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

[ Thread Index | Date Index | More Archives ]

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"?

"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?



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.


Mail converted by MHonArc 2.6.19+