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

81 lines
2.2 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 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_div(fmpz * Q, const fmpz * A, slong lenA, const fmpz * B, slong lenB)
{
_fmpz_poly_div_divconquer(Q, A, lenA, B, lenB);
}
void
fmpz_poly_div(fmpz_poly_t Q, const fmpz_poly_t A, const fmpz_poly_t B)
{
fmpz_poly_t tQ;
fmpz *q;
if (B->length == 0)
{
flint_printf("Exception (fmpz_poly_div). Division by zero.\n");
abort();
}
if (A->length < B->length)
{
fmpz_poly_zero(Q);
return;
}
if (Q == A || Q == B)
{
fmpz_poly_init2(tQ, A->length - B->length + 1);
q = tQ->coeffs;
}
else
{
fmpz_poly_fit_length(Q, A->length - B->length + 1);
q = Q->coeffs;
}
_fmpz_poly_div(q, A->coeffs, A->length, B->coeffs, B->length);
if (Q == A || Q == B)
{
_fmpz_poly_set_length(tQ, A->length - B->length + 1);
fmpz_poly_swap(tQ, Q);
fmpz_poly_clear(tQ);
}
else
_fmpz_poly_set_length(Q, A->length - B->length + 1);
_fmpz_poly_normalise(Q);
}