[Perf] Windows/x86: 7 Regressions on 7/17/2026 12:15:56 AM +00:00

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#76,533 opened on Jul 21, 2026 1 comment 0 reactions 0 assignees View on GitHub

arch-x86 branch-refs/heads/main compilationmode-tiered kind-micro Look Again os-windows perf-regression runkind-micro runtime-coreclr untriaged

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Stars: 10
Forks: 8
PR merge metrics: PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [1594ad1e1b5313c3ece119ced82b0a7ed2be7fbb](https://github.com/dotnet/runtime/commit/1594ad1e1b5313c3ece119ced82b0a7ed2be7fbb)
Compare | [09f41d9272e6dcff30bfa15653e124d013167e05](https://github.com/dotnet/runtime/commit/09f41d9272e6dcff30bfa15653e124d013167e05)
Diff | [Diff](https://github.com/dotnet/runtime/compare/1594ad1e1b5313c3ece119ced82b0a7ed2be7fbb...09f41d9272e6dcff30bfa15653e124d013167e05)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Runtime.Intrinsics.Tests.Perf_Vector128Of<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]()

| 25.92 ns | 32.21 ns | 1.24 | 0.03 | 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<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 | x86
OS | Windows 10.0.22631
Queue | ViperWindows
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, 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]()

| 26.66 ns | 36.64 ns | 1.37 | 0.02 | 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

---

### Run Information

### Regressions in System.Runtime.Intrinsics.Tests.Perf_Vector128Of<Int16>

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]()

| 20.97 ns | 23.00 ns | 1.10 | 0.00 | 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<Int16>.SquareRootBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Numerics.Tests.Perf_VectorOf<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]()

| 22.37 ns | 24.91 ns | 1.11 | 0.00 | 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<UInt16>.SquareRootBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### 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]()

| 21.02 ns | 22.78 ns | 1.08 | 0.00 | 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

---

### Run Information

### Regressions in System.Numerics.Tests.Perf_VectorOf<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]()

| 44.08 ns | 46.93 ns | 1.06 | 0.00 | 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<Byte>.SquareRootBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Numerics.Tests.Perf_VectorOf<Int16>

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]()

| 22.16 ns | 24.89 ns | 1.12 | 0.00 | 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<Int16>.SquareRootBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the benchmark sources in src/benchmarks/micro/libraries/System.Runtime.Intrinsics/Perf_Vector128OfT.cs and System.Numerics.Vectors/Perf_VectorOfT.cs, then run the provided benchmarks_ci.py filters on Windows x86. Compare the listed baseline and compare commits and inspect the linked reports; done means the reported regression is explained and the affected benchmark performance is restored or appropriately triaged.

Written by the indexing model from the issue text.

Assessment

Tech stack: csharp, python
Domain: performance, testing
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Quiet
Clarity: Mostly clear
Newbie friendliness: 42/100

[Perf] Windows/x86: 7 Regressions on 7/17/2026 12:15:56 AM +00:00

Description

Contributor guide

Research direction

Assessment

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