Re: cortex / arm-hardfloat-linux-gnueabi (was Re: armelfp: new architecture name for an armel variant)

[Konstantinos Margaritis <markos@genesi-usa.com>]

On Friday 16 July 2010 11:11:24 Loïc Minier wrote:
> On Fri, Jul 16, 2010, Konstantinos Margaritis wrote:
> > softfp:
> 
>  I wonder what you built with softfp exactly?  Did you rebuild
>  libc6, libpng12-0 for instance?  Not that I expect that most of the
>  time is spent in libpng12-0, but still.

I didn't build anything, I just installed the default package from karmic -
which as you already said is softfp.

>  As I understand it, we have these options:
>  - keep Debian armel as is, add a new armhf hard-float port
>  - keep Debian armel as is, and provide an archive of Debian armel+vfp
>    rebuilt with softfp
>  - keep Debian armel as is, and change a dozen of libs to provide a VFP
>    version (softfp)

Obviously, I vote for the first option :)

>  One way to check how well softfp performs would be to run povray in
>  Ubuntu versus in Debian; this will mix noise in the results, but I
>  don't expect the minor sourceful differences to make the biggest
>  impact, but rather the toolchain opts would.  (You're speaking of a
>  3-folds increase.)

I don't have a debian armel installation here, so I can't test how it performs 
there, however running the same version on a G4@1Ghz running squeeze -no 
altivec- I got total runtime 20 seconds, which is imho indicative of the 
potential performance of the iMX515@800Mhz, as the ARM vfp is much less 
powerful than the G4's. 20 vs 50, sounds almost expected, 20s vs ~3min sounds 
like a joke. -I know ARM is not a cpu fit for rendering, but that's beside the 
point.

>         archive         dist            toolchain defaults
>         -------         ----            ------------------
>         Debian armel    sid, squeeze    armv4t + soft
>         freevec.org     karmic          armv6 + hardfp
>         Ubuntu armel    karmic          armv6 + softfp
>         Ubuntu armel    jaunty          armv5t + soft
>         Ubuntu armel    lucid           armv7t2 + softfp
> 
>  Would be nice to know against which userspace you ran your povray
>  "softfp".

I did say that, it is a default karmic installation, the efikas come 
preinstalled with that.

Konstantinos