[Perf] Windows/x86: 4 Regressions on 4/9/2026 7:19:09 PM +00:00

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#71,317 opened on Apr 14, 2026 1 comment 0 reactions 0 assignees View on GitHub

arch-x86 branch-refs/heads/main compilationmode-tiered kind-micro 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 | [ab2f538fca8e2d278e592da1dd6e6ad82954e91c](https://github.com/dotnet/runtime/commit/ab2f538fca8e2d278e592da1dd6e6ad82954e91c)
Compare | [cc78323ef440208bab9bd99fee82e3ea40ec61a5](https://github.com/dotnet/runtime/commit/cc78323ef440208bab9bd99fee82e3ea40ec61a5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/ab2f538fca8e2d278e592da1dd6e6ad82954e91c...cc78323ef440208bab9bd99fee82e3ea40ec61a5)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.IO.Tests.StreamReaderReadLineTests

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

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

| 196.89 μs | 222.05 μs | 1.13 | 0.07 | False | | |
|

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

| 168.63 μs | 189.72 μs | 1.13 | 0.05 | False | | |
|

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

| 30.21 μs | 32.12 μs | 1.06 | 0.29 | False | | |

[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.IO.Tests.StreamReaderReadLineTests*'
```

### System.IO.Tests.StreamReaderReadLineTests.ReadLineAsync(LineLengthRange: [ 0, 0])

#### ETL Files

#### Histogram

#### JIT Disasms

### System.IO.Tests.StreamReaderReadLineTests.ReadLineAsync(LineLengthRange: [ 1, 1])

#### ETL Files

#### Histogram

#### JIT Disasms

### System.IO.Tests.StreamReaderReadLineTests.ReadLineAsync(LineLengthRange: [ 9, 32])

#### 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

### Regressions in System.Numerics.Tensors.Tests.Perf_FloatingPointTensorPrimitives<Double>

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

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

| 2.60 μs | 8.25 μs | 3.18 | 0.34 | False | | |

[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.Tensors.Tests.Perf_FloatingPointTensorPrimitives*'
```

### System.Numerics.Tensors.Tests.Perf_FloatingPointTensorPrimitives<Double>.Exp(BufferLength: 3079)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

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[Perf] Windows/x86: 4 Regressions on 4/9/2026 7:19:09 PM +00:00

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