qbe-rs VS c3c

Another problem with LLVM I’ve heard about is that it’s intermediate language or API or something is a moving, informally-specified target. People who know LLVM internals might weigh in on that claim. If true, it’s actually easier to target C or a subset of Rust just because it’s static and well-understood.

Two projects sought to mitigate these issues by going in different directions. One was a compiler backend that aimed to be easy to learn with well-specified IL. The other aimed to formalize LLVM’s IL.

http://c9x.me/compile/

https://github.com/AliveToolkit/alive2

There have also been typed, assembly languages to support verification from groups like FLINT. One can also compile language-specific analysis with a certified to LLVM IL compiler. Integrating pieces from different languages can have risks. That (IIRC) is being mitigated by people doing secure, abstract compilation.

> I think it uses a different backend than LLVM

harec uses https://c9x.me/compile/

Have you considered QBE?

I really hope other new projects (like QBE) can really grow and become widely used

I really liked targetting QBE (https://c9x.me/compile/) as an IR, as it gave me lots of back-end optimisations for free 😊.

There is: QBE.

You might be underestimating the accuracy of the CPU models LLVM uses.

For x86, the same data the code generator uses drives llvm-mca[1], which given a loop body can tell you the throughput, latency, and microarchitectural bottlenecks (decoding, ports, dependencies, store forwarding, etc.)—if not always precisely, then still not worse then IACA, the tool written at Intel by people who presumably knew how the CPUs work, unlike LLVM contributors and the rest of us who can only guess and measure. This separately for Haswell, Sandy Bridge, Skylake, etc.; not “x86”.

Now, is this the best model you can get? Not exactly[2], but it’s close enough to not matter. Do we often need machine code to be optimized to that level of detail? Perhaps not[3], and with that in mind you can shave at least a factor of ten off LLVM’s considerable bulk at the cost of 20—30% of performance[4,5]. But if you do want those as well, it seems that the complexity of LLVM is a fair price, or has the right order of magnitude at least.

(Frontend not included, C++ frontend required to bootstrap sold separately, at a similar markup compared to a C-only frontend with somewhat worse ergonomics.)

[1] https://llvm.org/docs/CommandGuide/llvm-mca.html

[2] https://www.uops.info/

[3] https://briancallahan.net/blog/20211010.html

[4] https://c9x.me/compile/

[5] https://drewdevault.com/talks/qbe.html

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.

C3, "The C-like for people who like C" just reached v0.5, marking its feature-stable release: https://c3.handmade.network/blog/p/8824-say_hello_to_c3_0.5

Feature stability ensures that version 0.5 will undergo bug fixes and maintenance separately from the main branch, providing projects with a stable compiler version to work with.

Try it out in the browser https://learn-c3.org

Github: https://github.com/c3lang/c3c

If you appreciate C, then maybe this is a language you'll enjoy. Dive into the documentation at https://c3-lang.org to view examples and read more in depth about the language.

Tuples are being discussed, although I am unsure if it would be sufficiently useful. (Discussion here and here if you want to leave some thoughts)

I've been trying to build c3lang on my local machine. The problem is that it requires static files for both llvm and lld. Now, the static files for llvm have been provided (llvm-static), but not for lld, at least that's what I think. I thought that maybe I've made a mistake somewhere by not search the package thoroughly. I just wanted to know what package will install static files for lld.

So (preferably) have a little look at the language (https://c3-lang.org/) and maybe try it out (https://learn-c3.org/) and then file whatever issue you want: https://github.com/c3lang/c3c/issues/new

Like this: https://github.com/c3lang/c3c

> I wish we had C+: C + a few niceties (and not C ++ everything). There's a whole bunch of newer languages aiming at the space C is sitting in, but with a few additions C could be much more ergonomic without having to invent an entire new language.

I’ve made a pre-processor for C to add some things I miss, although it is currently limited to what can be done without type information and has to keep compatibility with existing C syntax: https://sentido-labs.com/en/library/cedro/202106171400/

There is another language call C3 that “is a C-like language striving to be an evolution of C, rather than a completely new language”: https://github.com/c3lang/c3c

If you have the time, I’d like to hear which things you miss in C. There might be something I did not imagine that could be added to Cedro.

Off the top of my head, cc99 and c3 are two C dialects that both can do this.