Bug#569436: [Pkg-scicomp-devel] Bug#569436: Bug#569436: lapack: zgesvd seems to give incorrect results

[Sylvestre Ledru]

Le lundi 15 février 2010 à 22:02 -0600, Kumar Appaiah a écrit :
> On Mon, Feb 15, 2010 at 10:39:52AM -0600, Kumar Appaiah wrote:
> > On Sat, Feb 13, 2010 at 09:59:24AM -0600, Kumar Appaiah wrote:
> > > > * Explicit dependency on gcc 4.3 removed (Closes: #533807)
> > > > but the changelog does not say what this explicit dep has been added...
> > > 
> > > I would also suspect that this is a compiler related issue; for your
> > > modifications are only in the control file and changelog. I'll try to
> > > probe this further, and let you know.
> > 
> > Upon further probing, I can confirm that if I switch the -O3's in
> > debian/rules to -O2, then things start working fine. I'll try to probe
> > further and see how to put the blame elsewhere (on the compiler, that
> > is).
> 
> OK, after wasting several hours on this, I couldn't really get to the
> root of the problem. The trouble is that zgesvd causes several lapack
> calls, each of which calls several lapack functions; it is very
> difficult to isolate which Blas function actually causes the error.
> 
> Since SVD is something I consider very important, I would request you
> to please re-upload Blas with an optimization level of -O2, so that
> things remain sane with all the reverse dependencies.
OK, thank for your investigation. I will do that then.

> Thanks, and sorry.
Sorry for what ? :)

Sylvestre