#include <string.h> | |
#include <stdint.h> | |
#include <limits.h> | |
#define ALIGN (sizeof(size_t)) | |
#define ONES ((size_t)-1/UCHAR_MAX) | |
#define HIGHS (ONES * (UCHAR_MAX/2+1)) | |
#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS) | |
size_t strlen(const char *s) | |
{ | |
const char *a = s; | |
#ifdef __GNUC__ | |
typedef size_t __attribute__((__may_alias__)) word; | |
const word *w; | |
for (; (uintptr_t)s % ALIGN; s++) if (!*s) return s-a; | |
for (w = (const void *)s; !HASZERO(*w); w++); | |
s = (const void *)w; | |
#endif | |
for (; *s; s++); | |
return s-a; | |
} |