[Perf] Linux/x64: 1 Regression on 9/4/2026 7:52:17 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [25f20c2fd360fc0d7c126e50f7c784f8338d6faf](https://github.com/dotnet/runtime/commit/25f20c2fd360fc0d7c126e50f7c784f8338d6faf)
Compare | [aefed6dd306df5c1350a7a9b27a641a840ee16f8](https://github.com/dotnet/runtime/commit/aefed6dd306df5c1350a7a9b27a641a840ee16f8)
Diff | [Diff](https://github.com/dotnet/runtime/compare/25f20c2fd360fc0d7c126e50f7c784f8338d6faf...aefed6dd306df5c1350a7a9b27a641a840ee16f8)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.Perf_Frozen<ReferenceType>

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

• [ToFrozenSet - 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.Collections.Perf_Frozen*'
```

### System.Collections.Perf_Frozen<ReferenceType>.ToFrozenSet(Count: 512)

#### 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)

Start by running the documented benchmarks_ci.py command for System.Collections.Perf_Frozen and review the linked test report for ToFrozenSet(Count: 512). Compare the baseline and test commits, then inspect the benchmark source at src/benchmarks/micro/libraries/System.Collections/Frozen/Perf_Frozen.cs#L93-L94. Done means the regression is explained and the benchmark confirms the result after the relevant change.

Written by the indexing model from the issue text.