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/*-
* Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/libkern.h>
#include <sys/limits.h>
#include <sys/types.h>
#define IDX(c) ((u_char)(c) / LONG_BIT)
#define BIT(c) ((u_long)1 << ((u_char)(c) % LONG_BIT))
size_t
strspn(const char *s, const char *charset)
{
/*
* NB: idx and bit are temporaries whose use causes gcc 3.4.2 to
* generate better code. Without them, gcc gets a little confused.
*/
const char *s1;
u_long bit;
u_long tbl[(UCHAR_MAX + 1) / LONG_BIT];
int idx;
if(*s == '\0')
return (0);
#if LONG_BIT == 64 /* always better to unroll on 64-bit architectures */
tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0;
#else
for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++)
tbl[idx] = 0;
#endif
for (; *charset != '\0'; charset++) {
idx = IDX(*charset);
bit = BIT(*charset);
tbl[idx] |= bit;
}
for(s1 = s; ; s1++) {
idx = IDX(*s1);
bit = BIT(*s1);
if ((tbl[idx] & bit) == 0)
break;
}
return (s1 - s);
}
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