[Perf] Windows/x86: 3 Regressions on 5/28/2026 9:53:58 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [832949cd5f36aac20268e974fd07b3ffc73acdfd](https://github.com/dotnet/runtime/commit/832949cd5f36aac20268e974fd07b3ffc73acdfd)
Compare | [df1507806b4e2cd19bde86e5a945bd4bfd7839f5](https://github.com/dotnet/runtime/commit/df1507806b4e2cd19bde86e5a945bd4bfd7839f5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/832949cd5f36aac20268e974fd07b3ffc73acdfd...df1507806b4e2cd19bde86e5a945bd4bfd7839f5)
Configs | CompilationMode:tiered, RunKind:micro

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

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

• [LinkedList - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 1.95 μs | 2.37 μs | 1.21 | 0.27 | False | | |
|

• [HashSet - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 1.40 μs | 1.54 μs | 1.10 | 0.15 | False | | |

![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.IterateForEach*'
```

### System.Collections.IterateForEach<String>.LinkedList(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.IterateForEach<String>.HashSet(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)

---

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [832949cd5f36aac20268e974fd07b3ffc73acdfd](https://github.com/dotnet/runtime/commit/832949cd5f36aac20268e974fd07b3ffc73acdfd)
Compare | [df1507806b4e2cd19bde86e5a945bd4bfd7839f5](https://github.com/dotnet/runtime/commit/df1507806b4e2cd19bde86e5a945bd4bfd7839f5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/832949cd5f36aac20268e974fd07b3ffc73acdfd...df1507806b4e2cd19bde86e5a945bd4bfd7839f5)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Tests.Perf_Enum

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

• [ToString_Format_Flags_Large - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 15.05 ns | 16.78 ns | 1.11 | 0.32 | False | | |

![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.Tests.Perf_Enum*'
```

### System.Tests.Perf_Enum.ToString_Format_Flags_Large(value: All, format: "x")

#### 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)