1118937 - 20% slowdown on non-odin asmjs-ubench-skinning on 32-bit awfy, around PJS removal

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, defect)

Description

[Alon Zakai (:azakai)]

The range for the slowdown is

http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=46bd519c8e2b&tochange=0be44e8bf22a

which includes PJS removal bugs, bug 1117753, bug 1117735, bug 1117764.

Comment 1

[Lars T Hansen [:lth]]

If the PJS removal is the source of the regression then the regression is almost certainly caused by perturbations in object code for the GC, since a bunch of GC code that was previously active on Nightly - in the form of checks for whether the nursery was the ForkJoin nursery, and some functions defined on multiple nursery types - no longer is.  In particular I could imagine some functions that were previously not inlinable due to size or complexity becoming inlinable after these patches landed.

Comment 2

[Alon Zakai (:azakai)]

Looks like the regression went back down with the landing of bug 1118038. It does sound like some kind of minor perturbations, I guess we can close this.