[Perf] Linux/x64: 2 Regressions on 8/16/2026 9:16:30 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [19bc97f3dd3ab67c7810e4ab179125b7c6a60641](https://github.com/dotnet/sdk/commit/19bc97f3dd3ab67c7810e4ab179125b7c6a60641)
Compare | [b8c18a5c2f5d06efdd635120822953728b21678e](https://github.com/dotnet/sdk/commit/b8c18a5c2f5d06efdd635120822953728b21678e)
Diff | [Diff](https://github.com/dotnet/sdk/compare/19bc97f3dd3ab67c7810e4ab179125b7c6a60641...b8c18a5c2f5d06efdd635120822953728b21678e)
Configs | CompilationMode:tiered, RunKind:akadeindexedset

### Regressions in Akade.IndexedSet.Benchmarks.PrefixIndexBenchmarks

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

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

| 505.89 ns | 569.74 ns | 1.13 | 0.00 | True | | |

![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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'Akade.IndexedSet.Benchmarks.PrefixIndexBenchmarks*'
```

### Akade.IndexedSet.Benchmarks.PrefixIndexBenchmarks.StartsWith_IndexedSet

#### 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 | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [19bc97f3dd3ab67c7810e4ab179125b7c6a60641](https://github.com/dotnet/sdk/commit/19bc97f3dd3ab67c7810e4ab179125b7c6a60641)
Compare | [b8c18a5c2f5d06efdd635120822953728b21678e](https://github.com/dotnet/sdk/commit/b8c18a5c2f5d06efdd635120822953728b21678e)
Diff | [Diff](https://github.com/dotnet/sdk/compare/19bc97f3dd3ab67c7810e4ab179125b7c6a60641...b8c18a5c2f5d06efdd635120822953728b21678e)
Configs | CompilationMode:tiered, RunKind:akadeindexedset

### Regressions in Akade.IndexedSet.Benchmarks.FullTextIndexBenchmarks

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

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

| 150.75 μs | 167.88 μs | 1.11 | 0.00 | True | | |

![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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'Akade.IndexedSet.Benchmarks.FullTextIndexBenchmarks*'
```

### Akade.IndexedSet.Benchmarks.FullTextIndexBenchmarks.FuzzyContains_IndexedSet

#### 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/PrefixIndexBenchmarks.cs and FullTextIndexBenchmarks.cs, then run the provided benchmarks_ci.py filters on Ubuntu. Compare the reported StartsWith_IndexedSet and FuzzyContains_IndexedSet results between the baseline and compare commits; done means the regression is understood and addressed or an evidence-based cause is recorded.

Written by the indexing model from the issue text.