[Perf] Linux/x64: 2 Improvements on 6/30/2026 11:06:07 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [3ac60ce854ea8572cd8c510e838c7d4da85b21cb](https://github.com/dotnet/runtime/commit/3ac60ce854ea8572cd8c510e838c7d4da85b21cb)
Compare | [240be2ab0c0ee97dc4975eb9b3b7cc2908847793](https://github.com/dotnet/runtime/commit/240be2ab0c0ee97dc4975eb9b3b7cc2908847793)
Diff | [Diff](https://github.com/dotnet/runtime/compare/3ac60ce854ea8572cd8c510e838c7d4da85b21cb...240be2ab0c0ee97dc4975eb9b3b7cc2908847793)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Buffers.Binary.Tests.BinaryReadAndWriteTests

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

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

| 548.11 ns | 412.16 ns | 0.75 | 0.10 | 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.Buffers.Binary.Tests.BinaryReadAndWriteTests*'
```

### System.Buffers.Binary.Tests.BinaryReadAndWriteTests.MeasureReverseEndianness

#### 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 | [3ac60ce854ea8572cd8c510e838c7d4da85b21cb](https://github.com/dotnet/runtime/commit/3ac60ce854ea8572cd8c510e838c7d4da85b21cb)
Compare | [240be2ab0c0ee97dc4975eb9b3b7cc2908847793](https://github.com/dotnet/runtime/commit/240be2ab0c0ee97dc4975eb9b3b7cc2908847793)
Diff | [Diff](https://github.com/dotnet/runtime/compare/3ac60ce854ea8572cd8c510e838c7d4da85b21cb...240be2ab0c0ee97dc4975eb9b3b7cc2908847793)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Memory.Span<Int32>

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

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

| 27.10 ns | 23.13 ns | 0.85 | 0.27 | 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.Memory.Span*'
```

### System.Memory.Span<Int32>.IndexOfAnyFourValues(Size: 33)

#### 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 src/benchmarks/micro/libraries/System.Buffers/BinaryReadAndWriteTests.cs and src/benchmarks/micro/libraries/System.Memory/Span.cs, then follow docs/benchmarking-workflow-dotnet-runtime.md and the provided benchmark reports. The issue records performance improvements but does not specify a code change or acceptance criteria, so what counts as done is not defined.

Written by the indexing model from the issue text.