为什么表达式委托比il-code更快

Question

我有下一个测试代码：

    public static void Test1()
    {
        var a = Expression.Parameter(typeof(int), "a");
        var b = Expression.Parameter(typeof(int), "b");
        var expression = Expression.Lambda<Func<int,int,int>>(Expression.Block(Expression.Add(a,b)),a,b);
        var f = expression.Compile();
        f(1,2);
        var sw = Stopwatch.StartNew();
        for (var i = 0; i < int.MaxValue/10; i++)
        {
            f(1, 2);
        }
        sw.Stop();
        Console.WriteLine("TestExpression - {0}", sw.Elapsed.TotalMilliseconds);
    }

    public static void Test2()
    {
        var dm = new DynamicMethod("Add", typeof(int), new[] {typeof(int), typeof(int)}, true);

        var il = dm.GetILGenerator();

        il.Emit(OpCodes.Ldarg_0);
        il.Emit(OpCodes.Ldarg_1);
        il.Emit(OpCodes.Add);
        il.Emit(OpCodes.Ret);

        var f = (Func<int, int, int>) dm.CreateDelegate(typeof(Func<int, int, int>));
        RuntimeHelpers.PrepareDelegate(f);
        f(1, 2);

        var sw = Stopwatch.StartNew();
        for (var i = 0; i < int.MaxValue / 10; i++)
        {
            f(1, 2);
        }
        sw.Stop();
        Console.WriteLine("TestIl - {0}", sw.Elapsed.TotalMilliseconds);
    }

和时间：617毫秒vs 880毫秒。 你有什么想法？ 我检查一下网络源代码： https://referencesource.microsoft.com/#System.Core/Microsoft/Scripting/Compiler/LambdaCompiler.cs,c5ff378c3a5f8142

https://referencesource.microsoft.com/#System.Core/Microsoft/Scripting/Compiler/LambdaCompiler.cs,65b74d122162a33d 非常感谢。