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

88 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) 2010, 2011 Sebastian Pancratz
******************************************************************************/
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpz_poly.h"
void
_fmpz_poly_rem(fmpz * R, const fmpz * A, slong lenA, const fmpz * B, slong lenB)
{
if (lenA < 15)
{
_fmpz_poly_rem_basecase(R, A, lenA, B, lenB);
}
else
{
fmpz *Q = _fmpz_vec_init(lenA - lenB + 1);
_fmpz_poly_divrem(Q, R, A, lenA, B, lenB);
_fmpz_vec_clear(Q, lenA - lenB + 1);
}
}
void fmpz_poly_rem(fmpz_poly_t R, const fmpz_poly_t A, const fmpz_poly_t B)
{
const slong lenA = A->length, lenB = B->length;
fmpz *r;
if (lenB == 0)
{
flint_printf("Exception (fmpz_poly_rem). Division by zero.\n");
abort();
}
if (lenA < lenB)
{
fmpz_poly_set(R, A);
return;
}
if (R == A || R == B)
{
r = _fmpz_vec_init(lenA);
}
else
{
fmpz_poly_fit_length(R, lenA);
r = R->coeffs;
}
_fmpz_poly_rem(r, A->coeffs, lenA, B->coeffs, lenB);
if (R == A || R == B)
{
_fmpz_vec_clear(R->coeffs, R->alloc);
R->coeffs = r;
R->alloc = lenB - 1;
}
_fmpz_poly_set_length(R, lenA);
_fmpz_poly_normalise(R);
}