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Diffstat (limited to 'sysdeps/i386/i486/bits/string.h')
-rw-r--r--sysdeps/i386/i486/bits/string.h160
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 */