[Python-modules-team] Bug#489726: Fw: should numpy be built with atlas?

[Ondrej Certik]

On Tue, Jul 8, 2008 at 3:05 PM, Tiziano Zito <otizonaizit at yahoo.com> wrote:
> Hi Ondrej,
>
>> $ ./test_atlas.py
>> Using ATLAS:
>> 0.53141283989
>> $ wajig remove atlas3-base libatlas3gf-base
>> $ ./test_atlas.py
>> Using ATLAS:
>> 1.64572000504
>>
>> So it seems to work, even though the difference is not so big.
>
> the difference is not so big because the package contains a
> _dotblas.so file. When you remove the ATLAS libs, it simply uses the
> available lapack+blas routines, which are slower then ATLAS but
> still not so bad. If you build the package without the patch and
> without using ATLAS, not _dotblas.so file is present, and the slow
> down is much higher:
>
> $ aptitude search ~i~natlas
> i   libatlas3gf-sse2                - Automatically Tuned Linear Algebra Softwar
> $ ldd /usr/lib/python2.5/site-packages/numpy/core/_dotblas.so
>        linux-gate.so.1 =>  (0xffffe000)
>        libblas.so.3gf => /usr/lib/sse2/atlas/libblas.so.3gf (0xb79b6000)
>        libgfortran.so.3 => /usr/lib/libgfortran.so.3 (0xb7904000)
>        libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb78dd000)
>        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb78d0000)
>        libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7775000)
>        /lib/ld-linux.so.2 (0x80000000)
> $ python test_atlas.py
> Using ATLAS:
> 0.539413928986
> $ aptitude purge libatlas3gf-sse2
> $ python test_atlas.py
> Using ATLAS:
> 1.90855002403
> $ ldd /usr/lib/python2.5/site-packages/numpy/core/_dotblas.so
>        linux-gate.so.1 =>  (0xffffe000)
>        libblas.so.3gf => /usr/lib/libblas.so.3gf (0xb7f60000)
>        libgfortran.so.3 => /usr/lib/libgfortran.so.3 (0xb7eae000)
>        libm.so.6 => /lib/i686/cmov/libm.so.6 (0xb7e87000)
>        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7e7a000)
>        libc.so.6 => /lib/i686/cmov/libc.so.6 (0xb7d1f000)
>        /lib/ld-linux.so.2 (0x80000000)
> $ mv /usr/lib/python2.5/site-packages/numpy/core/_dotblas.so /usr/lib/python2.5/site-packages/numpy/core/_dotblas.so.bak
> $ python test_atlas.py
> No ATLAS:
> 7.52080416679

Ah, I see. Thanks for the clarification. If you could join DPMT and
maintain the package with us, it'd be great.

Anyway I finished my tests on i386 and I think all is ok. So I just
uploaded the fixed package. Let's see if all is fine now.

Ondrej