[Perf] Linux/x64: 5 Improvements on 8/19/2026 11:48:00 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [22645b47c400e6cc0aec97ddcb3f1998677b6d94](https://github.com/dotnet/runtime/commit/22645b47c400e6cc0aec97ddcb3f1998677b6d94)
Compare | [cb8ddc8cac0182e932903d921bd09300be7ae2a6](https://github.com/dotnet/runtime/commit/cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22645b47c400e6cc0aec97ddcb3f1998677b6d94...cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Improvements in System.Tests.Perf_Double

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

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

| 21.76 μs | 8.19 μs | 0.38 | 0.01 | False | | |
|

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

| 21.75 μs | 8.32 μs | 0.38 | 0.03 | 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.Tests.Perf_Double*'
```

### System.Tests.Perf_Double.ToStringWithFormat(value: -1.7976931348623157E+308, format: "F50")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.ToStringWithFormat(value: 1.7976931348623157E+308, format: "F50")

#### 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 | [22645b47c400e6cc0aec97ddcb3f1998677b6d94](https://github.com/dotnet/runtime/commit/22645b47c400e6cc0aec97ddcb3f1998677b6d94)
Compare | [cb8ddc8cac0182e932903d921bd09300be7ae2a6](https://github.com/dotnet/runtime/commit/cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22645b47c400e6cc0aec97ddcb3f1998677b6d94...cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Improvements in System.Tests.Perf_Single

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

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

| 1.25 μs | 1.15 μs | 0.92 | 0.04 | False | | |
|

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

| 1.25 μs | 1.17 μs | 0.94 | 0.03 | 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.Tests.Perf_Single*'
```

### System.Tests.Perf_Single.ToStringWithFormat(value: -3.4028235E+38, format: "F50")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.ToStringWithFormat(value: 3.4028235E+38, format: "F50")

#### 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 | [22645b47c400e6cc0aec97ddcb3f1998677b6d94](https://github.com/dotnet/runtime/commit/22645b47c400e6cc0aec97ddcb3f1998677b6d94)
Compare | [cb8ddc8cac0182e932903d921bd09300be7ae2a6](https://github.com/dotnet/runtime/commit/cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Diff | [Diff](https://github.com/dotnet/runtime/compare/22645b47c400e6cc0aec97ddcb3f1998677b6d94...cb8ddc8cac0182e932903d921bd09300be7ae2a6)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

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

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

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

| 84.92 μs | 76.74 μs | 0.90 | 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.Collections.IterateForEach*'
```

### System.Collections.IterateForEach<String>.ImmutableSortedSet(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 src/benchmarks/micro/libraries/System.Runtime/Perf.Double.cs, Perf.Single.cs, and src/benchmarks/micro/libraries/System.Collections/Iterate/IterateForEach.cs, then read the benchmarking workflow documentation. Run benchmarks_ci.py with the listed filters and compare the generated reports; completion is not defined beyond investigating the reported performance changes.

Written by the indexing model from the issue text.