Re: [Mingw-cross-env-list] blas, cblas, lapack, suitesparse [was Re: suitesparse support - help request]

[Volker Grabsch]

Alois Schlögl <address@hidden> schrieb:
>> I think that depends on getting a working BLAS/LAPACK. I started
>> having a look at Atlas, but it seems to have a very arcane
>> configuration.
>
> Yes, Atlas tries to do some performance test in order to identify the  
> optimal configuration.
> Because, the final target platform is not available at built time, some  
> workaround is needed.

Note that this is a general issue with packages that are not aware
of cross compiling. Usually this problem affects code generators,
in which case we simply compile them with the native instead of the
cross compiler.

However, (performance) test programs are a bigger issue. It might
be a good idea to contact the upstream project and to ask them
whether they indent to make their packages suitable for cross
compiling. They are usually in a better position to fix that than
we are, especially if it has to be fixed deeply in their build
scripts.

> I'm asking to include lapack.mk into mingw-cross-env, it provides  
> libblas.a and liblapack.a.

It looks okay to me. However, I'm a bit behind with including
contributions, so please be patient with me. :-)

However, I notices that your blas and cblas scripts have an
important flaw:

> $(PKG)_SUBDIR   := BLAS
> $(PKG)_FILE     := blas.tgz
> $(PKG)_WEBSITE  := http://www.netlib.org/
> $(PKG)_URL      := http://www.netlib.org/blas/blas.tgz

> $(PKG)_SUBDIR   := CBLAS
> $(PKG)_FILE     := cblas.tgz
> $(PKG)_WEBSITE  := http://www.netlib.org/
> $(PKG)_URL      := http://www.netlib.org/blas/blast-forum/cblas.tgz

Both do not download the source package of the given version.
Instead, they seem to download always the latest one. This is
almost never a good idea:

It can silently introduce build issues, and makes them
especially hard to reproduce and thus to debug. Also note that
Mingw-cross-env's checksum test will make your test script
unusable as soon as upstream releases a new version.


Greets,
Volker

-- 
Volker Grabsch
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