[Numpy-discussion] new mingw-w64 based numpy and scipy wheel (still experimental)

[Nathaniel Smith]

On Thu, Jan 22, 2015 at 9:29 PM, Carl Kleffner <cmkleffner at gmail.com> wrote:
> I took time to create mingw-w64 based wheels of numpy-1.9.1 and scipy-0.15.1
> source distributions and put them on
> https://bitbucket.org/carlkl/mingw-w64-for-python/downloads as well as on
> binstar.org. The test matrix is python-2.7 and 3.4 for both 32bit and 64bit.
>
> Feedback is welcome.
>
> The wheels can be pip installed with:
>
> pip install -i https://pypi.binstar.org/carlkl/simple numpy
> pip install -i https://pypi.binstar.org/carlkl/simple scipy
>
> Some technical details: the binaries are build upon OpenBLAS as accelerated
> BLAS/Lapack. OpenBLAS itself is build with dynamic kernels (similar to MKL)
> and automatic runtime selection depending on the CPU. The minimal requested
> feature supplied by the CPU is SSE2. SSE1 and non-SSE CPUs are not supported
> with this builds. This is the default for 64bit binaries anyway.

According to the steam hardware survey, 99.98% of windows computers
have SSE2. (http://store.steampowered.com/hwsurvey , click on "other
settings" at the bottom). So this is probably OK :-).

> OpenBLAS is deployed as part of the numpy wheel. That said, the scipy wheels
> mentioned above are dependant on the installation of the OpenBLAS based
> numpy and won't work i.e. with an installed  numpy-MKL.

This sounds like it probably needs to be fixed before we can recommend
the scipy wheels for anyone? OTOH it might be fine to start
distributing numpy wheels first.

> For the numpy 32bit builds there are 3 failures for special FP value tests,
> due to a bug in mingw-w64 that is still present. All scipy versions show up
> 7 failures with some numerical noise, that could be ignored (or corrected
> with relaxed asserts in the test code).
>
> PR's for numpy and scipy are in preparation. The mingw-w64 compiler used for
> building can be found at
> https://bitbucket.org/carlkl/mingw-w64-for-python/downloads.

Correct me if I'm wrong, but it looks like there isn't any details on
how exactly the compiler was set up? Which is fine, I know you've been
doing a ton of work on this and it's much appreciated :-). But
eventually I do think a prerequisite for us adopting these as official
builds is that we'll need a text document (or an executable script!)
that walks through all the steps in setting up the toolchain etc., so
that someone starting from scratch could get it all up and running.
Otherwise we run the risk of eventually ending up back where we are
today, with a creaky old mingw binary snapshot that no-one knows how
it works or how to reproduce...

-n

-- 
Nathaniel J. Smith
Postdoctoral researcher - Informatics - University of Edinburgh
http://vorpus.org