Re: [Qemu-devel] [PATCH 6/8] tcg: Add bytecode generator for tcg interpreter

[Andreas Färber]

Am 01.10.2011 23:25, schrieb Stefan Weil:
> Am 01.10.2011 18:54, schrieb Andreas Färber:
>> Am 17.09.2011 22:00, schrieb Stefan Weil:
>>> +The bytecode consists of opcodes (same numeric values as those used by
>>> +TCG), command length and arguments of variable size and number.
>>
>> While reusing TCG opcode values certainly makes things easy to
>> implement, have you evaluated using LLVM bitcode as alternative to a
>> fully custom intermediate code format?
> 
> I had a look on several bytecode representations - initially I thought
> of using Java. LLVM was on my list, too, but I cannot say that I really
> evaluated any of these alternatives. My primary goal was to learn more
> about TCG and to get something working, and as you said, reusing the
> TCG opcodes made things easier.

Okay, just thought I'd ask the blunt question. :)

We should be careful not to expose it to outside processes as discussed
elsewhere in the thread or we will have to start caring about ABI
versioning.

> LLVM might also be used as a replacement for TCG.
> It would be really interesting to see how both compare.

Maybe suited for a GSoC project?

Andreas