How can I benchmark two methods each running on different framework?

Question

I neet to compare two implementations of the same functionality but done for two frameworks: .net 4.6.2 and .net 7

How do I define this benchmark?

Answer 1

I have created 2 library projects, one in .net 4.6.2 and one in .net 7 with the same class and function.

namespace ClassLibrary1
{
    public class Class1
    {
        public int CalcInt32(int OperationsPerInvoke)
        {
            int firstDigit = 135;
            int secondDigit = 145;

            for (int i = 0; i < OperationsPerInvoke; i++)
            {
                firstDigit += secondDigit;
            }
            return firstDigit;
        }
    }
}

After that I've created a new test project .net 7 that will do the tests by invoking the method from each assembly:

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System.Reflection;

BenchmarkRunner.Run<PerformanceTest>();
public class PerformanceTest
{
    const int OperationsPerInvoke = 4096;

    [Benchmark(OperationsPerInvoke = OperationsPerInvoke)]
    public int TestClassLibrary7()
    {
        var myAssembly = Assembly.LoadFile("d:\\Teste\\.NetGeneral\\_Dlls\\ClassLibrary1\\bin\\Debug\\net7.0\\ClassLibrary1.dll");
        var myType = myAssembly.GetType("ClassLibrary1");
        if (myType == null)
            return 0;
        MethodInfo dllGetMethod = myType.GetMethod("CalcInt32", BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);

        object res = dllGetMethod?.Invoke(null, new object[] { OperationsPerInvoke });
        return (int)res;
    }


    [Benchmark(OperationsPerInvoke = OperationsPerInvoke)]
    public int TestClassLibrary462()
    {
        var myAssembly = Assembly.LoadFile("d:\\Teste\\.NetGeneral\\_Dlls\\ClassLibrary2\\bin\\Debug\\ClassLibrary2.dll");
        var myType = myAssembly.GetType("ClassLibrary1");
        if (myType == null)
            return 0;
        MethodInfo dllGetMethod = myType.GetMethod("CalcInt32", BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static | BindingFlags.FlattenHierarchy);

        object res = dllGetMethod?.Invoke(null, new object[] { OperationsPerInvoke });
        return (int)res;
    }
}

and it's working. Here are some results for my test:

Method	Mean	Error	StdDev
TestClassLibrary7	0.1374 ns	0.0017 ns	0.0015 ns
TestClassLibrary462	0.1308 ns	0.0019 ns	0.0017 ns