1#include <string.h>
2#include <stdint.h>
3#include <limits.h>
4
5#define ALIGN (sizeof(size_t))
6#define ONES ((size_t)-1/UCHAR_MAX)
7#define HIGHS (ONES * (UCHAR_MAX/2+1))
8#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
9
10size_t strlen(const char *s)
11{
12	const char *a = s;
13	const size_t *w;
14	for (; (uintptr_t)s % ALIGN; s++) if (!*s) return s-a;
15	for (w = (const void *)s; !HASZERO(*w); w++);
16	for (s = (const void *)w; *s; s++);
17	return s-a;
18}
19