pmc2c-multi-nativepccmethod branch ready for testing

[Jonathan "Duke" Leto]

Howdy,

Correctness wins over performance every time, so I am +1 for this
branch to merge.

Duke

On Fri, Mar 11, 2011 at 3:17 PM, Peter Lobsinger <plobsing at gmail.com> wrote:
> On Fri, Mar 11, 2011 at 5:57 PM, Jonathan "Duke" Leto <jonathan at leto.net> wrote:
>> Howdy,
>>
>> Peter, can you comment on the possible performance-related changes
>> that this branch could cause?
>
> We took a small hit for the indirection NCI caused. We're not doing
> that anymore, so it should be a little faster.
>
> MULTIs that aliased vtables used switch statements to dispatch based
> on their second argument. This optimization was not faithful to the
> MMD algorithm, leading to slight discrepancies (and outright wrong
> code in some corner cases). So while this aspect may have gotten
> slower, it was a change from fast and wrong to slow and correct. If
> the switch behaviour is desired, it should be made explicit, in stead
> of pretending to be MMD when it is not.
>
>> Have you done any benchmarks?
>
> No. The focus of this branch was correctness and decoupling.
> Performance was not of primary concern and is unlikely to be affected
> in any major way.
>
>> Duke
>>
>> On Fri, Mar 11, 2011 at 2:35 PM, Peter Lobsinger <plobsing at gmail.com> wrote:
>>> The pmc2c-multi-nativepccmethod branch changes the implementation of
>>> MULTIs in .pmc files from NCI to NativePCCMethod. This means that
>>> these now handle their own PCC, in stead of rellying on NCI thunks to
>>> accomplish this. These can now be modified to access a more broad
>>> range of PCC functionality. On the NCI side of things, this
>>> unentangles NCI from Pmc2c, allowing for changes to proceed.
>>>
>>> At the current time, the branch passes all tests in core and I am
>>> testing HLLs. Please test this with whatever you see fit.
>>> _______________________________________________
>>> http://lists.parrot.org/mailman/listinfo/parrot-dev
>>>
>>
>>
>>
>> --
>> Jonathan "Duke" Leto
>> jonathan at leto.net
>> http://leto.net
>>
>



-- 
Jonathan "Duke" Leto
jonathan at leto.net
http://leto.net