[Perf] Windows/x86: 1 Improvement on 8/17/2026 4:21:07 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [ab8aa8def4ca77d9eaba98377c4066f0d3313101](https://github.com/dotnet/runtime/commit/ab8aa8def4ca77d9eaba98377c4066f0d3313101)
Compare | [633df28f492810dd8b152eb72f3d77aae703db89](https://github.com/dotnet/runtime/commit/633df28f492810dd8b152eb72f3d77aae703db89)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ab8aa8def4ca77d9eaba98377c4066f0d3313101...633df28f492810dd8b152eb72f3d77aae703db89)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.IO.Tests.Perf_File

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

• [ReadAllBytesAsync - 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.Perf_File*'
```

### System.IO.Tests.Perf_File.ReadAllBytesAsync(size: 1048576)

#### 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.Perf_File.ReadAllBytesAsync benchmark source in performance/src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.File.cs, then run the provided benchmarks_ci.py command. Compare the Windows/x86 result with the linked test report and determine whether the reported improvement requires a runtime change; the investigation is done when its cause and next action are clear.

Written by the indexing model from the issue text.