[Perf] Windows/x86: 1 Regression on 7/22/2026 1:06:27 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [56c76e2f3594e2b6208c8bf61f5dda0eb476e353](https://github.com/dotnet/runtime/commit/56c76e2f3594e2b6208c8bf61f5dda0eb476e353)
Compare | [dc3757e67b2d6eb7d6db7e052574a02c3d445432](https://github.com/dotnet/runtime/commit/dc3757e67b2d6eb7d6db7e052574a02c3d445432)
Diff | [Diff](https://github.com/dotnet/runtime/compare/56c76e2f3594e2b6208c8bf61f5dda0eb476e353...dc3757e67b2d6eb7d6db7e052574a02c3d445432)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Memory.Span<Byte>

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

• [SequenceCompareTo - 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.Memory.Span*'
```

### System.Memory.Span<Byte>.SequenceCompareTo(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 benchmark source in performance/src/benchmarks/micro/libraries/System.Memory/Span.cs#L65-L66 and compare the listed baseline and compare commits. Run the provided benchmarks_ci.py command to confirm the System.Memory.Span.SequenceCompareTo regression; done means determining the responsible runtime change and documenting or addressing the confirmed regression.

Written by the indexing model from the issue text.