Uses the lower byte with memchr which is
significantly faster than a naive compare
Performance difference with bench (http://hastebin.com/xuxexataso.js):
old new
single character single character
Κ found at 922 Κ found at 922
3324 616
㎡ found at 13217 ㎡ found at 13217
42366 4931
က found at 4096 က found at 4096
13369 9836
found at 65280 found at 65280
207472 36149
ﾥ found at 65445 ﾥ found at 65445
209344 36666
found at 8197 found at 8197
26731 11757
倂 found at 20482 倂 found at 20482
66071 17193
linear search linear search
ΚΛ found at 922 ΚΛ found at 922
4112 504
㎡㎢ found at 13217 ㎡㎢ found at 13217
55105 5119
ﾥﾦ found at 65445 ﾥﾦ found at 65445
268016 35496
linear + bmh search linear + bmh search
ΚΛΜΝΞΟΠΡ found at 922 ΚΛΜΝΞΟΠΡ found at 922
2897 522
ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445 ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445
167687 35283
BUG=
Review URL: https://codereview.chromium.org/1324453007
Cr-Commit-Position: refs/heads/master@{#30597}
Reason for revert:
[Sheriff] Breaks fuzzer and msan:
http://build.chromium.org/p/client.v8/builders/V8%20Fuzzer/builds/4773
Repro with:
tools/fuzz-harness.sh out/Debug/d8
(in a ninja Debug build)
Msan:
http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20MSAN/builds/4097
Original issue's description:
> Speedup stringsearch for two byte strings
>
> Uses the lower byte with memchr which is
> significantly faster than a naive compare
>
> Performance difference with bench (http://hastebin.com/xuxexataso.js):
>
> old new
>
> single character single character
> Κ found at 922 Κ found at 922
> 3324 616
> ㎡ found at 13217 ㎡ found at 13217
> 42366 4931
> က found at 4096 က found at 4096
> 13369 9836
> found at 65280 found at 65280
> 207472 36149
> ﾥ found at 65445 ﾥ found at 65445
> 209344 36666
> found at 8197 found at 8197
> 26731 11757
> 倂 found at 20482 倂 found at 20482
> 66071 17193
>
> linear search linear search
> ΚΛ found at 922 ΚΛ found at 922
> 4112 504
> ㎡㎢ found at 13217 ㎡㎢ found at 13217
> 55105 5119
> ﾥﾦ found at 65445 ﾥﾦ found at 65445
> 268016 35496
>
> linear + bmh search linear + bmh search
> ΚΛΜΝΞΟΠΡ found at 922 ΚΛΜΝΞΟΠΡ found at 922
> 2897 522
> ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445 ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445
> 167687 158465
>
> Committed: https://crrev.com/fced280f37588f8a232a414201276e053117e9ea
> Cr-Commit-Position: refs/heads/master@{#30587}
TBR=danno@chromium.org,mstarzinger@chromium.org,jkummerow@chromium.org,karl@skomski.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1331433002
Cr-Commit-Position: refs/heads/master@{#30588}
Uses the lower byte with memchr which is
significantly faster than a naive compare
Performance difference with bench (http://hastebin.com/xuxexataso.js):
old new
single character single character
Κ found at 922 Κ found at 922
3324 616
㎡ found at 13217 ㎡ found at 13217
42366 4931
က found at 4096 က found at 4096
13369 9836
found at 65280 found at 65280
207472 36149
ﾥ found at 65445 ﾥ found at 65445
209344 36666
found at 8197 found at 8197
26731 11757
倂 found at 20482 倂 found at 20482
66071 17193
linear search linear search
ΚΛ found at 922 ΚΛ found at 922
4112 504
㎡㎢ found at 13217 ㎡㎢ found at 13217
55105 5119
ﾥﾦ found at 65445 ﾥﾦ found at 65445
268016 35496
linear + bmh search linear + bmh search
ΚΛΜΝΞΟΠΡ found at 922 ΚΛΜΝΞΟΠΡ found at 922
2897 522
ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445 ﾥﾦﾧﾨﾩﾪﾫﾬ found at 65445
167687 158465
Review URL: https://codereview.chromium.org/1303033012
Cr-Commit-Position: refs/heads/master@{#30587}
This shaves 416+ KB, just under 1% off the size of the debug d8 executable
on Linux (mostly because the CheckHelper functions for assertions were
getting separate copies for each compilation unit). The difference in
release builds is negligible---a size reduction of 0.1%.
Also, change namespace-level 'static const' variables to remove the static
storage class as it's the default.
R=danno@chromium.org
BUG=
TEST=
Review URL: http://codereview.chromium.org/8680013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10083 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
