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Re: [GLIBC][PATCH] Remove strcmp inlines
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org, Wilco Dijkstra <Wilco dot Dijkstra at arm dot com>
- Date: Thu, 9 Mar 2017 10:39:23 +0100
- Subject: Re: [GLIBC][PATCH] Remove strcmp inlines
- Authentication-results: sourceware.org; auth=none
- References: <AM5PR0802MB2610A1F99165A04F1C48645283980@AM5PR0802MB2610.eurprd08.prod.outlook.com> <AM5PR0802MB2610F842F677223D09E8E43783580@AM5PR0802MB2610.eurprd08.prod.outlook.com> <VI1PR0802MB2621ECE61FDDFFA0FECF2D37832F0@VI1PR0802MB2621.eurprd08.prod.outlook.com>
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
>
>
>
>
>
>