Add 2026-01-06 triage

triage/2026/2026-01-06.md

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+# 2026-01-06 Triage Log
+
+Not many PRs were merged, as it was still mostly a holiday week. [#149681](https://github.com/rust-lang/rust/pull/149681) caused small regressions across the board, this is pending investigation.
+
+Triage done by **@kobzol**.
+Revision range: [112a2742..7c04f5d2](https://perf.rust-lang.org/?start=112a274275d77ebc2b892f056a1e2fad141f4f08&end=7c04f5d216b5dcfff0a55fc20327a1c519004699&absolute=false&stat=instructions%3Au)
+
+**Summary**:
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.5%  | [0.1%, 1.4%]   | 146   |
+| Regressions ❌ <br /> (secondary)  | 0.6%  | [0.0%, 3.5%]   | 91    |
+| Improvements ✅ <br /> (primary)   | -3.1% | [-4.7%, -1.5%] | 2     |
+| Improvements ✅ <br /> (secondary) | -0.7% | [-6.4%, -0.1%] | 15    |
+| All ❌✅ (primary)                 | 0.4%  | [-4.7%, 1.4%]  | 148   |
+
+
+2 Regressions, 0 Improvements, 7 Mixed; 4 of them in rollups
+51 artifact comparisons made in total
+
+#### Regressions
+
+Use more principled check for generics in const ops [#150519](https://github.com/rust-lang/rust/pull/150519) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=056908d7f44ab901ae6573cf2d9c1d8b166ed1c5&end=a47f4dfd7f496ed51a383c540497899f9e3f91b4&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2% | [0.1%, 0.3%] | 6     |
+| Regressions ❌ <br /> (secondary)  | 0.2% | [0.2%, 0.2%] | 1     |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | 0.2% | [0.1%, 0.3%] | 6     |
+
+- Tiny regression on the diesel benchmark.
+- The compiler does more work here, and this fixes an ICE, so it seems warranted.
+- Marked as triaged.
+
+MGCA: Support for tuple constructors  [#150603](https://github.com/rust-lang/rust/pull/150603) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=451b7b6c775a2378fd18d2560bbfb31c3695d1cc&end=6885bdf1af7e0435b80bf79a780c3fe7a495094f&stat=instructions:u)
+
+| (instructions:u)                   | mean | range        | count |
+|:----------------------------------:|:----:|:------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -    | -            | 0     |
+| Regressions ❌ <br /> (secondary)  | 0.1% | [0.1%, 0.2%] | 11    |
+| Improvements ✅ <br /> (primary)   | -    | -            | 0     |
+| Improvements ✅ <br /> (secondary) | -    | -            | 0     |
+| All ❌✅ (primary)                 | -    | -            | 0     |
+
+- The regressions are only on a few secondary stress tests and they are tiny.
+- Marked as triaged.
+
+#### Mixed
+
+Remove the explicit branch hint from const_panic [#150386](https://github.com/rust-lang/rust/pull/150386) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=b082bd59d2f6d74913b904ffdb81c0b9dd09022c&end=d874dce1252fe409ce13e64d773046853bf5e6ca&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.6%  | [0.5%, 0.7%]   | 2     |
+| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
+| Improvements ✅ <br /> (primary)   | -0.4% | [-0.5%, -0.4%] | 2     |
+| Improvements ✅ <br /> (secondary) | -0.1% | [-0.1%, -0.0%] | 3     |
+| All ❌✅ (primary)                 | 0.1%  | [-0.5%, 0.7%]  | 4     |
+
+- Over all benchmarks it's a wash.
+- Marked as triaged.
+
+Make inliner cycle detection a fallible process [#147361](https://github.com/rust-lang/rust/pull/147361) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=629b092f8fab1b0370dfb749c4f5e00e70169dd2&end=2848c2ebe9a8a604cd63455263299d7258bc8252&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.6%  | [0.3%, 1.0%]   | 4     |
+| Regressions ❌ <br /> (secondary)  | 0.8%  | [0.1%, 1.3%]   | 6     |
+| Improvements ✅ <br /> (primary)   | -1.0% | [-4.9%, -0.1%] | 8     |
+| Improvements ✅ <br /> (secondary) | -0.6% | [-6.5%, -0.1%] | 18    |
+| All ❌✅ (primary)                 | -0.5% | [-4.9%, 1.0%]  | 12    |
+
+- The nalgebra win looks real.
+- This changes inlining behavior, so that always perturbs compile times.
+- Marked as triaged.
+
+Rollup of 3 pull requests [#150582](https://github.com/rust-lang/rust/pull/150582) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=a47f4dfd7f496ed51a383c540497899f9e3f91b4&end=1b4325211c3228dd10eea12e9b3f749f87363d95&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.2%  | [0.2%, 0.2%]   | 1     |
+| Regressions ❌ <br /> (secondary)  | 0.1%  | [0.1%, 0.2%]   | 2     |
+| Improvements ✅ <br /> (primary)   | -0.1% | [-0.2%, -0.1%] | 4     |
+| Improvements ✅ <br /> (secondary) | -0.7% | [-1.8%, -0.1%] | 3     |
+| All ❌✅ (primary)                 | -0.1% | [-0.2%, 0.2%]  | 5     |
+
+- Tiny changes, overall it's a wash.
+- Marked as triaged.
+
+Rollup of 7 pull requests [#150669](https://github.com/rust-lang/rust/pull/150669) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=f8b1d59a81c700cb7aa25cf69e3032b3ce333150&end=5afdf5d8c0377d6babd2504986982b5e5d724798&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.7%  | [0.7%, 0.7%]   | 1     |
+| Regressions ❌ <br /> (secondary)  | 0.1%  | [0.1%, 0.1%]   | 1     |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.5% | [-0.6%, -0.2%] | 4     |
+| All ❌✅ (primary)                 | 0.7%  | [0.7%, 0.7%]   | 1     |
+
+- The regressed cargo benchmark seems a bit noisy.
+- Over all benchmarks it's a wash, I don't think we need to investigate further.
+- Marked as triaged.
+
+Rollup of 3 pull requests [#150682](https://github.com/rust-lang/rust/pull/150682) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=e29fcf45e4ae686d77b490bf07320f0d3a2cf35f&end=451b7b6c775a2378fd18d2560bbfb31c3695d1cc&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | 0.5%  | [0.1%, 1.5%]   | 154   |
+| Regressions ❌ <br /> (secondary)  | 0.7%  | [0.0%, 3.5%]   | 87    |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.1% | [-0.1%, -0.1%] | 4     |
+| All ❌✅ (primary)                 | 0.5%  | [0.1%, 1.5%]   | 154   |
+
+- The regression was caused by [#149681](https://github.com/rust-lang/rust/pull/149681), continuing discussion there.
+- Marked as triaged.
+
+Rename the gcc component to gcc-dev [#150535](https://github.com/rust-lang/rust/pull/150535) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=6885bdf1af7e0435b80bf79a780c3fe7a495094f&end=0d162b25edd5bf0dba9a22e83b614f1113e90474&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 0.6%  | [0.5%, 0.6%]   | 3     |
+| Improvements ✅ <br /> (primary)   | -     | -              | 0     |
+| Improvements ✅ <br /> (secondary) | -0.1% | [-0.2%, -0.1%] | 9     |
+| All ❌✅ (primary)                 | -     | -              | 0     |
+
+- Noise, this only changed a CI component.
+- Marked as triaged.
+
+Rollup of 3 pull requests [#150700](https://github.com/rust-lang/rust/pull/150700) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=bd33b83cfdbac9bffa3b04aaef95ec97827909a9&end=4fa80a5e733e2202d7ca4c203c2fdfda41cfe7dc&stat=instructions:u)
+
+| (instructions:u)                   | mean  | range          | count |
+|:----------------------------------:|:-----:|:--------------:|:-----:|
+| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
+| Regressions ❌ <br /> (secondary)  | 0.0%  | [0.0%, 0.1%]   | 2     |
+| Improvements ✅ <br /> (primary)   | -0.1% | [-0.1%, -0.1%] | 1     |
+| Improvements ✅ <br /> (secondary) | -0.4% | [-0.8%, -0.0%] | 4     |
+| All ❌✅ (primary)                 | -0.1% | [-0.1%, -0.1%] | 1     |
+
+- Noise.
+- Marked as triaged.