FPUHelper.fxch(os, stack.fpuStack, this);
stack.fpuStack.pop(this);
// Convert & move to new space on normal stack
os.writeLEA(helper.SP, helper.SP, -helper.SLOTSIZE);
popFromFPU(os, helper.SP, 0);
os.writePOP(reg);
break;
case Kind.STACK:
// TODO: make sure 'this' is on top of stack
// TODO: implemen it for 64 bits