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

114 lines
3.5 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) 2012 Sebastian Pancratz
Copyright (C) 2013 Mike Hansen
******************************************************************************/
#ifdef T
#include "templates.h"
int
_TEMPLATE(T, poly_divides) (
TEMPLATE(T, struct) * Q,
const TEMPLATE(T, struct) * A, slong lenA,
const TEMPLATE(T, struct) * B, slong lenB,
const TEMPLATE(T, t) invB,
const TEMPLATE(T, ctx_t) ctx)
{
TEMPLATE(T, struct) * R;
slong lenR = 0;
R = _TEMPLATE(T, vec_init) (lenA, ctx);
_TEMPLATE(T, poly_divrem) (Q, R, A, lenA, B, lenB, invB, ctx);
TEMPLATE(CAP_T, VEC_NORM) (R, lenR, ctx);
_TEMPLATE(T, vec_clear) (R, lenA, ctx);
return (lenR == 0);
}
int
TEMPLATE(T, poly_divides) (TEMPLATE(T, poly_t) Q,
const TEMPLATE(T, poly_t) A,
const TEMPLATE(T, poly_t) B,
const TEMPLATE(T, ctx_t) ctx)
{
if (TEMPLATE(T, poly_is_zero) (B, ctx))
{
TEMPLATE_PRINTF("Exception (%s_poly_divides). B is zero.\n", T);
abort();
}
if (TEMPLATE(T, poly_is_zero) (A, ctx))
{
TEMPLATE(T, poly_zero) (Q, ctx);
return 1;
}
if (TEMPLATE(T, poly_length) (A, ctx) < TEMPLATE(T, poly_length) (B, ctx))
{
return 0;
}
{
const slong lenQ =
TEMPLATE(T, poly_length) (A, ctx) - TEMPLATE(T, poly_length) (B,
ctx)
+ 1;
int ans;
TEMPLATE(T, t) invB;
TEMPLATE(T, init) (invB, ctx);
TEMPLATE(T, inv) (invB, TEMPLATE(T, poly_lead) (B, ctx), ctx);
if (Q == A || Q == B)
{
TEMPLATE(T, poly_t) T;
TEMPLATE(T, poly_init2) (T, lenQ, ctx);
ans = _TEMPLATE(T, poly_divides) (T->coeffs, A->coeffs, A->length,
B->coeffs, B->length, invB, ctx);
_TEMPLATE(T, poly_set_length) (T, lenQ, ctx);
_TEMPLATE(T, poly_normalise) (T, ctx);
TEMPLATE(T, poly_swap) (Q, T, ctx);
TEMPLATE(T, poly_clear) (T, ctx);
}
else
{
TEMPLATE(T, poly_fit_length) (Q, lenQ, ctx);
ans = _TEMPLATE(T, poly_divides) (Q->coeffs, A->coeffs, A->length,
B->coeffs, B->length, invB, ctx);
_TEMPLATE(T, poly_set_length) (Q, lenQ, ctx);
_TEMPLATE(T, poly_normalise) (Q, ctx);
}
TEMPLATE(T, clear) (invB, ctx);
return ans;
}
}
#endif