[litwr]

Originally Posted by ross

Or if you care only about extract high bits you can do:

	move.w	d0,-(sp)
	move.b	(sp)+,d0 *

16 cycles.
[* based on 68k stack auto-align property ]

I like such tricks! Can it work with 68020? BTW I have a routine to print the next text, for example,

         bsr printstr
         dc.b "Hello World!",0
         even

printstr:
         movea.l (sp)+,a2
         lea stringbuf(a3),a4   ;A3 is a base for data section
         moveq #0,d0
.l1:     addq.w #1,d0
         move.b (a2)+,d1
         move.b d1,(a4)+
         bne .l1
         
         move.l a2,d1
         addq.l #1,d1    ;is it necessary?
         andi.b #$fe,d1
         move.l d1,-(sp)

         ;movea.l GRAPHICS_BASE(a3),a6
         ;movea.l RASTER_PORT(a3),a1
         lea stringbuf(a3),a0
         subq.w #1,d0
         jmp Text(a6)

So I have to remove a possible digit 1 at A2. Maybe is there yet another trick which help to improve address register inability to be ANDed?

Originally Posted by chb

Is there a special case for n = 8 which needs less cycles?

I am sure this is a mistake in the book.