1 /* 2 * Copyright 2011 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 */ 14 15 #include <linux/types.h> 16 #include <linux/string.h> 17 #include <linux/module.h> 18 #include "string-endian.h" 19 strlen(const char * s)20size_t strlen(const char *s) 21 { 22 /* Get an aligned pointer. */ 23 const uintptr_t s_int = (uintptr_t) s; 24 const uint64_t *p = (const uint64_t *)(s_int & -8); 25 26 /* Read and MASK the first word. */ 27 uint64_t v = *p | MASK(s_int); 28 29 uint64_t bits; 30 while ((bits = __insn_v1cmpeqi(v, 0)) == 0) 31 v = *++p; 32 33 return ((const char *)p) + (CFZ(bits) >> 3) - s; 34 } 35 EXPORT_SYMBOL(strlen); 36