[Perf] Linux/x64: 2 Regressions on 8/21/2026 7:05:07 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [76c60b960a2daa412c44a5061abf66f3286f6a92](https://github.com/dotnet/runtime/commit/76c60b960a2daa412c44a5061abf66f3286f6a92)
Compare | [58a829968e8d2624cbcb4e2ce7f1bb01cb9f652b](https://github.com/dotnet/runtime/commit/58a829968e8d2624cbcb4e2ce7f1bb01cb9f652b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/76c60b960a2daa412c44a5061abf66f3286f6a92...58a829968e8d2624cbcb4e2ce7f1bb01cb9f652b)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

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

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

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

| 3.44 μs | 4.99 μs | 1.45 | 0.28 | False | | |
|

• [OrderedDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 1.98 ms | 2.67 ms | 1.35 | 0.39 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.CtorFromCollection*'
```

### System.Collections.CtorFromCollection<String>.ImmutableArray(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.CtorFromCollection<String>.OrderedDictionary(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)

Start with the benchmark source at src/benchmarks/micro/libraries/System.Collections/Create/CtorFromCollection.cs, then follow the linked baseline, compare commit, and test report. Run the documented benchmarks_ci.py command for System.Collections.CtorFromCollection and compare both regressions with the reported baseline. Done means the regression is explained and the benchmark result is validated after the change.

Written by the indexing model from the issue text.