lineiform VS strop

Sounds similar to lineiform. Which isn't all that stable or actively developed, but it is a cute approach to writing a meta-jit in rust. It's a weird approach, but IMO it's worth more experimentation.

Working on Lineiform, my meta-JIT library, some more.

In response to Cranelift, switching to my own Tangle IR won't be using Cranelift at all (it uses raw dynasm-rs for emitting instructions). I go into a bit in https://github.com/chc4/lineiform/issues/19, but Cranelift specifically has some rules about iflags, the type they use to conceptualize processor flags effects (e.g. add's carryout or overflow). You can only have one iflags value live at a time, and it can't overlap with any other math operation. This is a problem because the x86 we're lifting doesn't always follow that rule, so if we just emit Cranelift as we go it will panic and say we built an invalid function.

I go into a bit in https://github.com/chc4/lineiform/issues/19, but it's less a problem with its optimizer and more a problem with its IR constraints. Cranelift specifically has some rules about `iflags`, the type they use to conceptualize processor flags effects (e.g. add's carryout or overflow). You can only have one `iflags` value live at a time, and it can't overlap with any other math operation. This is a problem because the x86 we're lifting doesn't always follow that rule, so if we just emit Cranelift as we go it will panic and say we built an invalid function.

The iflags design in general is kinda awkward too, and was being rethought a few months ago when I was first getting this working; I think they're planning on redesigning the add carryout interface and things to be slightly more streamlined. I suspect that any redesigned interface will have similar problems with mismatch between what I want from Cranelift and what 90% of other uses of Cranelfit want, though, and so I decided to just make my own IR instead.

Working on the codegen backend for Lineiform again. I sketched out a plan on how to implement register allocation in a way that hopefully doesn't have horrible behavior in the majority of cases, and implemented ~half of it last week, and hopefully I'll implement the other half and instruction scheduling this week.

Yup, https://github.com/chc4/lineiform. It's not usable at all yet - I was building it on top of Cranelift, which turned out to be a fairly bad idea, so I'm going to have to essentially rewrite all of it with my own codegen backend I think. I've been hacking on it on and off but it's been much slower progress due to work (and writing a codegen backend is hard...)

I got struck by either a very dumb or very good idea a few days ago, and finally have a working (minimal) proof-of-concept for it: Lineiform is a meta-JIT library to nearly automatically get an optimizing method JIT from a Rust interpreter. It does dynamic recompilation on closures by lifting from x86 to Cranelift IR for runtime function inlining and constant propagation.

I am completely rewriting strop, (the code sucks, and I know Rust a lot better than when I started, so I wanted to make it a bit better structured and more idiomatic). And I like to have static analysis make sure my code has certain qualities, so I stick this:

Do you think it's an architecture for strop then? It has a focus on code-generation on platforms not well supported by mainstream compilers

Here is a project for generating code for CPUs that do not have much support from mainstream compilers. Currently supported are the 6502 and the STM8 (I'll possibly be adding others in the future, feature requests welcome).

I could use some help on my project strop. Feel free to take a look and see if it's the kind of thing you feel you could contribute to! but be aware that the quality of the codebase is poor. There's a pull request to address this though.

It is my first time of making a Rust library. Actually, my project strop has been a binary crate and only recently have I started trying to use it from a different crate. This is happening on the breakapart branch.

Still working on a big rewrite of strop.

If you're offering free help, then I could use some help with my project strop. (TL;DR: instead of compiling code, it's evolving code. And it has a focus on architectures that don't have good support from mainstream compilers, but I'm open to adding other architectures as well).

My frustration with this kind of situation (and PICs are not unique here, the 6502, CP1600 and other very low end chips have similarly problematic toolchaining) led me to invent strop, for evolving code sequences. It has some basic PIC support.

Hadn't thought of this. I even encountered it recently too.

I am still working on strop. (TL;DR alternative to compiled code, it's evolved code. Tell it which function you want and which registers to use, and it'll randomly generate an assembly language program that does what you wanted)