           104:        size = va_arg (ap, unsigned long int);
        !           105:
        !           106:        /* Pick a scheme.  */
        !           107:        for (sp = __gmp_rand_lc_scheme; sp->m2exp != 0; sp++)
        !           108:          if (sp->m2exp / 2 >= size)
        !           109:            break;
        !           110:
        !           111:        if (sp->m2exp == 0)     /* Nothing big enough found.  */
        !           112:          {
        !           113:            gmp_errno |= GMP_ERROR_INVALID_ARGUMENT;
        !           114:            return;
        !           115:          }
        !           116:
        !           117:        /* Install scheme.  */
        !           118:        mpz_init_set_str (a, sp->astr, 0);
        !           119:        gmp_randinit_lc_2exp (rstate, a, sp->c, sp->m2exp);
        !           120:        mpz_clear (a);
        !           121:        break;
        !           122:       }
        !           123:
        !           124: #if 0
        !           125:     case GMP_RAND_ALG_BBS:     /* Blum, Blum, and Shub. */
        !           126:       {
        !           127:        mpz_t p, q;
        !           128:        mpz_t ztmp;
        !           129:
        !           130:        /* FIXME: Generate p and q.  They must be ``large'' primes,
        !           131:            congruent to 3 mod 4.  Should we ensure that they meet some
        !           132:            of the criterias for being ``hard primes''?*/
        !           133:
        !           134:        /* These are around 128 bits. */
        !           135:        mpz_init_set_str (p, "148028650191182616877187862194899201391", 10);
        !           136:        mpz_init_set_str (q, "315270837425234199477225845240496832591", 10);
        !           137:
        !           138:        /* Allocate algorithm specific data. */
        !           139:        rstate->data.bbs = (__gmp_rand_data_bbs *)
        !           140:          (*_mp_allocate_func) (sizeof (__gmp_rand_data_bbs));
        !           141:
        !           142:        mpz_init (rstate->data.bbs->bi); /* The Blum integer. */
        !           143:        mpz_mul (rstate->data.bbs->bi, p, q);
        !           144:
        !           145:        /* Find a seed, x, with gcd (x, bi) == 1. */
        !           146:        mpz_init (ztmp);
        !           147:        while (1)
        !           148:          {
        !           149:            mpz_gcd (ztmp, seed, rstate->data.bbs->bi);
        !           150:            if (!mpz_cmp_ui (ztmp, 1))
        !           151:              break;
        !           152:            mpz_add_ui (seed, seed, 1);
        !           153:          }
        !           154:
        !           155:        rstate->alg = alg;
        !           156:        rstate->size = size;            /* FIXME: Remove. */
        !           157:        mpz_set (rstate->seed, seed);
        !           158:
        !           159:        mpz_clear (p);
        !           160:        mpz_clear (q);
        !           161:        mpz_clear (ztmp);
        !           162:        break;
        !           163:       }
        !           164: #endif /* 0 */
        !           165:
        !           166:     default:                   /* Bad choice. */
        !           167:       gmp_errno |= GMP_ERROR_UNSUPPORTED_ARGUMENT;
        !           168:     }
        !           169:
        !           170:   va_end (ap);
        !           171: }