flsll.c revision 199096
10Sstevel@tonic-gate/*- 20Sstevel@tonic-gate * Copyright (c) 1990, 1993 30Sstevel@tonic-gate * The Regents of the University of California. All rights reserved. 40Sstevel@tonic-gate * 50Sstevel@tonic-gate * Redistribution and use in source and binary forms, with or without 60Sstevel@tonic-gate * modification, are permitted provided that the following conditions 70Sstevel@tonic-gate * are met: 80Sstevel@tonic-gate * 1. Redistributions of source code must retain the above copyright 90Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer. 100Sstevel@tonic-gate * 2. Redistributions in binary form must reproduce the above copyright 110Sstevel@tonic-gate * notice, this list of conditions and the following disclaimer in the 120Sstevel@tonic-gate * documentation and/or other materials provided with the distribution. 130Sstevel@tonic-gate * 4. Neither the name of the University nor the names of its contributors 140Sstevel@tonic-gate * may be used to endorse or promote products derived from this software 150Sstevel@tonic-gate * without specific prior written permission. 160Sstevel@tonic-gate * 170Sstevel@tonic-gate * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 180Sstevel@tonic-gate * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 190Sstevel@tonic-gate * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 200Sstevel@tonic-gate * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 210Sstevel@tonic-gate * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 220Sstevel@tonic-gate * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 230Sstevel@tonic-gate * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 240Sstevel@tonic-gate * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 250Sstevel@tonic-gate * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 260Sstevel@tonic-gate * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 270Sstevel@tonic-gate * SUCH DAMAGE. 280Sstevel@tonic-gate */ 290Sstevel@tonic-gate 300Sstevel@tonic-gate#include <sys/cdefs.h> 310Sstevel@tonic-gate__FBSDID("$FreeBSD: head/lib/libc/string/flsll.c 199096 2009-11-09 18:50:34Z jhb $"); 320Sstevel@tonic-gate 330Sstevel@tonic-gate#include <strings.h> 340Sstevel@tonic-gate 350Sstevel@tonic-gate/* 360Sstevel@tonic-gate * Find Last Set bit 370Sstevel@tonic-gate */ 380Sstevel@tonic-gateint 39flsll(long long mask) 40{ 41 int bit; 42 43 if (mask == 0) 44 return (0); 45 for (bit = 1; mask != 1; bit++) 46 mask = (unsigned long long)mask >> 1; 47 return (bit); 48} 49