Improve generic strpbrk performance

With now a faster strcspn implementation, it is faster to just use
it with some return tests than reimplementing strpbrk itself.
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, i386, and aarch64.

	* string/strpbrk.c (strpbrk): Rewrite function.
	* string/bits/string2.h (strpbrk): Use __builtin_strpbrk.
	(__strpbrk_c2): Likewise.
	(__strpbrk_c3): Likewise.
	* string/string-inlines.c
	[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strpbrk_c2):
	Likewise.
	[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strpbrk_c3):
	Likewise.

1 files changed, 21 insertions, 0 deletions

diff --git a/string/string-inlines.c b/string/string-inlines.c
index 754b31530f..06483760c3 100644
--- a/string/string-inlines.c
+++ b/string/string-inlines.c
@@ -107,4 +107,25 @@ __old_strspn_c3 (const char *__s, int __accept1, int __accept2,
 }
 compat_symbol (libc, __old_strspn_c3, __strspn_c3, GLIBC_2_1_1);
 
+char *
+__strpbrk_c2 (const char *__s, int __accept1, int __accept2)
+{
+  /* Please note that __accept1 and __accept2 never can be '\0'.  */
+  while (*__s != '\0' && *__s != __accept1 && *__s != __accept2)
+    ++__s;
+  return *__s == '\0' ? NULL : (char *) (size_t) __s;
+}
+compat_symbol (libc, __old_strpbrk_c2, __strpbrk_c2, GLIBC_2_1_1);
+
+char *
+__strpbrk_c3 (const char *__s, int __accept1, int __accept2, int __accept3)
+{
+  /* Please note that __accept1 to __accept3 never can be '\0'.  */
+  while (*__s != '\0' && *__s != __accept1 && *__s != __accept2
+	 && *__s != __accept3)
+    ++__s;
+  return *__s == '\0' ? NULL : (char *) (size_t) __s;
+}
+compat_symbol (libc, __old_strpbrk_c3, __strpbrk_c3, GLIBC_2_1_1);
+
 #endif