827995 - Avoid spending a lot of time in sprintf while assembling for ARM

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

Attachment: Avoid spending a lot of time in sprintf while assembling for ARM

During a profile of JS execution on B@G we're spending 10% of the time in __vfprintf. At least some of this is in the arm assembler. Since we're not actually using the strings we're printing we'd be better off not printing them.

Comment 1

[Benoit Girard (:BenWa)]

This appears to come, in part at least, from the initial check in of bug 564953.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ae69e98751c5

Comment 3

[(no longer active)]

You broke the builds, Jeff!

https://hg.mozilla.org/integration/mozilla-inbound/rev/ee1c423e8ac3

Comment 4

[Jeff Muizelaar [:jrmuizel]]

And relanded
https://hg.mozilla.org/integration/mozilla-inbound/rev/de0adc1cf18a

Comment 5

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

Boy it'd be great to get this into B2Gv1!

Comment 6

[Doug Turner (:dougt)]

Comment on attachment 699395 [details] [diff] [review]
Avoid spending a lot of time in sprintf while assembling for ARM

[Triage Comment]

Comment 7

[Doug Turner (:dougt)]

not blocking.  uplift sounds great.

Comment 8

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/de0adc1cf18a

Comment 9

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 699395 [details] [diff] [review]
Avoid spending a lot of time in sprintf while assembling for ARM

[Approval Request Comment]
Regression caused by (bug #): We've had this problem for a long time.
User impact if declined: Slower JS compilation on ARM
Testing completed (on m-c, etc.): on m-c
Risk to taking this patch (and alternatives if risky): Just disables some debug code that should've been disabled. There should be basically no risk to this at all.

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g18/rev/6186a47b9d91

Comment 11

[bhavana bajaj [:bajaj]]

Comment on attachment 699395 [details] [diff] [review]
Avoid spending a lot of time in sprintf while assembling for ARM

Considering where we are in the cycle (5 more beta's before release :) )and based on the risk profile of this bug vs the perf win, approving on branches

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/5c4c8602cf44
https://hg.mozilla.org/releases/mozilla-beta/rev/5afdcf09bae7