[Numpy-discussion] Changing the distributed binary for numpy 1.0.4 for windows ?

[David Cournapeau]

On Dec 11, 2007 11:59 AM, Andrew Straw <strawman at astraw.com> wrote:
> An idea that occurred to me after reading Fernando's email. A function
> could be called at numpy import time that specifically checks for the
> instruction set on the CPU running and makes sure that is completely
> covers the instruction set available through all the various calls,
> including to BLAS. If this kind of thing were added, numpy could fail
> with a loud warning rather than dying with mysterious errors later on.
> The trouble would seem that you can switch your BLAS shared library
> without re-compiling numpy, so numpy would have to do a run-time query
> of ATLAS, etc. for compilation issues. Which is likely
> library-dependent, and furthermore, not having looked into BLAS
> implementations, I'm not sure that (m)any of them provide such
> information. Do they? Is this idea technically possible?

It is possible, and has been done: that's how matlab did it when it
used ATLAS. Now, it is not easy, and would require some changes
Basically, the solution I would see would be to have a wrapper
library, to which every call would be done, and the wrapper library
could "reroute" the calls to the right, dynamically loaded library.
This requires several things which are not theoretically difficult,
but a pain to do right (cross platform library loader, etc...)

David