[Perf] Linux/x64: 2 Regressions on 9/12/2026 2:03:45 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro

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

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

• [GreaterThanAllBenchmark - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 16.21 ns | 17.21 ns | 1.06 | 0.23 | False | | |

![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<Double>.GreaterThanAllBenchmark

#### 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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in System.Tests.Perf_Random

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

• [Next_int_unseeded - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 53.62 ns | 58.66 ns | 1.09 | 0.22 | False | | |

![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.Tests.Perf_Random*'
```

### System.Tests.Perf_Random.Next_int_unseeded

#### 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 sources at src/benchmarks/micro/libraries/System.Runtime.Intrinsics/Perf_Vector128OfT.cs and src/benchmarks/micro/libraries/System.Runtime.Extensions/Perf.Random.cs, then run the two filters from the issue using benchmarks_ci.py. Compare the baseline and test commits and inspect the linked reports to reproduce both regressions. Done means the regressions are reproduced and their cause and resolution are established.

Written by the indexing model from the issue text.