[Perf] Windows/x86: 1 Regression on 6/27/2026 4:35:02 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [207ffd155f96b38be1749584b99f3ac0a505218c](https://github.com/dotnet/runtime/commit/207ffd155f96b38be1749584b99f3ac0a505218c)
Compare | [67d84fcca76e449edfe760195bf921f59e2f30fc](https://github.com/dotnet/runtime/commit/67d84fcca76e449edfe760195bf921f59e2f30fc)
Diff | [Diff](https://github.com/dotnet/runtime/compare/207ffd155f96b38be1749584b99f3ac0a505218c...67d84fcca76e449edfe760195bf921f59e2f30fc)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in LinqBenchmarks

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

• [Count00LinqMethodX - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config 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 'LinqBenchmarks*'
```

### LinqBenchmarks.Count00LinqMethodX

#### 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 by running the documented benchmarks_ci.py command with the LinqBenchmarks filter, then inspect performance/src/benchmarks/micro/runtime/Linq/Linq.cs lines 288-299 and the baseline/compare commits. Use the linked test report and profiling workflow to investigate Count00LinqMethodX; done means the x86 Windows regression is explained and addressed or confirmed as expected.

Written by the indexing model from the issue text.