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* string/bits/string2.h: Add more memset optimizations.
This commit is contained in:
Ulrich Drepper
1999-04-29 18:28:07 +00:00
parent 8a40ed6807
commit 9943472996
2 changed files with 61 additions and 3 deletions
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ChangeLog
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@ -1,5 +1,7 @@
1999-04-29 Ulrich Drepper <drepper@cygnus.com> 1999-04-29 Ulrich Drepper <drepper@cygnus.com>
* string/bits/string2.h: Add more memset optimizations.
* resolv/inet_addr.c (inet_aton): Optimize switch statement away. * resolv/inet_addr.c (inet_aton): Optimize switch statement away.
* resolv/inet_pton.c (inet_pton4): Little optimizations. * resolv/inet_pton.c (inet_pton4): Little optimizations.

62
string/bits/string2.h
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@ -94,9 +94,65 @@ __STRING2_COPY_TYPE (8);
/* Set N bytes of S to C. */ /* Set N bytes of S to C. */
#ifndef _HAVE_STRING_ARCH_memset #ifndef _HAVE_STRING_ARCH_memset
# define memset(s, c, n) \ # define memset(s, c, n) \
(__extension__ (__builtin_constant_p (c) && (c) == '\0' \ (__extension__ (__builtin_constant_p (n) && (n) <= 16 \
? ({ void *__s = (s); __bzero (__s, n); __s; }) \ ? (__builtin_constant_p (c) \
: memset (s, c, n))) ? __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 #endif