Rust and ARM is just fine. For example, Cloudflare famously keeps their entire stack cross-compilable to ARM, and even ships Rust on iPhones.

There's two areas where I believe you could call it second-class at the moment, though:

1. There is no ARM targets in Rust's "Tier 1" platform support.

2. std::arch doesn't have ARM intrinsics in stable.

For 1, ARM targets are in a weird space; they aren't Tier 1, but they're closer than most of the other Tier 2 targets. Several ARM targets are Tier 1 for Firefox, for example, so they get a bunch of work done there.

For 2, well, there hasn't been as much demand before. I expect that to change because of this.

... we'll see what the future holds :)

Sounds like this will cost Mozilla some time and money, but they will have to support it.

I’m not sure why. As I said, they’ve been using Rust on ARM (as part of Firefox) for a long time; I’m not aware of them being unsatisfied with the current state.

I expect that the Rust project will end up benefiting from the extra interest though, and improving on the things above.

There has been very good progress on filling in the gaps to officially get Rust's AArch64 Linux toolchain triple to Tier-1 this year. We have CI for the Rust compiler test suites on native AArch64 silicon in a joint collaboration between Arm and the Rust lang core team and are converging on zero compiler test failures. Overall, we are pretty close to attaining Tier-1!

> a joint collaboration between Arm

Is this public knowledge yet?

We haven't been very vocal about it just yet but all the bits to enable CI etc and the new t/compiler-arm Zulip stream are happening openly pretty much.

I'll be pinging all the relevant folks soon-ish (we're pushing out fixes to the last remaining compiler test suite failures this week).

I mean to keep you on CC as I did the last time!

Cool, I was dancing around it in this thread and recently because I wasn't sure how public it was :) I appreciate it!

Anything that runs Firefox also supports Rust as Rust is a core part of Firefox.

I've been working on an OS in Rust that has an aarch64 port, and I've for sure seen some... questionable output. It's all been valid code for the input, but not nearly as optimized as I've come to expect out of LLVM based compilers. I'm sure there's some low hanging fruit that needs attention is all.