EgorBot for EgorBo in #109036

[EgorBot]

Processing dotnet/runtime#109036 (comment) command:

Command

-arm64 --envvars DOTNET_JitDisasm:Bestcase

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;

public class Bench
{
    string s = "https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10/";

    [Benchmark]
    public bool Bestcase() => 
        s.StartsWith("https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10", StringComparison.Ordinal);
    
    [Benchmark]
    public bool Bestcase_IgnoreCase() => 
        s.StartsWith("https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10", StringComparison.OrdinalIgnoreCase);

    // Worst case: differs at 1st char:

    [Benchmark]
    public bool Worstcase() => 
        s.StartsWith("xttps://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10", StringComparison.Ordinal);
    
    [Benchmark]
    public bool Worstcase_IgnoreCase() => 
        s.StartsWith("xttps://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10", StringComparison.OrdinalIgnoreCase);
}

(EgorBot will reply in this issue)

[EgorBot]

Benchmark results on Arm64

BenchmarkDotNet v0.14.0, Ubuntu 24.04 LTS (Noble Numbat)
Arm64
  Job-NOPWKW : .NET 10.0.0 (42.42.42.42424), Arm64 RyuJIT AdvSIMD
  Job-CAQCQB : .NET 10.0.0 (42.42.42.42424), Arm64 RyuJIT AdvSIMD
EnvironmentVariables=DOTNET_JitDisasm=Bestcase

Method	Toolchain	Mean	Error	Ratio
Bestcase	Main	4.6838 ns	0.0037 ns	1.00
Bestcase	PR	0.8703 ns	0.0018 ns	0.19
Bestcase_IgnoreCase	Main	8.6444 ns	0.0931 ns	1.00
Bestcase_IgnoreCase	PR	2.1261 ns	0.0008 ns	0.25
Worstcase	Main	0.6058 ns	0.0004 ns	1.00
Worstcase	PR	0.7916 ns	0.0012 ns	1.31
Worstcase_IgnoreCase	Main	2.5311 ns	0.0011 ns	1.00
Worstcase_IgnoreCase	PR	2.2280 ns	0.0015 ns	0.88

BDN_Artifacts.zip

[EgorBot]

cc @EgorBo (logs)