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

49 lines
1.6 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"
#include "fmpz.h"
void
fmpz_abs(fmpz_t f1, const fmpz_t f2)
{
if (!COEFF_IS_MPZ(*f2)) /* coeff is small */
{
fmpz t = FLINT_ABS(*f2); /* Need to save value in case of aliasing */
_fmpz_demote(f1);
*f1 = t;
}
else /* coeff is large */
{
/* No need to retain value in promotion, as if aliased, both already large */
__mpz_struct *mpz_ptr = _fmpz_promote(f1);
mpz_abs(mpz_ptr, COEFF_TO_PTR(*f2));
}
}