[Perf] Linux/arm64: 4 Improvements on 8/19/2026 11:48:00 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [22645b47c400e6cc0aec97ddcb3f1998677b6d94](https://github.com/dotnet/runtime/commit/22645b47c400e6cc0aec97ddcb3f1998677b6d94)
Compare | [cb8ddc8cac0182e932903d921bd09300be7ae2a6](https://github.com/dotnet/runtime/commit/cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22645b47c400e6cc0aec97ddcb3f1998677b6d94...cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.Tests.Perf_Double

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]()

| 34.04 μs | 7.21 μs | 0.21 | 0.12 | False | | |
|

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

| 33.67 μs | 7.23 μs | 0.21 | 0.06 | False | | |

![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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_Double*'
```

### System.Tests.Perf_Double.ToStringWithFormat(value: -1.7976931348623157E+308, format: "F50")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.ToStringWithFormat(value: 1.7976931348623157E+308, format: "F50")

#### 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 | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [22645b47c400e6cc0aec97ddcb3f1998677b6d94](https://github.com/dotnet/runtime/commit/22645b47c400e6cc0aec97ddcb3f1998677b6d94)
Compare | [cb8ddc8cac0182e932903d921bd09300be7ae2a6](https://github.com/dotnet/runtime/commit/cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22645b47c400e6cc0aec97ddcb3f1998677b6d94...cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements 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]()

| 1631.61 ns | 634.03 ns | 0.39 | 0.07 | False | | |
|

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

| 1.59 μs | 1.03 μs | 0.65 | 0.12 | False | | |

![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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_Single*'
```

### System.Tests.Perf_Single.ToStringWithFormat(value: 3.4028235E+38, format: "F50")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.ToStringWithFormat(value: -3.4028235E+38, format: "F50")

#### 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 in performance/src/benchmarks/micro/libraries/System.Runtime/Perf.Double.cs and Perf.Single.cs, then run the provided benchmarks_ci.py command with the System.Tests.Perf_Double* and System.Tests.Perf_Single* filters. Compare the results with the linked reports; the issue does not define a code change or a completion criterion beyond investigating these performance results.

Written by the indexing model from the issue text.