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-rw-r--r--string/bits/string2.h292
1 files changed, 292 insertions, 0 deletions
diff --git a/string/bits/string2.h b/string/bits/string2.h
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+/* Machine-independant string function optimizations.
+ Copyright (C) 1997 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public License as
+ published by the Free Software Foundation; either version 2 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef _BITS_STRING2_H
+#define _BITS_STRING2_H 1
+
+/* Unlike the definitions in the header <bits/string.h> the
+ definitions contained here are not optimizing down to assembler
+ level. These optimizations are not always a good idea since this
+ means the code size increases a lot. Instead the definitions here
+ optimize some functions in a way which does not dramatically
+ increase the code size and which does not use assembler. The main
+ trick is to use GNU CC's `__builtin_constant_p' function.
+
+ Every function XXX which has a defined version in
+ <bits/string.h> must be accompanied by a have _HAVE_STRING_ARCH_XXX
+ to make sure we don't get redefinitions.
+
+ We must use here macros instead of inline functions since the
+ trick won't work with the later. */
+
+#ifdef __cplusplus
+# define __STRING_INLINE inline
+#else
+# define __STRING_INLINE extern __inline
+#endif
+
+/* We need some more types. */
+#include <bits/types.h>
+
+
+/* Copy SRC to DEST. */
+#ifndef _HAVE_STRING_ARCH_strcpy
+# define strcpy(dest, src) \
+ (__extension__ (__builtin_constant_p (src) \
+ ? (strlen (src) + 1 <= 8 \
+ ? __strcpy_small (dest, src, strlen (src) + 1) \
+ : (char *) memcpy (dest, src, strlen (src) + 1)) \
+ : strcpy (dest, src)))
+
+__STRING_INLINE char *
+__strcpy_small (char *__dest, __const char *__src, size_t __srclen)
+{
+ register char *__tmp = __dest;
+ switch (__srclen)
+ {
+ case 7:
+ *((__uint16_t *) __tmp)++ = *((__uint16_t *) __src)++;
+ case 5:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ *((unsigned char *) __tmp) = '\0';
+ break;
+
+ case 8:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ case 4:
+ *((__uint32_t *) __tmp) = *((__uint32_t *) __src);
+ break;
+
+ case 6:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ case 2:
+ *((__uint16_t *) __tmp) = *((__uint16_t *) __src);
+ break;
+
+ case 3:
+ *((__uint16_t *) __tmp)++ = *((__uint16_t *) __src)++;
+ case 1:
+ *((unsigned char *) __tmp) = '\0';
+ break;
+
+ default:
+ break;
+ }
+ return __dest;
+}
+#endif
+
+
+/* Copy SRC to DEST, returning pointer to final NUL byte. */
+#ifdef __USE_GNU
+# ifndef _HAVE_STRING_ARCH_stpcpy
+# define __stpcpy(dest, src) \
+ (__extension__ (__builtin_constant_p (src) \
+ ? (strlen (src) + 1 <= 8 \
+ ? __stpcpy_small (dest, src, strlen (src) + 1) \
+ : ((char *) __mempcpy (dest, src, strlen (src) + 1) - 1))\
+ : __stpcpy (dest, src)))
+/* In glibc we use this function frequently but for namespace reasons
+ we have to use the name `__stpcpy'. */
+# 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:
+ *((__uint16_t *) __tmp)++ = *((__uint16_t *) __src)++;
+ case 5:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ *((unsigned char *) __tmp) = '\0';
+ return __tmp;
+
+ case 8:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ case 4:
+ *((__uint32_t *) __tmp) = *((__uint32_t *) __src);
+ return __tmp + 3;
+
+ case 6:
+ *((__uint32_t *) __tmp)++ = *((__uint32_t *) __src)++;
+ case 2:
+ *((__uint16_t *) __tmp) = *((__uint16_t *) __src);
+ return __tmp + 1;
+
+ case 3:
+ *((__uint16_t *) __tmp)++ = *((__uint16_t *) __src)++;
+ case 1:
+ *((unsigned char *) __tmp) = '\0';
+ return __tmp;
+
+ default:
+ break;
+ }
+ /* This should never happen. */
+ return NULL;
+}
+# endif
+#endif
+
+
+/* Copy no more than N characters of SRC to DEST. */
+#ifndef _HAVE_STRING_ARCH_strncpy
+# if defined _HAVE_STRING_ARCH_memset && defined _HAVE_STRING_ARCH_mempcpy
+# define strncpy(dest, src, n) \
+ (__extension__ (__builtin_constant_p (src) && __builtin_constant_p (n) \
+ ? (strlen (src) + 1 >= ((size_t) (n)) \
+ ? (char *) memcpy (dest, src, n) \
+ : (memset (__mempcpy (dest, src, strlen (src)), '\0', \
+ n - strlen (src)), \
+ dest)) \
+ : strncpy (dest, src, n)))
+# else
+# define strncpy(dest, src, n) \
+ (__extension__ (__builtin_constant_p (src) && __builtin_constant_p (n) \
+ ? (strlen (src) + 1 >= ((size_t) (n)) \
+ ? (char *) memcpy (dest, src, n) \
+ : strncpy (dest, src, n)) \
+ : strncpy (dest, src, n)))
+# endif
+#endif
+
+
+/* Append no more than N characters from SRC onto DEST. */
+#ifndef _HAVE_STRING_ARCH_strncat
+# ifdef _HAVE_STRING_ARCH_strchr
+# define strncat(dest, src, n) \
+ (__extension__ (__builtin_constant_p (src) && __builtin_constant_p (n) \
+ ? (strlen (src) < ((size_t) (n)) \
+ ? strcat (dest, src) \
+ : (memcpy (strchr (dest, '\0'), src, n), dest)) \
+ : strncat (dest, src, n)))
+# else
+# define strncat(dest, src, n) \
+ (__extension__ (__builtin_constant_p (src) && __builtin_constant_p (n) \
+ ? (strlen (src) < ((size_t) (n)) \
+ ? strcat (dest, src) \
+ : strncat (dest, src, n)) \
+ : strncat (dest, src, n)))
+# endif
+#endif
+
+
+/* Compare N characters of S1 and S2. */
+#ifndef _HAVE_STRING_ARCH_strncmp
+# define strncmp(s1, s2, n) \
+ (__extension__ (__builtin_constant_p (s1) && strlen (s1) < ((size_t) (n)) \
+ ? strcmp (s1, s2) \
+ : (__builtin_constant_p (s2) && strlen (s2) < ((size_t) (n))\
+ ? strcmp (s1, s2) \
+ : strncmp (s1, s2, n))))
+#endif
+
+
+/* Return the length of the initial segment of S which
+ consists entirely of characters not in REJECT. */
+#ifndef _HAVE_STRING_ARCH_strcspn
+# define strcspn(s, reject) \
+ (__extension__ (__builtin_constant_p (reject) \
+ ? (((const char *) (reject))[0] == '\0' \
+ ? strlen (s) \
+ : (((const char *) (reject))[1] == '\0' \
+ ? __strcspn_c1 (s, ((((const char *) (reject))[0] \
+ & 0xff) << 8)) \
+ : strcspn (s, reject))) \
+ : strcspn (s, reject)))
+
+__STRING_INLINE size_t
+__strcspn_c1 (__const char *__s, char __reject)
+{
+ register size_t __result = 0;
+ while (__s[__result] != '\0' && __s[__result] != __reject)
+ ++__result;
+ return __result;
+}
+#endif
+
+
+/* Return the length of the initial segment of S which
+ consists entirely of characters in ACCEPT. */
+#ifndef _HAVE_STRING_ARCH_strspn
+# define strspn(s, accept) \
+ (__extension__ (__builtin_constant_p (accept) \
+ ? (((const char *) (accept))[0] == '\0' \
+ ? 0 \
+ : (((const char *) (accept))[1] == '\0' \
+ ? __strspn_c1 (s, ((const char *) (accept))[0]) \
+ : strspn (s, accept))) \
+ : strspn (s, accept)))
+
+__STRING_INLINE size_t
+__strspn_c1 (__const char *__s, char __accept)
+{
+ register size_t __result = 0;
+ /* Please note that __accept never can be '\0'. */
+ while (__s[__result] == __accept)
+ ++__result;
+ return __result;
+}
+#endif
+
+
+/* Find the first occurrence in S of any character in ACCEPT. */
+#ifndef _HAVE_STRING_ARCH_strpbrk
+# define strpbrk(s, accept) \
+ (__extension__ (__builtin_constant_p (accept) \
+ ? (((const char *) (accept))[0] == '\0' \
+ ? NULL \
+ : (((const char *) (accept))[1] == '\0' \
+ ? strchr (s, ((const char *) (accept))[0]) \
+ : strpbrk (s, accept))) \
+ : strpbrk (s, accept)))
+#endif
+
+
+/* Find the first occurrence of NEEDLE in HAYSTACK. */
+#ifndef _HAVE_STRING_ARCH_strstr
+# define strstr(haystack, needle) \
+ (__extension__ (__builtin_constant_p (needle) \
+ ? (((const char *) (needle))[0] == '\0' \
+ ? haystack \
+ : (((const char *) (needle))[1] == '\0' \
+ ? strchr (haystack, ((const char *) (needle))[0]) \
+ : strstr (haystack, needle))) \
+ : strstr (haystack, needle)))
+#endif
+
+
+#ifdef __USE_GNU
+# ifndef _HAVE_STRING_ARCH_strnlen
+extern __inline size_t
+strnlen (__const char *__string, size_t __maxlen)
+{
+ __const char *__end = (__const char *) memchr (__string, '\0', __maxlen);
+ return __end ? __end - __string : __maxlen;
+}
+# endif
+#endif
+
+
+#undef __STRING_INLINE
+
+#endif /* bits/string2.h */
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