1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374 |
- /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
- *
- * 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);
- }
|