[Mesa-dev] [PATCH v2 08/13] mesa/format_utils: Add a general format conversion function

[Dieter Nützel]

Am 15.08.2014 04:50, schrieb Jason Ekstrand:
> On Aug 14, 2014 7:13 PM, "Dieter Nützel" <Dieter at nuetzel-hh.de>
> wrote:
>  >
>  > Am 15.08.2014 02:36, schrieb Dave Airlie:
>  >
>  >>>> On 08/02/2014 02:11 PM, Jason Ekstrand wrote:
>  >>>>>
>  >>>>>
>  >>>>> Most format conversion operations required by GL can be
> performed by
>  >>>>> converting one channel at a time, shuffling the channels
> around, and
>  >>>>> optionally filling missing channels with zeros and ones.  This
> adds a
>  >>>>> function to do just that in a general, yet efficient, way.
>  >>>>>
>  >>>>> v2:
>  >>>>>   * Add better comments including full docs for functions
>  >>>>>   * Don't use __typeof__
>  >>>>>   * Use inline helpers instead of writing out conversions by
> hand,
>  >>>>>   * Force full loop unrolling for better performance
>  >>>>>
>  >>
>  >>
>  >> This file seems to anger gcc a lot.
>  >>
>  >> It seems to take upwards of a minute or two to compile here.
>  >>
>  >> gcc 4.8.3 on 32-bit x86.
>  >>
>  >> Dave.
>  >
>  >
>  > For me (on our poor little Duron 1800/2 GB) it ran ~5 minutes...
>  >
>  > gcc 4.8.1 on 32-bit x86.
> 
> If we'd like, the way the macros are set up, it would be easy to
> change it so that we do less unrolling in the cases where we are
> actually doing substantial format conversion and wouldn't notice the
> extra logic quite as much.  I'll play with it a bit tomorrow or next
> week and see how how much of a hit we would actually take if we
> unrolled a little less in places.
>  --Jason Ekstrand

Ping.

In a second it took 11+ minutes , here...

Thanks!
Dieter