A89: Re: Floating-point "imitation"
[Prev][Next][Index][Thread]
A89: Re: Floating-point "imitation"
>> mulu.w #39322,d0
>> swap d0
>>
>>The net effect is a multiply by 0.6000061, which is 0.001% off from 0.6.
>
>How exactly does this work? I see that 65535*.6 = 39321 (not 39322?) - can
>I do this with any fractial value? Say
Doh! I don't know WHY I didn't see before that you're doing the exact same
thing I did:
3 60 77 39322
- = --- ~= --- ~= -----
5 100 128 65535
>> mulu.w #39322,d0
>
>I don't quite understand this either - if the value I want is in the upper
>word, then the fractional portion would be in the lower word - so wouldn't
>half a word ~= .5? Wouldn't I add 32768?
Aha - you mean $8000, right?
32768 = $8000 = %1000000000000000
And this would round properly =)
Thanks again, Zoltan - where did you learn all this stuff, anyway?
-Scott
Follow-Ups: