[Numpy-discussion] Default builds of OpenBLAS development branch are now fork safe

[Matthew Brett]

Hi,

On Wed, Mar 26, 2014 at 11:34 AM, Julian Taylor
<jtaylor.debian at googlemail.com> wrote:
> On 26.03.2014 16:27, Olivier Grisel wrote:
>> Hi Carl,
>>
>> I installed Python 2.7.6 64 bits on a windows server instance from
>> rackspace cloud and then ran get-pip.py and then could successfully
>> install the numpy and scipy wheel packages from your google drive
>> folder. I tested dot products and scipy.linalg.svd and they work as
>> expected.
>>
>
>>
>> Would it make sense to embed the blas and lapack header files as part
>> of this numpy wheel and make numpy.distutils.system_info return the
>> lib and include folder pointing to the embedded libopenblas.dll and
>> header files so has to make third party libraries directly buildable
>> against those?
>>
>
> as for using openblas by default in binary builds, no.
> pthread openblas build is now fork safe which is great but it is still
> not reliable enough for a default.
> E.g. the current latest release 0.2.8 still has one crash bug on
> dgemv[1], and wrong results zherk/zer2[2] and dgemv/cgemv[3].
> git head has the former four fixed bug still has wrong results for cgemv.
> The not so old 0.2.8 also fixed whole bunch more crashes and wrong
> result issues (crashes on QR, uninitialized data use in dgemm, ...).
> None of the fixes received unit tests, so I am somewhat pessimistic that
> it will improve, especially as the maintainer is dissertating (is that
> the right word?) and most of the code is assembler code only few people
> can write (it is simply not required anymore, we have code generators
> and intrinsics for that).
>
> Openblas is great if you do not have the patience to build ATLAS and
> only use a restricted set of functionality and platforms you can easily
> test.
> Currently it is in my opinion not suitable for a general purpose library
> like numpy.
>
> I don't have any objections to adding get_info("openblas") if that does
> not work yet. Patches welcome.

Julian - do you have any opinion on using gotoBLAS instead of OpenBLAS
for the Windows binaries?

Cheers,

Matthew