[Perf] Linux/x64: 24 Regressions on 8/25/2026 10:44:15 PM +00:00

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#78,896 opened on Sep 3, 2026 1 comment 0 reactions 0 assignees View on GitHub

aot-true arch-wasm arch-x64 branch-refs/heads/main compilationmode-wasm kind-micro os-linux perf-regression runkind-micro untriaged wasm-aot

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Description

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [8baacb006f5615ebd705bdf9de98ca5df7bf1ba1](https://github.com/dotnet/runtime/commit/8baacb006f5615ebd705bdf9de98ca5df7bf1ba1)
Compare | [9f18a550aaa91ecd032ac024b67e03559df9e766](https://github.com/dotnet/runtime/commit/9f18a550aaa91ecd032ac024b67e03559df9e766)
Diff | [Diff](https://github.com/dotnet/runtime/compare/8baacb006f5615ebd705bdf9de98ca5df7bf1ba1...9f18a550aaa91ecd032ac024b67e03559df9e766)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Tests.Perf_Single

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

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

| 141.26 ns | 167.99 ns | 1.19 | 0.12 | False | | |
|

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

| 140.91 ns | 166.24 ns | 1.18 | 0.12 | False | | |
|

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

| 155.49 ns | 182.69 ns | 1.17 | 0.06 | False | | |
|

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

| 116.62 ns | 135.26 ns | 1.16 | 0.11 | False | | |
|

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

| 156.40 ns | 179.54 ns | 1.15 | 0.06 | False | | |
|

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

| 130.33 ns | 146.74 ns | 1.13 | 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.Tests.Perf_Single*'
```

### System.Tests.Perf_Single.TryParse(value: "-3.4028235E+38")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.TryParse(value: "3.4028235E+38")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.Parse(value: "-3.4028235E+38")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.TryParse(value: "12345")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.Parse(value: "3.4028235E+38")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Single.Parse(value: "12345")

#### 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

### Regressions in System.Tests.Perf_Double

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

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

| 162.59 ns | 201.71 ns | 1.24 | 0.11 | False | | |
|

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

| 173.04 ns | 214.23 ns | 1.24 | 0.08 | False | | |
|

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

| 179.62 ns | 218.65 ns | 1.22 | 0.10 | False | | |
|

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

| 166.89 ns | 202.86 ns | 1.22 | 0.04 | False | | |
|

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

| 129.08 ns | 147.96 ns | 1.15 | 0.09 | False | | |

![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.Tests.Perf_Double*'
```

### System.Tests.Perf_Double.TryParse(value: "1.7976931348623157e+308")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.Parse(value: "1.7976931348623157e+308")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.Parse(value: "-1.7976931348623157e+308")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.TryParse(value: "-1.7976931348623157e+308")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Double.Parse(value: "12345")

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Tests.Perf_Decimal

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

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

| 186.22 ns | 240.67 ns | 1.29 | 0.08 | False | | |
|

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

| 206.33 ns | 247.04 ns | 1.20 | 0.01 | False | | |
|

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

| 226.05 ns | 264.62 ns | 1.17 | 0.06 | False | | |

![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.Tests.Perf_Decimal*'
```

### System.Tests.Perf_Decimal.ToString(value: 123456.78900000000430736690760)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Decimal.TryParse(value: "123456.78900000000430736690760")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Decimal.Parse(value: "123456.78900000000430736690760")

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Tests.Perf_Int32

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

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

| 56.40 ns | 66.91 ns | 1.19 | 0.14 | False | | |
|

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

| 53.22 ns | 59.75 ns | 1.12 | 0.20 | False | | |
|

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

| 59.07 ns | 64.38 ns | 1.09 | 0.15 | False | | |

![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.Tests.Perf_Int32*'
```

### System.Tests.Perf_Int32.ToStringHex(value: 2147483647)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Int32.ToStringHex(value: 12345)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_Int32.ToStringHex(value: -2147483648)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Numerics.Tests.Perf_BigInteger

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

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

| 1.48 μs | 1.72 μs | 1.17 | 0.07 | False | | |
|

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

| 104.08 ns | 120.84 ns | 1.16 | 0.16 | False | | |
|

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

| 141.32 ns | 158.83 ns | 1.12 | 0.17 | False | | |

![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.Numerics.Tests.Perf_BigInteger*'
```

### System.Numerics.Tests.Perf_BigInteger.Parse(numberString: 12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890)

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_BigInteger.Subtract(arguments: 1024,1024 bits)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Buffers.Text.Tests.Utf8FormatterTests

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

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

| 182.18 ns | 241.62 ns | 1.33 | 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.Text.Tests.Utf8FormatterTests*'
```

### System.Buffers.Text.Tests.Utf8FormatterTests.FormatterDecimal(value: 123456.78900000000430736690760)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Tests.Perf_Int128

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

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

| 37.73 ns | 40.75 ns | 1.08 | 0.13 | 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.Tests.Perf_Int128*'
```

### System.Tests.Perf_Int128.TryFormat(value: 12345)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.IndexerSetReverse<Int32>

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

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

| 2.50 μs | 3.30 μs | 1.32 | 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.IndexerSetReverse*'
```

### System.Collections.IndexerSetReverse<Int32>.IList(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.IndexerSet<Int32>

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

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

| 4.51 μs | 5.04 μs | 1.12 | 0.04 | 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.IndexerSet*'
```

### System.Collections.IndexerSet<Int32>.IList(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the regression report and compare the baseline and test commits, then run the provided benchmarks_ci.py command with the System.Tests.Perf_Single filter. Inspect the benchmark source at performance/src/benchmarks/micro/libraries/System.Runtime/Perf.Single.cs and the linked test report. Done means the regression's cause is identified and the affected benchmark results are verified after the change.

Written by the indexing model from the issue text.

Assessment

Tech stack: python, ubuntu, wasm
Domain: performance
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Active
Clarity: Needs clarification
Newbie friendliness: 28/100

[Perf] Linux/x64: 24 Regressions on 8/25/2026 10:44:15 PM +00:00

Description

Contributor guide

Research direction

Assessment

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