rust-lang · Kobzol · Feb 23, 2024 · Feb 20, 2024 · Feb 20, 2024 · Feb 20, 2024
diff --git a/triage/2024-02-20.md b/triage/2024-02-20.md
@@ -0,0 +1,152 @@
+# 2024-02-20 Triage Log
+
+Relatively few PRs affecting performance, but massive improvements thanks to the
+update to LLVM 18 (PR #12005), as well as the merging of two related compiler
+queries (PR #120919) and other small improvements from a rollup (PR #121055).
+
+Triage done by **@pnkfelix**.
+Revision range: [74c3f5a1..5af21304](https://perf.rust-lang.org/?start=74c3f5a146860c94ff4d179fc3bfa34f879adf41&end=5af2130440c198afefbe5b8099342057cf272ef4&absolute=false&stat=instructions%3Au)
+
+**Summary**:
+
+| (instructions:u)                   | mean  | range           | count |
+|:----------------------------------:|:-----:|:---------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.5%  | [0.5%, 0.5%]    | 1     |
+| Regressions ❌ <br /> (secondary)  | 7.1%  | [0.5%, 78.5%]   | 17    |
+| Improvements ✅ <br /> (primary)   | -2.4% | [-13.9%, -0.4%] | 222   |
+| Improvements ✅ <br /> (secondary) | -2.0% | [-9.8%, -0.3%]  | 155   |
+| All ❌✅ (primary)                 | -2.4% | [-13.9%, 0.5%]  | 223   |
+
+
+3 Regressions, 1 Improvements, 6 Mixed; 1 of them in rollups
+65 artifact comparisons made in total
+
+#### Regressions
+
+Tracking import use types for more accurate redundant import checking [#117772](https://github.com/rust-lang/rust/pull/117772) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=6f726205a1b7992537ddec96c83f2b054b03e04f&end=8b21296b5db6d5724d6b8440dcf459fa82fd88b5&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4% | [0.2%, 1.0%] | 44    |
+| Regressions ❌ <br /> (secondary)  | 0.7% | [0.4%, 1.1%] | 13    |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.4% | [0.2%, 1.0%] | 44    |
+
+* regressions are [explained by petrochenkov](https://github.com/rust-lang/rust/pull/117772#issuecomment-1951430297): This lint is newly firing against benchmark code, which means that lint reporting machinery is being exercised that was previously not being exercised.
+* marked as triaged and filed rust-lang/rustc-perf#1819 to follow up with potential counter-action in benchmark tooling.
+
+macro_rules: Preserve all metavariable spans in a global side table [#119673](https://github.com/rust-lang/rust/pull/119673) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8a497723e311a62fccb1f0bf40e79c6519744a12&end=2bf78d12d33ae02d10010309a0d85dd04e7cff72&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4% | [0.1%, 1.3%] | 26    |
+| Regressions ❌ <br /> (secondary)  | 0.5% | [0.1%, 3.3%] | 12    |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.4% | [0.1%, 1.3%] | 26    |
+
+* Instruction count regressions flagged against serde_derive, diesel, serde, html5ever, syn
+* Most of these were anticipated in the final perf runs against the try builds.
+* Marking as triaged under assumption that the reviewers deemed this change to be worth the predicted cost.
+
+
+Always evaluate free constants and statics, even if previous errors occurred [#121087](https://github.com/rust-lang/rust/pull/121087) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=5af2130440c198afefbe5b8099342057cf272ef4&end=cce6a6e22e715bd74455f2560a956ab920c3a914&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.8% | [0.4%, 2.0%] | 4     |
+| Regressions ❌ <br /> (secondary)  | 1.0% | [0.3%, 5.2%] | 11    |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.8% | [0.4%, 2.0%] | 4     |
+
+
+#### Improvements
+
+pattern_analysis: Move constructor selection logic to `PlaceInfo` [#120692](https://github.com/rust-lang/rust/pull/120692) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0b9f6ad99482c9fc35baa5f40cebf21be4fd98b3&end=bcea3cb748040aa507f44abbd66c50725f35ea4f&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -1.8% | [-1.9%, -1.7%] | 6     |
+| All ❌✅ (primary)                 | -     | -              | 0     |
+
+
+#### Mixed
+
+Merge `impl_polarity` and `impl_trait_ref` queries [#120919](https://github.com/rust-lang/rust/pull/120919) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0a5b998c57a8681acc13206b5917340b053b3a30&end=d26b41711282042c4ea0c5733e7332b07cfa4933&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.6%  | [0.5%, 0.7%]   | 3     |
+| Regressions ❌ <br /> (secondary)  | 1.5%  | [1.5%, 1.5%]   | 1     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.7%, -0.2%] | 43    |
+| Improvements ✅ <br /> (secondary) | -0.4% | [-0.5%, -0.2%] | 5     |
+| All ❌✅ (primary)                 | -0.3% | [-0.7%, 0.7%]  | 46    |
+
+* already marked as triaged (more wins than losses)
+
+Update to LLVM 18 [#120055](https://github.com/rust-lang/rust/pull/120055) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bc1b9e0e9a813d27a09708b293dc2d41c472f0d0&end=eaff1af8fdd18ee3eb05167b2836042b7d4315f6&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range           | count |
+|:----------------------------------:|:-----:|:---------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -               | 0     |
+| Regressions ❌ <br /> (secondary)  | 1.1%  | [0.7%, 3.5%]    | 7     |
+| Improvements ✅ <br /> (primary)   | -2.4% | [-14.1%, -0.5%] | 233   |
+| Improvements ✅ <br /> (secondary) | -1.6% | [-8.0%, -0.3%]  | 160   |
+| All ❌✅ (primary)                 | -2.4% | [-14.1%, -0.5%] | 233   |
+
+* already marked as triaged (more wins than losses)
+
+Rollup of 8 pull requests [#121055](https://github.com/rust-lang/rust/pull/121055) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=37b65339c8cf1d18e331f184dbf70bbddcb1e4f7&end=7508c3e4c1349e3dd405547bc7dd8d9549e105b6&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2%  | [0.2%, 0.2%]   | 2     |
+| Regressions ❌ <br /> (secondary)  | 0.9%  | [0.8%, 0.9%]   | 2     |
+| Improvements ✅ <br /> (primary)   | -0.9% | [-1.8%, -0.2%] | 9     |
+| Improvements ✅ <br /> (secondary) | -0.6% | [-1.1%, -0.3%] | 21    |
+| All ❌✅ (primary)                 | -0.7% | [-1.8%, 0.2%]  | 11    |
+
+* already marked as triaged (more wins than losses)
+
+
+`cargo update` [#120454](https://github.com/rust-lang/rust/pull/120454) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=7508c3e4c1349e3dd405547bc7dd8d9549e105b6&end=cc1c0990ab6f7136d1d54fd008598095b2c53c66&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 1.4%  | [0.8%, 1.9%]   | 10    |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.9% | [-3.4%, -0.2%] | 15    |
+| All ❌✅ (primary)                 | -     | -              | 0     |
+
+* already marked as triaged (improvements and regressions balanced out, and the binary size regressions were deemed due to upstream dependencies)
+
+Store static initializers in metadata instead of the MIR of statics. [#116564](https://github.com/rust-lang/rust/pull/116564) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=4ae1e79876fcee94a56c1edf7c029a677084d7fc&end=6a4222b5119bce8c24e74dd3ad44006ce0c803e6&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 15.9% | [0.4%, 81.2%]  | 8     |
+| Improvements ✅ <br /> (primary)   | -0.4% | [-0.5%, -0.2%] | 8     |
+| Improvements ✅ <br /> (secondary) | -2.5% | [-8.9%, -0.4%] | 18    |
+| All ❌✅ (primary)                 | -0.4% | [-0.5%, -0.2%] | 8     |
+
+* already marked as triaged: the benchmark stress test is now writing an 8MB constant to metadata instead of a tiny bit of MIR
+
+Clean up potential_query_instability with FxIndexMap and UnordMap [#120931](https://github.com/rust-lang/rust/pull/120931) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=6a4222b5119bce8c24e74dd3ad44006ce0c803e6&end=fa9f77ff35b4b63ed0cef9a9642c8f881b33f14f&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 0.2%  | [0.2%, 0.2%]   | 4     |
+| Improvements ✅ <br /> (primary)   | -0.2% | [-0.2%, -0.2%] | 2     |
+| Improvements ✅ <br /> (secondary) | -6.6% | [-6.6%, -6.6%] | 1     |
+| All ❌✅ (primary)                 | -0.2% | [-0.2%, -0.2%] | 2     |
+
+* regressions are solely to the secondary many-assoc-items benchmark (check full, check/debug/opt incr-full), and was anticipated.
+* marking as triaged