Line data    Source code

       1             : /*      $OpenBSD: fls.c,v 1.1 2013/07/11 01:20:32 jsg Exp $     */
       2             : /*-
       3             :  * Copyright (c) 1990, 1993
       4             :  *      The Regents of the University of California.  All rights reserved.
       5             :  *
       6             :  * Redistribution and use in source and binary forms, with or without
       7             :  * modification, are permitted provided that the following conditions
       8             :  * are met:
       9             :  * 1. Redistributions of source code must retain the above copyright
      10             :  *    notice, this list of conditions and the following disclaimer.
      11             :  * 2. Redistributions in binary form must reproduce the above copyright
      12             :  *    notice, this list of conditions and the following disclaimer in the
      13             :  *    documentation and/or other materials provided with the distribution.
      14             :  * 3. Neither the name of the University nor the names of its contributors
      15             :  *    may be used to endorse or promote products derived from this software
      16             :  *    without specific prior written permission.
      17             :  *
      18             :  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      19             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      20             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      21             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      22             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      23             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      24             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      25             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      26             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      27             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      28             :  * SUCH DAMAGE.
      29             :  */
      30             : 
      31             : #include <lib/libkern/libkern.h>
      32             : 
      33             : /*
      34             :  * Find Last Set bit
      35             :  */
      36             : int
      37           0 : fls(int mask)
      38             : {
      39             :         int bit;
      40             : 
      41           0 :         if (mask == 0)
      42           0 :                 return (0);
      43           0 :         for (bit = 1; mask != 1; bit++)
      44           0 :                 mask = (unsigned int)mask >> 1;
      45           0 :         return (bit);
      46           0 : }