[Perf] Linux/x64: 4 Regressions on 5/19/2026 3:17:56 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [286dc1501f7bc16b2b170ec68d70bb755476d4ea](https://github.com/dotnet/runtime/commit/286dc1501f7bc16b2b170ec68d70bb755476d4ea)
Compare | [c6a8e4caf07c58141038ca47aedc61ff39d33d96](https://github.com/dotnet/runtime/commit/c6a8e4caf07c58141038ca47aedc61ff39d33d96)
Diff | [Diff](https://github.com/dotnet/runtime/compare/286dc1501f7bc16b2b170ec68d70bb755476d4ea...c6a8e4caf07c58141038ca47aedc61ff39d33d96)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Tests.Perf_Single

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

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

| 19.67 μs | 23.11 μs | 1.17 | 0.22 | False | | |
|

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

| 23.16 μs | 25.59 μs | 1.10 | 0.29 | False | | |
|

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

| 21.99 μs | 24.04 μs | 1.09 | 0.31 | False | | |
|

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

| 22.40 μs | 24.14 μs | 1.08 | 0.33 | 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.Tests.Perf_Single*'
```

### System.Tests.Perf_Single.ToStringWithFormat(value: -3.4028235E+38, format: "E")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.ToStringWithFormat(value: -3.4028235E+38, format: "R")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.ToString(value: 3.4028235E+38)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.ToStringWithCultureInfo(value: -3.4028235E+38, culture: zh)

#### 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)