[Vm-dev] #becomeUncompact not longer works in Cog/Stack VMs

[Mariano Martinez Peck]

On Sat, May 7, 2011 at 4:09 PM, Andreas Raab <andreas.raab at gmx.de> wrote:

>
> On 5/7/2011 2:33, Colin Putney wrote:
>
>>
>> On Fri, May 6, 2011 at 5:18 PM, Igor Stasenko<siguctua at gmail.com>  wrote:
>>
>>  No. its nothing to do with performance. It is about getting rid of
>>> them as a concept.
>>>
>> Well, if fixing it makes Cog slower, then it *is* about performance.
>>
>> Just making everything uncompact without changing the image format
>> doesn't really buy us much: it would make Cog slower and the image
>> bigger with no benefit. The benefit comes from having a new image
>> format that is optimized for speed rather than space - getting rid of
>> compact classes would just be a side-effect of the new format.
>>
>
> And interestingly, Eliot's proposal for a new format actually gets rid of
> the class pointer and makes "everything" a compact class.
>

I like this proposal, but wouldn't this have also an overhead?  I mean, ok,
we don't have to pay for the ifs to check whether a class is compact or not,
but we are gonna to pay always the indirection (which right now is only for
compact classes). You know much more than me so probably this overhead is
smaller that today.

cheers


-- 
Mariano
http://marianopeck.wordpress.com
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