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

61 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) 2012 Fredrik Johansson
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_poly.h"
#include "nmod_poly.h"
void
_fmpz_poly_taylor_shift_divconquer(fmpz * poly, const fmpz_t c, slong len)
{
fmpz d[2];
if (len <= 1 || fmpz_is_zero(c))
return;
if (len == 2)
{
fmpz_addmul(poly, poly + 1, c);
return;
}
d[0] = *c;
d[1] = 1;
_fmpz_poly_compose_divconquer(poly, poly, len, d, 2);
}
void
fmpz_poly_taylor_shift_divconquer(fmpz_poly_t g, const fmpz_poly_t f,
const fmpz_t c)
{
if (f != g)
fmpz_poly_set(g, f);
_fmpz_poly_taylor_shift_divconquer(g->coeffs, c, g->length);
}