Want to wade into the snowy surf of the abyss? Have a sneer percolating in your system but not enough time/energy to make a whole post about it? Go forth and be mid.
Welcome to the Stubsack, your first port of call for learning fresh Awful you’ll near-instantly regret.
Any awful.systems sub may be subsneered in this subthread, techtakes or no.
If your sneer seems higher quality than you thought, feel free to cut’n’paste it into its own post — there’s no quota for posting and the bar really isn’t that high.
The post Xitter web has spawned so many “esoteric” right wing freaks, but there’s no appropriate sneer-space for them. I’m talking redscare-ish, reality challenged “culture critics” who write about everything but understand nothing. I’m talking about reply-guys who make the same 6 tweets about the same 3 subjects. They’re inescapable at this point, yet I don’t see them mocked (as much as they should be)
Like, there was one dude a while back who insisted that women couldn’t be surgeons because they didn’t believe in the moon or in stars? I think each and every one of these guys is uniquely fucked up and if I can’t escape them, I would love to sneer at them.
(Credit and/or blame to David Gerard for starting this. A lot of people didn't survive January, but at least we did. This also ended up going up on my account's cake day, too, so that's cool.)
It seems that Anthropic has vibe coded a C compiler. This one is really good! The generated code is not very efficient. Even with all optimizations enabled, it outputs less efficient code than GCC with all optimizations disabled.
I wonder what actual experts in compilers think of this. There were some similar claims about vibe coding a browser from scratch that turned out to be a little overheated: https://pivot-to-ai.com/2026/01/27/cursor-lies-about-vibe-coding-a-web-browser-with-ai/
I do not believe that this demonstrates anything other than they kept making the AI brute force random shit until it happened to pass all the test cases. The only innovation was that they spent even more money than before. Also, it certainly doesn't help that GCC is open source, and they have almost certainly trained the model on the GCC source code (which the model can regurgitate poorly into Rust). Hell, even their blog post talks about how half their shit doesn't work and just calls GCC instead!
I wonder why this blog post was brazen enough to talk about these problems. Perhaps by throwing in a little humility, they can make the hype pill that much easier to swallow.
Sidenote: Rust seems to be the language of choice for a lot of these vibe coded "projects", perhaps because they don't want people immediately accusing them of plagiarism. But Rust syntax still reasonably follows languages like C. In most cases, blindly translating C code into Rust kinda works. Now, Rust does have the borrow checker which requires a lot of thinking to deal with, but I think this is not actually a disadvantage for the AI. Borrow checking is enforced by the compiler, so if you screw up in that department, your code won't even compile. This is great for an AI that is just brute forcing random shit until it "works".
Anthropic doesn't pay me and I'm not going to look over their pile of garbage for free, but just looking at the structure and READMEs it looks like a reasonable submission for an advanced student in a compiler's course: lowering to IR, SSA representation, dominators, phi elimination, some passes like strength reduction. The register allocator is very bad though, I'd expect at least something based on colouring.
The READMEs are also really annoying to read. They are overlong and they don't really explain what is going on in the module. There's no high-level overview of the architecture of the compiler. A lot of it is just redundant. Like, what is this:
Ye dude, of course it doesn't depend on the IR, because this is before IR is constructed. Are you just pretending to know how a compiler works? Wait, right, you are, you're a bot. The last sentence is also hilarious, my brother in christ, what, why is this in the README.
Now this evaluation only makes sense if the compiler actually works - which it doesn't. Looking at the filed issues there are glaring disqualifying problems (#177, #172, #171, #167, etc. etc. etc.). Like, those are not "oops, forgot something", those are "the code responsible for this is broken". Some of them look truly baffling, like how do you manage to get so many issues of the type "silently does something unexpected on error" when the code is IN RUST, which is explicitly designed to make those errors as hard as possible? Like I'm sorry, but the ones below? These are just "you did not even attempt to fulfill the assignment".
It's also not tested, it has no integration tests (even though the README says it does), which is plain unacceptable. And the unit tests that are there fail so lol, lmao.
It's worse than existing industry compilers and it doesn't offer anything interesting in terms of the implementation. If you're introducing your own IR and passes you have to have a good enough reason to not just target LLVM. Cranelift is... not great, but they at least have interesting design choices and offer quick unoptimized compilation. This? The only reason you'd write this is you were indeed a student learning compilers, in which case it'd be a very good experience. You'd probably learn why testing is important for the rest of your life at least.