public static unsafe uint CompareExchange(uint *location, uint value, uint comparand)
{
Asm.MOV(R32.ECX, location);
Asm.MOV(R32.EDX, &value);
Asm.MOV(R32.EAX, &comparand);
Asm.LOCK();
Asm.CMPXCHG(R32.ECX, R32.EDX);
Asm.MOV(location, R32.EAX);
return(*location);
}