The Cacao interpreter
The Cacao Java VM contains a
fast interpreter (not quite as fast as the JIT, but more portable).
Building and using the Cacao interpreter
Unfortunately the Cacao maintainers focus on the JIT compiler and
don't really maintain the intepreter. Now and then they make changes
that break the interpreter and then don't fix it, so in some releases
of Cacao the interpreter is broken. A known-good version is Cacao-0.97
(download)
working with Classpath 0.92.
To build it, you need vmgen, which comes with
Gforth
(available as a package on many popular platforms). When you build
it, IIRC you have to specify that you want to build the interpreter.
When you run the interpreter, you have to use
-noverify, or Cacao will crash.
If you have trouble building it, please let me know, and I will
work out how I did it and add a transkript here (and mail it to you).
If you are successful, please mail me a transcript and I will replace
this paragraph with it (with attribution).
Papers
- A
Fast Java Interpreter
- gives an overview of the Cacao interpreter.
- Implementing
an Efficient Java Interpreter
- has quite a bit of overlap with
"A Fast Java Interpreter
- vmgen - A
Generator of Efficient Virtual Machine Interpreters
- discusses
Vmgen and its capabilities in general, but also its use to implement
the Cacao interpreter and some performance results.
- Superinstructions
and Replication in the Cacao JVM interpreter
- about the
problems of implementing these optimizations in a JVM interpreter, how
to solve them, and how much speedup we get (up to a factor of 4).
Anton Ertl