[Perf] Linux/arm64: 1 Improvement on 9/2/2026 12:10:41 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [818ad35699cf9b1a3e3f2067c133d8dbe599da2e](https://github.com/dotnet/runtime/commit/818ad35699cf9b1a3e3f2067c133d8dbe599da2e)
Compare | [36ef18696f857aeb42a5fa537d3c9593b02a474d](https://github.com/dotnet/runtime/commit/36ef18696f857aeb42a5fa537d3c9593b02a474d)
Diff | [Diff](https://github.com/dotnet/runtime/compare/818ad35699cf9b1a3e3f2067c133d8dbe599da2e...36ef18696f857aeb42a5fa537d3c9593b02a474d)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in PerfLabTests.CastingPerf

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

• [IFooObjIsIFooInterAlia - 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 'PerfLabTests.CastingPerf*'
```

### PerfLabTests.CastingPerf.IFooObjIsIFooInterAlia

#### 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/runtime/perflab/CastingPerf.cs#L227-L232 and review the linked test report for PerfLabTests.CastingPerf.IFooObjIsIFooInterAlia. Run the provided benchmarks_ci.py command with the CastingPerf filter, then determine whether the arm64 improvement is reproducible and what follow-up is warranted; done means the result is validated and documented.

Written by the indexing model from the issue text.