]>
Commit | Line | Data |
---|---|---|
1 | /* Copyright (C) 1991-2025 Free Software Foundation, Inc. | |
2 | This file is part of the GNU C Library. | |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Lesser General Public | |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Lesser General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Lesser General Public | |
15 | License along with the GNU C Library; if not, see | |
16 | <https://www.gnu.org/licenses/>. */ | |
17 | ||
18 | #include <libc-pointer-arith.h> | |
19 | #include <string-fzb.h> | |
20 | #include <string-fzc.h> | |
21 | #include <string-fzi.h> | |
22 | #include <string-shift.h> | |
23 | #include <string.h> | |
24 | ||
25 | #ifdef STRLEN | |
26 | # define __strlen STRLEN | |
27 | #endif | |
28 | ||
29 | /* Return the length of the null-terminated string STR. Scan for | |
30 | the null terminator quickly by testing four bytes at a time. */ | |
31 | size_t | |
32 | __strlen (const char *str) | |
33 | { | |
34 | /* Align pointer to sizeof op_t. */ | |
35 | const uintptr_t s_int = (uintptr_t) str; | |
36 | const op_t *word_ptr = (const op_t*) PTR_ALIGN_DOWN (str, sizeof (op_t)); | |
37 | ||
38 | op_t word = *word_ptr; | |
39 | find_t mask = shift_find (find_zero_all (word), s_int); | |
40 | if (mask != 0) | |
41 | return index_first (mask); | |
42 | ||
43 | do | |
44 | word = *++word_ptr; | |
45 | while (! has_zero (word)); | |
46 | ||
47 | return ((const char *) word_ptr) + index_first_zero (word) - str; | |
48 | } | |
49 | #ifndef STRLEN | |
50 | weak_alias (__strlen, strlen) | |
51 | libc_hidden_builtin_def (strlen) | |
52 | #endif |