Subject: Re: [boost] different matrix library?
From: DE (satan66613_at_[hidden])
Date: 2009-08-14 13:52:57
on 14.08.2009 at 21:32
joel wrote :
>> looks smart and tricky but i don't see any advantages over computed
>> indeces but only wasted spaces and time (for allocating additiona storage for pointers)
> This si a trade-off. Beware that's only the allocating is slightly
> slower as the malloc itslef takes more time than the small loop.
>> at the same time dereferencing a pointer is like computing an index
> Look at generated assembly and you'll see what happen.
> At worst it's the same. At best, it replace all the idnex computation by
> a single LEA on INTEL.
> Also, it ease writing code that need to deal with multiple idnex.
for big sizes it might be better
> Index computation with dim > 2 becomes impractical when you ned to do
> thign like extarcting non rectangular area or doing tile blocking.
so i guess there should be at least two versions of storages
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