C 7.2传递函数参数的只读字段中引用的常量vs

class Test
{
    public const decimal x = 0.2m;
    public readonly decimal y = 0.2m;

    public void Method1(in decimal x)
    {
        Thread.MemoryBarrier();
    }
}

class Program
{
    static void Main(string[] args)
    {
        var t = new Test();

        var sw = new Stopwatch();
        sw.Start();
        for (var i = 0; i < 100000000; i++)
        {
            t.Method1(in t.y);
        }
        sw.Stop();
        Console.WriteLine(sw.ElapsedTicks);
        sw.Restart();
        for (var i = 0; i < 100000000; i++)
        {
            t.Method1(Test.x);
        }
        sw.Stop();
        Console.WriteLine(sw.ElapsedTicks);
        Console.ReadLine();
     } 
}

const

• IL_0001: ldc.i4.s 20
  IL_0003: ldc.i4.0
  IL_0004: ldc.i4.0
  IL_0005: ldc.i4.0
  IL_0006: ldc.i4.1
  IL_0007: newobj instance void [mscorlib]System.Decimal::.ctor(int32, int32, int32, bool, uint8)
  IL_000c: call instance bool C::Method2(valuetype [mscorlib]System.Decimal)
  

• IL_0002: ldflda valuetype [mscorlib]System.Decimal C::dd
  IL_0007: call instance bool C::Method1(valuetype [mscorlib]System.Decimal&)
  IL_000c: pop
  

readonly