on has immediate operand
         THEN (* Release parameters from stack *)
              SP ← SP + (SRC AND FFFFH);
    FI;
FI;
(* Protected mode, not virtual-8086 mode *)
IF (PE = 1 and VM = 0 and IA32_EFER.LMA = 0) and instruction = far return
    THEN
         IF OperandSize = 32
              THEN
                    IF second doubleword on stack is not within stack limits
                         THEN #SS(0); FI;
              ELSE (* OperandSize = 16 *)
                    IF second word on stack is