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rustc_target: Add various aarch64 features #128192

Merged
merged 5 commits into from
Aug 29, 2024
Merged

rustc_target: Add various aarch64 features #128192

merged 5 commits into from
Aug 29, 2024

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mrkajetanp
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Add various aarch64 features already supported by LLVM and Linux.
Additionally include some comment fixes to ensure consistency of feature names with the Arm ARM.
Compiler support for features added to stdarch by rust-lang/stdarch#1614.
Tracking issue for unstable aarch64 features is #127764.

List of added features:

  • FEAT_CSSC
  • FEAT_ECV
  • FEAT_FAMINMAX
  • FEAT_FLAGM2
  • FEAT_FP8
  • FEAT_FP8DOT2
  • FEAT_FP8DOT4
  • FEAT_FP8FMA
  • FEAT_HBC
  • FEAT_LSE128
  • FEAT_LSE2
  • FEAT_LUT
  • FEAT_MOPS
  • FEAT_LRCPC3
  • FEAT_SVE_B16B16
  • FEAT_SVE2p1
  • FEAT_WFxT
  • FEAT_SME
  • FEAT_SME_F16F16
  • FEAT_SME_F64F64
  • FEAT_SME_F8F16
  • FEAT_SME_F8F32
  • FEAT_SME_FA64
  • FEAT_SME_I16I64
  • FEAT_SME_LUTv2
  • FEAT_SME2
  • FEAT_SME2p1
  • FEAT_SSVE_FP8DOT2
  • FEAT_SSVE_FP8DOT4
  • FEAT_SSVE_FP8FMA

FEAT_FPMR is added in the first commit and then removed in a separate one to highlight it being removed from upstream LLVM 19. The intention is for it to be detectable at runtime through stdarch but not have a corresponding Rust compile-time feature.

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rustbot commented Jul 25, 2024

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @petrochenkov (or someone else) some time within the next two weeks.

Please see the contribution instructions for more information. Namely, in order to ensure the minimum review times lag, PR authors and assigned reviewers should ensure that the review label (S-waiting-on-review and S-waiting-on-author) stays updated, invoking these commands when appropriate:

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rustbot commented Jul 25, 2024

⚠️ Warning ⚠️

  • These commits modify submodules.

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Jul 25, 2024
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rustbot commented Jul 25, 2024

These commits modify compiler targets.
(See the Target Tier Policy.)

@mrkajetanp mrkajetanp mentioned this pull request Jul 25, 2024
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r? @Amanieu

@rustbot rustbot assigned Amanieu and unassigned petrochenkov Jul 25, 2024
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If I bump stdarch to e98c63893ed6b713b63d1df4882be12cab22495c even on a clean checkout GitHub master this still fails with the same error so I think this is a stdarch problem unrelated to the substance of this PR.

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Amanieu commented Jul 25, 2024

This is blocked on #128083.

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Amanieu commented Jul 25, 2024

It's not clear to me what the plan is for the FPMR feature. If it doesn't make sense to maintain it as a codegen feature in rustc, we could just only have it in std_detect like the v8.x features.

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mrkajetanp commented Jul 25, 2024 •
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It's not clear to me what the plan is for the FPMR feature. If it doesn't make sense to maintain it as a codegen feature in rustc, we could just only have it in std_detect like the v8.x features.

Yes, that's the approach we settled on as well. The issue is that LLVM 18 versions have it as an explicit feature, while from LLVM 19 onwards it's just supposed to be on by default. I made a separate commit for removing it from the codegen features to highlight this in case someone looks for it later.

With this PR it will not be a Rust codegen feature. We switch it on by default through target specs on LLVM 18, it's already switched on on LLVM 19+ and it doesn't exist on older LLVM versions. But we do keep the detection in std_detect.

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ehuss commented Jul 26, 2024

Thanks! Will there be a separate tracking issue for these?

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mrkajetanp commented Jul 26, 2024 •
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Thanks! Will there be a separate tracking issue for these?

Yes, already here: #127764
At least on the detection side. I'm not sure on the compiler side but we could always open one.

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Amanieu commented Jul 26, 2024

Rather than modifying the target specs, can you instead hard-code rustc to always add that feature when compiling on aarch64 for LLVM <= 18? That makes it easier to remove this in the future once we upgrade our minimum LLVM version to 19.

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nikic commented Jul 26, 2024

Why do we have to add this feature now at all, when we haven't been enabling it before?

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bors commented Jul 29, 2024

☔ The latest upstream changes (presumably #125443) made this pull request unmergeable. Please resolve the merge conflicts.

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can you instead hard-code rustc to always add that feature when compiling on aarch64 for LLVM <= 18?

Sure, done. This also made the changes to llvm_util unnecessary so I dropped those as well.

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Why do we have to add this feature now at all, when we haven't been enabling it before?

It's a target feature. If we don't handle it explicitly in some way then people who want to make use of it in Rust will not be able to do so until LLVM is bumped to 19 which would not be ideal. Explicitly enabling it ensures consistent behaviour with the upcoming changes.

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bors commented Aug 4, 2024

☔ The latest upstream changes (presumably #128466) made this pull request unmergeable. Please resolve the merge conflicts.

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Amanieu commented Aug 5, 2024

LGTM but this will conflict with #128221. I want to get #128221 merged first, then you can also review the feature dependencies on AArch64.

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@Amanieu it's failing because a lot of these features were only added in LLVM 18, should I just make using them conditional on version >= 18?

@mrkajetanp
rustc_target: Remove fpmr target feature
4fc4019 
FEAT_FPMR has been removed from upstream LLVM as of LLVM 19.
Remove the feature from the target features list and temporarily hack
the LLVM codegen to always enable it until the minimum LLVM version is
bumped to 19.
@mrkajetanp
rustc_codegen_llvm: Filter out unavailable LLVM features
3a0fbb5 
Convert to_llvm_features to return Option<LLVMFeature> so that it can
return None if the requested feature is not available for the current
LLVM version.

Add match rules to filter out aarch64 features not available in LLVM 17.
@mrkajetanp
tests: Update with new aarch64 target features
0f871b5 
Additionally, remove optional matching for +v8a given that the minimum LLVM version is now past 14.
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@rustbot ready

@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 27, 2024
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I rebased the branch and updated the tied-features-strength.rs test to drop optional matching for +v8a as well since it looks like it was a leftover todo - we're well past LLVM 14 at this point.

Was a little surprised that the pipeline didn't catch it earlier, looks like it does not run aarch64 codegen tests on pushes to PRs. They're not mentioned here either for what that's worth.

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@rustbot rustbot added I-lang-nominated Nominated for discussion during a lang team meeting. S-waiting-on-team Status: Awaiting decision from the relevant subteam (see the T-<team> label). T-lang Relevant to the language team, which will review and decide on the PR/issue. labels Aug 27, 2024
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@rustbot rustbot removed T-lang Relevant to the language team, which will review and decide on the PR/issue. I-lang-nominated Nominated for discussion during a lang team meeting. S-waiting-on-team Status: Awaiting decision from the relevant subteam (see the T-<team> label). labels Aug 28, 2024
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Amanieu commented Aug 28, 2024

@bors r+

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bors commented Aug 28, 2024

📌 Commit 0f871b5 has been approved by Amanieu

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 28, 2024
workingjubilee added a commit to workingjubilee/rustc that referenced this pull request Aug 29, 2024
@workingjubilee
Rollup merge of rust-lang#128192 - mrkajetanp:feature-detect, r=Amanieu
97d1417 
rustc_target: Add various aarch64 features

Add various aarch64 features already supported by LLVM and Linux.
Additionally include some comment fixes to ensure consistency of feature names with the Arm ARM.
Compiler support for features added to stdarch by rust-lang/stdarch#1614.
Tracking issue for unstable aarch64 features is rust-lang#127764.

List of added features:

- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_HBC
- FEAT_LSE128
- FEAT_LSE2
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT
- FEAT_SME
- FEAT_SME_F16F16
- FEAT_SME_F64F64
- FEAT_SME_F8F16
- FEAT_SME_F8F32
- FEAT_SME_FA64
- FEAT_SME_I16I64
- FEAT_SME_LUTv2
- FEAT_SME2
- FEAT_SME2p1
- FEAT_SSVE_FP8DOT2
- FEAT_SSVE_FP8DOT4
- FEAT_SSVE_FP8FMA

FEAT_FPMR is added in the first commit and then removed in a separate one to highlight it being removed from upstream LLVM 19. The intention is for it to be detectable at runtime through stdarch but not have a corresponding Rust compile-time feature.
This was referenced Aug 29, 2024
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bors added a commit to rust-lang-ci/rust that referenced this pull request Aug 29, 2024
@bors
Auto merge of rust-lang#129721 - workingjubilee:rollup-y2o1mnp, r=wor…
6cf068d 
…kingjubilee

Rollup of 14 pull requests

Successful merges:

 - rust-lang#128192 (rustc_target: Add various aarch64 features)
 - rust-lang#129170 (Add an ability to convert between `Span` and `visit::Location`)
 - rust-lang#129343 (Emit specific message for time<=0.3.35)
 - rust-lang#129378 (Clean up cfg-gating of ProcessPrng extern)
 - rust-lang#129401 (Partially stabilize `feature(new_uninit)`)
 - rust-lang#129467 (derive(SmartPointer): assume pointee from the single generic and better error messages)
 - rust-lang#129494 (format code in tests/ui/threads-sendsync)
 - rust-lang#129617 (Update books)
 - rust-lang#129673 (Add fmt::Debug to sync::Weak<T, A>)
 - rust-lang#129683 (copysign with sign being a NaN can have non-portable results)
 - rust-lang#129689 (Move `'tcx` lifetime off of impl and onto methods for `CrateMetadataRef`)
 - rust-lang#129695 (Fix path to run clippy on rustdoc)
 - rust-lang#129712 (Correct trusty targets to be tier 3)
 - rust-lang#129715 (Update `compiler_builtins` to `0.1.123`)

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit 4c8c9e0 into rust-lang:master Aug 29, 2024
6 checks passed
@rustbot rustbot added this to the 1.82.0 milestone Aug 29, 2024
rust-timer added a commit to rust-lang-ci/rust that referenced this pull request Aug 29, 2024
@rust-timer
Unrolled build for rust-lang#128192
acede25 
Rollup merge of rust-lang#128192 - mrkajetanp:feature-detect, r=Amanieu

rustc_target: Add various aarch64 features

Add various aarch64 features already supported by LLVM and Linux.
Additionally include some comment fixes to ensure consistency of feature names with the Arm ARM.
Compiler support for features added to stdarch by rust-lang/stdarch#1614.
Tracking issue for unstable aarch64 features is rust-lang#127764.

List of added features:

- FEAT_CSSC
- FEAT_ECV
- FEAT_FAMINMAX
- FEAT_FLAGM2
- FEAT_FP8
- FEAT_FP8DOT2
- FEAT_FP8DOT4
- FEAT_FP8FMA
- FEAT_HBC
- FEAT_LSE128
- FEAT_LSE2
- FEAT_LUT
- FEAT_MOPS
- FEAT_LRCPC3
- FEAT_SVE_B16B16
- FEAT_SVE2p1
- FEAT_WFxT
- FEAT_SME
- FEAT_SME_F16F16
- FEAT_SME_F64F64
- FEAT_SME_F8F16
- FEAT_SME_F8F32
- FEAT_SME_FA64
- FEAT_SME_I16I64
- FEAT_SME_LUTv2
- FEAT_SME2
- FEAT_SME2p1
- FEAT_SSVE_FP8DOT2
- FEAT_SSVE_FP8DOT4
- FEAT_SSVE_FP8FMA

FEAT_FPMR is added in the first commit and then removed in a separate one to highlight it being removed from upstream LLVM 19. The intention is for it to be detectable at runtime through stdarch but not have a corresponding Rust compile-time feature.
@sayantn sayantn mentioned this pull request Sep 14, 2024
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