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/* Test mpz_invert.
Copyright 1991, 1993, 1994, 1996, 1997, 2000-2005, 2008, 2009, 2012, 2014 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 "gmp-impl.h"
#include "tests.h"
int
main (int argc, char **argv)
{
mpz_t a, m, ainv, t;
int test, r;
gmp_randstate_ptr rands;
mpz_t bs;
unsigned long bsi, size_range;
int reps = 1000;
tests_start ();
TESTS_REPS (reps, argv, argc);
rands = RANDS;
mpz_init (bs);
mpz_init (a);
mpz_init (m);
mpz_init (ainv);
mpz_init (t);
for (test = 0; test < reps; test++)
{
mpz_urandomb (bs, rands, 32);
size_range = mpz_get_ui (bs) % 16 + 2;
mpz_urandomb (bs, rands, size_range);
mpz_rrandomb (a, rands, mpz_get_ui (bs));
do {
mpz_urandomb (bs, rands, size_range);
mpz_rrandomb (m, rands, mpz_get_ui (bs));
} while (mpz_sgn (m) == 0);
mpz_urandomb (bs, rands, 8);
bsi = mpz_get_ui (bs);
if ((bsi & 1) != 0)
mpz_neg (a, a);
if ((bsi & 2) != 0)
mpz_neg (m, m);
r = mpz_invert (ainv, a, m);
if (r != 0)
{
MPZ_CHECK_FORMAT (ainv);
if (mpz_cmp_ui (ainv, 0) < 0 || mpz_cmpabs (ainv, m) >= 0)
{
fprintf (stderr, "ERROR in test %d\n", test);
gmp_fprintf (stderr, "Inverse out of range.\n");
gmp_fprintf (stderr, "a = %Zx\n", a);
gmp_fprintf (stderr, "1/a = %Zx\n", ainv);
gmp_fprintf (stderr, "m = %Zx\n", m);
abort ();
}
mpz_mul (t, ainv, a);
mpz_mod (t, t, m);
if (mpz_cmp_ui (t, mpz_cmpabs_ui (m, 1) != 0) != 0)
{
fprintf (stderr, "ERROR in test %d\n", test);
gmp_fprintf (stderr, "a^(-1)*a != 1 (mod m)\n");
gmp_fprintf (stderr, "a = %Zx\n", a);
gmp_fprintf (stderr, "m = %Zx\n", m);
abort ();
}
}
else /* Inverse deos not exist */
{
mpz_gcd (t, a, m);
if (mpz_cmp_ui (t, 1) == 0)
{
fprintf (stderr, "ERROR in test %d\n", test);
gmp_fprintf (stderr, "Inverse exists, but was not found.\n");
gmp_fprintf (stderr, "a = %Zx\n", a);
gmp_fprintf (stderr, "m = %Zx\n", m);
abort ();
}
}
}
mpz_clear (bs);
mpz_clear (a);
mpz_clear (m);
mpz_clear (ainv);
mpz_clear (t);
tests_end ();
exit (0);
}
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