656665 - Huge Javascript performance difference with chromium on this testcase

Status: RESOLVED INCOMPLETE

(Core :: JavaScript Engine, defect)

Description

[Cedric Pinson]

User-Agent:       Mozilla/5.0 (X11; Linux i686) AppleWebKit/534.24 (KHTML, like Gecko) Ubuntu/11.04 Chromium/11.0.696.65 Chrome/11.0.696.65 Safari/534.24
Build Identifier: Mozilla/5.0 (X11; Linux i686; rv:2.0.1) Gecko/20100101 Firefox/4.0.1

I run the url on chromium, it run at 20 fps. I close it and run it on firefox 4.01 and I have 2 fps.
It's a typical scene to stress the browser with javascript and webgl drawelements

Reproducible: Always

Steps to Reproduce:
1.run it on chromium http://osgjs.org/osgjs/examples/performance/performance.html?Stats=1
2. then run it on firefox http://osgjs.org/osgjs/examples/performance/performance.html?Stats=1
3.

Actual Results:  
on my hardware I have 20 fps vs 2 fps

Comment 1

[Boris Zbarsky [:bzbarsky]]

Looking at a profile (on Mac, where I see us at 6fps while Chrome is at 20fps):

  60% of the time is spent in mjit-generated code.
  17% is under drawElements on the WebGL context.
   9% under UniformMatrix4fv; lots of making contexts current here.
   5% under js::mjit::stubs::GetElem (pure JS; this is NOT hitting the DOM), of
      which 1/3 is self time in js::PropertyTable::search.
   4% under stubs::GetProp (again, pure JS with no DOM involved)
   2% creating call objects
   2% creating arrays

Over to JS engine, because this seems like primarily a JS problem, not a graphics one.  

I'm a little confused by all the GetElem there; is the script indexing into non-array objects with numeric indices?

Cedric, would you be willing to put together a standalone example (one not linking to any resources on your server) that can be attached to this bug to make sure it doesn't go away?

Comment 2

[Cedric Pinson]

Attachment: sample test

Here the files to run the performance.html locally

Comment 3

[Mayank Bansal]

The original URL doesnt work, and does not exist on wayback mahchine. The attached testcase has some errors on both Chrome and Nightly. Closing this.