diff options
Diffstat (limited to 'string/bits')
| -rw-r--r-- | string/bits/string2.h | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/string/bits/string2.h b/string/bits/string2.h new file mode 100644 index 0000000000..b943fe9aa0 --- /dev/null +++ b/string/bits/string2.h @@ -0,0 +1,292 @@ +/* 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 */ |