glibc/string
Wilco Dijkstra 3ae725dfb6 Improve strstr performance
Improve strstr performance.  Strstr tends to be slow because it uses
many calls to memchr and a slow byte loop to scan for the next match.
Performance is significantly improved by using strnlen on larger blocks
and using strchr to search for the next matching character.  strcasestr
can also use strnlen to scan ahead, and memmem can use memchr to check
for the next match.

On the GLIBC bench tests the performance gains on Cortex-A72 are:
strstr: +25%
strcasestr: +4.3%
memmem: +18%

On a 256KB dataset strstr performance improves by 67%, strcasestr by 47%.

    Reviewd-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2018-07-16 17:51:52 +01:00
..
bits Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
Depend Update. 2001-03-19 21:40:15 +00:00
Makefile Unify and simplify bits/byteswap.h, bits/byteswap-16.h headers (bug 14508, bug 15512, bug 17082, bug 20530). 2018-02-06 21:55:08 +00:00
Versions New string function explicit_bzero (from OpenBSD). 2016-12-16 16:21:54 -05:00
_strerror.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-addsep.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-append.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-count.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-create.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-ctsep.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-delete.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-extract.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-insert.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-next.c Use libc_hidden_* for argz_next, __argz_next (bug 15105). 2018-02-15 21:00:02 +00:00
argz-replace.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz-stringify.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
argz.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
basename.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bcopy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bug-envz1.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
bug-strcoll1.c Update. 2001-04-26 20:45:18 +00:00
bug-strcoll2.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bug-strncat1.c Fix string/bug-strncat1.c build with GCC 8. 2017-11-14 17:50:36 +00:00
bug-strpbrk1.c Fix bug-strspn1.c, bug-strpbrk1.c build with GCC mainline. 2018-06-20 22:18:22 +00:00
bug-strspn1.c Fix bug-strspn1.c, bug-strpbrk1.c build with GCC mainline. 2018-06-20 22:18:22 +00:00
bug-strtok1.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
byteswap.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
bzero.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
endian.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
envz.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
envz.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
explicit_bzero.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
ffs.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
ffsll.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
inl-tester.c Update. 1997-09-11 12:09:10 +00:00
memccpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memfrob.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memmem.c Improve strstr performance 2018-07-16 17:51:52 +01:00
memmove.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memory.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
mempcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memrchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
memset.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
noinl-tester.c Update. 1997-09-16 00:42:43 +00:00
rawmemchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stpcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
stpncpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
str-two-way.h Improve strstr performance 2018-07-16 17:51:52 +01:00
stratcliff.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcasecmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcasecmp_l.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcasestr.c Improve strstr performance 2018-07-16 17:51:52 +01:00
strcat.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strchrnul.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcoll.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcoll_l.c Fix another -Os strcoll build issue. 2018-02-26 18:38:01 +00:00
strcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strcspn.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strdup.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strerror.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strerror_l.c libc: Extend __libc_freeres framework (Bug 23329). 2018-06-29 22:39:06 -04:00
strfry.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
string-inlines.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
string.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strings.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strlen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strncase.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strncase_l.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strncat.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strncmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strncpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strndup.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strnlen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strpbrk.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strrchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strsep.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strsignal.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strspn.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strstr.c Improve strstr performance 2018-07-16 17:51:52 +01:00
strtok.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strtok_r.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strverscmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strxfrm.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
strxfrm_l.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
swab.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-bcopy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-bzero.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-endian-file-scope.c Unify and simplify bits/byteswap.h, bits/byteswap-16.h headers (bug 14508, bug 15512, bug 17082, bug 20530). 2018-02-06 21:55:08 +00:00
test-endian-sign-conversion.c Unify and simplify bits/byteswap.h, bits/byteswap-16.h headers (bug 14508, bug 15512, bug 17082, bug 20530). 2018-02-06 21:55:08 +00:00
test-endian-types.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-explicit_bzero.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-ffs.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memccpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memcmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memcpy.c Add a test case for [BZ #23196] 2018-05-23 04:00:11 -07:00
test-memmem.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memmove.c Fix i386 memmove issue (bug 22644). 2018-03-23 16:19:45 +01:00
test-mempcpy.c Don't write beyond destination in __mempcpy_avx512_no_vzeroupper (bug 23196) 2018-05-23 09:50:57 +02:00
test-memrchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-memset.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-rawmemchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-stpcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-stpncpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strcasecmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strcasestr.c Improve strstr performance 2018-07-16 17:51:52 +01:00
test-strcat.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strchrnul.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strcmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strcpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strcspn.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-string.h Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strlen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strncasecmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strncat.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strncmp.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strncpy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strnlen.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strpbrk.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strrchr.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strspn.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
test-strstr.c Improve strstr performance 2018-07-16 17:51:52 +01:00
testcopy.c Move string/testcopy.c to test-driver.c and xmalloc (bug 19667). 2018-02-06 21:43:20 +00:00
tester.c Ignore -Wrestrict for one strncat test. 2018-06-14 14:20:00 +00:00
tst-bswap.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-cmp.c Fix tst-cmp.c build with GCC mainline. 2018-06-20 22:19:50 +00:00
tst-endian.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-inlcall.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-strcoll-overflow.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-strfry.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-strlen.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-strtok.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-strtok_r.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
tst-strxfrm.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-strxfrm2.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-svc.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-svc.expect * string/strverscmp.c (__strverscmp): Fix last cleanups. 2009-04-07 06:51:59 +00:00
tst-svc.input * string/strverscmp.c (__strverscmp): Fix last cleanups. 2009-04-07 06:51:59 +00:00
tst-svc2.c Update string tests to use the support test driver. 2017-03-23 11:32:29 -03:00
tst-xbzero-opt.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
wordcopy.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00
xpg-strerror.c Update copyright dates with scripts/update-copyrights. 2018-01-01 00:32:25 +00:00