Re: [Sablevm-developer] Extending SableVM with static stack caching

[Etienne G. <gag...@uq...>]

Hi Heinrich,

Heinrich Moser wrote:
> As my master's thesis (I'm a computer science student) I want to
> evaluate static stack caching. That's an interpreter technique where
> you keep the top n stack items in registers to minimize the amount of
> necessary memory move operations.
> 
> So what I'm planning to do is to take an existing JVM, run some
> benchmarks, implement static stack caching (e.g. using vmgen), run the
> benchmarks again and evaluate the results.
> 
> Therefore, I need a JVM that's (a) stable enough to run the benchmarks
> and (b) has clean code so that it is easy to extend. As far as I can
> tell from what I've read online, SableVM would be a good choice.
> 
> Now I thought I'd ask you a few questions before proceeding:
> 
> * What version should I use?

Currently: The "staging" version.  It's the best one available for the moment.
Soon, Greg (Grzegorz) and David will release a "bugfree" version which would
also be an interesting candidate.

Ideally, whichever version you pick, you should be working within a
Subversion working copy, so that you can easily extract "patches" against
a "precise" version, e.g.

$ svn info
....  // precide info about what you were working against
$ svn diff
... // "unified diff" of your changes against the code in the Subversion repository

> * Did someone already try some benchmarks on SableVM?

Look in my Ph.D. thesis for some performance numbers.  Others (Greg, David, Chris...)
might have additional information.  (BTF, AshesX, ... ???)

> * Any other comments or suggestions?

Just that you are very welcome to use SableVM and comment back about any improvement
you would suggest.

> Some other comments:
> 
> * "Stable" (as mentioned on <http://www.sablevm.org/getit.html>)
>   doesn't seem to be available -- at least I couldn't find a link to
>   it anywhere.

This is intentional, as the latest stable version uses a much too old
GNU Classpath snapshot.

> * The Wiki cannot be edited with IE or Opera. The reason is the
>   <plaintext> tag that's used to display the LGPL. <plaintext> cannot
>   be turned off (see RFC 1866: there is no </plaintext>) and is highly
>   deprecated.

I'll leave this to Greg, our web/admin master.

> * Although <http://devel.sablevm.org/docs/INSTALL.txt> claims that
>   only libart-dev is required for SABLEVM-CLASSPATH, you (also?) need
>   libart-2.0-dev to configure successfully.


I'll let Greg investigate this, too. :-)

> * I didn't really test it in-depth but SableVM seems to run well on my
>   testing system (user-mode-linux on i386 with Debian sarge/testing).

Super.

Have fun!

Etienne

-- 
Etienne M. Gagnon, Ph.D.             http://www.info.uqam.ca/~egagnon/
SableVM:                                       http://www.sablevm.org/
SableCC:                                       http://www.sablecc.org/