On 2011-03-04, at 4:52 PM, Maxime Chevalier-Boisvert wrote:
I think that technically, if we put the effort into it, we can be running in 64 bit mode some time next week. The issues relating to type size in the FFI code are not difficult to fix. There are other issues we are likely to run into, including:
- I don't think we tested our instruction encodings as extensively on
64 bits. There could be a few latent bugs there.
The x86 encoding logic was tested when it was Scheme code for the Gambit back-end. So I don't think there will be many bugs here.
- The C calling conventions are different in 64 bit mode. This would
require some more adjustments.
True. But from what I have seen in the code generator, the C register usage convention is easy to modify. So here too I don't see much work.
Personally, I've been working on preparing the current JavaScript code to support a GC. I think it's realistic to think we could have a copying GC working in two weeks. This will require some back-end modifications too. At the very least, the addition of GC maps and maps of the linked pointers inside compiled code blocks.
I think that getting a GC working is actually more work, but that the result will be worth it in the end. That being said, we also need to support 64 bit mode eventually.
I agree.
Marc