105431 - (deCOM) [meta] DeCOMtamination tasks

Status: NEW

(Core :: XPCOM, task, P5)

Description

[Chris Waterson]

Meta-bug to track removal of unneeded interface layers.

Comment 1

[Brendan Eich [:brendan]]

We need to deCOMtaminate most of the content and layout DLL internals.  Bryner's
keen to do it and just the man for the job!  I'll let him file more specific
bugs tracked here.

/be

Comment 2

[chris hofmann]

Here is our recent reportcard form performance analysis that we periodicially
get from In*&?...

-Great job with DeCOMtamination efforts
-Unnecessary virtual functions can cause a great deal of overhead –  a cache
line for each vtable & active object, indirection to call a function that isn’t
easily predicted and inefficiencies from get/setters and other small virtuals
that can’t be inlined due to calls through an interface
-Great job on reducing total instruction count per page load – probably 25%
improvement or more from 6.0 (but keep it up  - still ~1.5x vs IE)

Keep going on this!  We need the decomtamination of layout to happen as soon as
possible...

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

For anyone doing this kind of work --- after you've come up with a cleaned-up
interface, please consider appealing to drivers and super-reviewers for a
"review plus superreview in advance" blank cheque to go ahead and update all the
uses of that interface without having to get specific module owner review and
superreview for the changes.

Comment 4

[Zack Weinberg (:zwol)]

There are currently quite a few open bugs relating to deCOM; some of them have not seen attention in years.  Here is a search that will find them (as long as the string "decom" appears in the summary ;-) -- the boolean chart is necessary to avoid a bunch of false hits.

https://bugzilla.mozilla.org/buglist.cgi?short_desc=decom;resolution=---;negate0=1;field0-0-0=short_desc;type0-0-0=substring;value0-0-0=decomp;field0-0-1=short_desc;type0-0-1=substring;value0-0-1=decomm

I'm going to go through the list and ping all the old bugs, and I've marked all of the currently open ones as dependencies of this one, but let this also serve as a heads-up to reviewers and committers.