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

63 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) 2010 William Hart
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"
#include "nmod_poly.h"
mp_limb_t
_nmod_poly_evaluate_nmod(mp_srcptr poly, slong len, mp_limb_t c, nmod_t mod)
{
slong m;
mp_limb_t val;
if (len == 0)
return 0;
if (len == 1 || c == 0)
return poly[0];
m = len - 1;
val = poly[m];
m--;
for ( ; m >= 0; m--)
{
val = n_mulmod2_preinv(val, c, mod.n, mod.ninv);
val = n_addmod(val, poly[m], mod.n);
}
return val;
}
mp_limb_t
nmod_poly_evaluate_nmod(const nmod_poly_t poly, mp_limb_t c)
{
return _nmod_poly_evaluate_nmod(poly->coeffs, poly->length, c, poly->mod);
}