[Pkg-scicomp-devel] Fixing atlas on debian/Ubuntu

[David Cournapeau]

Hi,

I am a Numpy/Scipy developer, and we recently got a lot of trouble
from users of recent ubuntu and debian, because the atlas libraries
are broken (the SSE2 version give bogus results whenever complex
number are involved in 32 bits).

Since the current debian package is near-impossible to decipher, I
started from scratch a package so that we could point numpy/scipy
users to a an ubuntu build on PPA. Now, I would like this effort to be
useful for "upstream" debian packagers. The packaging was done under
git, and the code available there:

http://github.com/cournape/atlas-debian/tree/master

Although I am sure the package is far from perfect, I have tried to
make at least the patches clean enough so that they could easily be
reused. Supported features:
 - as long as the CPU support at least SSE2 instruction set, it can
produce binaries for no sse, sse 1 and sse2
 - the libraries follow as closely as possible the conventions used by
the former atlas package (liblapack renamed to liblapack_atlas,
/usr/lib/atlas contain a full BLAS/LAPACK implementation, etc...)

What is missing:
 - support for arch other than x86/amd64 (support for arch without
SIMD should be trivial, though)
 - the binaries are not exactly reproducible as is the case for the
current package. Although reproducibility is very nice to have, the
complexity needed at the build level to circumvent atlas build system
kind of defeat the purpose IMHO. The only working solution would be
upstream support.
 - support for fully optimized library if built by the user
 - threaded support

cheers,

David