Thread title says it all really.
I'm interested in the quickest ways to do things on the 68000 processor.
I imagine that an optimisation that is valid for 68000 might not necessarily be valid for > 68000 processors but my main interest is in vanilla 68000 coding.
So, if you have any, please post them here.
In the meantime, some from me. Right hand operand(s) accomplish (according to my own testing, correct me if I'm wrong!
) the same as the left hand operand(s) only faster:
Code:
68000 code speed optimisations
------------------------------
clr.l d0 --> moveq.l #0,d0
lsl.w #1,d0 --> add.w d0,d0
lsl.w #2,d0 --> add.w d0,d0
add.w d0,d0
adda.w #10,a0 --> lea 10(a0),a0
moveq.l #16,d0 --> swap d1
ror.l d0,d1
moveq.l #15,d0 --> swap d1
ror.l d0,d1 rol.l #1,d1