[Perf] Linux/x64: 2 Improvements on 1/22/2026 10:40:20 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | TigerUbuntu
Baseline | [2cd0cc89e2bdbcaa804c93a36adefa055d851c40](https://github.com/dotnet/runtime/commit/2cd0cc89e2bdbcaa804c93a36adefa055d851c40)
Compare | [0f61adc266b63df30e3e3136008567cc7d9077b9](https://github.com/dotnet/runtime/commit/0f61adc266b63df30e3e3136008567cc7d9077b9)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2cd0cc89e2bdbcaa804c93a36adefa055d851c40...0f61adc266b63df30e3e3136008567cc7d9077b9)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Tests.Perf_UInt64

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

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

| 22.87 ns | 20.71 ns | 0.91 | 0.12 | False | | |
|

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

| 9.68 ns | 8.14 ns | 0.84 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Tests.Perf_UInt64*'
```

### System.Tests.Perf_UInt64.ToString(value: 18446744073709551615)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_UInt64.ToString(value: 12345)

#### 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)