On 2009-03-22 09:45:32 +0100, Don <[email protected]> said:

Trass3r wrote:
Don schrieb:
I abandoned it largely because array operations got into the language; since then I've been working on getting the low-level math language stuff working.
Don't worry, I haven't gone away!

I see.


http://www.dsource.org/projects/lyla

Though array operations still only give us SIMD and no multithreading (?!).

There's absolutely no way you'd want multithreading on a BLAS1 operation. It's not until BLAS3 that you become computation-limited.

not true, if your vector is large you could still use several threads.
but you are right that using multiple thread at low level is a dangerous thing, because it might be better to use just one thread, and parallelize another operation at a higher level. Thus you need sort of know how many threads are really available for that operation. I am trying to tackle that problem in blip, by having a global scheduler, that I am rewriting.

I think the best approach is lyla's, taking an existing, optimized C BLAS library and writing some kind of wrapper using operator overloading etc. to make programming easier and more intuitive.

blyp.narray.NArray does that if compiled with -version=blas, but I think that for large vector/matrixes you can do better (exactly using multithreading).

In my opinion, we actually need matrices in the standard library, with a very small number of primitive operations built-in (much like Fortran does). Outside those, I agree, wrappers to an existing library should be used.


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