Still crashity crashing

[Rémi Forax]

Le 06/08/2009 00:42, John Rose a écrit :
> On Aug 5, 2009, at 8:43 AM, Rémi Forax wrote:
>
>    
>> The next room of improvement is to directly put the bytecode weaver
>> of the backport at the end of the JRuby ASM compiler.
>> I hope this will reduce the startup time.
>>      
>
> (Jumping into the middle...)
>
> Sounds like an ASM compatibility mode.  Does ASM have an option to
> automagically rewrite ldc of CONSTANT_Class into the old idiom
> (synthetic static class$ field, etc.)?

As far as I know, No !

> If so, can that pattern
> stretch another order of magnitude to support some or all of the
> backport logic?
>    

Ok, hacking JRuby, I was able to use the backport without
the agent, but that means also without the optimizer.
Basically, the code run 5 times slower with -server and
7 times slower with -client i.e not that far from the numbers
of my first report :(

John, as you see the backport needs the agent to be
able to recompile at runtime callsite target to have decent perf
so providing only a bytecode transformer is not that useful.

I have seen some small rooms of improvement in the JRuby code
(apart from replacing  DynamicMethod by MethodHandle which is
  what must be done but which is also in my opinion a more than one week 
job :)

I will send a separate email tomorrow, It's too late now.

> -- John
>    

cheers,
Rémi

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