> it might be useful to file a ticket in the Chromium issue tracker

I agree, it sounds like a perf bug in Chrome. Best thing is to file an
issue for them to take a look at.

On Tue, Aug 11, 2015 at 8:19 AM, Floh <[email protected]> wrote:

> No, sorry, no idea. I try to avoid the C++ RTTI system ;)
>
> I was thinking about tweaking the outlining-limit (see:
> http://mozakai.blogspot.de/2013/08/outlining-workaround-for-jits-and-big.html),
> if the generated code contains very large functions, JS engines may not
> optimize them. I was bitten by this problem a long time ago with sqlite. If
> this would be a problem you would get warnings about large functions in the
> linker step.
>
> But dynamic_cast, I have no idea what the problem could be... even if it
> is used heavily I couldn't imagine what would be so expensive about it.
>
> Is the performance in Firefox roughly the same as a native optimized
> executable, or is this also a lot slower?
>
> An isolated test case might be helpful, it could actually be a more
> serious code generation issue and/or a pathological case for Google's JS
> engine (in this case it might be useful to file a ticket in the Chromium
> issue tracker).
>
> Cheers,
> -Floh.
>
>
> Am Dienstag, 11. August 2015 16:05:39 UTC+2 schrieb Laurent Pugin:
>>
>>
>>> I would advice to compile your code with optimization on and -g2
>>> (preserves function names), and then use Chrome's JS profiler (part of
>>> Chrome Developer Tools panel). This should give you an idea what functions
>>> are especially slow and perhaps provide a hint which C/C++ code is the
>>> problem.
>>>
>>
>> It seems that dynamic_cast takes quite some of the time (nearly 50%?).
>> Any thoughts?
>>
>> --
> You received this message because you are subscribed to the Google Groups
> "emscripten-discuss" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> For more options, visit https://groups.google.com/d/optout.
>

-- 
You received this message because you are subscribed to the Google Groups 
"emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to