Issue 2989: Avoid the KMP overhead for simple indexOf() operations.

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Issue 2989: Avoid the KMP overhead for simple indexOf() operations. (Closed)

Created:
12 years, 3 months ago by Dean McNamee

Modified:
9 years, 7 months ago

Reviewers:
Kasper Lund, Mads Ager (chromium)

CC:
v8-dev

Visibility:
Public.

Description

Avoid the KMP overhead for simple indexOf() operations. Will look into evaluating the best cutoff between a simple search and KMP in the future. This improves some simple operations ~1.5x.

Patch Set 1 #

Patch Set 2 : Typo #

Created: 12 years, 3 months ago

Download [raw] [tar.bz2]

		Unified diffs	Side-by-side diffs	Delta from patch set	Stats (+24 lines, -7 lines)			Patch
	M	src/runtime.cc	View	1	2 chunks	+21 lines, -5 lines	3 comments	Download
	M	src/string.js	View		2 chunks	+3 lines, -2 lines	0 comments	Download

Messages

Total messages: 2 (0 generated)

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Mads Ager (chromium)

12 years, 3 months ago (2008-09-19 12:20:22 UTC) #2

LGTM

http://codereview.chromium.org/2989/diff/4/204
File src/runtime.cc (right):

http://codereview.chromium.org/2989/diff/4/204#newcode938
Line 938: // the overhead of setting up KMP.  TODO get more accurate cutoffs
here.
Either leave out the TODO or report a bug and use the bug ID here: TODO(bugid):
get more...

http://codereview.chromium.org/2989/diff/4/204#newcode941
Line 941: // the common case of the first character not matching is fast.
the the -> that the

http://codereview.chromium.org/2989/diff/4/204#newcode946
Line 946: for (int j = 1; j < pattern_length; ++j) {
I think we use j++ consistently in the rest of the code.  At least this should
be consistent with the outer for loop.

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