#include <string.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <limits.h>
-
-#define ALIGN (sizeof(size_t)-1)
-#define ONES ((size_t)-1/UCHAR_MAX)
-#define HIGHS (ONES * (UCHAR_MAX/2+1))
-#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
char *strchr(const char *s, int c)
{
- size_t *w, k;
-
- c = (unsigned char)c;
- if (!c) return (char *)s + strlen(s);
-
- for (; ((uintptr_t)s & ALIGN) && *s; s++)
- if (*(unsigned char *)s == c) return (char *)s;
- k = ONES * c;
- for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w^k); w++);
- for (s = (void *)w; *s; s++)
- if (*(unsigned char *)s == c) return (char *)s;
- return 0;
+ char *r = __strchrnul(s, c);
+ return *(unsigned char *)r == (unsigned char)c ? r : 0;
}