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authorWilco Dijkstra <wdijkstr@arm.com>2016-03-25 16:44:26 -0300
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2016-04-01 10:44:40 -0300
commitd3496c9f4f27d3009b71be87f6108b4fed7314bd (patch)
treeeefcd05beb1f6ed269167433a763c234483b7c0b /sysdeps
parentd8a012c5c9e4bfc1b8db2bc6deacb85b44a2e1eb (diff)
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Improve generic strcspn performance
Improve strcspn performance using a much faster algorithm.  It is kept simple
so it works well on most targets.  It is generally at least 10 times faster
than the existing implementation on bench-strcspn on a few AArch64
implementations, and for some tests 100 times as fast (repeatedly calling
strchr on a small string is extremely slow...).

In fact the string/bits/string2.h inlines make no longer sense, as GCC
already uses strlen if reject is an empty string, strchrnul is 5 times as
fast as __strcspn_c1, while __strcspn_c2 and __strcspn_c3 are slower than
the strcspn main loop for large strings (though reject length 2-4 could be
special cased in the future to gain even more performance).

Tested on x86_64, i686, and aarch64.

	* string/Version (libc): Add GLIBC_2.24.
	* string/strcspn.c (strcspn): Rewrite function.
	* string/bits/string2.h (strcspn): Use __builtin_strcspn.
	(__strcspn_c1): Remove inline function.
	(__strcspn_c2): Likewise.
	(__strcspn_c3): Likewise.
	* string/string-inline.c
	[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c1): Add
	compatibility symbol.
	[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c2):
	Likewise.
	[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c3):
	Likewise.
	* sysdeps/i386/string-inlines.c: Include generic string-inlines.c.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/i386/string-inlines.c19
1 files changed, 1 insertions, 18 deletions
diff --git a/sysdeps/i386/string-inlines.c b/sysdeps/i386/string-inlines.c
index c7de270c0a..64d80e8eef 100644
--- a/sysdeps/i386/string-inlines.c
+++ b/sysdeps/i386/string-inlines.c
@@ -15,27 +15,10 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-/*  <bits/string.h> and <bits/string2.h> declare some extern inline
-    functions.  These functions are declared additionally here if
-    inlining is not possible.  */
-
-#undef __USE_STRING_INLINES
-#define __USE_STRING_INLINES
-#define _FORCE_INLINES
-#define __STRING_INLINE /* empty */
-#define __NO_INLINE__
-
 /* This is to avoid PLT entries for the x86 version.  */
 #define __memcpy_g __memcpy_g_internal
 #define __strchr_g __strchr_g_internal
-
-#include <string.h>
-#undef index
-#undef rindex
-
-#undef __NO_INLINE__
-#include <bits/string.h>
-#include <bits/string2.h>
+#include <string/string-inlines.c>
 
 void *
 (__memcpy_c) (void *d, const void *s, size_t n)