Regressions in System.Collections.Tests.Perf_BitArray and System.Collections.IndexerSet<Int32>

### Run Information

Architecture | arm64
-- | --
OS | Windows 10.0.19041
Baseline | [63fd977f7d57e0c0e434caecfff0dd0a07d2f27f](https://github.com/dotnet/runtime/commit/63fd977f7d57e0c0e434caecfff0dd0a07d2f27f)
Compare | [466b0f66aafe63a31696c16dca43a727cd4bbce5](https://github.com/dotnet/runtime/commit/466b0f66aafe63a31696c16dca43a727cd4bbce5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/63fd977f7d57e0c0e434caecfff0dd0a07d2f27f...466b0f66aafe63a31696c16dca43a727cd4bbce5)


### Regressions in System.Collections.Tests.Perf_BitArray

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio | Baseline ETL | Compare ETL
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --
[BitArraySetLengthShrink - Duration of single invocation](<https://pvscmdupload.blob.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_Windows 10.0.19041/System.Collections.Tests.Perf_BitArray.BitArraySetLengthShrink(Size%3a%20512).html>) | 237.51 ns | 257.46 ns | 1.08 | 0.00 | False | | |

![graph](<https://pvscmdupload.blob.core.windows.net/autofilereport/autofilereports/03_16_2022/refs/heads/main_arm64_Windows%2010.0.19041_Regression/System.Collections.Tests.Perf_BitArray_1.png>)
[Test Report](<https://pvscmdupload.blob.core.windows.net/autofilereport/autofilereports/03_16_2022/refs/heads/main_arm64_Windows%2010.0.19041_Regression/System.Collections.Tests.Perf_BitArray.html>)

### Repro

```cmd
git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Collections.Tests.Perf_BitArray*'
```
<details>

### Payloads

[Baseline](<https://helixdi8s23ayyeko0k025g8.blob.core.windows.net/helix-job-1658e217-9af8-40b6-aeeb-38e68ccb81d90dcf09d7bf243a380/93864d79-cade-451f-be11-9a973afba87b.zip?sv=2019-07-07&se=2022-04-13T20%3A40%3A48Z&sr=c&sp=rl&sig=Z3j3hvuvdgoMyQrNwM6Xa0dZekuus8162G390Zxey3o%3D>)
[Compare](<https://helixdi8s23ayyeko0k025g8.blob.core.windows.net/helix-job-4ee9c804-02eb-49b9-a701-ffb14929a55b57b8774c21b4ca9b2/75656ca6-3795-46c6-a199-094584f4e053.zip?sv=2019-07-07&se=2022-04-14T15%3A11%3A58Z&sr=c&sp=rl&sig=gX9X26fsA%2BhXXUC5rRbRvVUuWQDRHDzTCDGYPdfCEd8%3D>)
### Histogram

#### System.Collections.Tests.Perf_BitArray.BitArraySetLengthShrink(Size: 512)

```log

```
### Description of detection logic
```IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsRegressionWindowed: Marked as regression because 257.45578083352854 > 250.07199194800694.
IsChangePoint: Marked as a change because one of 3/15/2022 12:53:39 AM, 3/17/2022 12:08:34 AM falls between 3/8/2022 5:51:58 AM and 3/17/2022 12:08:34 AM.
IsRegressionStdDev: Marked as regression because -11.78109322334737 (T) = (0 -258.6891193534734) / Math.Sqrt((8.595811911146967 / (36)) + (13.040673937399216 / (6))) is less than -2.0210753903043583 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (36) + (6) - 2, .025) and -0.07611578445829842 = (240.391529507853 - 258.6891193534734) / 240.391529507853 is less than -0.05.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsChangeEdgeDetector: Marked not as a regression because Edge Detector said so.

```

### 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)

</details>
### Run Information

Architecture | arm64
-- | --
OS | Windows 10.0.19041
Baseline | [63fd977f7d57e0c0e434caecfff0dd0a07d2f27f](https://github.com/dotnet/runtime/commit/63fd977f7d57e0c0e434caecfff0dd0a07d2f27f)
Compare | [466b0f66aafe63a31696c16dca43a727cd4bbce5](https://github.com/dotnet/runtime/commit/466b0f66aafe63a31696c16dca43a727cd4bbce5)
Diff | [Diff](https://github.com/dotnet/runtime/compare/63fd977f7d57e0c0e434caecfff0dd0a07d2f27f...466b0f66aafe63a31696c16dca43a727cd4bbce5)


### Regressions in System.Collections.IndexerSet&lt;Int32&gt;

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio | Baseline ETL | Compare ETL
-- | -- | -- | -- | -- | -- | -- | -- | -- | -- | --
[Span - Duration of single invocation](<https://pvscmdupload.blob.core.windows.net/reports/allTestHistory/refs/heads/main_arm64_Windows 10.0.19041/System.Collections.IndexerSet(Int32).Span(Size%3a%20512).html>) | 177.00 ns | 187.44 ns | 1.06 | 0.07 | False | | |

![graph](<https://pvscmdupload.blob.core.windows.net/autofilereport/autofilereports/03_16_2022/refs/heads/main_arm64_Windows%2010.0.19041_Regression/System.Collections.IndexerSet(Int32)_1.png>)
[Test Report](<https://pvscmdupload.blob.core.windows.net/autofilereport/autofilereports/03_16_2022/refs/heads/main_arm64_Windows%2010.0.19041_Regression/System.Collections.IndexerSet(Int32).html>)

### Repro

```cmd
git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Collections.IndexerSet&lt;Int32&gt;*'
```
<details>

### Payloads

[Baseline](<https://helixdi8s23ayyeko0k025g8.blob.core.windows.net/helix-job-1658e217-9af8-40b6-aeeb-38e68ccb81d90dcf09d7bf243a380/93864d79-cade-451f-be11-9a973afba87b.zip?sv=2019-07-07&se=2022-04-13T20%3A40%3A48Z&sr=c&sp=rl&sig=Z3j3hvuvdgoMyQrNwM6Xa0dZekuus8162G390Zxey3o%3D>)
[Compare](<https://helixdi8s23ayyeko0k025g8.blob.core.windows.net/helix-job-4ee9c804-02eb-49b9-a701-ffb14929a55b57b8774c21b4ca9b2/75656ca6-3795-46c6-a199-094584f4e053.zip?sv=2019-07-07&se=2022-04-14T15%3A11%3A58Z&sr=c&sp=rl&sig=gX9X26fsA%2BhXXUC5rRbRvVUuWQDRHDzTCDGYPdfCEd8%3D>)
### Histogram

#### System.Collections.IndexerSet&lt;Int32&gt;.Span(Size: 512)

```log

```
### Description of detection logic
```IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsRegressionWindowed: Marked as regression because 187.44322490494397 > 180.31185587212346.
IsChangePoint: Marked as a change because one of 3/15/2022 12:53:39 AM, 3/17/2022 12:08:34 AM falls between 3/8/2022 5:51:58 AM and 3/17/2022 12:08:34 AM.
IsRegressionStdDev: Marked as regression because -17.407749272978624 (T) = (0 -188.7349199381894) / Math.Sqrt((6.275661946704857 / (36)) + (4.068162474412199 / (6))) is less than -2.0210753903043583 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (36) + (6) - 2, .025) and -0.0930788703937596 = (172.66358819121757 - 188.7349199381894) / 172.66358819121757 is less than -0.05.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsChangeEdgeDetector: Marked not as a regression because Edge Detector said so.

```

### 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)

</details>




category:performance
theme:benchmarks

Architecture	arm64
OS	Windows 10.0.19041
Baseline	63fd977f7d57e0c0e434caecfff0dd0a07d2f27f
Compare	466b0f66aafe63a31696c16dca43a727cd4bbce5
Diff	Diff

Uh oh!

Regressions in System.Collections.Tests.Perf_BitArray and System.Collections.IndexerSet<Int32> #66769

Description

Run Information