[Vm-dev] Re: Direct object pointers vs indirect ones pros and cons

Javier Burroni javier.burroni at gmail.com
Wed Oct 26 22:50:51 UTC 2011


> But taking a register away from e.g. the calling convention has costs, especially on x86 (6 user registers).
Agree. I can use one register in the environment I'm using, but is not
costless (one extra push in methods with block closure
instantiations).
> But what is selfID?  Is that the object table index for self, or something related to self's class or?
selfId is simple the object table index for self.

But the point that I wanted to make was the no overhead when accessing
ivars, and the gain in gc


saludos
jb

ps: for completeness. When optimizing message send to self, the
instance check must be perform (over self and not selfId), as #become:
may be sent to self
>>
>> saludos
>> jb
>>
>>
>> --
>> View this message in context: http://forum.world.st/Direct-object-pointers-vs-indirect-ones-pros-and-cons-tp3039203p3942123.html
>> Sent from the Squeak VM mailing list archive at Nabble.com.
>
>
>
> --
> best,
> Eliot
>
>



-- 
" To be is to do " ( Socrates )
" To be or not to be " ( Shakespeare )
" To do is to be " ( Sartre )
" Do be do be do " ( Sinatra )


More information about the Vm-dev mailing list