[Perf] Linux/x64: 6 Regressions on 7/19/2026 9:49:55 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [4c9e771cbd5e35313cef06c4d7efb55070fd5493](https://github.com/dotnet/runtime/commit/4c9e771cbd5e35313cef06c4d7efb55070fd5493)
Compare | [563abf220847ed66cab58f0d7d166cb264874f40](https://github.com/dotnet/runtime/commit/563abf220847ed66cab58f0d7d166cb264874f40)
Diff | [Diff](https://github.com/dotnet/runtime/compare/4c9e771cbd5e35313cef06c4d7efb55070fd5493...563abf220847ed66cab58f0d7d166cb264874f40)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Buffers.Text.Tests.Utf8ParserTests

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

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

| 52.67 ns | 61.53 ns | 1.17 | 0.06 | False | | |
|

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

| 52.66 ns | 60.80 ns | 1.15 | 0.11 | False | | |
|

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

| 88.70 ns | 98.61 ns | 1.11 | 0.13 | False | | |
|

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

| 79.85 ns | 88.09 ns | 1.10 | 0.10 | False | | |
|

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

| 89.07 ns | 98.11 ns | 1.10 | 0.09 | False | | |
|

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

| 78.43 ns | 86.08 ns | 1.10 | 0.08 | False | | |

![graph]()
![graph]()
![graph]()
![graph]()
![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.Buffers.Text.Tests.Utf8ParserTests*'
```

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseSingle(value: 12345)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseDouble(value: 12345)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseDouble(value: 1.7976931348623157e+308)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseSingle(value: -3.4028235E+38)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseDouble(value: -1.7976931348623157e+308)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Buffers.Text.Tests.Utf8ParserTests.TryParseSingle(value: 3.4028235E+38)

#### 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 docs/benchmarking-workflow-dotnet-runtime.md and the benchmark definitions in src/benchmarks/micro/libraries/System.Buffers/Utf8ParserTests.cs at lines 109-120. Run benchmarks_ci.py with the listed Utf8ParserTests filter, then compare the AOT wasm results between the baseline and compare commits. Done means the reported regression is reproduced and its cause or triage outcome is recorded.

Written by the indexing model from the issue text.