[Perf] Linux/x64: 2 Improvements on 6/18/2026 2:00:10 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [8f2341959451d05a276af3760b45b16310a19baf](https://github.com/dotnet/runtime/commit/8f2341959451d05a276af3760b45b16310a19baf)
Compare | [b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b](https://github.com/dotnet/runtime/commit/b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8f2341959451d05a276af3760b45b16310a19baf...b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Improvements in System.Numerics.Tests.Perf_BigInteger

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

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

| 2.00 μs | 1.77 μs | 0.89 | 0.25 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Numerics.Tests.Perf_BigInteger*'
```

### System.Numerics.Tests.Perf_BigInteger.ToStringD(numberString: 123)

#### 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 | [8f2341959451d05a276af3760b45b16310a19baf](https://github.com/dotnet/runtime/commit/8f2341959451d05a276af3760b45b16310a19baf)
Compare | [b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b](https://github.com/dotnet/runtime/commit/b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8f2341959451d05a276af3760b45b16310a19baf...b1ea6ff8a102c76f5f8ffdf55a8a2a7fc40de61b)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Improvements in System.Collections.ContainsTrue<String>

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

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

| 281.23 ms | 135.87 ms | 0.48 | 0.32 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.ContainsTrue*'
```

### System.Collections.ContainsTrue<String>.Span(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 sources at src/benchmarks/micro/libraries/System.Runtime.Numerics/Perf.BigInteger.cs and src/benchmarks/micro/libraries/System.Collections/Contains/ContainsTrue.cs, then read the benchmarking workflow and rerun the two filters. The report shows improvements, but it does not define a code change or acceptance criteria, so triage must first establish what result would be considered done.

Written by the indexing model from the issue text.