65 lines
2.2 KiB
C
65 lines
2.2 KiB
C
/* $NetBSD: ffs.c,v 1.10 2003/08/07 16:32:07 agc Exp $ */
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/*-
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* Copyright (c) 1990, 1993
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* The Regents of the University of California. All rights reserved.
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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 <sys/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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static char sccsid[] = "@(#)ffs.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: ffs.c,v 1.10 2003/08/07 16:32:07 agc Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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#if !defined(_KERNEL) && !defined(_STANDALONE)
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#include <string.h>
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#else
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#include <lib/libkern/libkern.h>
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#endif
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/* #undef ffs() - might be defined as macro to __builtin_ffs() */
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#undef ffs
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/*
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* ffs - find first bit set in a bit string (C version)
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*/
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int
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ffs(mask)
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int mask;
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{
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int bit;
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if (mask == 0)
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return(0);
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for (bit = 1; !(mask & 1); bit++)
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mask >>= 1;
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return(bit);
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}
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