pqc/external/flint-2.4.3/padic_poly/set_padic.c

62 lines
1.9 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(padic_poly_t poly,
const padic_t x, const padic_ctx_t ctx)
{
slong N1 = padic_poly_prec(poly);
if (padic_is_zero(x) || padic_val(x) >= N1)
{
padic_poly_zero(poly);
}
else
{
padic_poly_fit_length(poly, 1);
_padic_poly_set_length(poly, 1);
poly->val = padic_val(x);
if (N1 >= padic_prec(x)) /* No reduction */
{
fmpz_set(poly->coeffs, padic_unit(x));
}
else /* Reduction */
{
fmpz_t pow;
int alloc;
alloc = _padic_ctx_pow_ui(pow, N1 - padic_val(x), ctx);
fmpz_mod(poly->coeffs, padic_unit(x), pow);
if (alloc)
fmpz_clear(pow);
}
}
}