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

114 lines
3.2 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 "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpz_poly.h"
#include "nmod_poly.h"
void
_fmpz_poly_CRT_ui_precomp(fmpz * res, const fmpz * poly1, slong len1,
const fmpz_t m1, mp_srcptr poly2, slong len2, mp_limb_t m2,
mp_limb_t m2inv, fmpz_t m1m2, mp_limb_t c, int sign)
{
slong i;
for (i = 0; i < FLINT_MIN(len1, len2); i++)
{
_fmpz_CRT_ui_precomp(res + i, poly1 + i, m1,
poly2[i], m2, m2inv, m1m2, c, sign);
}
if (len2 > len1)
{
fmpz_t zero;
fmpz_init(zero);
for (i = len1; i < len2; i++)
{
_fmpz_CRT_ui_precomp(res + i, zero, m1,
poly2[i], m2, m2inv, m1m2, c, sign);
}
fmpz_clear(zero);
}
for (i = len2; i < len1; i++)
{
_fmpz_CRT_ui_precomp(res + i, res + i, m1,
0, m2, m2inv, m1m2, c, sign);
}
}
void
_fmpz_poly_CRT_ui(fmpz * res, const fmpz * poly1, slong len1,
const fmpz_t m1, mp_srcptr poly2, slong len2, mp_limb_t m2,
mp_limb_t m2inv, int sign)
{
mp_limb_t c;
fmpz_t m1m2;
c = fmpz_fdiv_ui(m1, m2);
c = n_invmod(c, m2);
if (c == 0)
{
flint_printf("Exception (_fmpz_poly_CRT_ui): m1 not invertible modulo m2.\n");
abort();
}
fmpz_init(m1m2);
fmpz_mul_ui(m1m2, m1, m2);
_fmpz_poly_CRT_ui_precomp(res, poly1, len1, m1,
poly2, len2, m2, m2inv, m1m2, c, sign);
fmpz_clear(m1m2);
}
void
fmpz_poly_CRT_ui(fmpz_poly_t res, const fmpz_poly_t poly1,
const fmpz_t m1, const nmod_poly_t poly2, int sign)
{
slong len1 = poly1->length;
slong len2 = poly2->length;
slong len = FLINT_MAX(len1, len2);
if (len == 0)
{
fmpz_poly_zero(res);
return;
}
fmpz_poly_fit_length(res, len);
_fmpz_poly_CRT_ui(res->coeffs, poly1->coeffs, poly1->length, m1,
poly2->coeffs, poly2->length, poly2->mod.n, poly2->mod.ninv, sign);
_fmpz_poly_set_length(res, len);
_fmpz_poly_normalise(res);
}