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/*
Copyright 2000 Free Software Foundation, Inc.
This file is part of the GNU MP Library test suite.
The GNU MP Library test suite is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the License,
or (at your option) any later version.
The GNU MP Library test suite is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
You should have received a copy of the GNU General Public License along with
the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <math.h>
#include "gmpstat.h"
#define RCSID(msg) \
static /**/const char *const rcsid[] = { (char *)rcsid, "\100(#)" msg }
RCSID("$Id$");
int g_debug = 0;
static mpz_t a;
static void
sh_status (int sig)
{
printf ("sh_status: signal %d caught. dumping status.\n", sig);
printf (" a = ");
mpz_out_str (stdout, 10, a);
printf ("\n");
fflush (stdout);
if (SIGSEGV == sig) /* remove SEGV handler */
signal (SIGSEGV, SIG_DFL);
}
/* Input is a modulus (m). We shall find multiplier (a) and adder (c)
conforming to the rules found in the first comment block in file
mpz/urandom.c.
Then run a spectral test on the generator and discard any
multipliers not passing. */
/* TODO:
. find a better algorithm than a+=8; bigger jumps perhaps?
*/
void
mpz_true_random (mpz_t s, unsigned long int nbits)
{
#if __FreeBSD__
FILE *fs;
char c[1];
int i;
mpz_set_ui (s, 0);
for (i = 0; i < nbits; i += 8)
{
for (;;)
{
int nread;
fs = fopen ("/dev/random", "r");
nread = fread (c, 1, 1, fs);
fclose (fs);
if (nread != 0)
break;
sleep (1);
}
mpz_mul_2exp (s, s, 8);
mpz_add_ui (s, s, ((unsigned long int) c[0]) & 0xff);
printf ("%d random bits\n", i + 8);
}
if (nbits % 8 != 0)
mpz_mod_2exp (s, s, nbits);
#endif
}
int
main (int argc, char *argv[])
{
const char usage[] = "usage: findlc [-dv] m2exp [low_merit [high_merit]]\n";
int f;
int v_lose, m_lose, v_best, m_best;
int c;
int debug = 1;
int cnt_high_merit;
mpz_t m;
unsigned long int m2exp;
#define DIMS 6 /* dimensions run in spectral test */
mpf_t v[DIMS-1]; /* spectral test result (there's no v
for 1st dimension */
mpf_t f_merit, low_merit, high_merit;
mpz_t acc, minus8;
mpz_t min, max;
mpz_t s;
mpz_init (m);
mpz_init (a);
for (f = 0; f < DIMS-1; f++)
mpf_init (v[f]);
mpf_init (f_merit);
mpf_init_set_d (low_merit, .1);
mpf_init_set_d (high_merit, .1);
while ((c = getopt (argc, argv, "a:di:hv")) != -1)
switch (c)
{
case 'd': /* debug */
g_debug++;
break;
case 'v': /* print version */
puts (rcsid[1]);
exit (0);
case 'h':
case '?':
default:
fputs (usage, stderr);
exit (1);
}
argc -= optind;
argv += optind;
if (argc < 1)
{
fputs (usage, stderr);
exit (1);
}
/* Install signal handler. */
if (SIG_ERR == signal (SIGSEGV, sh_status))
{
perror ("signal (SIGSEGV)");
exit (1);
}
if (SIG_ERR == signal (SIGHUP, sh_status))
{
perror ("signal (SIGHUP)");
exit (1);
}
printf ("findlc: version: %s\n", rcsid[1]);
m2exp = atol (argv[0]);
mpz_init_set_ui (m, 1);
mpz_mul_2exp (m, m, m2exp);
printf ("m = 0x");
mpz_out_str (stdout, 16, m);
puts ("");
if (argc > 1) /* have low_merit */
mpf_set_str (low_merit, argv[1], 0);
if (argc > 2) /* have high_merit */
mpf_set_str (high_merit, argv[2], 0);
if (debug)
{
fprintf (stderr, "low_merit = ");
mpf_out_str (stderr, 10, 2, low_merit);
fprintf (stderr, "; high_merit = ");
mpf_out_str (stderr, 10, 2, high_merit);
fputs ("\n", stderr);
}
mpz_init (minus8);
mpz_set_si (minus8, -8L);
mpz_init_set_ui (acc, 0);
mpz_init (s);
mpz_init_set_d (min, 0.01 * pow (2.0, (double) m2exp));
mpz_init_set_d (max, 0.99 * pow (2.0, (double) m2exp));
mpz_true_random (s, m2exp); /* Start. */
mpz_setbit (s, 0); /* Make it odd. */
v_best = m_best = 2*(DIMS-1);
for (;;)
{
mpz_add (acc, acc, s);
mpz_mod_2exp (acc, acc, m2exp);
#if later
mpz_and_si (a, acc, -8L);
#else
mpz_and (a, acc, minus8);
#endif
mpz_add_ui (a, a, 5);
if (mpz_cmp (a, min) <= 0 || mpz_cmp (a, max) >= 0)
continue;
spectral_test (v, DIMS, a, m);
for (f = 0, v_lose = m_lose = 0, cnt_high_merit = DIMS-1;
f < DIMS-1; f++)
{
merit (f_merit, f + 2, v[f], m);
if (mpf_cmp_ui (v[f], 1 << (30 / (f + 2) + (f == 2))) < 0)
v_lose++;
if (mpf_cmp (f_merit, low_merit) < 0)
m_lose++;
if (mpf_cmp (f_merit, high_merit) >= 0)
cnt_high_merit--;
}
if (0 == v_lose && 0 == m_lose)
{
mpz_out_str (stdout, 10, a); puts (""); fflush (stdout);
if (0 == cnt_high_merit)
break; /* leave loop */
}
if (v_lose < v_best)
{
v_best = v_lose;
printf ("best (v_lose=%d; m_lose=%d): ", v_lose, m_lose);
mpz_out_str (stdout, 10, a); puts (""); fflush (stdout);
}
if (m_lose < m_best)
{
m_best = m_lose;
printf ("best (v_lose=%d; m_lose=%d): ", v_lose, m_lose);
mpz_out_str (stdout, 10, a); puts (""); fflush (stdout);
}
}
mpz_clear (m);
mpz_clear (a);
for (f = 0; f < DIMS-1; f++)
mpf_clear (v[f]);
mpf_clear (f_merit);
mpf_clear (low_merit);
mpf_clear (high_merit);
printf ("done.\n");
return 0;
}
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