pqc/external/flint-2.4.3/fmpq_poly/scalar_mul_ui.c

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2014-05-18 22:03:37 +00:00
/*=============================================================================
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
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpq_poly.h"
void _fmpq_poly_scalar_mul_ui(fmpz * rpoly, fmpz_t rden,
const fmpz * poly, const fmpz_t den, slong len,
ulong c)
{
fmpz_t gcd; /* GCD( den, c ) */
if (c == 0)
{
_fmpz_vec_zero(rpoly, len);
fmpz_one(rden);
return;
}
fmpz_init(gcd);
fmpz_set_ui(gcd, c);
fmpz_gcd(gcd, gcd, den);
if (*gcd == WORD(1))
{
_fmpz_vec_scalar_mul_ui(rpoly, poly, len, c);
fmpz_set(rden, den);
}
else
{
ulong gcd2 = fmpz_get_ui(gcd);
ulong c2 = c / gcd2;
_fmpz_vec_scalar_mul_ui(rpoly, poly, len, c2);
fmpz_fdiv_q_ui(rden, den, gcd2);
}
fmpz_clear(gcd);
}
void fmpq_poly_scalar_mul_ui(fmpq_poly_t rop, const fmpq_poly_t op, ulong c)
{
if (c == 0 || fmpq_poly_is_zero(op))
{
fmpq_poly_zero(rop);
return;
}
fmpq_poly_fit_length(rop, op->length);
_fmpq_poly_set_length(rop, op->length);
_fmpq_poly_scalar_mul_ui(rop->coeffs, rop->den,
op->coeffs, op->den, op->length, c);
}