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

46 lines
1.5 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) 2011 Fredrik Johansson
******************************************************************************/
#include <gmp.h>
#include <stdlib.h>
#include "flint.h"
#include "ulong_extras.h"
#include "nmod_vec.h"
int
_nmod_vec_dot_bound_limbs(slong len, nmod_t mod)
{
mp_limb_t t2, t1, t0, u1, u0;
umul_ppmm(t1, t0, mod.n - 1, mod.n - 1);
umul_ppmm(t2, t1, t1, len);
umul_ppmm(u1, u0, t0, len);
add_sssaaaaaa(t2, t1, t0, t2, t1, UWORD(0), UWORD(0), u1, u0);
if (t2 != 0) return 3;
if (t1 != 0) return 2;
return (t0 != 0);
}