[Numpy-discussion] Using library-specific headers

[Robert McLeod]

Pavlyk,

NumExpr optionally includes MKL's VML at compile-time.  You may want to
look at its implementation.  From what I recall it relies on a function in
a bootstrapped __config__.py to determine if MKL is present.

Robert

On Thu, Sep 29, 2016 at 7:27 PM, Pavlyk, Oleksandr <
oleksandr.pavlyk at intel.com> wrote:

> Hi Julian,
>
> Thank you very much for the response. It appears to work.
>
> I work on "Intel Distribution for Python" at Intel Corp. This question was
> motivated by work needed to
> prepare pull requests with our changes/optimizations to numpy source code.
> In particular, the numpy.random_intel package
>
>    https://mail.scipy.org/pipermail/numpy-discussion/2016-June/075693.html
>
> relies on MKL, but its potential inclusion in numpy should not break the
> build if MKL is unavailable.
>
> Also our benchmarking was pointing at Numpy's sequential memory copying as
> a bottleneck.
> I am working to open a pull request into the main trunk of numpy to take
> advantage of multithreaded
> MKL's BLAS dcopy function to do memory copying in parallel for
> sufficiently large sizes.
>
> Related to numpy.random_inter, I noticed that the randomstate package,
> which extends numpy.random was
> not being made a part of numpy, but rather published on PyPI as a
> stand-alone module. Does that mean that
> the community decided against  including it in numpy's codebase? If so, I
> would appreciate if someone could
> elaborate on or point me to the reasoning behind that decision.
>
> Thank you,
> Oleksandr
>
>
>
> -----Original Message-----
> From: NumPy-Discussion [mailto:numpy-discussion-bounces at scipy.org] On
> Behalf Of Julian Taylor
> Sent: Thursday, September 29, 2016 8:10 AM
> To: numpy-discussion at scipy.org
> Subject: Re: [Numpy-discussion] Using library-specific headers
>
> On 09/27/2016 11:09 PM, Pavlyk, Oleksandr wrote:
> > Suppose I would like to take advantage of some functions from MKL in
> > numpy C source code, which would require to use
> >
> >
> >
> > #include "mkl.h"
> >
> >
> >
> > Ideally this include line must not break the build of numpy when MKL
> > is not present, so my initial approach was to use
> >
> >
> >
> > #if defined(SCIPY_MKL_H)
> >
> > #include "mkl.h"
> >
> > #endif
> >
> >
> >
> > Unfortunately, this did not work when building with gcc on a machine
> > where MKL is present on default LD_LIBRARY_PATH, because then the
> > distutils code was setting SCIPY_MKL_H preprocessor variable, even
> > though mkl headers are not on the C_INCLUDE_PATH.
> >
> >
> >
> > What is the preferred solution to include an external library header
> > to ensure that code-base continues to build in most common cases?
> >
> >
> >
> > One approach I can think of is to set a preprocessor variable, say
> > HAVE_MKL_HEADERS in numpy/core/includes/numpy/config.h depending on an
> > outcome of building of a simple _configtest.c using
> > config.try_compile(), like it is done in numpy/core/setup.py //
> >
> > / /
> >
> > Is there a simpler, or a better way?
> >
>
> hi,
> you could put the header into OPTIONAL_HEADERS in
> numpy/core/setup_common.py. This will define HAVE_HEADERFILENAME_H for you
> but this will not check that the corresponding the library actually exists
> and can be linked.
> For that SCIPY_MKL_H is probably the right macro, though its name is
> confusing as it does not check for the header presence ...
>
> Can you tell us more about what from mkl you are attempting to add and for
> what purpos, e.g. is it something that should go into numpy proper or just
> for personal/internal use?
>
> cheers,
> Julian
>
>
>
>
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> https://mail.scipy.org/mailman/listinfo/numpy-discussion
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
> https://mail.scipy.org/mailman/listinfo/numpy-discussion
>



-- 
Robert McLeod, Ph.D.
Center for Cellular Imaging and Nano Analytics (C-CINA)
Biozentrum der Universität Basel
Mattenstrasse 26, 4058 Basel
Work: +41.061.387.3225
robert.mcleod at unibas.ch
robert.mcleod at bsse.ethz.ch <robert.mcleod at ethz.ch>
robbmcleod at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20160929/74a161a2/attachment.html>