[Perf] Linux/arm64: 1 Improvement on 6/28/2026 5:31:55 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [19a803d6d08a846656d1116d0f4e7001e792d5a1](https://github.com/dotnet/runtime/commit/19a803d6d08a846656d1116d0f4e7001e792d5a1)
Compare | [9cb68cd564627fd80fb9077731093f46d1e0e667](https://github.com/dotnet/runtime/commit/9cb68cd564627fd80fb9077731093f46d1e0e667)
Diff | [Diff](https://github.com/dotnet/runtime/compare/19a803d6d08a846656d1116d0f4e7001e792d5a1...9cb68cd564627fd80fb9077731093f46d1e0e667)
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
py .\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 in dotnet/performance at src/benchmarks/micro/libraries/System.Collections/Indexer/IndexerSet.cs lines 140-148, then run the provided benchmarks_ci.py command for the System.Collections.IndexerSet filter. Compare the arm64 AzureLinux report and linked history to determine whether the improvement needs follow-up; the issue provides no code-change scope or acceptance criterion.

Written by the indexing model from the issue text.