128 lines
3.7 KiB
C
128 lines
3.7 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 Sebastian Pancratz
|
|
Copyright (C) 2011 Fredrik Johansson
|
|
|
|
******************************************************************************/
|
|
|
|
#include <gmp.h>
|
|
#include "flint.h"
|
|
#include "nmod_vec.h"
|
|
#include "nmod_poly.h"
|
|
#include "ulong_extras.h"
|
|
|
|
void
|
|
_nmod_poly_compose_series_horner(mp_ptr res, mp_srcptr poly1, slong len1,
|
|
mp_srcptr poly2, slong len2, slong n, nmod_t mod)
|
|
{
|
|
if (n == 1)
|
|
{
|
|
res[0] = poly1[0];
|
|
}
|
|
else
|
|
{
|
|
slong i = len1 - 1;
|
|
slong lenr;
|
|
|
|
mp_ptr t = _nmod_vec_init(n);
|
|
|
|
lenr = len2;
|
|
_nmod_vec_scalar_mul_nmod(res, poly2, len2, poly1[i], mod);
|
|
i--;
|
|
res[0] = nmod_add(res[0], poly1[i], mod);
|
|
|
|
while (i > 0)
|
|
{
|
|
i--;
|
|
if (lenr + len2 - 1 < n)
|
|
{
|
|
_nmod_poly_mul(t, res, lenr, poly2, len2, mod);
|
|
lenr = lenr + len2 - 1;
|
|
}
|
|
else
|
|
{
|
|
_nmod_poly_mullow(t, res, lenr, poly2, len2, n, mod);
|
|
lenr = n;
|
|
}
|
|
_nmod_poly_add(res, t, lenr, poly1 + i, 1, mod);
|
|
}
|
|
|
|
_nmod_vec_zero(res + lenr, n - lenr);
|
|
_nmod_vec_clear(t);
|
|
}
|
|
}
|
|
|
|
void
|
|
nmod_poly_compose_series_horner(nmod_poly_t res,
|
|
const nmod_poly_t poly1, const nmod_poly_t poly2, slong n)
|
|
{
|
|
slong len1 = poly1->length;
|
|
slong len2 = poly2->length;
|
|
slong lenr;
|
|
|
|
if (len2 != 0 && poly2->coeffs[0] != 0)
|
|
{
|
|
flint_printf("Exception (nmod_poly_compose_series_horner). Inner polynomial "
|
|
"must have zero constant term.\n");
|
|
abort();
|
|
}
|
|
|
|
if (len1 == 0 || n == 0)
|
|
{
|
|
nmod_poly_zero(res);
|
|
return;
|
|
}
|
|
|
|
if (len2 == 0 || len1 == 1)
|
|
{
|
|
nmod_poly_fit_length(res, 1);
|
|
res->coeffs[0] = poly1->coeffs[0];
|
|
res->length = 1;
|
|
_nmod_poly_normalise(res);
|
|
return;
|
|
}
|
|
|
|
lenr = FLINT_MIN((len1 - 1) * (len2 - 1) + 1, n);
|
|
len1 = FLINT_MIN(len1, lenr);
|
|
len2 = FLINT_MIN(len2, lenr);
|
|
|
|
if ((res != poly1) && (res != poly2))
|
|
{
|
|
nmod_poly_fit_length(res, lenr);
|
|
_nmod_poly_compose_series_horner(res->coeffs, poly1->coeffs, len1,
|
|
poly2->coeffs, len2, lenr, res->mod);
|
|
res->length = lenr;
|
|
_nmod_poly_normalise(res);
|
|
}
|
|
else
|
|
{
|
|
nmod_poly_t t;
|
|
nmod_poly_init2_preinv(t, res->mod.n, res->mod.ninv, lenr);
|
|
_nmod_poly_compose_series_horner(t->coeffs, poly1->coeffs, len1,
|
|
poly2->coeffs, len2, lenr, res->mod);
|
|
t->length = lenr;
|
|
_nmod_poly_normalise(t);
|
|
nmod_poly_swap(res, t);
|
|
nmod_poly_clear(t);
|
|
}
|
|
}
|