[Perf] Linux/x64: 2 Regressions on 6/25/2026 3:50:04 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [818cfd5edcda78ac3eb201af392fd301ab9ad46b](https://github.com/dotnet/runtime/commit/818cfd5edcda78ac3eb201af392fd301ab9ad46b)
Compare | [4e28c96c3bd32ce2811ef7128641e8926874020e](https://github.com/dotnet/runtime/commit/4e28c96c3bd32ce2811ef7128641e8926874020e)
Diff | [Diff](https://github.com/dotnet/runtime/compare/818cfd5edcda78ac3eb201af392fd301ab9ad46b...4e28c96c3bd32ce2811ef7128641e8926874020e)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in Burgers

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

• [Test2 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 11.17 secs | 19.65 secs | 1.76 | 0.34 | 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 'Burgers*'
```

### Burgers.Test2

#### 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 | [818cfd5edcda78ac3eb201af392fd301ab9ad46b](https://github.com/dotnet/runtime/commit/818cfd5edcda78ac3eb201af392fd301ab9ad46b)
Compare | [4e28c96c3bd32ce2811ef7128641e8926874020e](https://github.com/dotnet/runtime/commit/4e28c96c3bd32ce2811ef7128641e8926874020e)
Diff | [Diff](https://github.com/dotnet/runtime/compare/818cfd5edcda78ac3eb201af392fd301ab9ad46b...4e28c96c3bd32ce2811ef7128641e8926874020e)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Memory.Span<Int32>

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

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

| 464.38 ns | 557.51 ns | 1.20 | 0.21 | 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.Memory.Span*'
```

### System.Memory.Span<Int32>.Clear(Size: 3000)

#### 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 Burgers.cs and Span.cs, then read the linked benchmarking and profiling workflow documentation. Reproduce the reported benchmarks with benchmarks_ci.py and compare the baseline and comparison commits and reports. Done means the cause of both performance regressions is understood and the benchmark results have been reevaluated.

Written by the indexing model from the issue text.