[Perf] Linux/arm64: 3 Regressions on 7/17/2026 12:15:56 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [b78a8f8b1d15898ba39eb4fd63e2578edcf16c37](https://github.com/dotnet/runtime/commit/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37)
Compare | [09f41d9272e6dcff30bfa15653e124d013167e05](https://github.com/dotnet/runtime/commit/09f41d9272e6dcff30bfa15653e124d013167e05)
Diff | [Diff](https://github.com/dotnet/runtime/compare/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37...09f41d9272e6dcff30bfa15653e124d013167e05)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Regressions in System.Runtime.Intrinsics.Tests.Perf_Vector128Of<Byte>

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

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

| 43.26 ns | 55.96 ns | 1.29 | 0.09 | 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.Runtime.Intrinsics.Tests.Perf_Vector128Of*'
```

### System.Runtime.Intrinsics.Tests.Perf_Vector128Of<Byte>.SquareRootBenchmark

#### 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 | [b78a8f8b1d15898ba39eb4fd63e2578edcf16c37](https://github.com/dotnet/runtime/commit/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37)
Compare | [09f41d9272e6dcff30bfa15653e124d013167e05](https://github.com/dotnet/runtime/commit/09f41d9272e6dcff30bfa15653e124d013167e05)
Diff | [Diff](https://github.com/dotnet/runtime/compare/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37...09f41d9272e6dcff30bfa15653e124d013167e05)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Regressions in System.Numerics.Tests.Perf_VectorOf<SByte>

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

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

| 27.69 ns | 39.21 ns | 1.42 | 0.36 | 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.Numerics.Tests.Perf_VectorOf*'
```

### System.Numerics.Tests.Perf_VectorOf<SByte>.SquareRootBenchmark

#### 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 | [b78a8f8b1d15898ba39eb4fd63e2578edcf16c37](https://github.com/dotnet/runtime/commit/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37)
Compare | [09f41d9272e6dcff30bfa15653e124d013167e05](https://github.com/dotnet/runtime/commit/09f41d9272e6dcff30bfa15653e124d013167e05)
Diff | [Diff](https://github.com/dotnet/runtime/compare/b78a8f8b1d15898ba39eb4fd63e2578edcf16c37...09f41d9272e6dcff30bfa15653e124d013167e05)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Regressions in System.Runtime.Intrinsics.Tests.Perf_Vector128Of<UInt16>

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

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

| 37.27 ns | 47.81 ns | 1.28 | 0.17 | 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.Runtime.Intrinsics.Tests.Perf_Vector128Of*'
```

### System.Runtime.Intrinsics.Tests.Perf_Vector128Of<UInt16>.SquareRootBenchmark

#### 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/libraries/System.Runtime.Intrinsics/Perf_Vector128OfT.cs and src/benchmarks/micro/libraries/System.Numerics.Vectors/Perf_VectorOfT.cs, then run the listed filters. Compare the baseline and compare commits with the linked performance reports and ARM64 data. Done means the three reported regressions have a confirmed cause and a validated resolution.

Written by the indexing model from the issue text.