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

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Le 29/01/2013 17:05, Douglas Little a écrit :
Hi Nicolas,

    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.

Ok I see. So what is the expected behaviour for a program using these
instructions in Hatari?

BadMood uses these instructions and I have not studied any diverse
effects from using them (timing, accuracy, invalid results....). It just
appeared to work....


If I recall correctly, the number of cycles is the average of the best case / worst case given in the 68030 documentation.

This will certainly gives you different results from a real Falcon, but there's not much that can be done on this now.


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