[Perf] Linux/x64: 2 Regressions on 6/25/2026 4:49:37 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [ce71db3201f610d5a8cbf692cc3081f8784992fc](https://github.com/dotnet/runtime/commit/ce71db3201f610d5a8cbf692cc3081f8784992fc)
Compare | [42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8](https://github.com/dotnet/runtime/commit/42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ce71db3201f610d5a8cbf692cc3081f8784992fc...42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.CreateAddAndRemove<String>

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

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

| 33.18 ms | 41.48 ms | 1.25 | 0.36 | 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.Collections.CreateAddAndRemove*'
```

### System.Collections.CreateAddAndRemove<String>.SortedList(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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [ce71db3201f610d5a8cbf692cc3081f8784992fc](https://github.com/dotnet/runtime/commit/ce71db3201f610d5a8cbf692cc3081f8784992fc)
Compare | [42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8](https://github.com/dotnet/runtime/commit/42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ce71db3201f610d5a8cbf692cc3081f8784992fc...42f3669b3a7f418f571ad63a77b3e7ebf9ee64a8)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in Benchstone.BenchF.LLoops

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

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

| 19.31 secs | 20.96 secs | 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 'Benchstone.BenchF.LLoops*'
```

### Benchstone.BenchF.LLoops.Test

#### 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)

Reproduce System.Collections.CreateAddAndRemove with src/benchmarks/micro/libraries/System.Collections/CreateAddAndRemove.cs and Benchstone.BenchF.LLoops with src/benchmarks/micro/runtime/Benchstones/BenchF/LLoops.cs using the provided benchmarks_ci.py filters. Compare the baseline and compare commits, then follow the linked profiling and benchmarking workflow docs. Done means the cause of both regressions is identified and the affected benchmark results no longer regress.

Written by the indexing model from the issue text.