Re: GSoC project about binary packaging

[Jordi Gutiérrez Hermoso]

On 21 June 2013 17:04, John D <address@hidden> wrote:
> On Behalf Of Jordi Gutiérrez Hermoso

> > On 21 June 2013 16:43, John D <address@hidden> wrote:
> >
> >
> >> Also I haven’t looked at what speed differences/advantages there
> >> are in using openblas vs blas in octave
> >
> > You mean vs ATLAS? We haven't shipped a reference BLAS with Octave
> > for a long time.
>
> I was meaning the blas we were compiling against in mingw if
> openblas isn’t used.

Right, that's usually ATLAS. Do you know anything about the following
part?

> >> OpenBLAS seems to compile ok for native mingw compile, however
> >> might be a little flaky on cross builds? I have one linux
> >> computer that compiled it fine, another that did not – I hadn’t
> >> looked into why.
> >
> > There's something I don't understand. Most BLASes try at compile
> > time to figure out what the optimal build flags are and how to
> > produce the best binary (e.g. which vector instructions the CPU
> > supports, etc). How can this work for distributing a compiled
> > BLAS? Does the OpenBLAS build know how to delegate these questions
> > to runtime instead of compile time?

- Jordi G. H.