| /* Copyright (C) 1991-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <string.h> |
| #include <stdint.h> |
| #include <libc-pointer-arith.h> |
| |
| #undef strspn |
| #ifndef STRSPN |
| # define STRSPN strspn |
| #endif |
| |
| /* Return the length of the maximum initial segment |
| of S which contains only characters in ACCEPT. */ |
| size_t |
| STRSPN (const char *str, const char *accept) |
| { |
| if (accept[0] == '\0') |
| return 0; |
| if (__glibc_unlikely (accept[1] == '\0')) |
| { |
| const char *a = str; |
| for (; *str == *accept; str++); |
| return str - a; |
| } |
| |
| /* Use multiple small memsets to enable inlining on most targets. */ |
| unsigned char table[256]; |
| unsigned char *p = memset (table, 0, 64); |
| memset (p + 64, 0, 64); |
| memset (p + 128, 0, 64); |
| memset (p + 192, 0, 64); |
| |
| unsigned char *s = (unsigned char*) accept; |
| /* Different from strcspn it does not add the NULL on the table |
| so can avoid check if str[i] is NULL, since table['\0'] will |
| be 0 and thus stopping the loop check. */ |
| do |
| p[*s++] = 1; |
| while (*s); |
| |
| s = (unsigned char*) str; |
| if (!p[s[0]]) return 0; |
| if (!p[s[1]]) return 1; |
| if (!p[s[2]]) return 2; |
| if (!p[s[3]]) return 3; |
| |
| s = (unsigned char *) PTR_ALIGN_DOWN (s, 4); |
| |
| unsigned int c0, c1, c2, c3; |
| do { |
| s += 4; |
| c0 = p[s[0]]; |
| c1 = p[s[1]]; |
| c2 = p[s[2]]; |
| c3 = p[s[3]]; |
| } while ((c0 & c1 & c2 & c3) != 0); |
| |
| size_t count = s - (unsigned char *) str; |
| return (c0 & c1) == 0 ? count + c0 : count + c2 + 2; |
| } |
| libc_hidden_builtin_def (strspn) |