1*84d9c625SLionel Sambuc/* $NetBSD: ffs.S,v 1.6 2013/09/07 19:06:29 chs Exp $ */ 2b6cbf720SGianluca Guida 3b6cbf720SGianluca Guida/*- 4b6cbf720SGianluca Guida * Copyright (c) 1990 The Regents of the University of California. 5b6cbf720SGianluca Guida * All rights reserved. 6b6cbf720SGianluca Guida * 7b6cbf720SGianluca Guida * This code is derived from software contributed to Berkeley by 8b6cbf720SGianluca Guida * the Systems Programming Group of the University of Utah Computer 9b6cbf720SGianluca Guida * Science Department. 10b6cbf720SGianluca Guida * 11b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without 12b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions 13b6cbf720SGianluca Guida * are met: 14b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright 15b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer. 16b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright 17b6cbf720SGianluca Guida * notice, this list of conditions and the following disclaimer in the 18b6cbf720SGianluca Guida * documentation and/or other materials provided with the distribution. 19b6cbf720SGianluca Guida * 3. Neither the name of the University nor the names of its contributors 20b6cbf720SGianluca Guida * may be used to endorse or promote products derived from this software 21b6cbf720SGianluca Guida * without specific prior written permission. 22b6cbf720SGianluca Guida * 23b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24b6cbf720SGianluca Guida * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25b6cbf720SGianluca Guida * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26b6cbf720SGianluca Guida * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27b6cbf720SGianluca Guida * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28b6cbf720SGianluca Guida * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29b6cbf720SGianluca Guida * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30b6cbf720SGianluca Guida * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31b6cbf720SGianluca Guida * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32b6cbf720SGianluca Guida * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33b6cbf720SGianluca Guida * SUCH DAMAGE. 34b6cbf720SGianluca Guida */ 35b6cbf720SGianluca Guida 36b6cbf720SGianluca Guida#include <machine/asm.h> 37b6cbf720SGianluca Guida 38b6cbf720SGianluca Guida#if defined(LIBC_SCCS) && !defined(lint) 39b6cbf720SGianluca Guida#if 0 40b6cbf720SGianluca Guida RCSID("from: @(#)ffs.s 5.1 (Berkeley) 5/12/90") 41b6cbf720SGianluca Guida#else 42*84d9c625SLionel Sambuc RCSID("$NetBSD: ffs.S,v 1.6 2013/09/07 19:06:29 chs Exp $") 43b6cbf720SGianluca Guida#endif 44b6cbf720SGianluca Guida#endif /* LIBC_SCCS and not lint */ 45b6cbf720SGianluca Guida 46b6cbf720SGianluca Guida/* bit = ffs(value) */ 47b6cbf720SGianluca Guida 48f14fb602SLionel SambucWEAK_ALIAS(__ffssi2,ffs) 49f14fb602SLionel Sambuc 50*84d9c625SLionel Sambuc#if (!defined(__mc68010__) && !defined(__mcoldfire__)) || defined(__mcfisac__) 51b6cbf720SGianluca Guida 52b6cbf720SGianluca GuidaENTRY(ffs) 53*84d9c625SLionel Sambuc movl 4(%sp),%d0 54b6cbf720SGianluca Guida movl %d0,%d1 55b6cbf720SGianluca Guida negl %d0 56b6cbf720SGianluca Guida andl %d0,%d1 57b6cbf720SGianluca Guida movql #32,%d0 58*84d9c625SLionel Sambuc#if defined(__mcfisac__) 59*84d9c625SLionel Sambuc ff1.l %d1 | count leading zeros 60*84d9c625SLionel Sambuc#else 61b6cbf720SGianluca Guida bfffo %d1{#0:#32},%d1 62*84d9c625SLionel Sambuc#endif 63b6cbf720SGianluca Guida subl %d1,%d0 64b6cbf720SGianluca Guida rts 65*84d9c625SLionel SambucEND(ffs) 66*84d9c625SLionel Sambuc 67*84d9c625SLionel Sambuc#elif defined(__mcoldfire__) 68*84d9c625SLionel Sambuc 69*84d9c625SLionel SambucENTRY(ffs) 70*84d9c625SLionel Sambuc clrl %d0 71*84d9c625SLionel Sambuc movl 4(%sp),%d1 72*84d9c625SLionel Sambuc jeq .L2 | return 0 if 0 73*84d9c625SLionel Sambuc.L1: 74*84d9c625SLionel Sambuc addql #1,%d0 75*84d9c625SLionel Sambuc lsrl #1,%d1 | shift low bit into carry 76*84d9c625SLionel Sambuc jcc .L1 | keep looping while carry is clear. 77*84d9c625SLionel Sambuc.L2: 78*84d9c625SLionel Sambuc rts 79b6cbf720SGianluca Guida 80b6cbf720SGianluca Guida#else /* __mc68010__ */ 81b6cbf720SGianluca Guida 82b6cbf720SGianluca GuidaENTRY(ffs) 83*84d9c625SLionel Sambuc movl 4(%sp),%d0 84*84d9c625SLionel Sambuc jeq .L2 85b6cbf720SGianluca Guida movql #31,%d1 86*84d9c625SLionel Sambuc.L1: 87b6cbf720SGianluca Guida lsrl #1,%d0 88*84d9c625SLionel Sambuc dbcs %d1,.L1 89b6cbf720SGianluca Guida movql #32,%d0 90b6cbf720SGianluca Guida subl %d1,%d0 91*84d9c625SLionel Sambuc.L2: 92b6cbf720SGianluca Guida rts 93*84d9c625SLionel SambucEND(ffs) 94b6cbf720SGianluca Guida 95b6cbf720SGianluca Guida#endif /* __mc68010__ */ 96