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

63 lines
1.8 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) 2009 William Hart
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"
#include "fmpz.h"
ulong
fmpz_fdiv_ui(const fmpz_t g, ulong h)
{
fmpz c1 = *g;
ulong r;
if (h == UWORD(0))
{
flint_printf("Exception (fmpz_fdiv_ui). Division by 0.\n");
abort();
}
if (!COEFF_IS_MPZ(c1)) /* g is small */
{
if (c1 < WORD(0))
{
r = h - (-c1 % h); /* C doesn't correctly handle negative mods */
if (r == h)
r = 0;
}
else
r = c1 % h;
return r;
}
else /* g is large */
{
return flint_mpz_fdiv_ui(COEFF_TO_PTR(c1), h);
}
}