pqc/external/flint-2.4.3/fmpz_poly_q/canonicalise.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, 2011 Sebastian Pancratz
******************************************************************************/
#include "fmpz_poly_q.h"
void fmpz_poly_q_canonicalise(fmpz_poly_q_t rop)
{
fmpz_poly_t gcd;
if (fmpz_poly_is_zero(rop->den))
{
flint_printf("Exception (fmpz_poly_q_canonicalise). Denominator is zero.\n");
abort();
}
if (fmpz_poly_is_one(rop->den))
return;
fmpz_poly_init(gcd);
fmpz_poly_gcd(gcd, rop->num, rop->den);
if (!fmpz_poly_is_unit(gcd))
{
fmpz_poly_div(rop->num, rop->num, gcd);
fmpz_poly_div(rop->den, rop->den, gcd);
}
fmpz_poly_clear(gcd);
if (fmpz_sgn(fmpz_poly_lead(rop->den)) < 0)
{
fmpz_poly_neg(rop->num, rop->num);
fmpz_poly_neg(rop->den, rop->den);
}
}