A Linux system running over JavaScript [LWN.net]

A Linux system running over JavaScript

Posted May 18, 2011 6:50 UTC (Wed) by przemoc (guest, #67594)
In reply to: A Linux system running over JavaScript by kripkenstein
Parent article: A Linux system running over JavaScript

Not sure whether it is the same problem in Chrome dev as in beta, but if the answer is yes, then you can track the issue here:

http://code.google.com/p/chromium/issues/detail?id=82828

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A Linux system running over JavaScript

Posted May 18, 2011 16:22 UTC (Wed) by nlucas (subscriber, #33793) [Link] (1 responses)

They seem to have identified the problem as a bug on the javascript optimization compiler:

http://code.google.com/p/v8/issues/detail?id=1394#c2

A Linux system running over JavaScript

Posted May 26, 2011 7:18 UTC (Thu) by przemoc (guest, #67594) [Link]

Just a follow-up.

http://codereview.chromium.org/7037023

It's theoretically addressing v8 issue 1394, but in fact it's more about Chromium issue 82828. The problem of v12/13 was just briefly mentioned in "PC emulator is about 2 times slower using V8 than Jaeger Monkey" report and did not have deserving separate issue in v8 project.

> Fix bug in optimized compiler's switch-statement.
>
> In the case where the default-clause occurs as the first clause, the case-blocks were not wired up correctly.

So it was a matter of extracting non-NULL check equivalently from if block into inner if. That shouldn't be really needed in obtaining correct behavior though...

Speed deficiency (when compared to Fx) remains for the time being.