|  | /* Determine the length of a string.  For Intel 80x86, x>=3. | 
|  | Copyright (C) 1991-2016 Free Software Foundation, Inc. | 
|  | This file is part of the GNU C Library. | 
|  | Contributed by Torbjorn Granlund (tege@sics.se). | 
|  |  | 
|  | 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> | 
|  |  | 
|  | size_t | 
|  | strlen (const char *str) | 
|  | { | 
|  | int cnt; | 
|  |  | 
|  | asm("cld\n"			/* Search forward.  */ | 
|  | /* Some old versions of gas need `repne' instead of `repnz'.  */ | 
|  | "repnz\n"			/* Look for a zero byte.  */ | 
|  | "scasb" /* %0, %1, %3 */ : | 
|  | "=c" (cnt) : "D" (str), "0" (-1), "a" (0)); | 
|  |  | 
|  | return -2 - cnt; | 
|  | } | 
|  | libc_hidden_builtin_def (strlen) |