ffs.c revision 69bb4bb45c98da60d21839c4dc3c01ea1be60585
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Common implementation of ffs for kernel, mdb, and libc. Note that mdb
* renames ffs into mdb_ffs to avoid user-space clashes with the signature of
* ffs(3C).
*/
#if defined(_KERNEL) || defined(ffs)
#include <sys/int_types.h>
#define arg_t uintmax_t
#else
#pragma weak ffs = _ffs
#define arg_t int
#include "synonyms.h"
#endif
int
ffs(arg_t bits)
{
int i;
if (bits == 0)
return (0);
for (i = 1; ; i++, bits >>= 1) {
if (bits & 1)
break;
}
return (i);
}