[Perf] Linux/arm64: 2 Improvements on 6/26/2026 6:28:17 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55](https://github.com/dotnet/runtime/commit/22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55)
Compare | [207ffd155f96b38be1749584b99f3ac0a505218c](https://github.com/dotnet/runtime/commit/207ffd155f96b38be1749584b99f3ac0a505218c)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55...207ffd155f96b38be1749584b99f3ac0a505218c)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.AddGivenSize<Int32>

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

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

| 5.08 μs | 3.50 μs | 0.69 | 0.40 | 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.AddGivenSize*'
```

### System.Collections.AddGivenSize<Int32>.Dictionary(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)

---

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55](https://github.com/dotnet/runtime/commit/22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55)
Compare | [207ffd155f96b38be1749584b99f3ac0a505218c](https://github.com/dotnet/runtime/commit/207ffd155f96b38be1749584b99f3ac0a505218c)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22c1ced1d71c05e96f9cca3c2d6171ba9e5f0a55...207ffd155f96b38be1749584b99f3ac0a505218c)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in Struct.GSeq

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

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

| 14.51 μs | 12.49 μs | 0.86 | 0.16 | 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 'Struct.GSeq*'
```

### Struct.GSeq.FilterSkipMapSum

#### 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 at src/benchmarks/micro/libraries/System.Collections/Add/AddGivenSize.cs and src/benchmarks/micro/runtime/Struct/GSeq.cs, then follow the linked comparison and test reports. Reproduce each case with the provided benchmarks_ci.py commands and inspect the reported ARM64 improvements. Done means the two measurements are understood and any actionable runtime performance change is identified.

Written by the indexing model from the issue text.