Remove strcmp inlines

Submitted by Wilco Dijkstra on March 7, 2017, 3:32 p.m.

Details

Message ID VI1PR0802MB2621ECE61FDDFFA0FECF2D37832F0@VI1PR0802MB2621.eurprd08.prod.outlook.com
State New
Headers show

Commit Message

Wilco Dijkstra March 7, 2017, 3:32 p.m.
ping

    
Remove the str(n)cmp inlines from string/bits/string2.h.  The strncmp
optimization seems unlikely to ever be useful, but if it occurs in
real code it should be added to GCC.  Expanding strcmp of small strings
does appear useful (benchmarking shows it is 2-3x faster), so this would
be useful to implement in GCC (PR 78809).

ChangeLog:
2015-12-12  Wilco Dijkstra  <wdijkstr@arm.com>

        * string/bits/string2.h (strcmp): Remove define.
        (__strcmp_cg): Likewise.
        (strncmp): Likewise.
--

Comments

Adhemerval Zanella March 9, 2017, 9:39 a.m.
https://sourceware.org/ml/libc-alpha/2017-02/msg00260.html

On 07/03/2017 16:32, Wilco Dijkstra wrote:
> 
>     
> ping
> 
>     
> Remove the str(n)cmp inlines from string/bits/string2.h.  The strncmp
> optimization seems unlikely to ever be useful, but if it occurs in
> real code it should be added to GCC.  Expanding strcmp of small strings
> does appear useful (benchmarking shows it is 2-3x faster), so this would
> be useful to implement in GCC (PR 78809).
> 
> ChangeLog:
> 2015-12-12  Wilco Dijkstra  <wdijkstr@arm.com>
> 
>         * string/bits/string2.h (strcmp): Remove define.
>         (__strcmp_cg): Likewise.
>         (strncmp): Likewise.
> --
> 
> diff --git a/string/bits/string2.h b/string/bits/string2.h
> index b0be5f6a49024a0bedfc37e9ec2c0356e0e4fa09..5e0339223697256fff7eba4cc32d2eb618f07713 100644
> --- a/string/bits/string2.h
> +++ b/string/bits/string2.h
> @@ -60,64 +60,6 @@
>  # define __stpcpy(dest, src) __builtin_stpcpy (dest, src)
>  #endif
>  
> -/* Compare characters of S1 and S2.  */
> -#ifndef strcmp
> -# define strcmp(s1, s2) \
> -  __extension__                                                                      \
> -  ({ size_t __s1_len, __s2_len;                                                      \
> -     (__builtin_constant_p (s1) && __builtin_constant_p (s2)                 \
> -      && (__s1_len = strlen (s1), __s2_len = strlen (s2),                    \
> -         (!__string2_1bptr_p (s1) || __s1_len >= 4)                           \
> -         && (!__string2_1bptr_p (s2) || __s2_len >= 4))               \
> -      ? __builtin_strcmp (s1, s2)                                            \
> -      : (__builtin_constant_p (s1) && __string2_1bptr_p (s1)                 \
> -        && (__s1_len = strlen (s1), __s1_len < 4)                             \
> -        ? (__builtin_constant_p (s2) && __string2_1bptr_p (s2)                \
> -           ? __builtin_strcmp (s1, s2)                                        \
> -           : __strcmp_cg (s1, s2, __s1_len))                                  \
> -        : (__builtin_constant_p (s2) && __string2_1bptr_p (s2)                \
> -           && (__s2_len = strlen (s2), __s2_len < 4)                          \
> -           ? (__builtin_constant_p (s1) && __string2_1bptr_p (s1)             \
> -              ? __builtin_strcmp (s1, s2)                                     \
> -              : -__strcmp_cg (s2, s1, __s2_len))                              \
> -            : __builtin_strcmp (s1, s2)))); })
> -
> -# define __strcmp_cg(s1, s2, l1) \
> -  (__extension__ ({ const unsigned char *__s2 =                                      \
> -                     (const unsigned char *) (const char *) (s2);             \
> -                   int __result =                                             \
> -                     (((const unsigned char *) (const char *) (s1))[0]        \
> -                      - __s2[0]);                                             \
> -                   if (l1 > 0 && __result == 0)                       \
> -                     {                                                        \
> -                       __result = (((const unsigned char *)                  \
> -                                    (const char *) (s1))[1] - __s2[1]);      \
> -                       if (l1 > 1 && __result == 0)                          \
> -                         {                                                    \
> -                           __result = (((const unsigned char *)       \
> -                                        (const char *) (s1))[2] - __s2[2]);  \
> -                           if (l1 > 2 && __result == 0)               \
> -                             __result = (((const unsigned char *)             \
> -                                         (const char *)  (s1))[3]             \
> -                                         - __s2[3]);                          \
> -                         }                                                    \
> -                     }                                                        \
> -                   __result; }))
> -#endif
> -
> -
> -/* Compare N characters of S1 and S2.  */
> -#ifndef strncmp
> -# define strncmp(s1, s2, n)                                                  \
> -  (__extension__ (__builtin_constant_p (n)                                   \
> -                 && ((__builtin_constant_p (s1)                       \
> -                      && strlen (s1) < ((size_t) (n)))                        \
> -                     || (__builtin_constant_p (s2)                            \
> -                         && strlen (s2) < ((size_t) (n))))                    \
> -                 ? strcmp (s1, s2) : strncmp (s1, s2, n)))
> -#endif
> -
> -
>  #ifndef _FORCE_INLINES
>  # undef __STRING_INLINE
>  #endif
> 
> 
> 
> 
>         
>

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diff --git a/string/bits/string2.h b/string/bits/string2.h
index b0be5f6a49024a0bedfc37e9ec2c0356e0e4fa09..5e0339223697256fff7eba4cc32d2eb618f07713 100644
--- a/string/bits/string2.h
+++ b/string/bits/string2.h
@@ -60,64 +60,6 @@ 
 # define __stpcpy(dest, src) __builtin_stpcpy (dest, src)
 #endif
 
-/* Compare characters of S1 and S2.  */
-#ifndef strcmp
-# define strcmp(s1, s2) \
-  __extension__                                                                      \
-  ({ size_t __s1_len, __s2_len;                                                      \
-     (__builtin_constant_p (s1) && __builtin_constant_p (s2)                 \
-      && (__s1_len = strlen (s1), __s2_len = strlen (s2),                    \
-         (!__string2_1bptr_p (s1) || __s1_len >= 4)                           \
-         && (!__string2_1bptr_p (s2) || __s2_len >= 4))               \
-      ? __builtin_strcmp (s1, s2)                                            \
-      : (__builtin_constant_p (s1) && __string2_1bptr_p (s1)                 \
-        && (__s1_len = strlen (s1), __s1_len < 4)                             \
-        ? (__builtin_constant_p (s2) && __string2_1bptr_p (s2)                \
-           ? __builtin_strcmp (s1, s2)                                        \
-           : __strcmp_cg (s1, s2, __s1_len))                                  \
-        : (__builtin_constant_p (s2) && __string2_1bptr_p (s2)                \
-           && (__s2_len = strlen (s2), __s2_len < 4)                          \
-           ? (__builtin_constant_p (s1) && __string2_1bptr_p (s1)             \
-              ? __builtin_strcmp (s1, s2)                                     \
-              : -__strcmp_cg (s2, s1, __s2_len))                              \
-            : __builtin_strcmp (s1, s2)))); })
-
-# define __strcmp_cg(s1, s2, l1) \
-  (__extension__ ({ const unsigned char *__s2 =                                      \
-                     (const unsigned char *) (const char *) (s2);             \
-                   int __result =                                             \
-                     (((const unsigned char *) (const char *) (s1))[0]        \
-                      - __s2[0]);                                             \
-                   if (l1 > 0 && __result == 0)                       \
-                     {                                                        \
-                       __result = (((const unsigned char *)                  \
-                                    (const char *) (s1))[1] - __s2[1]);      \
-                       if (l1 > 1 && __result == 0)                          \
-                         {                                                    \
-                           __result = (((const unsigned char *)       \
-                                        (const char *) (s1))[2] - __s2[2]);  \
-                           if (l1 > 2 && __result == 0)               \
-                             __result = (((const unsigned char *)             \
-                                         (const char *)  (s1))[3]             \
-                                         - __s2[3]);                          \
-                         }                                                    \
-                     }                                                        \
-                   __result; }))
-#endif
-
-
-/* Compare N characters of S1 and S2.  */
-#ifndef strncmp
-# define strncmp(s1, s2, n)                                                  \
-  (__extension__ (__builtin_constant_p (n)                                   \
-                 && ((__builtin_constant_p (s1)                       \
-                      && strlen (s1) < ((size_t) (n)))                        \
-                     || (__builtin_constant_p (s2)                            \
-                         && strlen (s2) < ((size_t) (n))))                    \
-                 ? strcmp (s1, s2) : strncmp (s1, s2, n)))
-#endif
-
-
 #ifndef _FORCE_INLINES
 # undef __STRING_INLINE
 #endif