Regressions in System.Tests.Perf_Version

[performanceautofiler]

Run Information

Architecture	x86
OS	Windows 10.0.18362
Baseline	eb51b02b158c3ff71a1ec7eac8a211d1d464c1a5
Compare	9717f3b5fad58a74ee2042ff0580e7f7c2a952b0
Diff	Diff

Regressions in System.Tests.Perf_Version

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
ToStringL - Duration of single invocation	129.99 ns	139.47 ns	1.07	0.00	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Tests.Perf_Version*'

Payloads

Baseline
Compare

Histogram

System.Tests.Perf_Version.ToStringL

Description of detection logic

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 139.46641704644725 > 136.29187640015746.
IsChangePoint: Marked as a change because one of 3/21/2022 1:28:14 PM, 3/22/2022 5:30:27 AM falls between 3/13/2022 11:50:20 AM and 3/22/2022 5:30:27 AM.
IsRegressionStdDev: Marked as regression because -152.34294169800796 (T) = (0 -139.54260788896707) / Math.Sqrt((0.1282829580265031 / (54)) + (0.0053249185136311295 / (3))) is less than -2.0040447832881556 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (54) + (3) - 2, .025) and -0.07565601700465245 = (129.72791085903768 - 139.54260788896707) / 129.72791085903768 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
Benchmarking workflow for dotnet/runtime repository

[kunalspathak]

Local test history graph:

[kunalspathak]

Possibly introduced by #66257 @BruceForstall

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Issue Details

---

Run Information

Architecture	x86
OS	Windows 10.0.18362
Baseline	eb51b02b158c3ff71a1ec7eac8a211d1d464c1a5
Compare	9717f3b5fad58a74ee2042ff0580e7f7c2a952b0
Diff	Diff

Regressions in System.Tests.Perf_Version

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
ToStringL - Duration of single invocation	129.99 ns	139.47 ns	1.07	0.00	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Tests.Perf_Version*'

Payloads

Baseline
Compare

Histogram

System.Tests.Perf_Version.ToStringL

Description of detection logic

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 139.46641704644725 > 136.29187640015746.
IsChangePoint: Marked as a change because one of 3/21/2022 1:28:14 PM, 3/22/2022 5:30:27 AM falls between 3/13/2022 11:50:20 AM and 3/22/2022 5:30:27 AM.
IsRegressionStdDev: Marked as regression because -152.34294169800796 (T) = (0 -139.54260788896707) / Math.Sqrt((0.1282829580265031 / (54)) + (0.0053249185136311295 / (3))) is less than -2.0040447832881556 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (54) + (3) - 2, .025) and -0.07565601700465245 = (129.72791085903768 - 139.54260788896707) / 129.72791085903768 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
Benchmarking workflow for dotnet/runtime repository

Author:	performanceautofiler[bot]
Assignees:	-
Labels:	area-CodeGen-coreclr, untriaged, refs/heads/main, RunKind=micro, Windows 10.0.18362, Regression, CoreClr, x86
Milestone:	-

[BruceForstall]

I can't repro any regression locally when I revert #66257.

When I use the --disasm switch, it dumps two functions, with identical asm from before: System.Tests.Perf_Version.ToStringL(), ; System.Version.ToString(Int32). Actually, in these two functions there are no loops (so no loop cloning).

I'm going to unassign myself.

[kunalspathak]

Seems this might be some kind of noise because the perf did came back to the normal position without any related changes
4cfe07c...11e38ca