6 #define SS (sizeof(size_t))
7 #define ALIGN (sizeof(size_t)-1)
8 #define ONES ((size_t)-1/UCHAR_MAX)
9 #define HIGHS (ONES * (UCHAR_MAX/2+1))
10 #define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
12 void *memchr(const void *src, int c, size_t n)
14 const unsigned char *s = src;
16 for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--);
20 for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS);
21 for (s = (const void *)w; n && *s != c; s++, n--);
23 return n ? (void *)s : 0;