1209231Sjchandra/* $NetBSD: ffs.S,v 1.2 2009/12/14 00:39:00 matt Exp $ */ 2178580Simp 3178580Simp/*- 4178580Simp * Copyright (c) 1991, 1993 5178580Simp * The Regents of the University of California. All rights reserved. 6178580Simp * 7178580Simp * This code is derived from software contributed to Berkeley by 8178580Simp * Ralph Campbell. 9178580Simp * 10178580Simp * Redistribution and use in source and binary forms, with or without 11178580Simp * modification, are permitted provided that the following conditions 12178580Simp * are met: 13178580Simp * 1. Redistributions of source code must retain the above copyright 14178580Simp * notice, this list of conditions and the following disclaimer. 15178580Simp * 2. Redistributions in binary form must reproduce the above copyright 16178580Simp * notice, this list of conditions and the following disclaimer in the 17178580Simp * documentation and/or other materials provided with the distribution. 18178580Simp * 3. Neither the name of the University nor the names of its contributors 19178580Simp * may be used to endorse or promote products derived from this software 20178580Simp * without specific prior written permission. 21178580Simp * 22178580Simp * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23178580Simp * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24178580Simp * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25178580Simp * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26178580Simp * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27178580Simp * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28178580Simp * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29178580Simp * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30178580Simp * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31178580Simp * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32178580Simp * SUCH DAMAGE. 33178580Simp */ 34178580Simp 35178580Simp#include <machine/asm.h> 36178580Simp__FBSDID("$FreeBSD$"); 37178580Simp 38178580Simp#if defined(LIBC_SCCS) && !defined(lint) 39178580Simp ASMSTR("from: @(#)ffs.s 8.1 (Berkeley) 6/4/93") 40209231Sjchandra ASMSTR("$NetBSD: ffs.S,v 1.2 2009/12/14 00:39:00 matt Exp $") 41178580Simp#endif /* LIBC_SCCS and not lint */ 42178580Simp 43178580Simp#ifdef __ABICALLS__ 44178580Simp .abicalls 45178580Simp#endif 46178580Simp 47178580Simp/* bit = ffs(value) */ 48178580Simp 49178580SimpLEAF(ffs) 50178580Simp move v0, zero 51178580Simp beq a0, zero, done 52178580Simp1: 53178580Simp and v1, a0, 1 # bit set? 54178580Simp addu v0, v0, 1 55178580Simp srl a0, a0, 1 56178580Simp beq v1, zero, 1b # no, continue 57178580Simpdone: 58178580Simp j ra 59178580SimpEND(ffs) 60