Benchmarks for #116453 (AndyAyersMS)

[EgorBot]

Processing dotnet/runtime#116453 (comment) command:

Command

-intel -arm64

using System;
using BenchmarkDotNet.Attributes;
using System.Runtime.CompilerServices;
using BenchmarkDotNet.Running;

public class StringComparisons
{
    private string s1 = "1";
    private string s2 = "1";

    [Benchmark]
    public bool Equals_inline() => string.Equals(s1, s2);

    [Benchmark]
    public bool Equals_specialized() => EqualityComparer<string>.Default.Equals(s1, s2);

    [Benchmark]
    public bool Equals_generic() => GenericEquals(s1, s2);

    [MethodImpl(MethodImplOptions.NoInlining)]
    private static bool GenericEquals<T>(T a, T b) => EqualityComparer<T>.Default.Equals(a, b);
}

(EgorBot will reply in this issue)

[EgorBot]

Benchmark results on linux_azure_cobalt100

BenchmarkDotNet v0.14.0, Ubuntu 24.04.2 LTS (Noble Numbat)
azure_cobalt100
  Job-YWVLTB : .NET 10.0.0 (42.42.42.42424), Arm64 RyuJIT AdvSIMD
  Job-KRMFZY : .NET 10.0.0 (42.42.42.42424), Arm64 RyuJIT AdvSIMD

Method	Toolchain	Mean	Error	Ratio
Equals_inline	Main	0.0000 ns	0.0000 ns	?
Equals_inline	PR	0.0000 ns	0.0000 ns	?
Equals_specialized	Main	0.0000 ns	0.0000 ns	?
Equals_specialized	PR	0.1390 ns	0.0004 ns	?
Equals_generic	Main	1.5113 ns	0.0007 ns	1.00
Equals_generic	PR	1.7887 ns	0.0007 ns	1.18

BDN_Artifacts.zip

cc @AndyAyersMS (agent_logs.txt). EgorBot manual: link.

[EgorBo]

@AndyAyersMS I presume for

    private string s1 = "1";
    private string s2 = "1";

Equals just quickly compares them by references and early outs. Although probably doesn't matter for you if you want to measure the cost of devirtualization...

[EgorBot]

Benchmark results on linux_azure_cascadelake

BenchmarkDotNet v0.14.0, Ubuntu 24.04.2 LTS (Noble Numbat)
Intel Xeon Platinum 8370C CPU 2.80GHz, 1 CPU, 8 logical and 4 physical cores
  Job-RWGKML : .NET 10.0.0 (42.42.42.42424), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI
  Job-YEGZHJ : .NET 10.0.0 (42.42.42.42424), X64 RyuJIT AVX-512F+CD+BW+DQ+VL+VBMI

Method	Toolchain	Mean	Error	Ratio
Equals_inline	Main	0.0000 ns	0.0000 ns	?
Equals_inline	PR	0.0003 ns	0.0004 ns	?
Equals_specialized	Main	0.2877 ns	0.0004 ns	1.00
Equals_specialized	PR	0.2880 ns	0.0003 ns	1.00
Equals_generic	Main	1.8558 ns	0.0264 ns	1.00
Equals_generic	PR	2.5754 ns	0.0135 ns	1.39

BDN_Artifacts.zip

cc @AndyAyersMS (agent_logs.txt). EgorBot manual: link.

[AndyAyersMS]

@AndyAyersMS I presume for

    private string s1 = "1";
    private string s2 = "1";

Equals just quickly compares them by references and early outs. Although probably doesn't matter for you if you want to measure the cost of devirtualization...

Ah, right. Let me rerun with common prefix to make it actually do comparisons.

#381

Interesting that the case above is seemingly a bit slower.