[Benchmark]
public void Original()
{
    SizeOfInt = (uint)Marshal.SizeOf(typeof(int));
    SizeOfUInt = (uint)Marshal.SizeOf(typeof(uint));
    SizeOfUShort = (uint)Marshal.SizeOf(typeof(ushort));
    SizeOfByte = (uint)Marshal.SizeOf(typeof(byte));
    SizeOfFloat = (uint)Marshal.SizeOf(typeof(float));
    SizeOfDouble = (uint)Marshal.SizeOf(typeof(double));
    SizeOfGuid = (uint)Marshal.SizeOf(typeof(Guid));
    SizeOfDecimal = (uint)Marshal.SizeOf(typeof(decimal));
}

[Benchmark]
public void PR__EDIT()
{
    SizeOfInt = sizeof(int);
    SizeOfUInt = sizeof(uint);
    SizeOfUShort = sizeof(ushort);
    SizeOfByte = sizeof(byte);
    SizeOfFloat = sizeof(float);
    SizeOfDouble = sizeof(double);
    SizeOfGuid = (uint)Unsafe.SizeOf<Guid>();
    SizeOfDecimal = sizeof(decimal);
}