IRET/IRETD - Interrupt Return

	Usage:	IRET
		IRETD  (386+ only)
	Modifies flags: AF CF DF IF PF SF TF ZF

	Returns control to point of interruption by popping IP, CS
	and then the Flags from the stack and continues execution at
	this location.	CPU exception interrupts will return to the
	instruction that cause the exception because the CS:IP placed
	on the stack during the interrupt is the address of the offending
	instruction.

					 Clocks			Size
	    Operands		808x   286   386   486		Bytes

    iret		       32/44  17+m    22    15		  1
    iret  (prot. mode)	         -    31+m    38    15		  1
    iret  (to less privilege)	 -    55+m    82    36		  1
    iret  (different task, NT=1) -   169+m    TS  TS+32		  1
    iretd			 -	-   22/38   15		  1
    iretd (to less privilege)	 -	-     82    36		  1
    iretd (to VM86 mode)	 -	-     60    15		  1
    iretd (different task, NT=1) -	-     TS  TS+32		  1


    - 386 timings are listed as real-mode/protected-mode
	- see Instruction Timing