[Perf] Windows/x86: 3 Improvements on 4/18/2026 7:08:15 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [dbd3e33df9ccf74b91045e095477726c2bf83916](https://github.com/dotnet/runtime/commit/dbd3e33df9ccf74b91045e095477726c2bf83916)
Compare | [b3753182ea941245f8f755b1a16a68b32a76e9b5](https://github.com/dotnet/runtime/commit/b3753182ea941245f8f755b1a16a68b32a76e9b5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/dbd3e33df9ccf74b91045e095477726c2bf83916...b3753182ea941245f8f755b1a16a68b32a76e9b5)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Linq.Tests.Perf_Enumerable

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

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

| 224.02 ns | 195.68 ns | 0.87 | 0.22 | False | | |
|

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

| 237.78 ns | 210.43 ns | 0.88 | 0.18 | 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.Linq.Tests.Perf_Enumerable*'
```

### System.Linq.Tests.Perf_Enumerable.WhereFirst_LastElementMatches(input: Array)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Linq.Tests.Perf_Enumerable.SelectToArray(input: List)

#### 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 | [dbd3e33df9ccf74b91045e095477726c2bf83916](https://github.com/dotnet/runtime/commit/dbd3e33df9ccf74b91045e095477726c2bf83916)
Compare | [b3753182ea941245f8f755b1a16a68b32a76e9b5](https://github.com/dotnet/runtime/commit/b3753182ea941245f8f755b1a16a68b32a76e9b5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/dbd3e33df9ccf74b91045e095477726c2bf83916...b3753182ea941245f8f755b1a16a68b32a76e9b5)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.IterateForEach<Int32>

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

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

| 2.23 μs | 1.96 μs | 0.88 | 0.35 | 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.IterateForEach*'
```

### System.Collections.IterateForEach<Int32>.ImmutableQueue(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)