qbe-rs VS mir

You can try buildling you own backend like llvm. A good example or starting point is probably QBE since it is extremely small but very functional.

How big is the whole backend? I've heard that it is small but I wanted to compare it to QBE which is around 8 KLoC and it is quite interesting too.

I think QBE might be what you're looking for?

https://c9x.me/compile/

As far as I know, there is QBE, which is actually kinda underrated, and Cranelift, mainly designed for JIT compilation

Before that, I had spent a bit of time working with QBE, which is much simpler and really easy to write a frontend for. I switched to libgccjit though, because I got frustrated with a few of the things lacking from QBE (like the ability to easily keep track of where different variables live on the stack). I think for many hobby language projects, QBE would be a good option (my project was off the ground very fast using QBE, and I got pretty far before I ran into limitations I couldn't easily work around).

If one of your parameters is size/complexity of the backend and you prefer something smaller, have a look at qbe and cwerg

The alternatives are generally hidden inside of another compiler. The big exception seems to be qbe (https://c9x.me/compile/) however since the author appears to have written this code without peer review, it's not easy to read it's source code.

So my question is this: if a backend like QBE (~12k Loc) was added to Zig and Zig only had to compile Zig code (no C, etc) for that QBE backend -- about how many LoC would that Zig need to be?

GCC is written in C++ these days, so something like QBE(https://c9x.me/compile/) would be needed.

When you say a fork of LLVM, am I correct in assuming that you specifically mean a fork of Clang? I don't see how the compiler backend would affect support for language extensions, regardless of whether it's an exception to that such as Tcc, Cproc, the MIR C jitter, lacc, 8cc, 9cc, and chibicc. Most of those are not for production, excluding Cproc and Tcc (at least according to Suckless or Oasis).

MIR

> I wish C was scriptable

C kinda can be used as scripting language with MIR project https://github.com/vnmakarov/mir

It was released just a few days ago, and I've successfully use it as an alternative and fast C compiler with Nelua.

Like the recently released MIR jit compiler?

The compiler is written in C, and translates input code to an Abstract Syntax Tree. This is then transformed to a linear IR, which is finally translated to C code. The generated C code can be JIT compiled using the MIR backend or compiled ahead-of-time into shared library.