[Perf] Windows/x86: 1 Improvement on 8/4/2026 11:00:59 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [10c04f707d28097296d509a66c6123ee848361e0](https://github.com/dotnet/runtime/commit/10c04f707d28097296d509a66c6123ee848361e0)
Compare | [ac85c6849c56dcb47e036b2a729c1e99dc413bab](https://github.com/dotnet/runtime/commit/ac85c6849c56dcb47e036b2a729c1e99dc413bab)
Diff | [Diff](https://github.com/dotnet/runtime/compare/10c04f707d28097296d509a66c6123ee848361e0...ac85c6849c56dcb47e036b2a729c1e99dc413bab)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.IO.Tests.BinaryWriterExtendedTests

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

• [WriteAsciiCharArray - 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.IO.Tests.BinaryWriterExtendedTests*'
```

### System.IO.Tests.BinaryWriterExtendedTests.WriteAsciiCharArray(StringLengthInChars: 2000000)

#### 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 referenced benchmark source, performance/micro/libraries/System.IO/BinaryWriterExtendedTests.cs lines 29-34, and review the WriteAsciiCharArray result for x86 on Windows. Run the provided benchmarks_ci.py command to confirm the measurement; done means determining whether the reported improvement needs a runtime change or further investigation.

Written by the indexing model from the issue text.