inkwell VS mold

Secondly, I have learned about LLVM, and I have learned about the Inkwell library on Rust (It's a New Kind of Wrapper for Exposing LLVM (Safely)). Has anyone used this library before? Is this a good practice? Is it suitable for my compiler? Can I write some optimization passes of my own using this library?

inkwell is a great llvm binding for rust and it has an implementation of kaleidoscope

I'm working on a compiler that uses the LLVM wrapper Inkwell for compilation. In order to compile something in inkwell, unless I'm missing something (which I very well might be), you need two structs:

Compiler backends (If building JIT/machine compiled langauges) 1. cranelift 2. inkwell - safe rust wrapper around llvm

I'm currently using the Inkwell bindings for Rust, which I've found actually pretty nice. In terms of generating LLVM IR, the C bindings (which is what Inkwell uses internally) can do anything you want them to (definitely not limited to trivial languages as someone else here said.) I'm even using the LLVM garbage collection infrastructure, with no problems (well, no problems in generating it; the LLVM GC infrastructure works pretty well but is sparsely documented, so actually writing a GC is fairly difficult, but it's doable). The C bindings are actually more stable than the C++ bindings (!), although not quite as stable as the textual IR format; but without the bindings you would have to write code to generate the IR yourself, the compiler would be slower as it must be emitted as text and then reparsed in a different process, and you would have less control over optimization.

safe llvm bindings https://github.com/TheDan64/inkwell

As we reviewed in this article LLVM IR has many use-cases and allows us to analyze and optimize source code through its passes. Knowing IR language itself will help us to write our passes and build projects around it for debugging, testing, optimizing. Currently, LLVM IR doesn't have Rust API. It's mainly used through the C++ library. However, some user-created repos are available on crates.io. There is a Rust binding to LLVM's C API - llvm-sys and two other, more Rusty APIs that are using LLVM: inkwell and llvm-ir. And finally, if you want to learn how to write a LLVM pass you should start here.

The high level crate is called inkwell.

https://github.com/TheDan64/inkwell is about as high-level as it gets (from what I've seen). It's based on top of llvm-sys, which is thankfully kept up-to-date with the LLVM releases.

On a side note, there are good high level bindings to llvm-sys, inkwell

I assume this submission is trying to highlight the specific message (2023-01-24) : https://github.com/rui314/mold/issues/190#issuecomment-14028...

Fyi... the author wrote a more expansive blog post about selling dev tools a few months later (2023-06-06) and there was a related HN thread about it: https://news.ycombinator.com/item?id=36225016

It looks like HN automatically stripped the comment I originally linked to: https://github.com/rui314/mold/issues/190#issuecomment-14028.... The title should be more clear in this context.

I'm amazed at how quickly the author responds to requests: https://github.com/rui314/mold/issues/1057

From the report to the fix in less than two days.

I'm not sure how competitive it will be with lld, especially if we consider ThinLTO (which takes multiple minutes on 64-core machine) - it can make the advantages of mold insignificant.

> it wasn't worth the hassle

Did the authors say that? According to their changelog [1] they stated "we've been attempting to monetize our product...this approach didn't meet our expectations...we don't want to persist with a strategy that didn't work well" which I infer to mean they didn't sell enough licenses.

Even if selling licenses is a hassle, then that indicates a problem with the open source ecosystem as GitHub and other code hosting websites should offer monetization tools for selling closed-source licenses directly from their web interface. I'm talking legal forms, templates, payment processors, and product tracking. Selling licenses should be easy, not a hassle.

[1] https://github.com/rui314/mold/releases/tag/v2.0.0

> Mold did it first, though: https://github.com/rui314/mold

Before LLD?

The problem is not Apple-specific and actually can (and perhaps will) be spread elsewhere

The specific optimization this achieves is during build time only: these new files are primarily quicker to link static libraries. It is a small shift of some of the linking pipeline into the (parallel) builds of dependencies, rather than heaping it all onto the linker at the end of the build, having to essentially re-link from scratch for every small change

Parallelization has long been known as the best way to speed up linking. This change comes in addition to a rewritten parallel linker. Mold did it first: https://github.com/rui314/mold

This is one of the largest improvements that Zig brings – lightning fast recompiles, bringing the native development cycle closer to web speed.

Static linking is required to get the best performance: with cross-language PGO, LTO and dead code elimination

If this optimization is generally applicable and developers find it worthwhile, I could imagine this making its way to GCC land

I've read good things about https://github.com/rui314/mold , at least on development. YMMV.