[Perf] Linux/x64: 1 Improvement on 4/28/2026 1:30:15 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [a9bbe530c25e60e1da9cf29f3646062498d69b28](https://github.com/dotnet/runtime/commit/a9bbe530c25e60e1da9cf29f3646062498d69b28)
Compare | [5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981](https://github.com/dotnet/runtime/commit/5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981)
Diff | [Diff](https://github.com/dotnet/runtime/compare/a9bbe530c25e60e1da9cf29f3646062498d69b28...5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Tests.Perf_Char

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [Char_IsLower - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

![graph]()
[Test Report]()

### Repro
General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

```cmd
git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_Char*'
```

### System.Tests.Perf_Char.Char_IsLower(input: "Good afternoon, Constable!")

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)