[Perf 75%] System.Memory.ReadOnlySpan.IndexOfString

[performanceautofiler]

Run Information

Architecture	x64
OS	Windows 10.0.18362
Changes	diff

Regressions in System.Memory.ReadOnlySpan

Benchmark	Baseline	Test	Test/Base	Modality	Baseline Outlier	Baseline ETL	Comapre ETL
IndexOfString	4.85 μs	1.22 μs	0.25		False

Related Issue on x64 ubuntu

[Perf 69%] System.Memory.ReadOnlySpan.IndexOfString

Related Issue on x64 ubuntu

[Perf 69%] System.Memory.ReadOnlySpan.IndexOfString

Related Issue on x86 Windows

[Perf 28%] System.Memory.ReadOnlySpan (4)

Historical Data in Reporting System

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f netcoreapp5.0 --filter 'System.Memory.ReadOnlySpan*'

Histogram

System.Memory.ReadOnlySpan.IndexOfString(input: "だ", value: "た", comparisonType: InvariantCulture)

[ 706.859 ; 1688.299) | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
[1688.299 ; 2639.994) | 
[2639.994 ; 3591.689) | 
[3591.689 ; 4452.841) | 
[4452.841 ; 5577.042) | @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Docs

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