diff options
Diffstat (limited to 'string')
| -rw-r--r-- | string/bits/string2.h | 62 |
1 files changed, 59 insertions, 3 deletions
diff --git a/string/bits/string2.h b/string/bits/string2.h index 3de175d0a8..d9ed80b3b5 100644 --- a/string/bits/string2.h +++ b/string/bits/string2.h @@ -94,9 +94,65 @@ __STRING2_COPY_TYPE (8); /* Set N bytes of S to C. */ #ifndef _HAVE_STRING_ARCH_memset # define memset(s, c, n) \ - (__extension__ (__builtin_constant_p (c) && (c) == '\0' \ - ? ({ void *__s = (s); __bzero (__s, n); __s; }) \ - : memset (s, c, n))) + (__extension__ (__builtin_constant_p (n) && (n) <= 16 \ + ? (__builtin_constant_p (c) \ + ? __memset_gc (s, (c) * 0x01010101, n) \ + : __memset_gc (s, (n) == 1 ? (c) : (c) * 0x01010101, n)) \ + : (__builtin_constant_p (c) && (c) == '\0' \ + ? ({ void *__s = (s); __bzero (__s, n); __s; }) \ + : memset (s, c, n)))) + +#define __memset_gc(s, c, n) \ + ({ void *__s = (s); \ + __uint32_t *__ts = (__uint32_t *) __s; \ + \ + /* This `switch' statement will be removed at compile-time. */ \ + switch (n) \ + { \ + case 15: \ + *__ts++ = c; \ + case 11: \ + *__ts++ = c; \ + case 7: \ + *__ts++ = c; \ + case 3: \ + *((__uint16_t *) __ts)++ = c; \ + *((__uint8_t *) __ts) = c; \ + break; \ + \ + case 14: \ + *__ts++ = c; \ + case 10: \ + *__ts++ = c; \ + case 6: \ + *__ts++ = c; \ + case 2: \ + *((__uint16_t *) __ts) = c; \ + break; \ + \ + case 13: \ + *__ts++ = c; \ + case 9: \ + *__ts++ = c; \ + case 5: \ + *__ts++ = c; \ + case 1: \ + *((__uint8_t *) __ts) = c; \ + break; \ + \ + case 16: \ + *__ts++ = c; \ + case 12: \ + *__ts++ = c; \ + case 8: \ + *__ts++ = c; \ + case 4: \ + *__ts = c; \ + case 0: \ + break; \ + } \ + \ + __s; }) #endif |