diff options
Diffstat (limited to 'sysdeps/i386/i486/bits/string.h')
| -rw-r--r-- | sysdeps/i386/i486/bits/string.h | 160 |
1 files changed, 118 insertions, 42 deletions
diff --git a/sysdeps/i386/i486/bits/string.h b/sysdeps/i386/i486/bits/string.h index 770f5c1e15..5e4abbc3e5 100644 --- a/sysdeps/i386/i486/bits/string.h +++ b/sysdeps/i386/i486/bits/string.h @@ -18,11 +18,17 @@ Boston, MA 02111-1307, USA. */ #ifndef _STRING_H -#error "Never use <bits/string.h> directly; include <string.h> instead." +# error "Never use <bits/string.h> directly; include <string.h> instead." #endif -/* We only provide optimizations for the GNU CC. */ -#if defined __GNUC__ && __GNUC__ >= 2 +/* The ix86 processors can access unaligned multi-byte variables. */ +#define _STRING_ARCH_unaligned 1 + + +/* We only provide optimizations if the user selects them and if + GNU CC is used. */ +#if !defined __NO_STRING_INLINES && defined __USE_STRING_INLINES \ + && defined __GNUC__ && __GNUC__ >= 2 #ifdef __cplusplus # define __STRING_INLINE inline @@ -30,6 +36,13 @@ # define __STRING_INLINE extern __inline #endif +/* The macros are used in some of the optimized implementations below. */ +#define __STRING_SMALL_GET16(src, idx) \ + (((src)[idx + 1] << 8) | (src)[idx]) +#define __STRING_SMALL_GET32(src, idx) \ + ((((src)[idx + 3] << 8 | (src)[idx + 2]) << 8 \ + | (src)[idx + 1]) << 8 | (src)[idx]) + /* Copy N bytes of SRC to DEST. */ #define _HAVE_STRING_ARCH_memcpy 1 @@ -355,9 +368,59 @@ __strlen_g (__const char *__str) #define _HAVE_STRING_ARCH_strcpy 1 #define strcpy(dest, src) \ (__extension__ (__builtin_constant_p (src) \ - ? (char *) memcpy (dest, src, strlen (src) + 1) \ + ? (sizeof (src[0]) == 1 && strlen (src) + 1 <= 8 \ + ? __strcpy_small (dest, src, strlen (src) + 1) \ + : (char *) memcpy (dest, src, strlen (src) + 1)) \ : __strcpy_g (dest, src))) +# define __strcpy_small(dest, src, srclen) \ + (__extension__ ({ char *__retval = (dest); \ + char *__cp = __retval; \ + switch (srclen) \ + { \ + case 1: \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 2: \ + *((__uint16_t *) __cp) = \ + __STRING_SMALL_GET16 (src, 0); \ + break; \ + case 3: \ + *((__uint16_t *) __cp)++ = \ + __STRING_SMALL_GET16 (src, 0); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 4: \ + *((__uint32_t *) __cp) = \ + __STRING_SMALL_GET32 (src, 0); \ + break; \ + case 5: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 6: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint16_t *) __cp) = \ + __STRING_SMALL_GET16 (src, 4); \ + break; \ + case 7: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint16_t *) __cp)++ = \ + __STRING_SMALL_GET16 (src, 4); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 8: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint32_t *) __cp) = \ + __STRING_SMALL_GET32 (src, 4); \ + break; \ + } \ + __retval; })) + __STRING_INLINE char * __strcpy_g (char *__dest, __const char *__src) { @@ -398,43 +461,56 @@ __strcpy_g (char *__dest, __const char *__src) /* In glibc itself we use this symbol for namespace reasons. */ # define stpcpy(dest, src) __stpcpy (dest, src) -__STRING_INLINE char * -__stpcpy_small (char *__dest, __const char __src[], size_t __srclen) -{ - register char *__tmp = __dest; - switch (__srclen) - { - case 7: - *((unsigned short int *) __tmp)++ = *((unsigned short int *) __src)++; - case 5: - *((unsigned int *) __tmp)++ = *((unsigned int *) __src)++; - *((unsigned char *) __tmp) = '\0'; - return __tmp; - - case 8: - *((unsigned int *) __tmp)++ = *((unsigned int *) __src)++; - case 4: - *((unsigned int *) __tmp) = *((unsigned int *) __src); - return __tmp + 3; - - case 6: - *((unsigned int *) __tmp)++ = *((unsigned int *) __src)++; - case 2: - *((unsigned short int *) __tmp) = *((unsigned short int *) __src); - return __tmp + 1; - - case 3: - *((unsigned short int *) __tmp)++ = *((unsigned short int *) __src)++; - case 1: - *((unsigned char *) __tmp) = '\0'; - return __tmp; - - default: - break; - } - /* This should never happen. */ - return NULL; -} +# define __stpcpy_small(dest, src, srclen) \ + (__extension__ ({ char *__cp = (dest); \ + switch (srclen) \ + { \ + case 1: \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 2: \ + *((__uint16_t *) __cp) = \ + __STRING_SMALL_GET16 (src, 0); \ + ++cp; \ + break; \ + case 3: \ + *((__uint16_t *) __cp)++ = \ + __STRING_SMALL_GET16 (src, 0); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 4: \ + *((__uint32_t *) __cp) = \ + __STRING_SMALL_GET32 (src, 0); \ + cp += 3; \ + break; \ + case 5: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 6: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint16_t *) __cp) = \ + __STRING_SMALL_GET16 (src, 4); \ + ++cp; \ + break; \ + case 7: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint16_t *) __cp)++ = \ + __STRING_SMALL_GET16 (src, 4); \ + *((unsigned char *) __cp) = '\0'; \ + break; \ + case 8: \ + *((__uint32_t *) __cp)++ = \ + __STRING_SMALL_GET32 (src, 0); \ + *((__uint32_t *) __cp) = \ + __STRING_SMALL_GET32 (src, 4); \ + cp += 3; \ + break; \ + } \ + __cp; })) __STRING_INLINE char * __mempcpy_by4 (char *__dest, __const char *__src, size_t __srclen) @@ -1458,4 +1534,4 @@ __strstr_g (__const char *__haystack, __const char *__needle) #undef __STRING_INLINE -#endif /* GNU CC */ +#endif /* use string inlines && GNU CC */ |