[Perf] Linux/arm64: 3 Improvements on 1/27/2026 2:19:52 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [21d48d1320e12f5a8859496b669d36f520e5beba](https://github.com/dotnet/runtime/commit/21d48d1320e12f5a8859496b669d36f520e5beba)
Compare | [6b70e930b4b7568286ba54f2b8e70a901c8ac7b5](https://github.com/dotnet/runtime/commit/6b70e930b4b7568286ba54f2b8e70a901c8ac7b5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/21d48d1320e12f5a8859496b669d36f520e5beba...6b70e930b4b7568286ba54f2b8e70a901c8ac7b5)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.IO.Tests.BinaryWriterExtendedTests

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

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

| 24.66 ns | 21.86 ns | 0.89 | 0.03 | 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.IO.Tests.BinaryWriterExtendedTests*'
```

### System.IO.Tests.BinaryWriterExtendedTests.WriteAsciiCharArray(StringLengthInChars: 32)

#### 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 | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [21d48d1320e12f5a8859496b669d36f520e5beba](https://github.com/dotnet/runtime/commit/21d48d1320e12f5a8859496b669d36f520e5beba)
Compare | [6b70e930b4b7568286ba54f2b8e70a901c8ac7b5](https://github.com/dotnet/runtime/commit/6b70e930b4b7568286ba54f2b8e70a901c8ac7b5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/21d48d1320e12f5a8859496b669d36f520e5beba...6b70e930b4b7568286ba54f2b8e70a901c8ac7b5)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.RegularExpressions.Tests.Perf_Regex_Industry_Leipzig

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

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

| 469.67 ms | 265.39 ms | 0.57 | 0.01 | False | | |
|

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

| 472.69 ms | 276.54 ms | 0.59 | 0.00 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.RegularExpressions.Tests.Perf_Regex_Industry_Leipzig*'
```

### System.Text.RegularExpressions.Tests.Perf_Regex_Industry_Leipzig.Count(Pattern: ".{0,2}(Tom|Sawyer|Huckleberry|Finn)", Options: Compiled)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.RegularExpressions.Tests.Perf_Regex_Industry_Leipzig.Count(Pattern: ".{2,4}(Tom|Sawyer|Huckleberry|Finn)", Options: Compiled)

#### 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)