2013-12-06 12:04:52 +01:00
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/* $NetBSD: ffs.S,v 1.6 2013/09/07 19:06:29 chs Exp $ */
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2011-02-14 20:36:03 +01:00
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/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* the Systems Programming Group of the University of Utah Computer
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* Science Department.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <machine/asm.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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RCSID("from: @(#)ffs.s 5.1 (Berkeley) 5/12/90")
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#else
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2013-12-06 12:04:52 +01:00
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RCSID("$NetBSD: ffs.S,v 1.6 2013/09/07 19:06:29 chs Exp $")
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2011-02-14 20:36:03 +01:00
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#endif
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#endif /* LIBC_SCCS and not lint */
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/* bit = ffs(value) */
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2012-11-15 12:06:41 +01:00
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WEAK_ALIAS(__ffssi2,ffs)
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2013-12-06 12:04:52 +01:00
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#if (!defined(__mc68010__) && !defined(__mcoldfire__)) || defined(__mcfisac__)
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2011-02-14 20:36:03 +01:00
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ENTRY(ffs)
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2013-12-06 12:04:52 +01:00
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movl 4(%sp),%d0
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2011-02-14 20:36:03 +01:00
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movl %d0,%d1
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negl %d0
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andl %d0,%d1
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movql #32,%d0
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2013-12-06 12:04:52 +01:00
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#if defined(__mcfisac__)
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ff1.l %d1 | count leading zeros
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#else
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2011-02-14 20:36:03 +01:00
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bfffo %d1{#0:#32},%d1
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2013-12-06 12:04:52 +01:00
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#endif
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2011-02-14 20:36:03 +01:00
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subl %d1,%d0
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rts
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2013-12-06 12:04:52 +01:00
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END(ffs)
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#elif defined(__mcoldfire__)
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ENTRY(ffs)
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clrl %d0
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movl 4(%sp),%d1
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jeq .L2 | return 0 if 0
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.L1:
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addql #1,%d0
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lsrl #1,%d1 | shift low bit into carry
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jcc .L1 | keep looping while carry is clear.
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.L2:
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rts
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2011-02-14 20:36:03 +01:00
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#else /* __mc68010__ */
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ENTRY(ffs)
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2013-12-06 12:04:52 +01:00
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movl 4(%sp),%d0
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jeq .L2
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2011-02-14 20:36:03 +01:00
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movql #31,%d1
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2013-12-06 12:04:52 +01:00
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.L1:
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2011-02-14 20:36:03 +01:00
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lsrl #1,%d0
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2013-12-06 12:04:52 +01:00
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dbcs %d1,.L1
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2011-02-14 20:36:03 +01:00
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movql #32,%d0
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subl %d1,%d0
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2013-12-06 12:04:52 +01:00
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.L2:
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2011-02-14 20:36:03 +01:00
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rts
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2013-12-06 12:04:52 +01:00
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END(ffs)
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2011-02-14 20:36:03 +01:00
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#endif /* __mc68010__ */
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