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Subject: Re: [boost] different matrix library?
From: DE (satan66613_at_[hidden])
Date: 2009-08-27 11:28:59

on 26.08.2009 at 20:38
 joel wrote :
>> a thought about operations tweaks
>> one may want to tile and/or partially unroll operation loops
>> but since such thing characterize operations rather than objects
>> themselves it is wrong to tag the objects with such info
>> consider
>> matrix<double, tile<3, 3> > tiled1; //the first one
>> //...
>> matrix<double, tile<3, 1> > tiled2; //far from the first one
>> //...
>> matrix<double> result = tiled1*tiled2; //what tiling would occure
> In those cases, we compute the smallest common multiple of tiling shape
> as stated in all loop optimization techniques paper.
i consider it a bad (erroneos) practice because in such a case neither
of programmers intentions would take place but something totally
different instead

'3' is a common number as well as 'power of 2'
in such a common case like

    matrix<double, tile<32, 32> > t32;
    matrix<double, tile<3, 3> > t3; //maybe in some function
    //... //intention is to tile 3x3
    m = t32*t3; //don't know about func'
                                     //parameter tiling
according to your words, tiling would not occure at all!!!
but that is not the programmer's intention indeed!

i would prefer at least one of either tiling (most appropriate) to take
place but not that totally different thing


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