| | 1 | /*- |
| | 2 | * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG> |
| | 3 | * All rights reserved. |
| | 4 | * |
| | 5 | * Redistribution and use in source and binary forms, with or without |
| | 6 | * modification, are permitted provided that the following conditions |
| | 7 | * are met: |
| | 8 | * 1. Redistributions of source code must retain the above copyright |
| | 9 | * notice, this list of conditions and the following disclaimer. |
| | 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| | 11 | * notice, this list of conditions and the following disclaimer in the |
| | 12 | * documentation and/or other materials provided with the distribution. |
| | 13 | * |
| | 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| | 15 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| | 16 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| | 17 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| | 18 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| | 19 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| | 20 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| | 21 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| | 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| | 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| | 24 | * SUCH DAMAGE. |
| | 25 | */ |
| | 26 | |
| | 27 | #include <sys/cdefs.h> |
| | 28 | __FBSDID("$FreeBSD: src/lib/libc/string/strspn.c,v 1.5 2005/04/02 18:52:44 das Exp $"); |
| | 29 | |
| | 30 | #include <sys/types.h> |
| | 31 | #include <limits.h> |
| | 32 | #include <string.h> |
| | 33 | |
| | 34 | #define IDX(c) ((u_char)(c) / LONG_BIT) |
| | 35 | #define BIT(c) ((u_long)1 << ((u_char)(c) % LONG_BIT)) |
| | 36 | |
| | 37 | size_t |
| | 38 | strspn(const char *s, const char *charset) |
| | 39 | { |
| | 40 | /* |
| | 41 | * NB: idx and bit are temporaries whose use causes gcc 3.4.2 to |
| | 42 | * generate better code. Without them, gcc gets a little confused. |
| | 43 | */ |
| | 44 | const char *s1; |
| | 45 | u_long bit; |
| | 46 | u_long tbl[(UCHAR_MAX + 1) / LONG_BIT]; |
| | 47 | int idx; |
| | 48 | |
| | 49 | if(*s == '\0') |
| | 50 | return (0); |
| | 51 | |
| | 52 | #if LONG_BIT == 64 /* always better to unroll on 64-bit architectures */ |
| | 53 | tbl[3] = tbl[2] = tbl[1] = tbl[0] = 0; |
| | 54 | #else |
| | 55 | for (idx = 0; idx < sizeof(tbl) / sizeof(tbl[0]); idx++) |
| | 56 | tbl[idx] = 0; |
| | 57 | #endif |
| | 58 | for (; *charset != '\0'; charset++) { |
| | 59 | idx = IDX(*charset); |
| | 60 | bit = BIT(*charset); |
| | 61 | tbl[idx] |= bit; |
| | 62 | } |
| | 63 | |
| | 64 | for(s1 = s; ; s1++) { |
| | 65 | idx = IDX(*s1); |
| | 66 | bit = BIT(*s1); |
| | 67 | if ((tbl[idx] & bit) == 0) |
| | 68 | break; |
| | 69 | } |
| | 70 | return (s1 - s); |
| | 71 | } |
projects / apple / libc.git / blame_incremental