pqc/external/flint-2.4.3/fmpz/sqrtrem.c

59 lines
1.9 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) 2010 Sebastian Pancratz
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"
#include "fmpz.h"
void fmpz_sqrtrem(fmpz_t f, fmpz_t r, const fmpz_t g)
{
if (fmpz_sgn(g) < 0)
{
flint_printf("Exception (fmpz_sqrtrem). g is negative.\n");
abort();
}
if (!COEFF_IS_MPZ(*g))
{
if (COEFF_IS_MPZ(*r))
_fmpz_clear_mpz(*r);
fmpz_set_ui(f, n_sqrtrem((mp_limb_t *) r, *g));
}
else
{
__mpz_struct * r_mpz_ptr, * f_mpz_ptr;
_fmpz_promote(f); /* must not hang on to pointer whilst promoting */
r_mpz_ptr = _fmpz_promote(r);
f_mpz_ptr = COEFF_TO_PTR(*f);
mpz_sqrtrem(f_mpz_ptr, r_mpz_ptr, COEFF_TO_PTR(*g));
_fmpz_demote_val(f);
_fmpz_demote_val(r);
}
}