Re: [hatari-devel] 68030 cycle timings for 64bit div/mul

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 29/01/2013 16:49, Douglas Little a écrit :
> This is a question for Laurent I think...
>
> Where can I find the instruction times for the 'div' and 'mul' 64bit
> (long form) instructions in the Hatari timing table "falcon_cycle030.h"?
> e.g.
>
> "divs.l <ea>,Dr:Dq"
> "mulu.l" <ea>,Dr:Dq"
>
> I see indirection to certain tables "table_falcon_cycles_DIVS_L" but the
> addressing mode for Dr:Dq does not seem to be present in the comments.
> Is it handled specially somewhere else?
>
> Thanks,
> Doug.

Hello

it's not handled. 64 bit mul/div are more complex than the 68000 
equivalent and so far no one has reverse engineered those instructions 
to "guess" the algorithm and its timing.

Nicolas