Add perf triage for 2024-06-18

triage/2024-06-18.md

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+# 2024-06-18 Triage Log
+
+Regressions outnumbered the improvements this week, but most of the regressions were deemed worth it for one reason or another. Overall, compiler performance didn't end up changing very much.
+
+Triage done by **@rylev**.
+Revision range: [b5b13568..c2932aaf](https://perf.rust-lang.org/?start=b5b13568fb5da4ac988bde370008d6134d3dfe6c&end=c2932aaf9d20acbc9259c762f1a06f8767c6f13f&absolute=false&stat=instructions%3Au)
+
+**Summary**:
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4%  | [0.2%, 1.0%]   | 63    |
+| Regressions ❌ <br /> (secondary)  | 0.7%  | [0.2%, 2.4%]   | 70    |
+| Improvements ✅ <br /> (primary)   | -0.6% | [-1.2%, -0.2%] | 8     |
+| Improvements ✅ <br /> (secondary) | -1.1% | [-5.2%, -0.2%] | 7     |
+| All ❌✅ (primary)                 | 0.3%  | [-1.2%, 1.0%]  | 71    |
+
+
+5 Regressions, 2 Improvements, 7 Mixed; 2 of them in rollups
+58 artifact comparisons made in total
+
+#### Regressions
+
+Print `token::Interpolated` with token stream pretty printing. [#125174](https://github.com/rust-lang/rust/pull/125174) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=3ea5e236ecb4c5f22437059f82d3915d311e4ec0&end=d0227c6a19c2d6e8dceb87c7a2776dc2b10d2a04&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3% | [0.2%, 0.4%] | 9     |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.3% | [0.2%, 0.4%] | 9     |
+- No discussion of the perf run done before merging, so I asked the author/reviewer for their thoughts.
+- It seems like most libc benchmarks were negatively impacted while no other benchmarks were. I'm not quite sure why that would be.
+
+
+Add `TyCtxt::is_lang_item`, use it in the compiler [#126491](https://github.com/rust-lang/rust/pull/126491) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=9239d3eb2b08bfdff30c86cdd9ce32687e488f5d&end=8217b412a235407243f2516ebc859e7b3af8345a&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3% | [0.2%, 0.4%] | 10    |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.3% | [0.2%, 0.4%] | 10    |
+- The change was deemed worth it despite the perf regression.
+
+
+Indicate in `non_local_defs` lint that the macro needs to change [#125722](https://github.com/rust-lang/rust/pull/125722) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8217b412a235407243f2516ebc859e7b3af8345a&end=1d1356d0f67131f97b4f1631a24cd10d7dbcca42&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2% | [0.2%, 0.2%] | 6     |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.2% | [0.2%, 0.2%] | 6     |
+- Only the diesel benchmark is affected, which is somewhat expected as it triggers the lint many many times (over 150 times).
+
+
+Rollup of 6 pull requests [#126605](https://github.com/rust-lang/rust/pull/126605) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=11380368dc53d0b2fc3a627408818eff1973ce9a&end=04ab7b2be0db3e6787f5303285c6b2ee6279868d&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3% | [0.3%, 0.4%] | 6     |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.3% | [0.3%, 0.4%] | 6     |
+- The benchmarks impacted seem to now swing wildly back and forth with every run so this isn't a perf regression per say.
+
+
+Migrate `inaccessible-temp-dir`, `output-with-hyphens` and `issue-10971-temps-dir` `run-make` tests to `rmake` [#126279](https://github.com/rust-lang/rust/pull/126279) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=59e2c01c2217a01546222e4d9ff4e6695ee8a1db&end=c2932aaf9d20acbc9259c762f1a06f8767c6f13f&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.3% | [0.3%, 0.3%] | 6     |
+| Regressions ❌ <br /> (secondary)  | -    | -            | 0     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.3% | [0.3%, 0.3%] | 6     |
+- This has to be noise, this PR only modified tests.
+
+
+#### Improvements
+
+Migrate `link-arg`, `link-dedup` and `issue-26092` `run-make` tests to `rmake` format [#125500](https://github.com/rust-lang/rust/pull/125500) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=04ab7b2be0db3e6787f5303285c6b2ee6279868d&end=59e2c01c2217a01546222e4d9ff4e6695ee8a1db&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.4% | [-0.4%, -0.3%] | 6     |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.4% | [-0.4%, -0.3%] | 6     |
+
+
+Migrate `extern-flag-fun`, `incremental-debugger-visualiser` and `incremental-session-fail` `run-make` tests to `rmake.rs` [#126490](https://github.com/rust-lang/rust/pull/126490) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=c2932aaf9d20acbc9259c762f1a06f8767c6f13f&end=67cfc3a558a54e351d14120099bf3158812b4130&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.4%, -0.3%] | 6     |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.3% | [-0.4%, -0.3%] | 6     |
+
+
+#### Mixed
+
+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     |
+- Wash on instruction counts, but nice binary size wins. The cycles improvements on tt-muncher is noise returning back to normal.
+
+
+Make `ObligationEmittingRelation`s emit `Goal` rather than `Obligation` [#126130](https://github.com/rust-lang/rust/pull/126130) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=9a7bf4ae947feddac27007cbe26d161f4ff5a910&end=76c73827dcd0b363e60b22c3cef64bde4171bf17&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 0.4%  | [0.1%, 0.6%]   | 14    |
+| Improvements ✅ <br /> (primary)   | -0.2% | [-0.2%, -0.2%] | 1     |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.2% | [-0.2%, -0.2%] | 1     |
+-  I'm asssuming the perf regression was deemed acceptable since these only occurred in stress tests?
+
+
+Tait must be constrained if in sig [#113169](https://github.com/rust-lang/rust/pull/113169) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bdb1b7f5d9715cc96cb437134eff93fa229defd1&end=02c7a5921e3de5c2b3ecb2e0082c1dafce0729a1&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.7%  | [0.7%, 0.7%]   | 1     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.4%, -0.3%] | 2     |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.0% | [-0.4%, 0.7%]  | 3     |
+- Probably noise + we need the fix 
+
+
+Extend SCC construction to enable extra functionality  [#125069](https://github.com/rust-lang/rust/pull/125069) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8337ba9189de188e2ed417018af2bf17a57d51ac&end=8cf5101d77cd9eeb12751c563d8098aba2c604d0&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2%  | [0.2%, 0.3%]   | 6     |
+| Regressions ❌ <br /> (secondary)  | 0.5%  | [0.1%, 1.0%]   | 10    |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.3% | [-0.3%, -0.3%] | 2     |
+| All ❌✅ (primary)                 | 0.2%  | [0.2%, 0.3%]   | 6     |
+- The perf regressions were brought down since the first perf run, but there's still instruction count regressions in primary benchmarks here (albeit not large ones). I asked the author/reviewer for thoughts.
+
+
+Remove superfluous UbChecks from `SliceIndex` methods [#126299](https://github.com/rust-lang/rust/pull/126299) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bc3618f31ea3866e6abea6995ec3979d12ffc65d&end=cd0c944b0750db887291bc25f20a05f8f31a8195&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.4%  | [0.2%, 0.6%]   | 4     |
+| Regressions ❌ <br /> (secondary)  | 0.8%  | [0.5%, 1.3%]   | 5     |
+| Improvements ✅ <br /> (primary)   | -0.4% | [-0.6%, -0.2%] | 3     |
+| Improvements ✅ <br /> (secondary) | -0.6% | [-0.8%, -0.4%] | 7     |
+| All ❌✅ (primary)                 | 0.1%  | [-0.6%, 0.6%]  | 7     |
+- Perf is largely a wash and was expected to have far reach consequences since it changes how slices are codegened.
+
+
+rustc_span: Optimize more hygiene operations using `Span::map_ctxt` [#126543](https://github.com/rust-lang/rust/pull/126543) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=d7f6ebacee13b6c03623c4b74197280454ede8de&end=6b65c30f8e0f6c18aa5f32cbad869b1d036c7851&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2%  | [0.2%, 0.2%]   | 1     |
+| Regressions ❌ <br /> (secondary)  | 0.3%  | [0.2%, 0.4%]   | 3     |
+| Improvements ✅ <br /> (primary)   | -1.1% | [-1.4%, -0.3%] | 4     |
+| Improvements ✅ <br /> (secondary) | -0.3% | [-0.3%, -0.2%] | 3     |
+| All ❌✅ (primary)                 | -0.8% | [-1.4%, 0.2%]  | 5     |
+- Improvements outweigh the regressions which all seemed to be reversed sometime soon after this landed. 
+
+
+Rollup of 3 pull requests [#126581](https://github.com/rust-lang/rust/pull/126581) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e23ae72ac7a393961886ea62df065ebb6def7d51&end=3baa20b783474330adb7ba7b3ddb02ac9facdf49&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 1.3%  | [1.3%, 1.3%]   | 1     |
+| Improvements ✅ <br /> (primary)   | -0.3% | [-0.4%, -0.2%] | 6     |
+| Improvements ✅ <br /> (secondary) | -     | -              | 0     |
+| All ❌✅ (primary)                 | -0.3% | [-0.4%, -0.2%] | 6     |
+- Regression might be noise (and isn't big enough to care about even if it isn't)
+