[Perf] Linux/arm64: 1 Improvement on 6/28/2026 9:49:46 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [44ed03469c1169d68d543ae1f4fecae67ce47a82](https://github.com/dotnet/runtime/commit/44ed03469c1169d68d543ae1f4fecae67ce47a82)
Compare | [0d3df07c6048d8cbe4f544227462cae62040e587](https://github.com/dotnet/runtime/commit/0d3df07c6048d8cbe4f544227462cae62040e587)
Diff | [Diff](https://github.com/dotnet/runtime/compare/44ed03469c1169d68d543ae1f4fecae67ce47a82...0d3df07c6048d8cbe4f544227462cae62040e587)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.IndexerSet<String>

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

• [ConcurrentDictionary - 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.IndexerSet*'
```

### System.Collections.IndexerSet<String>.ConcurrentDictionary(Size: 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 with the benchmark source at src/benchmarks/micro/libraries/System.Collections/Indexer/IndexerSet.cs#L140-L148 and review the linked baseline/compare commits and test report. Run the supplied benchmarks_ci.py command with the System.Collections.IndexerSet filter, then compare the arm64 Ubuntu results to the reported baseline. Done means determining whether the improvement is actionable and documenting the finding or follow-up.

Written by the indexing model from the issue text.