# 2021-05-04 Triage Log

Quiet week overall.

Triage done by **@simulacrum**.
Revision range: [537544b1061467ee4b74ef7f552fab3d513e5caf..7a0f1781d04662041db5deaef89598a8edd53717](https://perf.rust-lang.org/?start=537544b1061467ee4b74ef7f552fab3d513e5caf&end=7a0f1781d04662041db5deaef89598a8edd53717&absolute=false&stat=instructions%3Au)

2 Regressions, 1 Improvements, 1 Mixed

#### Regressions

Revert PR 77885 everywhere [#84708](https://github.com/rust-lang/rust/issues/84708)
- Moderate regression in [instruction counts](https://perf.rust-lang.org/compare.html?start=18587b14d1d820d31151d5c0a633621a67149e78&end=478a07df05e3fe8df964291d8b25dd80b7e0e76b&stat=instructions:u) (up to 2.0% on `incr-unchanged` builds of `cargo-check`)

Update BARE_TRAIT_OBJECT and ELLIPSIS_INCLUSIVE_RANGE_PATTERNS to errors in Rust 2021 [#83213](https://github.com/rust-lang/rust/issues/83213)
- Moderate regression in [instruction counts](https://perf.rust-lang.org/compare.html?start=c20c9219dae5ea56ce9bf1c211fafdc7da8700b9&end=7a0f1781d04662041db5deaef89598a8edd53717&stat=instructions:u) (up to 3.0% on `incr-unchanged` builds of `encoding-check`)

#### Improvements

"const" initialized thread locals in rustc [#84833](https://github.com/rust-lang/rust/issues/84833)
- Moderate improvement in [instruction counts](https://perf.rust-lang.org/compare.html?start=14f863c44369c5abde6379afb7e1b206eef099e8&end=0309953232d9957aef4c7c5a24fcb30735b2066b&stat=instructions:u) (up to -1.6% on `incr-full` builds of `unused-warnings-check`)

#### Mixed

Move HIR parenting information out of hir_owner [#83114](https://github.com/rust-lang/rust/issues/83114)
- Large improvement in [instruction counts](https://perf.rust-lang.org/compare.html?start=5f304a5d7908d9dd55dda3baadd3cf564d907369&end=6e2a34474bb86911c5235476d2ea820e163629fe&stat=instructions:u) (up to -5.0% on `incr-patched: println` builds of `piston-image-check`)
- Moderate regression in [instruction counts](https://perf.rust-lang.org/compare.html?start=5f304a5d7908d9dd55dda3baadd3cf564d907369&end=6e2a34474bb86911c5235476d2ea820e163629fe&stat=instructions:u) (up to 2.2% on `incr-unchanged` builds of `unused-warnings-check`)

#### Nags requiring follow up

* None this week
