[pypy-dev] [pypy-sprint] AVM2 / Tamarin backend at the sprint

[Toby Watson]

>> [much snippage of intro to Tamarin/AVM2]

> I think this task is probably sprint-sized and relevant to PyPy. The  
> question is whether some of the core-devs would like to work on it,  
> so you can pair with that person.
>
> Then there are technical questions too, for example whether the  
> tamarin VM is good enough to actually run all the full PyPy Python  
> interpreter on top of it.
>
> Cheers,
>
> Carl Friedrich

Hi,

What do you think may be the tripping points?

- some datatype support problems? surely this is mostly a case of  
emulating the correct types modulo gross problems with the 'native'  
AVM types.

- speed. The new VM is a lot faster than the old one and has a JITer.  
I know that this has a go at all non-constructor methods as classes  
are loaded and can be very fast. AS3 is now running things like the  
Papervision3D library which is pretty CPU intensive, though I admit  
making particular type of requirements on the VM.

- some piece of machinery like the bytecode verifier getting in the  
way? AFAIK this just does relatively simple overflow checks and the  
like.

- I've also seen small schemes/LISPs running on the AVM so there's  
some confidence there.
Infact I've generated my own images using a basic stack machine  
interpreter (a bit like the PyPy JIT test toy). Additionally I've  
generated code at runtime, which is then dynamically loaded, bound to  
and executed to make the same images.

With regard to support I was mainly not expecting any unless this  
effort started to show some progress on my part and interest from  
others. However I expected to benefit from any intro talks (I think  
some were muted on 13/14?) and talking to other developers who have  
written backends. Not to mention general environment of  
industriousness ;-) Of course I'd be delighted if anyone else did  
become interested in it!

cheers,
Toby