[Perf] Linux/arm64: 1 Improvement on 7/21/2026 3:22:49 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [2c87bd2b64912ec925d9c419c35fe82d5086b13f](https://github.com/dotnet/runtime/commit/2c87bd2b64912ec925d9c419c35fe82d5086b13f)
Compare | [5ffdd753b0146f0ec95786b2af0ab7da0b37d061](https://github.com/dotnet/runtime/commit/5ffdd753b0146f0ec95786b2af0ab7da0b37d061)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2c87bd2b64912ec925d9c419c35fe82d5086b13f...5ffdd753b0146f0ec95786b2af0ab7da0b37d061)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.Json.Tests.Perf_Get

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

• [GetUInt64 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config 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.Json.Tests.Perf_Get*'
```

### System.Text.Json.Tests.Perf_Get.GetUInt64

#### 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 linked benchmark source in performance/src/benchmarks/micro/libraries/System.Text.Json/Utf8JsonReader/Perf.Get.cs around lines 146-159, then reproduce the System.Text.Json.Tests.Perf_Get run with the provided benchmarks_ci.py command. Compare the arm64 AzureLinux results and inspect the linked report and diff; done means the GetUInt64 improvement is explained and any needed runtime change is validated by the benchmark.

Written by the indexing model from the issue text.