2013/12/19, Sébastien Villemot <sebast...@debian.org>: > Le mardi 17 décembre 2013 à 16:47 +0100, Andrey Gursky a écrit : > >> Sebastien, thanks for pointing this out. I've also got caught in the >> same trap. But this would mean a trade-off, since openblas's version >> of lapack is just striped away for now. Should I open a new bug for >> openblas or could it be, that optimizations of openblas's lapack are >> not significant enough? > > My understanding is that OpenBLAS does not provide a specialized version > of LAPACK. It just gives the possibility of bundling LAPACK within the > libopenblas.a, which is uninteresting for us. But I have not > investigated this too much, so if OpenBLAS provides a customized LAPACK > as ATLAS does, then please open a wishlist bug against openblas.
I just was confused by the thread [1], where an opinion(?) was expressed: "Now, because the both ATLAS and OpenBLAS versions of LAPACK have some functions overridden with more efficient versions..." Now comparing OpenBLAS.git and lapack-3.5.0 yields: ... Only in OpenBLAS.git/lapack: getf2 Only in OpenBLAS.git/lapack: getrf Only in OpenBLAS.git/lapack: getri Only in OpenBLAS.git/lapack: getrs ... Only in OpenBLAS.git/lapack: laswp Only in OpenBLAS.git/lapack: lauu2 Only in OpenBLAS.git/lapack: lauum ... Only in OpenBLAS.git/lapack: potf2 Only in OpenBLAS.git/lapack: potrf Only in OpenBLAS.git/lapack: trti2 Only in OpenBLAS.git/lapack: trtri >> I'm wondering, whether lapack interface could be remaining general >> modified in a way, atlas and openblas could use it without changing. >> Or the things are more complicated? > > When you use the general LAPACK in Debian, you still benefit from ATLAS > and OpenBLAS optimizations everytime LAPACK calls a BLAS function. Does > this answer your question? Yes, I was surprised, that besides a BLAS optimization an optimization of LAPACK is also needed. Considering at least a statement from ATLAS FAQ [2]: "The provided LAPACK routines utilize a recursive algorithm that should yield reliably better results than the more common staticly-blocked algorithms." and it seems the ATLAS LAPACK is not a patched general netlib LAPACK at all. Anyway, I believe, this bug report belongs to be merged with the one you've mentioned (#576972). [1] https://fedorahosted.org/fpc/ticket/352 [2] http://math-atlas.sourceforge.net/faq.html#optcomp -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
