Update stdarch submodule to latest head

[vertexclique]

Includes avx512 work & aarch64 tme.

[rust-highfive]

r? @LukasKalbertodt

(rust_highfive has picked a reviewer for you, use r? to override)

[rust-highfive]

⚠️Warning⚠️

• These commits modify submodules.

[vertexclique]

r? @Amanieu

[Amanieu]

@bors r+

[bors]

📌 Commit 5b01cd5e1b51c89be8e13a7924e70645363dab09 has been approved by Amanieu

[vertexclique]

@Amanieu failed on Linux, might be hwcap issue?

[Amanieu]

It's because the stage0 compiler doesn't support the tme extension. Rustc stage0 uses the current beta compiler to compile master.

You need to add #[cfg(not(bootstrap))] to the tme module in stdarch to exclude it from the stage0 build.

[Amanieu]

@bors r-

[Mark-Simulacrum]

(Continuing from the other thread)

We generally want x.py doc src/libstd --stage 0 to "just work" because it's significantly better for docs contributors as opposed to forcing them to build a full std/compiler toolchain just to document std. However, that said, I am surprised to see this working with the rustc bootstrap compiler which ran x.py check on that crate already? Is there some bug in bootstrap perhaps that is only sometimes passing --cfg bootstrap?

[Amanieu]

It seems that CI is running a stage0 rustdoc which doesn't understand the "tme" feature as part of the mingw-check builder.

I'm not exactly sure what the right course of action is here. cc @pietroalbini

[Amanieu]

So it seems that this is caused by #56627:

So far this starts to enable the std::arch in stage0 builds of rustc.
This means that we may need stage0/not(stage0) in stdsimd itself, but
more and more code is starting to use std::arch so I think it's time
to start shifting the balance of work here.

I guess we'll just need to add cfg(bootstrap) to stdarch.

[Mark-Simulacrum]

In the cases where we do need it I'm hoping we can make sure that the current nightly compiler will still work -- i.e., that you just get a less featureful stdsimd but not actually breakage when we upgrade the bootstrap compiler. If that's not possible then please ping me when landing such a change, as it means we need to bump stdsimd when bumping the bootstrap compiler in rust-lang/rust (and in the long run probably means we should subtree/merge in stdsimd to this repo).

[Amanieu]

The TME instructions are not available on any physical CPU yet (and I don't think even QEMU supports them), so I doubt this will cause any breakage in practice.

[Amanieu]

@bors r+

[bors]

📌 Commit 2915d8e4224c80d08f0f1d75ad6e745964f652c7 has been approved by Amanieu

[vertexclique]

The TME instructions are not available on any physical CPU yet (and I don't think even QEMU supports them), so I doubt this will cause any breakage in practice.

Yes, yes, and yes. So far only llvm and gcc incorporated this support.

[vertexclique]

Can someone add this to rollup if it is ok? @rust-lang/release

[Amanieu]

@bors r+

[bors]

📌 Commit 15201af has been approved by Amanieu