attempt to resolve #852

[matthiascy]

This PR introduces _MM_{GET,SET}_DENORMALS_ZERO_MODE, MM_DENORMALS_ZERO_ON, MM_DENORMALS_ZERO_OFF, MM_DENORMALS_ZERO_MASK. One remaining question is that in which file these should be placed? sse.rs or sse3.rs?

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @Amanieu (or someone else) soon.

[matthiascy]

_MM_{SET, GET}_DENORMALS_ZERO_MODE is not defined in Intel Intrinsics Guid but can be found in emmintrin.h of llvm, pmmintrin.h of gcc, and pmmintrin.h of Intel C++ Compiler.

[Amanieu]

LGTM! For the CI failure, you can add an exception in crates/stdarch-verify/tests/x86-intel.rs to ignore the check for this function.

This requires an FCP since it is adding a stable API.

@rfcbot fcp merge

[rfcbot]

Team member @Amanieu has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Amanieu
• @BurntSushi
• @dtolnay
• @joshtriplett
• @m-ou-se

Concerns:

• unstable for a time (attempt to resolve #852 #1377 (comment))

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

psst @Amanieu, I wasn't able to add the final-comment-period label, please do so.

[BurntSushi]

My understanding is that we should try to land new APIs as unstable, and only after some time has passed, then we can mark them stable.

@rfcbot concern unstable for a time

EDIT: Not sure why, but rfcbot doesn't seem to be registering my concern.

[Amanieu]

That's a good point.

@matthiascy Could you change your PR to make these functions unstable and open a tracking issue in rust-lang/rust?

[Amanieu]

@rfcbot fcp cancel

[rfcbot]

@Amanieu proposal cancelled.

[bors]

☔ The latest upstream changes (presumably 87158e6) made this pull request unmergeable. Please resolve the merge conflicts.