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 __strchrnul(const char * s,int c)10char *__strchrnul(const char *s, int c) 11 { 12 c = (unsigned char)c; 13 if (!c) return (char *)s + strlen(s); 14 15 #ifdef __GNUC__ 16 typedef size_t __attribute__((__may_alias__)) word; 17 const word *w; 18 for (; (uintptr_t)s % ALIGN; s++) 19 if (!*s || *(unsigned char *)s == c) return (char *)s; 20 size_t k = ONES * c; 21 for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++); 22 s = (void *)w; 23 #endif 24 for (; *s && *(unsigned char *)s != c; s++); 25 return (char *)s; 26 } 27 28 weak_alias(__strchrnul, strchrnul); 29