pqc/external/flint-2.4.3/fmpz/lcm.c

60 lines
1.6 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 Fredrik Johansson
******************************************************************************/
#include <gmp.h>
#include "flint.h"
#include "fmpz.h"
void
fmpz_lcm(fmpz_t f, const fmpz_t g, const fmpz_t h)
{
fmpz_t t;
if (fmpz_is_zero(g) || fmpz_is_zero(h))
{
fmpz_zero(f);
return;
}
if (fmpz_is_pm1(g))
{
fmpz_abs(f, h);
return;
}
if (fmpz_is_pm1(h))
{
fmpz_abs(f, g);
return;
}
fmpz_init(t);
fmpz_gcd(t, g, h);
fmpz_divexact(t, g, t);
fmpz_mul(f, t, h);
fmpz_abs(f, f);
fmpz_clear(t);
}