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

84 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 "fmpq_poly.h"
#include "padic_poly.h"
/*
Assumes that len > 0.
*/
static void _padic_poly_get_fmpq_poly(fmpz *rop, fmpz_t den,
const fmpz *op, slong val, slong len,
const fmpz_t p)
{
if (val == 0)
{
_fmpz_vec_set(rop, op, len);
fmpz_one(den);
}
else if (val == 1)
{
_fmpz_vec_scalar_mul_fmpz(rop, op, len, p);
fmpz_one(den);
}
else if (val > 1)
{
fmpz_t t;
fmpz_init(t);
fmpz_pow_ui(t, p, val);
_fmpz_vec_scalar_mul_fmpz(rop, op, len, t);
fmpz_one(den);
fmpz_clear(t);
}
else
{
_fmpz_vec_set(rop, op, len);
fmpz_pow_ui(den, p, -val);
}
}
void padic_poly_get_fmpq_poly(fmpq_poly_t rop,
const padic_poly_t op, const padic_ctx_t ctx)
{
const slong len = op->length;
if (len == 0)
{
fmpq_poly_zero(rop);
}
else
{
fmpq_poly_fit_length(rop, len);
_padic_poly_get_fmpq_poly(rop->coeffs, rop->den,
op->coeffs, op->val, op->length, ctx->p);
_fmpq_poly_set_length(rop, len);
}
}