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| author | Wilco Dijkstra <wdijkstr@arm.com> | 2016-03-25 16:44:26 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2016-04-01 10:44:40 -0300 |
| commit | d3496c9f4f27d3009b71be87f6108b4fed7314bd (patch) | |
| tree | eefcd05beb1f6ed269167433a763c234483b7c0b /ChangeLog | |
| parent | d8a012c5c9e4bfc1b8db2bc6deacb85b44a2e1eb (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 'ChangeLog')
| -rw-r--r-- | ChangeLog | 18 |
1 files changed, 18 insertions, 0 deletions
@@ -1,3 +1,21 @@ +2016-04-01 Wilco Dijkstra <wdijkstr@arm.com> + Adhemerval Zanella <adhemerval.zanella@linaro.org> + + * 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. + 2016-04-01 Stefan Liebler <stli@linux.vnet.ibm.com> * sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve): |