Enum.HasFlag performance loss

Enum.HasFlag performance loss.cs

// Based on https://stackoverflow.com/q/7368652/4215389

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace app
{
    public class Program
    {
        [Flags]
        public enum Test
        {
            Flag1 = 1,
            Flag2 = 2,
            Flag3 = 4,
            Flag4 = 8
        }
        static int num = 0;
        static Random rand;
        static void Main(string[] args)
        {
            int seed = (int)DateTime.UtcNow.Ticks;

            var st1 = new SpeedTest(delegate
            {
                Test t = Test.Flag1;
                t |= (Test)rand.Next(1, 9);
                if (t.HasFlag(Test.Flag4))
                    num++;
            });

            var st2 = new SpeedTest(delegate
            {
                Test t = Test.Flag1;
                t |= (Test)rand.Next(1, 9);
                if (CustomHasFlag(t, Test.Flag4))
                    num++;
            });

            rand = new Random(seed);
            st1.Test();
            rand = new Random(seed);
            st2.Test();

            Console.WriteLine("Random to prevent optimizing out things {0}", num);
            Console.WriteLine("HasFlag: {0}ms {1}ms {2}ms", st1.Min, st1.Average, st1.Max);
            Console.WriteLine("Bitwise: {0}ms {1}ms {2}ms", st2.Min, st2.Average, st2.Max);
            Console.ReadLine();
        }
        static bool CustomHasFlag(Test flags, Test flag)
        {
            return (flags & flag) != 0;
        }
    }
    [DebuggerDisplay("Average = {Average}")]
    class SpeedTest
    {
        public int Iterations { get; set; }

        public int Times { get; set; }

        public List<Stopwatch> Watches { get; set; }

        public Action Function { get; set; }

        public long Min { get { return Watches.Min(s => s.ElapsedMilliseconds); } }

        public long Max { get { return Watches.Max(s => s.ElapsedMilliseconds); } }

        public double Average { get { return Watches.Average(s => s.ElapsedMilliseconds); } }

        public SpeedTest(Action func)
        {
            Times = 100;
            Iterations = 1000000;
            Function = func;
            Watches = new List<Stopwatch>();
        }

        public void Test()
        {
            Watches.Clear();
            for (int i = 0; i < Times; i++)
            {
                var sw = Stopwatch.StartNew();
                for (int o = 0; o < Iterations; o++)
                {
                    Function();
                }
                sw.Stop();
                Watches.Add(sw);
            }
        }
    }
}

Shared on Medium, don't delete!