[2.0] [C#]CDQ - Convert Double to Quad (386+)?

I am wondering how exactly CDQ would work in C#. Anyone know a C# equivalent?

What does a processor instruction have to do with a high-level language like C#?

Something like this...

Code:

---

    ulong CDQ(uint d)
    {
        if((d & 0x80000000) != 0)
            return 0xffffffff00000000 | (ulong)d; //sign extend 1
        else
            return (ulong)d;    //sign extend 0 (this is implicit)
    }

---

In fact since C# is so much higher-level than ASM, the above would be virtually identical to the implementation of the MOVSE (move with sign extend) opcode.