37 lines
1.3 KiB
C
37 lines
1.3 KiB
C
/* *****************************************************************************
|
|
* bcd/is_zero.c -- check if a BCD is zero or not.
|
|
* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
|
|
*
|
|
* This file is part of libg1m.
|
|
* libg1m is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU Lesser General Public License as published by
|
|
* the Free Software Foundation; either version 3.0 of the License,
|
|
* or (at your option) any later version.
|
|
*
|
|
* libg1m 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 Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public License
|
|
* along with libg1m; if not, see <http://www.gnu.org/licenses/>.
|
|
* ************************************************************************** */
|
|
#include <libg1m/internals.h>
|
|
#include <libg1m/internals/bcd.h>
|
|
|
|
/**
|
|
* g1m_bcd_is_nonzero:
|
|
* Check if a BCD is zero.
|
|
*
|
|
* @arg bcd pointer to the bcd.
|
|
* @return true or false.
|
|
*/
|
|
|
|
int g1m_bcd_is_nonzero(struct bcd *bcd)
|
|
{
|
|
static struct bcd ref = {.BCDval = {}};
|
|
unsigned char *bytes = bcd->BCDval;
|
|
|
|
return (lwr(1) | memcmp(&bytes[2], &ref.BCDval[2], 7));
|
|
}
|