[linux-dvb] Large arrays

Manu Abraham abraham.manu at gmail.com
Tue Aug 28 17:52:45 CEST 2007


Henk Vergonet wrote:
> On Tue, Aug 28, 2007 at 12:19:57AM +0400, Manu Abraham wrote:
>> Hi all
>>
>> While working on a tuner, i stumbled upon one of the usual problems
>> (floating point operations) in kernel
>> The options what i had were:
>>
>> * use integer math calculations
>> * precompute the values where double precision is needed.
>>
>> That said, the first option i tried for a while, after a few days (i
>> almost gave up ?) got really irritated with it.
>> The second option seemed a bit more comfortable, to precalculate the values.
>>
>> The disadvantage in such a case is that the array which holds the
>> precomputed value is quite large in size, with that in mind, a different
>> question arose in my mind, whether such large arrays would be frowned
>> upon in kernel
>>
>> The precomputed array is here
>>
>> http://www.jusst.de/manu/mc44s80x_array.c
>>
> 
> Hi Manu,
> 
> What kind of calculations are we talking about? There must be a more space
> efficient way...

The calculations what i based it upon is here:

http://paste.debian.net/35554
http://jusst.de/manu/1086M_36.125M.c
http://jusst.de/manu/1086M_36.166M.c


Thanks




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