[Perf] Linux/arm64: 2 Regressions on 8/25/2026 11:54:37 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [6d57017f1cbf04efa931389d38ca4755e4da8add](https://github.com/dotnet/runtime/commit/6d57017f1cbf04efa931389d38ca4755e4da8add)
Compare | [519e88bf80b5d39bc2c4e788a025a499136a1661](https://github.com/dotnet/runtime/commit/519e88bf80b5d39bc2c4e788a025a499136a1661)
Diff | [Diff](https://github.com/dotnet/runtime/compare/6d57017f1cbf04efa931389d38ca4755e4da8add...519e88bf80b5d39bc2c4e788a025a499136a1661)
Configs | CompilationMode:tiered, RunKind:sve

### Regressions in SveBenchmarks.StrCmp

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

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

| 66.83 ns | 75.98 ns | 1.14 | 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 'SveBenchmarks.StrCmp*'
```

### SveBenchmarks.StrCmp.SveTail(Size: 527, Modify: "None")

#### 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 | [6d57017f1cbf04efa931389d38ca4755e4da8add](https://github.com/dotnet/runtime/commit/6d57017f1cbf04efa931389d38ca4755e4da8add)
Compare | [519e88bf80b5d39bc2c4e788a025a499136a1661](https://github.com/dotnet/runtime/commit/519e88bf80b5d39bc2c4e788a025a499136a1661)
Diff | [Diff](https://github.com/dotnet/runtime/compare/6d57017f1cbf04efa931389d38ca4755e4da8add...519e88bf80b5d39bc2c4e788a025a499136a1661)
Configs | CompilationMode:tiered, RunKind:sve

### Regressions in SveBenchmarks.StrIndexOf

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

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

| 3.56 ns | 5.76 ns | 1.62 | 0.18 | 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 'SveBenchmarks.StrIndexOf*'
```

### SveBenchmarks.StrIndexOf.SveIndexOf(Size: 19)

#### 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 src/benchmarks/micro/sve/StrCmp.cs and src/benchmarks/micro/sve/StrIndexOf.cs, then run the provided benchmarks_ci.py commands with the listed filters. Compare the results with the linked baseline and test commits and inspect the benchmark reports. Done means the arm64 regressions are explained and the affected benchmark no longer shows the reported slowdown.

Written by the indexing model from the issue text.