| #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) |
| |
| #if defined(USE_COBALT_CUSTOMIZATIONS) |
| #ifdef __GNUC__ |
| __attribute__((no_sanitize("address"))) |
| #endif // __GNUC__ |
| #endif // defined(USE_COBALT_CUSTOMIZATIONS) |
| void *memchr(const void *src, int c, size_t n) |
| { |
| const unsigned char *s = src; |
| c = (unsigned char)c; |
| #ifdef __GNUC__ |
| for (; ((uintptr_t)s & ALIGN) && n && *s != c; s++, n--); |
| if (n && *s != c) { |
| typedef size_t __attribute__((__may_alias__)) word; |
| const word *w; |
| size_t k = ONES * c; |
| for (w = (const void *)s; n>=SS && !HASZERO(*w^k); w++, n-=SS); |
| s = (const void *)w; |
| } |
| #endif |
| for (; n && *s != c; s++, n--); |
| return n ? (void *)s : 0; |
| } |