Api compat benchmarks (optimizing for multiple rights for the same left)

ApiCompatBenchmarks.cs

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using Microsoft.CodeAnalysis;
using Microsoft.DotNet.ApiCompatibility;
using Microsoft.DotNet.ApiCompatibility.Abstractions;
using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace apicompatbenchmarks
{
    class Program
    {
        static void Main(string[] args)
        {
            var summary = BenchmarkRunner.Run(typeof(Program).Assembly);
        }
    }

    public class ApiCompatBenchmarks
    {
        private static readonly string[] _rightPaths = new string[]
        {
            @"C:\repos\runtime\artifacts\bin\System.Runtime\net6.0-Debug\System.Runtime.dll",
            @"C:\repos\runtime\artifacts\bin\System.Runtime\net6.0-Debug\System.Runtime.dll",
            @"C:\repos\runtime\artifacts\bin\System.Runtime\net6.0-Debug\System.Runtime.dll",
            @"C:\repos\runtime\artifacts\bin\System.Runtime\net6.0-Debug\System.Runtime.dll",
        };

        private const string _leftPath = @"C:\repos\runtime\artifacts\bin\microsoft.netcore.app.ref\ref\net6.0\System.Runtime.dll";

        private const string _coreLibDir = @"C:\repos\runtime\artifacts\bin\coreclr\windows.x64.Debug\IL\";

        private List<IAssemblySymbol> _rightAssemblies = new();

        private IAssemblySymbol _leftAssembly;

        [GlobalSetup(Targets = new[] { nameof(UseOneApiCompatPerPath), nameof(CompareOnePerSide) })]
        public void LoadAssembliesSetup()
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            _rightAssemblies.Clear();
            AssemblySymbolLoader leftLoader = new AssemblySymbolLoader();
            _leftAssembly = leftLoader.LoadAssembly(_leftPath);

            foreach (string path in _rightPaths)
            {
                AssemblySymbolLoader rightLoader = new AssemblySymbolLoader(resolveAssemblyReferences: true);
                rightLoader.AddReferenceSearchDirectories(_coreLibDir);
                IAssemblySymbol right = rightLoader.LoadAssembly(path);
                _rightAssemblies.Add(right);
            }
            sw.Stop();

            Console.WriteLine($"Time loading assemblies {sw.ElapsedMilliseconds}ms");
        }

        [Benchmark]
        public void UseOneApiCompatPerPath()
        {   
            foreach (IAssemblySymbol right in _rightAssemblies)
            {
                ApiComparer comparer = new ApiComparer();
                var _ = comparer.GetDifferences(_leftAssembly, right);
            }
        }

        [Benchmark]
        public void CompareOnePerSide()
        {
            ApiComparer comparer = new ApiComparer();
            var _ = comparer.GetDifferences(_leftAssembly, _rightAssemblies[0]);
        }

#if NEW_APICOMPAT

        private List<ElementContainer<IAssemblySymbol>> _rightElements = new();
        [GlobalSetup(Target = nameof(UseOneApiCompatOverall))]
        public void SetupToUseOneApiCompat()
        {
            LoadAssembliesSetup();
            _rightElements.Clear();
            for (int i = 0; i < _rightAssemblies.Count; i++)
            {
                _rightElements.Add(new ElementContainer<IAssemblySymbol>(_rightAssemblies[i], new MetadataInformation("", "", i.ToString())));
            }
        }

        [Benchmark]
        public void UseOneApiCompatOverall()
        {
            ApiComparer comparer = new ApiComparer();
            var _ = comparer.GetDifferences(new ElementContainer<IAssemblySymbol>(_leftAssembly, default), _rightElements);
        }
#endif
    }
}