496450 - TM: 3x performance loss with JIT on Ball Pool demo.

Status: RESOLVED DUPLICATE of bug 479090

(Core :: JavaScript Engine, defect)

Description

[Sylvain Pasche]

I noticed this on this demo:
http://mrdoob.com/projects/chromeexperiments/ball_pool/

Try to click and drag in the window to add some balls. When the screen is nearly filled, the demo gets very sluggish.
I've modified this demo to remove all drawing operations/randomness in order to get some numbers. The following url runs 100 iterations in a 800x600 pool with 100 balls without drawing and reports the time it takes:
http://www.spasche.net/files/testcases/ball_pool/?iterations=100&balls=100&norand=1&nopaint=1

Fx 3.0: 6.5
Fx 3.6, JIT off: 5.5
Fx 3.6, JIT on: 16.75 (3x slower than non JIT)

And how others are doing:
Opera 10 beta: 4.8
Safari 4: 3.0
Chrome 3: 1.5

That demo is using the Box2DJS library (http://box2d-js.sourceforge.net/).

I'll try to reduce the testcase when I have a chance.

Comment 1

[David Mandelin [:dmandelin]]

Dup of bug 479090?

Comment 2

[Sylvain Pasche]

yeah that should be the same issue. The same library is used and the demo just calls into it.