luajit-remake VS idel

It's really cool that Haoran Xu copy-and-patch technique is catching on, I remember discovering it through his blog posts on applying these techniques to his own LuaJIT remake project[0][1] (and I probably found those through a post here). I highly recommend them if you're into that sort of thing, BTW. They're incredible deep dives, but he uses the details-element to keep the metaphorical descents into Mariana Trench optional so it doesn't get too overwhelming.

I even had the privilege of congratulating him the 1000th star of the GH repo[2], where he reassured me and others that he's still working on it despite the long pause after the last blog post, and that this mainly has to do with behind-the-scenes rewrites that make no sense to publish in part.

[0] https://sillycross.github.io/2022/11/22/2022-11-22/

[1] https://sillycross.github.io/2023/05/12/2023-05-12/

[2] https://github.com/luajit-remake/luajit-remake/issues/11

This seems like an awesome way of writing faster interpreters – i.e. not in assembly, but in C++ snippets you stitch together with a tool.

I did peek at the deegen tool a bit, and it seems quite large? https://github.com/luajit-remake/luajit-remake/tree/master/d...

I would be interested in an overview of all the analysis it has to do, which as I understand is basically “automated Mike Pall”

FWIW I think this is the hand-written equivalent with LuaJIT’s dynasm tool: https://github.com/LuaJIT/LuaJIT/blob/v2.1/src/vm_x64.dasc (just under 5000 lines)

Also there are several of these files with no apparent sharing, as you would get with deegen:

https://github.com/LuaJIT/LuaJIT/blob/v2.1/src/vm_x86.dasc

https://github.com/LuaJIT/LuaJIT/blob/v2.1/src/vm_ppc.dasc

There was a wasm predecessor (by, well, me) with a bit more of the Forth flavor: https://github.com/darius/idel

From >20 years ago and my main regret is a failure to carry it through to be more than a demo.

I don't know -- there were at least a couple papers about it, but I haven't been following. At the time it was first announced I used some of the ideas in one of my projects (https://github.com/darius/idel/blob/master/src/opcodes.awk) but unfortunately didn't develop it further.

Thanks, Chris!

Another interesting thing that came out of the object-capability ferment around E and EROS was Darius Bacon's Idel secure virtual machine: https://github.com/darius/idel

Though no other software is as influential as JS, other currently influential ocap systems include Genode, most of the current implementations of L4 (including seL4), and CHERI.