[Perf] Linux/arm64: 5 Regressions on 5/22/2026 1:11:45 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [b77e008c4bd457ef29c4af17bfc99a7525949185](https://github.com/dotnet/runtime/commit/b77e008c4bd457ef29c4af17bfc99a7525949185)
Compare | [4a84da2cda2a2d7425d5f30204bc0d4a84aadef0](https://github.com/dotnet/runtime/commit/4a84da2cda2a2d7425d5f30204bc0d4a84aadef0)
Diff | [Diff](https://github.com/dotnet/runtime/compare/b77e008c4bd457ef29c4af17bfc99a7525949185...4a84da2cda2a2d7425d5f30204bc0d4a84aadef0)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Regressions in System.Text.Perf_Utf8Encoding

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

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

| 83.02 μs | 95.54 μs | 1.15 | 0.32 | False | | |
|

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

| 269.28 μs | 297.90 μs | 1.11 | 0.16 | False | | |
|

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

| 141.46 μs | 156.01 μs | 1.10 | 0.18 | False | | |
|

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

| 160.85 μs | 174.17 μs | 1.08 | 0.18 | False | | |
|

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

| 203.73 μs | 215.44 μs | 1.06 | 0.17 | False | | |

![graph]()
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[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.Perf_Utf8Encoding*'
```

### System.Text.Perf_Utf8Encoding.GetBytes(Input: EnglishAllAscii)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Perf_Utf8Encoding.GetString(Input: EnglishMostlyAscii)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Perf_Utf8Encoding.GetString(Input: EnglishAllAscii)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Perf_Utf8Encoding.GetBytes(Input: Cyrillic)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Perf_Utf8Encoding.GetBytes(Input: EnglishMostlyAscii)

#### 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)