On 8/9/07, David Cournapeau <[EMAIL PROTECTED]> wrote: > > Charles R Harris wrote: > > > > Well, what you want might be very easy to do in python, we just need > > to check the default alignments for doubles and floats for some of the > > other compilers, architectures, and OS's out there. On the other hand, > > you might not be able to request a c malloc that is aligned in a > > portable way without resorting to the same tricks as you do in python. > > So why not use python and get the reference counting and garbage > > collection along with it? > First, doing it in python means that I cannot use the facility from C > easily. But this is exactly where I need it, and where I would guess > most people need it. People want to interface numpy with the mkl ? They > will do it in C, right ? And maybe I am just too dumb to see the > problem, but I don't see the need for garbage collection and so on :) > Again, what is needed is: > - aligned allocator -> we can use the one from Steven Johnson, used > in fftw, which support more or less the same archs than numpy > - Refactor the array creation functions in C such as the > implementation takes one additional alignement argument, and the > original functions are kept identical to before > - Add a few utilities function to check whether it is SSE aligned, > arbitrary aligned, etc... > > The only non trivial point is 2 . Actually, when I first thought about > it, I thought about fixing alignement at compile time, which would have > made it totally avoidable: it would have been a simple change of the > definition of PyDataMem_New to an aligned malloc with a constant. I have > already the code for this, and besides aligned malloc code, it is like a > 5 lines change of numpy code, nothing terrible, really.
Ah, you want it in C. Well, I think it would not be too difficult to change PyDataMem_New, however, the function signature would change and all the code that used it would break. That is pretty drastic. Better to define PyDataMem_New_Aligned, then redefine PyDataMem_New to use the new function. That way nothing breaks and you get the function you need. I don't think Travis would get upset if you added such a function and documented it. Chuck
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