[Perf] Windows/x64: 4 Regressions on 5/7/2026 3:57:15 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b](https://github.com/dotnet/runtime/commit/cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b)
Compare | [c3caf4d3163c429efbdefe7756a71702e9e6c982](https://github.com/dotnet/runtime/commit/c3caf4d3163c429efbdefe7756a71702e9e6c982)
Diff | [Diff](https://github.com/dotnet/runtime/compare/cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b...c3caf4d3163c429efbdefe7756a71702e9e6c982)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Numerics.Tensors.Tests.Perf_NumberTensorPrimitives<Single>

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

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

| 35.65 ns | 48.26 ns | 1.35 | 0.08 | False | | |
|

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

| 856.05 ns | 1120.50 ns | 1.31 | 0.00 | False | | |

![graph]()
![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.Tensors.Tests.Perf_NumberTensorPrimitives*'
```

### System.Numerics.Tensors.Tests.Perf_NumberTensorPrimitives<Single>.IndexOfMax(BufferLength: 128)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tensors.Tests.Perf_NumberTensorPrimitives<Single>.IndexOfMax(BufferLength: 3079)

#### 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 | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [06ca6751830996c1c815bfdd73a3fb4c8b53d77f](https://github.com/dotnet/runtime/commit/06ca6751830996c1c815bfdd73a3fb4c8b53d77f)
Compare | [c3caf4d3163c429efbdefe7756a71702e9e6c982](https://github.com/dotnet/runtime/commit/c3caf4d3163c429efbdefe7756a71702e9e6c982)
Diff | [Diff](https://github.com/dotnet/runtime/compare/06ca6751830996c1c815bfdd73a3fb4c8b53d77f...c3caf4d3163c429efbdefe7756a71702e9e6c982)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Collections.CtorFromCollection<Int32>

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

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

| 48.50 μs | 52.17 μs | 1.08 | 0.14 | 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.Collections.CtorFromCollection*'
```

### System.Collections.CtorFromCollection<Int32>.ImmutableHashSet(Size: 512)

#### 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 | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b](https://github.com/dotnet/runtime/commit/cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b)
Compare | [c3caf4d3163c429efbdefe7756a71702e9e6c982](https://github.com/dotnet/runtime/commit/c3caf4d3163c429efbdefe7756a71702e9e6c982)
Diff | [Diff](https://github.com/dotnet/runtime/compare/cdbf0c2ba8a84fdc9d83f019baa2103a0afd580b...c3caf4d3163c429efbdefe7756a71702e9e6c982)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Text.Json.Tests.Perf_Reader

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

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

| 4.27 μs | 4.56 μs | 1.07 | 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 'System.Text.Json.Tests.Perf_Reader*'
```

### System.Text.Json.Tests.Perf_Reader.ReadSpanEmptyLoop(IsDataCompact: False, TestCase: DeepTree)

#### 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)