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/* $NetBSD: strspn.c,v 1.1 2014/07/19 18:38:33 lneto Exp $ */
/*-
* Copyright (c) 2008 Joerg Sonnenberger
* 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(S) ``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(S) 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>
__RCSID("$NetBSD: strspn.c,v 1.1 2014/07/19 18:38:33 lneto Exp $");
#if !defined(_KERNEL) && !defined(_STANDALONE)
#include <assert.h>
#include <inttypes.h>
#include <limits.h>
#include <string.h>
#else
#include <lib/libkern/libkern.h>
#endif
#if ULONG_MAX != 0xffffffffffffffffull
size_t
strspn(const char *s, const char *charset)
{
static const uint8_t idx[8] = { 1, 2, 4, 8, 16, 32, 64, 128 };
uint8_t set[32];
const char *t;
#define UC(a) ((unsigned int)(unsigned char)(a))
_DIAGASSERT(s != NULL);
_DIAGASSERT(charset != NULL);
if (charset[0] == '\0')
return 0;
if (charset[1] == '\0') {
for (t = s; *t != '\0'; ++t) {
if (*t != *charset)
break;
}
return t - s;
}
(void)memset(set, 0, sizeof(set));
for (; *charset != '\0'; ++charset)
set[UC(*charset) >> 3] |= idx[UC(*charset) & 7];
for (t = s; *t != '\0'; ++t)
if ((set[UC(*t) >> 3] & idx[UC(*t) & 7]) == 0)
break;
return t - s;
}
#else
/* 64 bit system, use four 64 bits registers for bitmask */
static size_t
strspn_x(const char *s_s, const char *charset_s, unsigned long invert)
{
const unsigned char *s = (const unsigned char *)s_s;
const unsigned char *charset = (const unsigned char *)charset_s;
unsigned long m_0, m_4, m_8, m_c;
unsigned char ch, next_ch;
unsigned long bit;
unsigned long check;
size_t count;
/* Four 64bit registers have one bit for each character value */
m_0 = 0;
m_4 = 0;
m_8 = 0;
m_c = 0;
for (ch = *charset; ch != 0; ch = next_ch) {
next_ch = *++charset;
bit = 1ul << (ch & 0x3f);
if (__predict_true(ch < 0x80)) {
if (ch < 0x40)
m_0 |= bit;
else
m_4 |= bit;
} else {
if (ch < 0xc0)
m_8 |= bit;
else
m_c |= bit;
}
}
/* For strcspn() we just invert the validity set */
m_0 ^= invert;
m_4 ^= invert;
m_8 ^= invert;
m_c ^= invert;
/*
* We could do remove the lsb from m_0 to terminate at the
* end of the input string.
* However prefetching the next char is benifitial and we must
* not read the byte after the \0 - as it might fault!
* So we take the 'hit' of the compare against 0.
*/
ch = *s++;
for (count = 0; ch != 0; ch = next_ch) {
next_ch = s[count];
if (__predict_true(ch < 0x80)) {
check = m_0;
if (ch >= 0x40)
check = m_4;
} else {
check = m_8;
if (ch >= 0xc0)
check = m_c;
}
if (!((check >> (ch & 0x3f)) & 1))
break;
count++;
}
return count;
}
size_t
strspn(const char *s, const char *charset)
{
return strspn_x(s, charset, 0);
}
size_t
strcspn(const char *s, const char *charset)
{
return strspn_x(s, charset, ~0ul);
}
#endif
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