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

85 lines
2.8 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) 2008-2011 William Hart
******************************************************************************/
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpz_poly.h"
#include "fft.h"
void _fmpz_vec_set_fft(fmpz * coeffs_m, slong length,
const mp_ptr * coeffs_f, slong limbs, slong sign)
{
slong i, size;
mp_limb_t * data;
__mpz_struct * mpz_ptr;
if (sign)
{
for (i = 0; i < length; i++)
{
mpz_ptr = _fmpz_promote(coeffs_m);
if (mpz_ptr->_mp_alloc < limbs) _mpz_realloc(mpz_ptr, limbs);
data = mpz_ptr->_mp_d;
if ((coeffs_f[i][limbs - 1] >> (FLINT_BITS - 1)) || coeffs_f[i][limbs])
{
mpn_neg_n(data, coeffs_f[i], limbs);
mpn_add_1(data, data, limbs, WORD(1));
size = limbs;
while ((size) && (data[size - 1] == 0)) size--; /* normalise */
mpz_ptr->_mp_size = -size;
if (size >= WORD(-1)) _fmpz_demote_val(coeffs_m); /* coefficient may be small*/
} else
{
flint_mpn_copyi(data, coeffs_f[i], limbs);
size = limbs;
while ((size) && (data[size - 1] == WORD(0))) size--; /* normalise */
mpz_ptr->_mp_size = size;
if (size <= 1) _fmpz_demote_val(coeffs_m); /* coefficient may be small */
}
coeffs_m++;
}
} else
{
for (i = 0; i < length; i++)
{
mpz_ptr = _fmpz_promote(coeffs_m);
if (mpz_ptr->_mp_alloc < limbs) _mpz_realloc(mpz_ptr, limbs);
data = mpz_ptr->_mp_d;
flint_mpn_copyi(data, coeffs_f[i], limbs);
size = limbs;
while ((size) && (data[size - 1] == WORD(0))) size--; /* normalise */
mpz_ptr->_mp_size = size;
if (size <= 1) _fmpz_demote_val(coeffs_m); /* coefficient may be small */
coeffs_m++;
}
}
}