[Vm-dev] change to struct foo {} fum declaration

Esteban Lorenzano estebanlm at gmail.com
Fri Dec 3 13:29:02 UTC 2010

Hi David, 
please, go ahead... my vmmaker image right now is polluted with alien stuff (which overrides things in vmmaker), and it will be faster if you do it :)


El 02/12/2010, a las 8:33p.m., David T. Lewis escribió:

> On Fri, Dec 03, 2010 at 12:12:20AM +0100, Igor Stasenko wrote:
>> On 2 December 2010 23:30, Esteban Lorenzano <estebanlm at gmail.com> wrote:
>>> Hi,
>>> As part of my new role, I'm still trying to compile and understand all the building process... and testing with a 5.x produced I found that the tiny benchmarks for my vm and for the 5.x series was significantly worse than it's predecessors (4.x). The difference is significative (32 million send in 5.x/44 million send in 4.x). Trying several optimizations with John, he found that changing the declaration:
>>> struct foo { ... } fum;
>>> to
>>> static struct foo { ... } fum;
>>> speeds the execution, up to 48 million send, ??which is very reasonable.
>>> So, I want to change the default definition of fum variable (to "static struct foo").
>>> What do you think?
> This change sounds fine to me. Esteban, please feel free to make
> the update to VMMaker on SqueakSource (or I will be happy to do it
> on your behalf if you prefer, just let me know). Eliot will probably
> want to make the corresponding change in the oscog branch of VMMaker
> on SqueakSource.
>> +1
>> it could change depending on compiler.. some could compile 'static' to
>> be more slower than auto.
>> and that's what we should live with.
> If it turns out to be an issue on some platforms, we can alway change
> it later, maybe using a macro that would be set at compile time. So
> no reason not to make the change now.
> Thanks!
> Dave

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