[Perf] Regressions in System.Memory.ReadOnlySpan

[performanceautofiler]

Run Information

Architecture	x86
OS	Windows 10.0.18362
Baseline	285b8259af30e255980b1ebfb2ddd60ca291a83a
Compare	0c64bdf3afc1fdc9166ad6c22c1990d3e0a6c509
Diff	Diff

Regressions in System.Memory.ReadOnlySpan

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
IndexOfString - Duration of single invocation	20.22 ns	21.71 ns	1.07	0.01	False

Test Report

Repro

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

Payloads

Baseline
Compare

Histogram

System.Memory.ReadOnlySpan.IndexOfString(input: "StrIng", value: "string", comparisonType: OrdinalIgnoreCase)

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 21.708424795274013 > 20.97468532055912.
IsChangePoint: Marked as a change because one of 3/17/2022 6:54:53 PM, 4/9/2022 5:43:54 AM, 4/12/2022 5:02:33 PM falls between 4/4/2022 4:14:58 AM and 4/12/2022 5:02:33 PM.
IsRegressionStdDev: Marked as regression because -32.95537559884967 (T) = (0 -21.692417802325732) / Math.Sqrt((0.05449117002768166 / (42)) + (0.015887934761378314 / (15))) is less than -2.0040447832881556 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (42) + (15) - 2, .025) and -0.07962205868801316 = (20.09260335851878 - 21.692417802325732) / 20.09260335851878 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

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[DrewScoggins]

Related to #67758 @EgorBo

[danmoseley]

This is the worst possible case for the vectorization change, it's a very short string with a hit on index 0. I'm assuming this is an acceptable price to pay.

[ghost]

Tagging subscribers to this area: @dotnet/area-system-globalization
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Run Information

Architecture	x86
OS	Windows 10.0.18362
Baseline	285b8259af30e255980b1ebfb2ddd60ca291a83a
Compare	0c64bdf3afc1fdc9166ad6c22c1990d3e0a6c509
Diff	Diff

Regressions in System.Memory.ReadOnlySpan

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
IndexOfString - Duration of single invocation	20.22 ns	21.71 ns	1.07	0.01	False

Test Report

Repro

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

Payloads

Baseline
Compare

Histogram

System.Memory.ReadOnlySpan.IndexOfString(input: "StrIng", value: "string", comparisonType: OrdinalIgnoreCase)

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 21.708424795274013 > 20.97468532055912.
IsChangePoint: Marked as a change because one of 3/17/2022 6:54:53 PM, 4/9/2022 5:43:54 AM, 4/12/2022 5:02:33 PM falls between 4/4/2022 4:14:58 AM and 4/12/2022 5:02:33 PM.
IsRegressionStdDev: Marked as regression because -32.95537559884967 (T) = (0 -21.692417802325732) / Math.Sqrt((0.05449117002768166 / (42)) + (0.015887934761378314 / (15))) is less than -2.0040447832881556 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (42) + (15) - 2, .025) and -0.07962205868801316 = (20.09260335851878 - 21.692417802325732) / 20.09260335851878 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-System.Globalization, tenet-performance, tenet-performance-benchmarks, untriaged, refs/heads/main, RunKind=micro, Windows 10.0.18362, Regression, CoreClr, x86
Milestone:	-

[tarekgh]

@EgorBo could you please advise if this regression is acceptable in the failed case. Looks it is x86 specific too.

[ghost]

Tagging subscribers to this area: @dotnet/area-system-memory
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Run Information

Architecture	x86
OS	Windows 10.0.18362
Baseline	285b8259af30e255980b1ebfb2ddd60ca291a83a
Compare	0c64bdf3afc1fdc9166ad6c22c1990d3e0a6c509
Diff	Diff

Regressions in System.Memory.ReadOnlySpan

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
IndexOfString - Duration of single invocation	20.22 ns	21.71 ns	1.07	0.01	False

Test Report

Repro

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

Payloads

Baseline
Compare

Histogram

System.Memory.ReadOnlySpan.IndexOfString(input: "StrIng", value: "string", comparisonType: OrdinalIgnoreCase)

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 21.708424795274013 > 20.97468532055912.
IsChangePoint: Marked as a change because one of 3/17/2022 6:54:53 PM, 4/9/2022 5:43:54 AM, 4/12/2022 5:02:33 PM falls between 4/4/2022 4:14:58 AM and 4/12/2022 5:02:33 PM.
IsRegressionStdDev: Marked as regression because -32.95537559884967 (T) = (0 -21.692417802325732) / Math.Sqrt((0.05449117002768166 / (42)) + (0.015887934761378314 / (15))) is less than -2.0040447832881556 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (42) + (15) - 2, .025) and -0.07962205868801316 = (20.09260335851878 - 21.692417802325732) / 20.09260335851878 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:	arch-x86, area-System.Memory, os-windows, tenet-performance, tenet-performance-benchmarks, runtime-coreclr
Milestone:	Future