[Perf] Linux/x64: 1 Regression on 6/19/2026 7:59:52 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [63ac72962bb61d0f9131483dd3916c7e352b1a3d](https://github.com/dotnet/runtime/commit/63ac72962bb61d0f9131483dd3916c7e352b1a3d)
Compare | [95aa263d8387779ef28b1ac89fe186d523bb6c0b](https://github.com/dotnet/runtime/commit/95aa263d8387779ef28b1ac89fe186d523bb6c0b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/63ac72962bb61d0f9131483dd3916c7e352b1a3d...95aa263d8387779ef28b1ac89fe186d523bb6c0b)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Runtime.Intrinsics.Tests.Perf_Vector128Of<UInt16>

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

• [ConditionalSelectBenchmark - 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Runtime.Intrinsics.Tests.Perf_Vector128Of*'
```

### System.Runtime.Intrinsics.Tests.Perf_Vector128Of<UInt16>.ConditionalSelectBenchmark

#### 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 ConditionalSelectBenchmark source in performance/src/benchmarks/micro/libraries/System.Runtime.Intrinsics/Perf_Vector128OfT.cs, then reproduce it with the documented benchmarks_ci.py command and filter. Compare the baseline commit 63ac72962bb61d0f9131483dd3916c7e352b1a3d with 95aa263d8387779ef28b1ac89fe186d523bb6c0b using the linked report and disassembly data; done means identifying and addressing the cause of the 4.66 ns to 250 ns regression.

Written by the indexing model from the issue text.