T Compiler Meeting Agenda 2024 02 08

T-compiler Meeting Agenda 2024-02-08

Announcements

  • Today Rust stable 1.76 is out :top_hat: :rabbit: Blog post
  • Announcement: experts/interested in C++/Rust interop might be interested to take part to the new initiative meant to work on long term goals in this area (Zulip thread). Funding provided by Google, blog post of the Foundation.
  • Reminder: if you see a PR/issue that seems like there might be legal implications due to copyright/IP/etc, please let us know (or at least message @davidtwco or @Wesley Wiser so we can pass it along).

Other WG meetings

MCPs/FCPs

WG checkins

  • @_WG-llvm by @nagisa and @Nikita Popov (previous checkin):

    We have an ongoing update to LLVM 18, which will land soon(TM) and has some nice perf results.

  • @_WG-mir-opt by @oli:

    I did not track updates this cycle.

Backport nominations

T-compiler beta / T-compiler stable

  • :beta: “Correctly check never_type feature gating” rust#120552
    • Fixes p-high #120542, the never_type ! slipped out of the feaature gate.
    • nominated by Michael (comment) in case it doesn’t make it to 1.77
    • By reading the milestone (1.78), unsure if it made it
  • No stable nominations for T-compiler this time.

T-types stable / T-types beta

  • No beta nominations for T-types this time.
  • No stable nominations for T-types this time.

PRs S-waiting-on-team

T-compiler

Issues of Note

Short Summary

P-critical

T-compiler

  • No P-critical issues for T-compiler this time.

T-types

  • No P-critical issues for T-types this time.

P-high regressions

P-high beta regressions

  • No P-high beta regressions this time.

Unassigned P-high nightly regressions

  • No unassigned P-high nightly regressions this time.

Performance logs

triage logs for 2023-02-05

Rust’s CI was down most of the week, leading to a much smaller collection of commits than usual.

Triage done by @simulacrum. Revision range: 5c9c3c7871d603ba13d38372830eca0c9013e575..0984becf01112cbd3583c796541760b65340c8db

Summary:

(instructions:u) mean range count
Regressions (primary) - - 0
Regressions (secondary) 0.3% [0.2%, 0.3%] 3
Improvements (primary) -0.3% [-0.7%, -0.2%] 7
Improvements (secondary) -0.6% [-1.0%, -0.5%] 7
All (primary) -0.3% [-0.7%, -0.2%] 7

0 Regressions, 2 Improvements, 1 Mixed; 1 of them in rollups 17 artifact comparisons made in total

Regressions

  • None this week.

Improvements

Normalize region obligation in lexical region resolution with next-gen solver #119101 (Comparison Link)

(instructions:u) mean range count
Regressions (primary) - - 0
Regressions (secondary) - - 0
Improvements (primary) -0.2% [-0.3%, -0.2%] 4
Improvements (secondary) - - 0
All (primary) -0.2% [-0.3%, -0.2%] 4

hir: Refactor getters for owner nodes #120346 (Comparison Link)

(instructions:u) mean range count
Regressions (primary) - - 0
Regressions (secondary) - - 0
Improvements (primary) -3.6% [-3.6%, -3.6%] 1
Improvements (secondary) -0.6% [-1.0%, -0.5%] 7
All (primary) -3.6% [-3.6%, -3.6%] 1

Mixed

Rollup of 9 pull requests #120660 (Comparison Link)

(instructions:u) mean range count
Regressions (primary) 0.8% [0.2%, 1.4%] 2
Regressions (secondary) - - 0
Improvements (primary) - - 0
Improvements (secondary) -0.2% [-0.3%, -0.2%] 2
All (primary) 0.8% [0.2%, 1.4%] 2

Needs further investigation. This just landed so it’s hard to say whether the regressions are noise or not. Kicked off another run on the PR to see if that helps.

Nominated Issues

T-compiler

  • No I-compiler-nominated issues this time.

RFC

  • No I-compiler-nominated RFCs this time.

Oldest PRs waiting for review

T-compiler

  • “Add rustc_intrinsic_const_vector_arg attribute to allow vectors to be passed as constants” rust#118980
    • cc Wesley
  • “tidy watcher” rust#114209
    • Wesley autoassigned (but in case we can re-roll)
  • “Fix type resolution of associated const equality bounds (take 2)” rust#119385
    • cc @Michael Goulet (compiler-errors) (though PR author is fine with waiting a bit)

Next week’s WG checkins

  • @_T-rust-analyzer by @Lukas Wirth

Next meetings' agenda draft: hackmd link