[Perf] Linux/x64: 4 Regressions on 5/5/2026 8:56:26 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [004c358f4376950ead5ef31b95bf4f91a725b42a](https://github.com/dotnet/runtime/commit/004c358f4376950ead5ef31b95bf4f91a725b42a)
Compare | [2e33a3e335d509dda962bf1ca463d6c970b7393b](https://github.com/dotnet/runtime/commit/2e33a3e335d509dda962bf1ca463d6c970b7393b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/004c358f4376950ead5ef31b95bf4f91a725b42a...2e33a3e335d509dda962bf1ca463d6c970b7393b)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.Perf_SubstringFrozenDictionary

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

• [ToFrozenDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 66.34 ms | 101.73 ms | 1.53 | 0.27 | False | | |
|

• [TryGetValue_False_FrozenDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 8.56 ms | 9.45 ms | 1.10 | 0.30 | False | | |
|

• [TryGetValue_False_FrozenDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 85.31 μs | 93.30 μs | 1.09 | 0.29 | False | | |
|

• [TryGetValue_False_FrozenDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 878.25 μs | 947.66 μs | 1.08 | 0.29 | False | | |

![graph]()
![graph]()
![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.Collections.Perf_SubstringFrozenDictionary*'
```

### System.Collections.Perf_SubstringFrozenDictionary.ToFrozenDictionary(Count: 10000)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Perf_SubstringFrozenDictionary.TryGetValue_False_FrozenDictionary(Count: 10000)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Perf_SubstringFrozenDictionary.TryGetValue_False_FrozenDictionary(Count: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Perf_SubstringFrozenDictionary.TryGetValue_False_FrozenDictionary(Count: 1000)

#### 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)