597446 - YARR repeatedly re-jits the same regexp(s)

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Julian Seward [:jseward]]

This is with m-c, 15 Sept 10.  STR: build Fx on a valgrind capable platform.

Then run it, with valgrind flags 
"--tool=none --trace-flags=10000000 --smc-check=all"

and load http://news.bbc.co.uk

V prints out one line per basic block it has to translate.  Before YARR it
would translate roughly 250k blocks to start fx and load said URL.  Now, it
never comes to rest.  

Once the initial mass of startup translations have been made, it makes a 
bunch of translations (400 ish) every time the ticker line towards the top
of the web page starts to fade.

Most of the translations valgrind makes are labelled with a symbol name 
and offset, so you can see what it is doing.  But the ones that this bug
concerns are nameless, which is usually a sign that V is dealing with
unlabelled (dynamically generated) code.

Comment 1

[Ryan VanderMeulen [:RyanVM]]

Is this bug valid with lazy compilation?

Comment 2

[Chris Leary [:cdleary] (not checking bugmail)]

We should verify that we can't see valgrind churning on the BBC page, but it was hopefully fixed by bug 634654.

Comment 3

[Till Schneidereit [:till]]

Mass-reassigning cdleary's bugs to default. He won't work on any of them, anymore. I guess, at least.

@cdleary: shout if you take issue with this.

Comment 4

[Chris Peterson [:cpeterson]]

This bug is no longer relevant because we replaced YARR with irregexp in Firefox 32 (bug 976446).