pqc/external/flint-2.4.3/fmpz_poly/pseudo_div.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 <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
#include "fmpz_vec.h"
#include "fmpz_poly.h"
void _fmpz_poly_pseudo_div(fmpz * Q, ulong * d, const fmpz * A, slong lenA,
const fmpz * B, slong lenB, const fmpz_preinvn_t inv)
{
fmpz * R = _fmpz_vec_init(lenA);
_fmpz_poly_pseudo_divrem(Q, R, d, A, lenA, B, lenB, inv);
_fmpz_vec_clear(R, lenA);
}
void fmpz_poly_pseudo_div(fmpz_poly_t Q, ulong * d, const fmpz_poly_t A,
const fmpz_poly_t B)
{
slong lenq;
fmpz * q;
if (B->length == 0)
{
flint_printf("Exception (fmpz_poly_pseudo_div). Division by zero.\n");
abort();
}
if (A->length < B->length)
{
fmpz_poly_zero(Q);
*d = 0;
return;
}
lenq = A->length - B->length + 1;
if (Q == A || Q == B)
q = _fmpz_vec_init(lenq);
else
{
fmpz_poly_fit_length(Q, lenq);
q = Q->coeffs;
}
_fmpz_poly_pseudo_div(q, d, A->coeffs, A->length,
B->coeffs, B->length, NULL);
if (Q == A || Q == B)
{
_fmpz_vec_clear(Q->coeffs, Q->alloc);
Q->coeffs = q;
Q->alloc = lenq;
Q->length = lenq;
}
else
_fmpz_poly_set_length(Q, lenq);
}