rust-lang · Kobzol · Jun 11, 2024 · Jun 11, 2024
diff --git a/triage/2024-06-11.md b/triage/2024-06-11.md
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+# 2024-06-11 Triage Log
+
+This week saw more regressions than wins, caused mostly by code being reorganized within the
+compiler and a new feature being implemented. There have also been some nice improvements caused
+by better optimizing spans.
+
+Triage done by **@kobzol**.
+Revision range: [1d52972d..b5b13568](https://perf.rust-lang.org/?start=1d52972dd8592edf4026aa577c8ce69acc0ac2d1&end=b5b13568fb5da4ac988bde370008d6134d3dfe6c&absolute=false&stat=instructions%3Au)
+
+**Summary**:
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.6%  | [0.2%, 2.7%]   | 105   |
+| Regressions ❌ <br /> (secondary)  | 1.0%  | [0.1%, 6.9%]   | 74    |
+| Improvements ✅ <br /> (primary)   | -0.5% | [-1.0%, -0.2%] | 20    |
+| Improvements ✅ <br /> (secondary) | -1.4% | [-8.8%, -0.2%] | 32    |
+| All ❌✅ (primary)                 | 0.5%  | [-1.0%, 2.7%]  | 125   |
+
+
+5 Regressions, 3 Improvements, 4 Mixed; 5 of them in rollups
+59 artifact comparisons made in total
+
+#### Regressions
+
+Rollup of 8 pull requests [#125976](https://github.com/rust-lang/rust/pull/125976) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bc33782c23bc3e04eab7c85c43bbe1a108b11f80&end=30ea1a2693bb1ba4b119ac6257985b9e11e45b83&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.9% | [0.2%, 1.3%] | 14    |
+| Regressions ❌ <br /> (secondary)  | 0.9% | [0.4%, 2.8%] | 5     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.9% | [0.2%, 1.3%] | 14    |
+
+* Looks like it was caused by [#125968](https://github.com/rust-lang/rust/pull/125968).
+* This PR resulted in some code being shuffled around the compiler (what we call "codegen noise"),
+we determined that it is not worth investigating further.
+
+Don't walk the bodies of free constants for reachability. [#122505](https://github.com/rust-lang/rust/pull/122505) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=72fdf913c53dd0e75313ba83e4aa80df3f6e2871&end=d0ccb5413ee2d9d40b574ad7998ffa866811d3f8&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 1.8% | [0.2%, 2.6%] | 4     |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 1.8% | [0.2%, 2.6%] | 4     |
+
+* The compiler needs to do a little bit more work after this PR, so the regression is expected.
+
+Unsafe extern blocks [#124482](https://github.com/rust-lang/rust/pull/124482) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=2b6a34273d820df4140a00984d38d40c745fb565&end=2d28b6384e5e0a2c9d1500a1f65e35423453fbf6&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3% | [0.2%, 0.4%] | 32    |
+| Regressions ❌ <br /> (secondary)  | 0.2% | [0.2%, 0.3%] | 4     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.3% | [0.2%, 0.4%] | 32    |
+
+* This PR adds a new feature, so a small performance regression is expected.
+
+Rollup of 7 pull requests [#126108](https://github.com/rust-lang/rust/pull/126108) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=b74702fbb2a2bd56b39849d66bd59a453ed8c89e&end=468310ea0cdec87460b83710a3a78825bcae73c5&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2% | [0.2%, 0.3%] | 5     |
+| Regressions ❌ <br /> (secondary)  | 0.9% | [0.5%, 1.5%] | 15    |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.2% | [0.2%, 0.3%] | 5     |
+
+* Caused by [#125724](https://github.com/rust-lang/rust/pull/125724), which moves some code to
+a different compiler package, so that it can be used with the new trait solver.
+
+Add Rust for Linux `auto` CI job [#125209](https://github.com/rust-lang/rust/pull/125209) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=a3167859f2fd8ff2241295469876a2b687280bdc&end=d402830c8a356332de93761d6996faf5a2ca29ca&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -    | -            | 0     |
+| Regressions ❌ <br /> (secondary)  | 4.3% | [2.5%, 6.1%] | 2     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | -    | -            | 0     |
+
+* This PR did not modify the compiler at all, so this has to be noise.
+
+#### Improvements
+
+Rollup of 11 pull requests [#125989](https://github.com/rust-lang/rust/pull/125989) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=23e040adec50e10d3ff8103e405ff79e44908e70&end=a330e49593ee890f9197727a3a558b6e6b37f843&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 2.0%  | [2.0%, 2.0%]   | 1     |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.3% | [-0.3%, -0.2%] | 10    |
+| All ❌✅ (primary)                 | -     | -              | 0     |
+
+
+Revert: create const block bodies in typeck via query feeding [#125918](https://github.com/rust-lang/rust/pull/125918) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=468310ea0cdec87460b83710a3a78825bcae73c5&end=1be24d70ced0d6b8d41a48b6a28b3790f6facf4c&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.5%, -0.2%] | 35    |
+| Improvements ✅ <br /> (secondary) | -0.4% | [-0.4%, -0.3%] | 9     |
+| All ❌✅ (primary)                 | -0.3% | [-0.5%, -0.2%] | 35    |
+
+
+Rollup of 9 pull requests [#126240](https://github.com/rust-lang/rust/pull/126240) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=d402830c8a356332de93761d6996faf5a2ca29ca&end=b5b13568fb5da4ac988bde370008d6134d3dfe6c&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -2.3% | [-6.4%, -0.2%] | 3     |
+| All ❌✅ (primary)                 | -     | -              | 0     |
+
+
+#### Mixed
+
+Make TLS accessors closures that return pointers [#125525](https://github.com/rust-lang/rust/pull/125525) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=90d6255d82dcfd0b73dbaa4f172a7f9886dcc2c1&end=27529d5c2526eab5aa03d765426c44ea55c5d269&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3%  | [0.2%, 0.4%]   | 6     |
+| Regressions ❌ <br /> (secondary)  | 2.9%  | [2.9%, 2.9%]   | 1     |
+| Improvements ✅ <br /> (primary)   | -0.5% | [-1.1%, -0.3%] | 14    |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.2% | [-1.1%, 0.4%]  | 20    |
+
+* More wins than losses.
+
+Rollup of 11 pull requests [#126134](https://github.com/rust-lang/rust/pull/126134) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=4dc24ae394a03755cf337bebc8cd2e022a1a4848&end=804421dff5542c9c7da5c60257b5dbc849719505&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4%  | [0.2%, 1.0%]   | 43    |
+| Regressions ❌ <br /> (secondary)  | 0.4%  | [0.1%, 0.8%]   | 14    |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.2% | [-0.2%, -0.2%] | 3     |
+| All ❌✅ (primary)                 | 0.4%  | [0.2%, 1.0%]   | 43    |
+
+
+rustc_span: Optimize syntax context updates in spans [#125017](https://github.com/rust-lang/rust/pull/125017) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=0de24a5177b1d49d6304f76f3ab159faaec134f9&end=a3167859f2fd8ff2241295469876a2b687280bdc&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.5%  | [0.2%, 0.6%]   | 6     |
+| Regressions ❌ <br /> (secondary)  | 0.7%  | [0.4%, 1.0%]   | 10    |
+| Improvements ✅ <br /> (primary)   | -0.4% | [-1.5%, -0.2%] | 37    |
+| Improvements ✅ <br /> (secondary) | -1.5% | [-9.3%, -0.2%] | 33    |
+| All ❌✅ (primary)                 | -0.3% | [-1.5%, 0.6%]  | 43    |
+
+* More improvements than regressions. 
+
+Add `SingleUseConsts` mir-opt pass [#125910](https://github.com/rust-lang/rust/pull/125910) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=b5b13568fb5da4ac988bde370008d6134d3dfe6c&end=fa1681c9f6a66f0240c46c98bfef6209c9d6df23&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4%  | [0.3%, 0.4%]   | 2     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.4%, -0.2%] | 4     |
+| Improvements ✅ <br /> (secondary) | -2.3% | [-2.9%, -1.7%] | 2     |
+| All ❌✅ (primary)                 | -0.1% | [-0.4%, 0.4%]  | 6     |
+
+* Slighty more wins than losses on instructions.
+* Small binary size win.