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

70 lines
2.3 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, 2012 Sebastian Pancratz
******************************************************************************/
#include "padic_poly.h"
void padic_poly_set(padic_poly_t poly1,
const padic_poly_t poly2, const padic_ctx_t ctx)
{
if (poly1 != poly2) /* Aliasing is trivial */
{
slong len2 = poly2->length, N1 = padic_poly_prec(poly1);
if (len2 == 0 || poly2->val >= N1)
{
padic_poly_zero(poly1);
}
else
{
padic_poly_fit_length(poly1, len2);
_padic_poly_set_length(poly1, len2);
poly1->val = poly2->val;
if (N1 >= padic_poly_prec(poly2)) /* No reduction */
{
_fmpz_vec_set(poly1->coeffs, poly2->coeffs, len2);
}
else /* Reduction necessary */
{
fmpz_t pow;
int alloc;
alloc = _padic_ctx_pow_ui(pow, N1 - poly1->val, ctx);
_fmpz_vec_scalar_mod_fmpz(poly1->coeffs, poly2->coeffs, len2, pow);
if (alloc)
fmpz_clear(pow);
_padic_poly_normalise(poly1);
/* Length cannot be zero, so no need to check */
/* if (poly->length == 0) */
/* poly->val = 0; */
}
}
}
}