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/* Test mpz_gcd_ui.
Copyright 2003 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"
/* Check mpz_gcd_ui doesn't try to return a value out of range.
This was wrong in gmp 4.1.2 with a long long limb. */
static void
check_ui_range (void)
{
unsigned long got;
mpz_t x;
int i;
mpz_init_set_ui (x, ULONG_MAX);
for (i = 0; i < 20; i++)
{
mpz_mul_2exp (x, x, 1L);
got = mpz_gcd_ui (NULL, x, 0L);
if (got != 0)
{
printf ("mpz_gcd_ui (ULONG_MAX*2^%d, 0)\n", i);
printf (" return %#lx\n", got);
printf (" should be 0\n");
abort ();
}
}
mpz_clear (x);
}
static void
check_ui_factors (void)
{
#define NUM_FACTORS 9
static const char* factors[NUM_FACTORS] = {
"641", "274177", "3", "5", "17", "257", "65537",
"59649589127497217", "1238926361552897" };
unsigned long got;
mpz_t x, b, d, f, g;
int i, j;
gmp_randstate_ptr rands;
if (GMP_NUMB_BITS < 5 || GMP_NUMB_BITS == 8
|| GMP_NUMB_BITS == 16 || GMP_NUMB_BITS > 511)
{
printf ("No usable factors for 2^%i+1.\n", GMP_NUMB_BITS);
return;
}
mpz_init (x);
mpz_init (d);
mpz_init (f);
mpz_init (g);
mpz_setbit (x, GMP_NUMB_BITS);
mpz_add_ui (x, x, 1);
for (i = 0; i < NUM_FACTORS; ++i)
{
mpz_set_str (f, factors[i], 10);
if (mpz_divisible_p (x, f))
{
mpz_mul_2exp (f, f, 1);
/* d is an odd multiple of the factor f, exactly filling a limb. */
mpz_sub (d, x, f);
/* f = 2^GMP_NUMB_BITS mod d. */
mpz_sub_ui (f, f, 1);
break;
}
}
mpz_gcd (g, f, d);
if (mpz_even_p (d) || mpz_cmp (d, f) <= 0 || mpz_cmp_ui (g, 1) != 0)
{
printf ("No usable factor found.\n");
abort ();
}
rands = RANDS;
mpz_mul_ui (x, d, gmp_urandomm_ui (rands, 30000) + 1);
mpz_init (b);
mpz_setbit (b, GMP_NUMB_BITS - 1);
for (j = 0; j < 4; ++j)
{
mpz_add (x, x, b);
for (i = 1; i >= -1; --i)
{
if (mpz_fits_ulong_p (d)
&& ((got = mpz_gcd_ui (NULL, x, mpz_get_ui (d)))
!= (i != 0 ? 1 : mpz_get_ui (d))))
{
printf ("mpz_gcd_ui (f, kV+%i*2^%i, V): error (j = %i)\n", i, GMP_NUMB_BITS - 1, j);
printf (" return %#lx\n", got);
printf (" should be %#lx\n", (i != 0 ? 1 : mpz_get_ui (d)));
abort ();
}
mpz_gcd (g, x, d);
if ((mpz_cmp_ui (g, 1) == 0) != (i != 0))
{
printf ("mpz_gcd (f, kV+%i*2^%i, V): error (j = %i)\n", i, GMP_NUMB_BITS - 1, j);
printf (" should%s be one.\n",(i != 0 ? "" : " not"));
abort ();
}
mpz_sub (x, x, b);
}
/* Back to the original x. */
mpz_addmul_ui (x, b, 2);
mpz_mul (b, b, f);
mpz_mod (b, b, d);
}
mpz_clear (g);
mpz_clear (x);
mpz_clear (f);
mpz_clear (d);
mpz_clear (b);
}
int
main (void)
{
tests_start ();
check_ui_range ();
check_ui_factors ();
tests_end ();
exit (0);
}
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