[Perf] Windows/x64: 1 Regression on 9/1/2026 5:07:37 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [a1d60271d589de52ba513a8265a9038da9eaba5c](https://github.com/dotnet/sdk/commit/a1d60271d589de52ba513a8265a9038da9eaba5c)
Compare | [f8a811758057986566da27d06d8f03a7e5e226bf](https://github.com/dotnet/sdk/commit/f8a811758057986566da27d06d8f03a7e5e226bf)
Diff | [Diff](https://github.com/dotnet/sdk/compare/a1d60271d589de52ba513a8265a9038da9eaba5c...f8a811758057986566da27d06d8f03a7e5e226bf)
Configs | CompilationMode:tiered, RunKind:akadeindexedset

### Regressions in Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks

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

• [UniqueLookup - 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 'Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks*'
```

### Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks.UniqueLookup

#### 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 with src/benchmarks/real-world/Akade.IndexedSet.Benchmarks/ConcurrentSetBenchmarks.cs at lines 46-50 and reproduce the UniqueLookup benchmark using the provided benchmarks_ci.py command. Compare the baseline and test commits and inspect the linked benchmark and test reports to identify the cause of the Windows/x64 regression. Done means the regression is explained and the benchmark no longer shows the reported slowdown.

Written by the indexing model from the issue text.