pqc/external/flint-2.4.3/ulong_extras/factor_trial_range.c
2014-05-24 23:16:06 +02:00

53 lines
1.7 KiB
C

/*=============================================================================
This file is part of FLINT.
FLINT 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 2 of the License, or
(at your option) any later version.
FLINT 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 FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2009 William Hart
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"
mp_limb_t n_factor_trial_range(n_factor_t * factors, mp_limb_t n, ulong start, ulong num_primes)
{
unsigned int exp;
mp_limb_t p;
double ppre;
ulong i;
const mp_limb_t * primes;
const double * inverses;
primes = n_primes_arr_readonly(num_primes);
inverses = n_prime_inverses_arr_readonly(num_primes);
for (i = start; i < num_primes; i++)
{
p = primes[i];
if (p*p > n) break;
ppre = inverses[i];
exp = n_remove2_precomp(&n, p, ppre);
if (exp) n_factor_insert(factors, p, exp);
}
return n;
}