# 2024-12-31 Triage Log

A pretty quiet week, with the exception of a significant improvement due to
landing LTO for C / C++ programs compiled as part of the build.

Triage done by **@simulacrum**.
Revision range: [0eca4dd3..93722f7e](https://perf.rust-lang.org/?start=0eca4dd3205a01dba4bd7b7c140ec370aff03440&end=93722f7ed56bcf27839a6355074095c4320b7d37&absolute=false&stat=instructions%3Au)

**Summary**:

| (instructions:u)                   | mean  | range          | count |
|:----------------------------------:|:-----:|:--------------:|:-----:|
| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
| Improvements ✅ <br /> (primary)   | -0.6% | [-5.6%, -0.2%] | 265   |
| Improvements ✅ <br /> (secondary) | -0.7% | [-1.8%, -0.2%] | 187   |
| All ❌✅ (primary)                 | -0.6% | [-5.6%, -0.2%] | 265   |

0 Regressions, 1 Improvements, 1 Mixed; 0 of them in rollups
53 artifact comparisons made in total

#### Regressions

No meaningful regressions this week.

#### Improvements

CI: Add LTO support to clang in dist-x86_64-linux [#134690](https://github.com/rust-lang/rust/pull/134690) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=dd84b7d5eec3c20d7fcd13e6450af029d3cece9d&end=ecc189922dac830ff866f4609311e6afcc4a91f6&stat=instructions:u)

| (instructions:u)                   | mean  | range          | count |
|:----------------------------------:|:-----:|:--------------:|:-----:|
| Regressions ❌ <br /> (primary)    | -     | -              | 0     |
| Regressions ❌ <br /> (secondary)  | -     | -              | 0     |
| Improvements ✅ <br /> (primary)   | -0.7% | [-5.5%, -0.3%] | 275   |
| Improvements ✅ <br /> (secondary) | -0.9% | [-2.6%, -0.2%] | 235   |
| All ❌✅ (primary)                 | -0.7% | [-5.5%, -0.3%] | 275   |

#### Mixed

Consider empty-unreachable otherwise branches in MatchBranchSimplification [#131244](https://github.com/rust-lang/rust/pull/131244) [(Comparison Link)](https://perf.rust-lang.org/compare.html?start=8b3f7ac5262531aefa227f90387cf2eb34aae800&end=4e0bc490c60d3588f3ec0aa2eee2cf0696c7c333&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%, 0.3%]   | 4     |
| Improvements ✅ <br /> (primary)   | -0.6% | [-0.7%, -0.5%] | 2     |
| Improvements ✅ <br /> (secondary) | -0.2% | [-0.3%, -0.1%] | 2     |
| All ❌✅ (primary)                 | -0.3% | [-0.7%, 0.2%]  | 3     |
