[Pkg-scicomp-devel] Bug#578052: [atlas] providing >20 separate optimized library packages is insane

[Fabian Greffrath]

Package: atlas
Version: 3.8.3-20
Severity: Important

Hi,

thanks alot for the effort you put in packaging the several optimized 
versions of the atlas libraries, BUT I consider it completely 
unnecessary to put them all into separate packages and leave it up to 
the user to manually select the one optimized for his system.

1) Many users do not even know which features their processor 
supports. What happens if I install the core2sse3-optimized library 
(and it becomes the main alternative due to its higher priority in the 
update-alternatives machanism) if my processor is a simple Pentium 3?

2) It is possible to let the dynamic linker select special optimized 
libraries based on information the kernel knows about my system (no 
human intervention necessary). You can simply install libraries in 
subdirectories of /usr/lib which are named after the feature that they 
make use of. For example, you put the altivec-optimized library into 
/usr/lib/altivec and the normal one into /usr/lib. The linker will 
select the right one for you and give the optimized one a higher 
priority. It works on all architectures and has already proven in 
other packages that benefit from architecture-dependent optimizations.

This is already done in e.g. libavcodec:
<http://packages.debian.org/sid/armel/libavcodec52/filelist>
<http://packages.debian.org/sid/i386/libavcodec52/filelist>
<http://packages.debian.org/sid/powerpc/libavcodec52/filelist>
<http://packages.debian.org/sid/sparc/libavcodec52/filelist>

and libssl:
<http://packages.debian.org/sid/alpha/libssl0.9.8/filelist>
<http://packages.debian.org/sid/i386/libssl0.9.8/filelist>
<http://packages.debian.org/sid/sparc/libssl0.9.8/filelist>

Please consider reverting the separation into the multitude of library 
packages and make use of this neat feature instead.

Cheers,
Fabian

-- 
Dipl.-Phys. Fabian Greffrath

Ruhr-Universität Bochum
Lehrstuhl für Energieanlagen und Energieprozesstechnik (LEAT)
Universitätsstr. 150, IB 3/134
D-44780 Bochum

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E-Mail:  greffrath at leat.ruhr-uni-bochum.de