Bug 133924

Summary: Bracket access is significantly slower than property access
Product: WebKit Reporter: Ryosuke Niwa <rniwa>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: NEW    
Severity: Enhancement CC: barraclough, fpizlo, kling, mhahnenberg, mike
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Microbenchmark none

Ryosuke Niwa
Reported 2014-06-14 23:05:59 PDT
Created attachment 233135 [details] Microbenchmark function getByVal(object, property) { return object[property]; } function getById(object) { return object.myProperty; } The first function appears to be ~3.5x slower than the second function even if getByVal is always called as getByVal(object, 'myProperty'). It's only 1.5x slower on Chrome 35 and 2.2x slower on Firefox 30.
Attachments
Microbenchmark (1.03 KB, text/html)
2014-06-14 23:05 PDT, Ryosuke Niwa 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Ryosuke Niwa
Comment 1 2014-06-14 23:07:14 PDT
Note that it's 3.7x slower in the shipping Safari so it has gotten better.
Ryosuke Niwa
Comment 2 2014-06-14 23:07:27 PDT
(In reply to comment #1) > Note that it's 3.7x slower in the shipping Safari so it has gotten better. 4.7x*
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