From 91f3b75f47c9eca3299098c3dcc2f5d9dad320b1 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Sat, 26 Mar 2016 19:09:07 +0000 Subject: Improve generic strspn performance As for strcspn, this patch improves strspn performance using a much faster algorithm. It first constructs a 256-entry table based on the accept string and then uses it as a lookup table for the input string. As for strcspn optimization, it is generally at least 10 times faster than the existing implementation on bench-strspn on a few AArch64 implementations. Also the string/bits/string2.h inlines make no longer sense, as current implementation will already implement most of the optimizations. Tested on x86_64, i686, and aarch64. * string/strspn.c (strcspn): Rewrite function. * string/bits/string2.h (strspn): Use __builtin_strcspn. (__strspn_c1): Remove inline function. (__strspn_c2): Likewise. (__strspn_c3): Likewise. * string/string-inlines.c [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strspn_c1): Add compatibility symbol. [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strspn_c2): Likewise. [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strspn_c3): Likewise. --- string/bits/string2.h | 74 +++------------------------------------------------ 1 file changed, 3 insertions(+), 71 deletions(-) (limited to 'string/bits/string2.h') diff --git a/string/bits/string2.h b/string/bits/string2.h index a8df0db14a..75a66a12e7 100644 --- a/string/bits/string2.h +++ b/string/bits/string2.h @@ -914,78 +914,10 @@ __stpcpy_small (char *__dest, /* Return the length of the initial segment of S which consists entirely of characters in ACCEPT. */ -#if !defined _HAVE_STRING_ARCH_strspn || defined _FORCE_INLINES -# ifndef _HAVE_STRING_ARCH_strspn -# if __GNUC_PREREQ (3, 2) -# define strspn(s, accept) \ - __extension__ \ - ({ char __a0, __a1, __a2; \ - (__builtin_constant_p (accept) && __string2_1bptr_p (accept) \ - ? ((__builtin_constant_p (s) && __string2_1bptr_p (s)) \ - ? __builtin_strspn (s, accept) \ - : ((__a0 = ((const char *) (accept))[0], __a0 == '\0') \ - ? ((void) (s), (size_t) 0) \ - : ((__a1 = ((const char *) (accept))[1], __a1 == '\0') \ - ? __strspn_c1 (s, __a0) \ - : ((__a2 = ((const char *) (accept))[2], __a2 == '\0') \ - ? __strspn_c2 (s, __a0, __a1) \ - : (((const char *) (accept))[3] == '\0' \ - ? __strspn_c3 (s, __a0, __a1, __a2) \ - : __builtin_strspn (s, accept)))))) \ - : __builtin_strspn (s, accept)); }) -# else -# define strspn(s, accept) \ - __extension__ \ - ({ char __a0, __a1, __a2; \ - (__builtin_constant_p (accept) && __string2_1bptr_p (accept) \ - ? ((__a0 = ((const char *) (accept))[0], __a0 == '\0') \ - ? ((void) (s), (size_t) 0) \ - : ((__a1 = ((const char *) (accept))[1], __a1 == '\0') \ - ? __strspn_c1 (s, __a0) \ - : ((__a2 = ((const char *) (accept))[2], __a2 == '\0') \ - ? __strspn_c2 (s, __a0, __a1) \ - : (((const char *) (accept))[3] == '\0' \ - ? __strspn_c3 (s, __a0, __a1, __a2) \ - : strspn (s, accept))))) \ - : strspn (s, accept)); }) -# endif +#ifndef _HAVE_STRING_ARCH_strspn +# if __GNUC_PREREQ (3, 2) +# define strspn(s, accept) __builtin_strspn (s, accept) # endif - -__STRING_INLINE size_t __strspn_c1 (const char *__s, int __accept); -__STRING_INLINE size_t -__strspn_c1 (const char *__s, int __accept) -{ - size_t __result = 0; - /* Please note that __accept never can be '\0'. */ - while (__s[__result] == __accept) - ++__result; - return __result; -} - -__STRING_INLINE size_t __strspn_c2 (const char *__s, int __accept1, - int __accept2); -__STRING_INLINE size_t -__strspn_c2 (const char *__s, int __accept1, int __accept2) -{ - size_t __result = 0; - /* Please note that __accept1 and __accept2 never can be '\0'. */ - while (__s[__result] == __accept1 || __s[__result] == __accept2) - ++__result; - return __result; -} - -__STRING_INLINE size_t __strspn_c3 (const char *__s, int __accept1, - int __accept2, int __accept3); -__STRING_INLINE size_t -__strspn_c3 (const char *__s, int __accept1, int __accept2, int __accept3) -{ - size_t __result = 0; - /* Please note that __accept1 to __accept3 never can be '\0'. */ - while (__s[__result] == __accept1 || __s[__result] == __accept2 - || __s[__result] == __accept3) - ++__result; - return __result; -} #endif -- cgit v1.2.3