[Perf] Linux/x64: 1 Regression on 6/11/2026 12:13:53 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [f1e9e366ff197e2037ae581af2963e98cec59ea6](https://github.com/dotnet/runtime/commit/f1e9e366ff197e2037ae581af2963e98cec59ea6)
Compare | [e563422012f994091f0f1d52deeed8c6273edecb](https://github.com/dotnet/runtime/commit/e563422012f994091f0f1d52deeed8c6273edecb)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f1e9e366ff197e2037ae581af2963e98cec59ea6...e563422012f994091f0f1d52deeed8c6273edecb)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Collections.IterateFor<String>

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

• [Span - 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.IterateFor*'
```

### System.Collections.IterateFor<String>.Span(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 System.Collections.IterateFor.Span benchmark and its source in performance/src/benchmarks/micro/libraries/System.Collections/Iterate/IterateFor.cs#L49-L58. Follow the benchmarking workflow, reproduce the AOT WebAssembly result with the provided benchmarks_ci.py command, and compare the baseline and comparison commits. Done means the regression has been investigated and its cause or next corrective step is documented.

Written by the indexing model from the issue text.