Re: ATLAS and octave

[R Clint Whaley]

Steven,

Thanks for the comments.  I've read several of your fftw papers; fftw was
the first empiricaly optimized library I heard about, kind of the grandfather
of these kinds of projects . . .

>> The most direct method is, with a previously installed ATLAS, build 
>> octave's libcruft as normal, but you then ar into it the contents of:
>>   ATLAS/lib/<arch>/liblapack.a (overwriting some LAPACK routines)
>>   ATLAS/lib/<arch>/libatlas.a  (ATLAS internals)
>>   ATLAS/lib/<arch>/libf77blas.a (F77 BLAS interface -- overwrite BLAS)
>>   ATLAS/lib/<arch>/libcblas.a (C BLAS interface)
>
>This doesn't seem like the right thing for a permanent solution--too much
>manual hacking of the build process. The right thing would be to modify
>the configure.in file so that the configure script checked for these
>libraries, e.g.
>
>       AC_CHECK_LIB(atlas, ATL_xerbla)

I was trying to get across the mechanics of the operation; my feeling is that
not being an octave maintainer, I don't have much insight into how to best
do this in octave.  I certainly wasn't indicating that my 6AM hack was the
key to success . . .

>One problem may be that ATLAS calls its replacement for LAPACK routines
>"liblapack.a", which is also what one would normally call the real LAPACK
>library.  Since you don't provide a replacement for all of LAPACK, you
>should probably call it libatlaslapack.a or something like that, so that
>one can conveniently link with both libraries.

ATLAS's liblapack.a was actually designed to be archived directly into
netlib's lapack.a, overwriting several of LAPACK's routines, and thus
providing a complete lapack library.  This process is covered in 
  ATLAS/doc/LAPACK.txt
if anyone is interested.  Again, a bit of a kludge, but it gives a full
library in this way . . .

>Autoconf works well even for this sort of thing; e.g. we do it for FFTW
Thanks for the info.

Cheers,
Clint



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