Loading...
#include <string.h> #include <stdint.h> #include <limits.h> #define SS (sizeof(size_t)) #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) void *memchr(const void *src, int c, size_t n) { const unsigned char *s = src; c = (unsigned char)c; for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--); if (n && *s != c) { const size_t *w; size_t k = ONES * c; for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS); for (s = (const void *)w; n && *s != c; s++, n--); } return n ? (void *)s : 0; } |