> It's a question where you want to push the complexity of parsing the
> language and verifying the executed code. I'd image it's easier to
> evolve an ABI if we use an intermediate form ("bytecode") on the
> kernel side. Supporting multiple versions of a C-like language is
> probably going to be painful. You also probably don't want to put
> heavy-weight compiler optimization passes in the kernel so with an
> intermediate form, you can do much of that in user-space.
>
> I'm guessing this thing is expected to work on all architectures? If
> that's true, I'd forget about JIT'ing for the time being and write an
> interpreter first because it's much easier to port. There are
> techniques in making an interpreter pretty fast too. Google for
> "inlining interpreter" if you're interested.
>
> As for the intermediate form, you might want to take a look at Dalvik:
>
>
http://www.netmite.com/android/mydroid/dalvik/docs/dalvik-bytecode.html
>
> and probably ParrotVM bytecode too. The thing to avoid is stack-based
> instructions like in Java bytecode because although it's easy to write
> interpreters for them, it makes JIT'ing harder (which needs to convert
> stack-based representation to register-based) and probably doesn't
> lend itself well to stack-constrained kernel code.
