DynamicPrimitives

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DynamicPrimitives

With the current Squeak system, you can write primitives in Smalltalk, but must translate them into C to compile and link them to the virtual machine. This is a very slow, cumbersome process, and has hindered my work on 3D primitives so much that I started working on a way to compile primitives into machine language directly.

The current state of affairs is that I can translate CompiledMethods into an intermediate form, that is very close to real machine language. During the translation, I do a limited form of type inferencing, and based on the information gathered, message sends are either inlined or translated into appropriate machine-level operations.

I now target the PowerPC processor since that's what I have at home. But, adding other code generators should not be too difficult. As soon as PPC works, I will start adding a 68K generator, because that's what the PPC Mac can emulate directly, and after that works, a generator for the Intel family. As soon as these are done, it should be possible to add new code generators in a matter of a few days to weeks.

--Hans-Martin Mosner

Update Nov 18, 1998:
Compiling and executing the PluckedSound and SampledSound primitives is now possible.
I've also done some primitives working on Bitmaps, for example one that dithers a 32-bit Form into an 8-bit Form using an ordered dither.

Open Issues:

There's still a small problem with storing inst vars in inlined methods, which I hope to get fixed by the end of this week.
Floats are still not supported in any way.
There are no optimizations yet
The instruction selection mechanism is crude. I'll need to implement some pattern-matching algorithm before I start on other architectures.

Code is available at http://www.heeg.de/~hmm/squeak/Translator-981121/