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7f0f7929ba
- Replaced ISO Latin 1 code #160 with a plain blank space (ASCII code #32) where necessary git-svn-id: file:///Users/olsen/Code/migration-svn-zu-git/logical-line-staging/clib2/trunk@15305 87f5fb63-7c3d-0410-a384-fd976d0f7a62
72 lines
2.4 KiB
C
72 lines
2.4 KiB
C
/*
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* $Id: strings_ffs.c,v 1.2 2006-01-08 12:04:27 obarthel Exp $
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*
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* :ts=4
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*
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* Portable ISO 'C' (1994) runtime library for the Amiga computer
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* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
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* 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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*
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* - 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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*
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* - Neither the name of Olaf Barthel nor the names of contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND 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 COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef _STDLIB_NULL_POINTER_CHECK_H
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#include "stdlib_null_pointer_check.h"
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#endif /* _STDLIB_NULL_POINTER_CHECK_H */
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/****************************************************************************/
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#ifndef _STRINGS_HEADERS_H
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#include "strings_headers.h"
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#endif /* _STRINGS_HEADERS_H */
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/****************************************************************************/
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/* The following is not part of the ISO 'C' (1994) standard. */
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/****************************************************************************/
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/* Return the index of the lowest set bit. (Counted from one) */
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int
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ffs(int i)
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{
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int result = 0;
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if(i != 0)
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{
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int x;
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x = (i & (-i)) - 1;
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x -= ((x >> 1) & 0x55555555);
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x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
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x = ((x >> 4) + x) & 0x0f0f0f0f;
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x += (x >> 8);
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x += (x >> 16);
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result = 1 + (x & 0x3f); /* The first bit has index 1. */
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}
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return(result);
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}
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