An interesting use case - for the compiler as-is or for the essentiall idea of barely-C - might be in bootstrapping chains, i.e. starting from tiny platform-specific binaries one could verify the disassembly of, and gradually building more complex tools, interpreters, and compiler, so that eventually you get to something like a version of GCC and can then build an entire OS distribution.

Examples:

https://github.com/cosinusoidally/mishmashvm/

and https://github.com/cosinusoidally/tcc_bootstrap_alt/

Two reasons.

First, YJIT/ZJIT do much better when they know the type signatures of methods. You pay a performance penalty for implicit polymorphism, e.g. using a mix of types (Integer, Symbol, String) etc in the same method argument.

Second, from my experience with Typescript, as much as I naturally dislike type declarations, I find it does help LLMs. Having strongly typed libs/gems and being able to mix in untyped app code would be a nice balance.

I’m assuming that when you talk about crashing processes as the status quo you’re referring to earlier versions of zjit rather than current Ruby on yjit? Because I’ve never seen a Ruby process crash because + was called with different arguments.

I'm a little sad to see YJIT go down in favour of a traditional design. (Yes, YJIT isn't "deprecated" but the people working on it are now mainly working on something else. That's hardly a great place to be in.)

I'm personally quite interested in trying out an LBBV JIT for JavaScript, following in Chevalier-Boisvert's Higgs engine's footsteps. The note about a traditional method JIT giving more code for the compiler to work with does ring very true, but I'd just like to see more variety in the compiler and JIT world.

Like: perhaps it would be possible to conjoin (say) an LBBV with a SoN compiler such that LBBV takes care of the quick, basic compilation and leaves behind enough data such that a SoN compiler can be put to use on the whole-method result once the whole method has been deemed hot enough? This is perhaps a totally ridiculous idea, but it's the kind of idea that will never get explored in a world with only traditional method JITs.

I guess I’m confused why an actual add instruction is emitted rather than whatever overloaded operation takes place when the + symbol (or overloaded add vtable entry) is called (like it would in other OOP languages).