Regressions in System.Buffers.Text.Tests.Utf8ParserTests

[performanceautofiler]

Run Information

Name	Value
Architecture	arm64
OS	ubuntu 20.04
Queue	AmpereUbuntu
Baseline	4e48d2d85ed15140b95323e615a5433726b583b2
Compare	11fbd151912a3c5d1e72386fb037595b71e214d6
Diff	Diff
Configs	CompilationMode:tiered, 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	37.60 ns	40.83 ns	1.09	0.01	False

Test Report

Repro

General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Buffers.Text.Tests.Utf8ParserTests*'

Payloads

Baseline
Compare

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

ETL Files

Histogram

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 40.828730634561595 > 39.29663517446423.
IsChangePoint: Marked as a change because one of 4/25/2023 6:46:56 PM, 5/15/2023 9:18:21 AM, 7/11/2023 7:34:35 PM, 7/18/2023 4:12:30 PM falls between 7/10/2023 3:14:43 AM and 7/18/2023 4:12:30 PM.
IsRegressionStdDev: Marked as regression because -15.351106528911764 (T) = (0 -40.50466641693999) / Math.Sqrt((0.1264184911309328 / (10)) + (0.21321768908095398 / (7))) is less than -2.131449545559758 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (10) + (7) - 2, .025) and -0.08540274483565771 = (37.31763772448618 - 40.50466641693999) / 37.31763772448618 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.

JIT Disasms

Docs

Profiling workflow for dotnet/runtime repository
Benchmarking workflow for dotnet/runtime repository

[cincuranet]

Commit range is 14e8b82...d3d910e. Out best guess is #86875.

cc @tannergooding

[tannergooding]

A small regression was expected since we had to generalize a little bit of code to share the algorithm between UTF-8 and UTF-16. A regression of 3ns is more than acceptable given the amount of code complexity we were able to avoid.