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

106 lines
3.1 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 William Hart
Copyright (C) 2011 Sebastian Pancratz
Copyright (C) 2013 Martin Lee
Copyright (C) 2013 Mike Hansen
******************************************************************************/
#ifdef T
#include "templates.h"
void
_TEMPLATE(T, poly_div_newton_n_preinv) (
TEMPLATE(T, struct) *Q,
const TEMPLATE(T, struct) *A, slong lenA,
const TEMPLATE(T, struct) *B, slong lenB,
const TEMPLATE(T, struct) * Binv, slong lenBinv,
const TEMPLATE(T, ctx_t) ctx)
{
const slong lenQ = lenA - lenB + 1;
TEMPLATE(T, struct) * Arev;
Arev = _TEMPLATE(T, vec_init) (lenQ, ctx);
_TEMPLATE(T, poly_reverse) (Arev, A + (lenA - lenQ), lenQ, lenQ, ctx);
_TEMPLATE(T, poly_mullow) (Q, Arev, lenQ, Binv, FLINT_MIN(lenQ, lenBinv),
lenQ, ctx);
_TEMPLATE(T, poly_reverse) (Q, Q, lenQ, lenQ, ctx);
_TEMPLATE(T, vec_clear) (Arev, lenQ, ctx);
}
void
TEMPLATE(T, poly_div_newton_n_preinv) (TEMPLATE(T, poly_t) Q,
const TEMPLATE(T, poly_t) A,
const TEMPLATE(T, poly_t) B,
const TEMPLATE(T, poly_t) Binv,
const TEMPLATE(T, ctx_t) ctx)
{
const slong lenA = A->length,
lenB = B->length, lenQ = lenA - lenB + 1, lenBinv = Binv->length;
TEMPLATE(T, struct) * q;
if (lenB == 0)
{
TEMPLATE_PRINTF("Exception (%s_poly_div_newton). Division by zero.\n",
T);
abort();
}
if (lenA < lenB)
{
TEMPLATE(T, poly_zero) (Q, ctx);
return;
}
if (Q == A || Q == B || Q == Binv)
{
q = _TEMPLATE(T, vec_init) (lenQ, ctx);
}
else
{
TEMPLATE(T, poly_fit_length) (Q, lenQ, ctx);
q = Q->coeffs;
}
_TEMPLATE(T, poly_div_newton_n_preinv) (q, A->coeffs, lenA, B->coeffs,
lenB, Binv->coeffs, lenBinv, ctx);
if (Q == A || Q == B || Q == Binv)
{
flint_free(Q->coeffs);
Q->coeffs = q;
Q->alloc = lenQ;
}
Q->length = lenQ;
}
#endif