#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; }