Re: [OT] GCC vs Intel C++ compiler benchmark - don't forget ia64

[Andreas Jaeger <aj at suse dot de>]

"Scott Robert Ladd" <scott@coyotegulch.com> writes:

>> this translates to time, effort and availability, all
>> three which intel has a lot of.
>
> Then perhaps it is in gcc's interest to focus on processors
> other than Intel's. Has anyone approached AMD about assistance
> im making sure that gcc produces the best possible code on
> Athlon/Duron processors?

There's an Athlon optimization guide - like there're Intel
optimizations guide out.  I've contacts to AMD folks that can give
sometimes additional insight into optimization issues.

The SPEC testing of GCC I do (http://www.suse.de/~aj/SPEC) uses AMD
Athlon systems.

There're different optimizations for let's say Athlons:
- scheduling etc.  This has been done long ago (included in GCC 3.0
  for Athlon) and smaller adjustments are done over the time.
- generic optimizations that need platform specific support,
  e.g. recently prefetch
- generic optimizations that help all architectures but might have a
  different impact on different architectures

Generic optimizations are most needed and I expect that those are
difficult to convince most companies to support since they help
everybody.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj