pqc/external/flint-2.4.3/fmpq/inv.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) 2011 Fredrik Johansson
******************************************************************************/
#include "fmpq.h"
void fmpq_inv(fmpq_t dest, const fmpq_t src)
{
fmpz tmp;
if (dest != src)
{
fmpq_set(dest, src);
}
tmp = dest->num;
dest->num = dest->den;
dest->den = tmp;
if (fmpz_sgn(&dest->den) < 0)
{
fmpz_neg(&dest->den, &dest->den);
fmpz_neg(&dest->num, &dest->num);
}
}