[Perf] Windows/x86: 1 Regression on 8/10/2026 5:40:28 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [c668fd41fd95a3b52c783bfdc761604712010ba3](https://github.com/dotnet/runtime/commit/c668fd41fd95a3b52c783bfdc761604712010ba3)
Compare | [ab094c18ba7f4a96d145afd8b34f965c5c3ef31d](https://github.com/dotnet/runtime/commit/ab094c18ba7f4a96d145afd8b34f965c5c3ef31d)
Diff | [Diff](https://github.com/dotnet/runtime/compare/c668fd41fd95a3b52c783bfdc761604712010ba3...ab094c18ba7f4a96d145afd8b34f965c5c3ef31d)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.IO.Tests.BinaryWriterTests

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

• [WriteHalf - Duration of single invocation]()
• [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.IO.Tests.BinaryWriterTests*'
```

### System.IO.Tests.BinaryWriterTests.WriteHalf

#### 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.IO.Tests.BinaryWriterTests.WriteHalf benchmark report and the linked baseline/compare commits, then reproduce it using the benchmarks_ci.py command in the issue. Compare the 8.89 ns baseline with the 10.94 ns result and use the profiling and benchmarking workflow docs to investigate; done means the regression is explained and the benchmark returns to its expected performance.

Written by the indexing model from the issue text.