1*4a5d661aSToomas Soome /*-
2*4a5d661aSToomas Soome * Copyright (c) 1990, 1993
3*4a5d661aSToomas Soome * The Regents of the University of California. All rights reserved.
4*4a5d661aSToomas Soome *
5*4a5d661aSToomas Soome * Redistribution and use in source and binary forms, with or without
6*4a5d661aSToomas Soome * modification, are permitted provided that the following conditions
7*4a5d661aSToomas Soome * are met:
8*4a5d661aSToomas Soome * 1. Redistributions of source code must retain the above copyright
9*4a5d661aSToomas Soome * notice, this list of conditions and the following disclaimer.
10*4a5d661aSToomas Soome * 2. Redistributions in binary form must reproduce the above copyright
11*4a5d661aSToomas Soome * notice, this list of conditions and the following disclaimer in the
12*4a5d661aSToomas Soome * documentation and/or other materials provided with the distribution.
13*4a5d661aSToomas Soome * 3. Neither the name of the University nor the names of its contributors
14*4a5d661aSToomas Soome * may be used to endorse or promote products derived from this software
15*4a5d661aSToomas Soome * without specific prior written permission.
16*4a5d661aSToomas Soome *
17*4a5d661aSToomas Soome * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18*4a5d661aSToomas Soome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19*4a5d661aSToomas Soome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20*4a5d661aSToomas Soome * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21*4a5d661aSToomas Soome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22*4a5d661aSToomas Soome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23*4a5d661aSToomas Soome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24*4a5d661aSToomas Soome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25*4a5d661aSToomas Soome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26*4a5d661aSToomas Soome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27*4a5d661aSToomas Soome * SUCH DAMAGE.
28*4a5d661aSToomas Soome */
29*4a5d661aSToomas Soome
30*4a5d661aSToomas Soome #if defined(LIBC_SCCS) && !defined(lint)
31*4a5d661aSToomas Soome static char sccsid[] = "@(#)ffs.c 8.1 (Berkeley) 6/4/93";
32*4a5d661aSToomas Soome #endif /* LIBC_SCCS and not lint */
33*4a5d661aSToomas Soome #include <sys/cdefs.h>
34*4a5d661aSToomas Soome __FBSDID("$FreeBSD$");
35*4a5d661aSToomas Soome
36*4a5d661aSToomas Soome #include <strings.h>
37*4a5d661aSToomas Soome
38*4a5d661aSToomas Soome /*
39*4a5d661aSToomas Soome * Find First Set bit
40*4a5d661aSToomas Soome */
41*4a5d661aSToomas Soome int
ffs(int mask)42*4a5d661aSToomas Soome ffs(int mask)
43*4a5d661aSToomas Soome {
44*4a5d661aSToomas Soome int bit;
45*4a5d661aSToomas Soome
46*4a5d661aSToomas Soome if (mask == 0)
47*4a5d661aSToomas Soome return(0);
48*4a5d661aSToomas Soome for (bit = 1; !(mask & 1); bit++)
49*4a5d661aSToomas Soome mask = (unsigned int)mask >> 1;
50*4a5d661aSToomas Soome return (bit);
51*4a5d661aSToomas Soome }
52