[Perf] Linux/arm64: 4 Improvements on 5/20/2026 1:12:20 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [c6a8e4caf07c58141038ca47aedc61ff39d33d96](https://github.com/dotnet/runtime/commit/c6a8e4caf07c58141038ca47aedc61ff39d33d96)
Compare | [b129b7c103a567531537d2256e58aaa1dc76dbdf](https://github.com/dotnet/runtime/commit/b129b7c103a567531537d2256e58aaa1dc76dbdf)
Diff | [Diff](https://github.com/dotnet/runtime/compare/c6a8e4caf07c58141038ca47aedc61ff39d33d96...b129b7c103a567531537d2256e58aaa1dc76dbdf)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.Tests.Perf_StringBuilder

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

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

| 40.80 ns | 34.20 ns | 0.84 | 0.26 | False | | |
|

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

| 32.55 ns | 27.81 ns | 0.85 | 0.41 | False | | |
|

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

| 265.44 ns | 251.59 ns | 0.95 | 0.24 | False | | |

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

### System.Text.Tests.Perf_StringBuilder.ctor_string(length: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Tests.Perf_StringBuilder.ctor_capacity(length: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Tests.Perf_StringBuilder.AppendLine_Strings

#### 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 | [c6a8e4caf07c58141038ca47aedc61ff39d33d96](https://github.com/dotnet/runtime/commit/c6a8e4caf07c58141038ca47aedc61ff39d33d96)
Compare | [b129b7c103a567531537d2256e58aaa1dc76dbdf](https://github.com/dotnet/runtime/commit/b129b7c103a567531537d2256e58aaa1dc76dbdf)
Diff | [Diff](https://github.com/dotnet/runtime/compare/c6a8e4caf07c58141038ca47aedc61ff39d33d96...b129b7c103a567531537d2256e58aaa1dc76dbdf)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.IterateForEachNonGeneric<String>

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

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

| 13.33 μs | 11.55 μs | 0.87 | 0.17 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.IterateForEachNonGeneric*'
```

### System.Collections.IterateForEachNonGeneric<String>.Hashtable(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)