This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: DFA and ppc?
- From: David Edelsohn <dje at watson dot ibm dot com>
- To: Jack Howarth <howarth at bromo dot med dot uc dot edu>
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 22 Oct 2003 11:01:45 -0400
- Subject: Re: DFA and ppc?
>>>>> Jack Howarth writes:
Jack> In building g77 from the latest gcc 3.4 snapshot I noticed
Jack> that DFA is now being set up on ppc. Does anyone know how
Jack> functional this is currently on ppc? Also is the ppc DFA
Jack> support specific to gcc 3.4 only or does it exist in the
Jack> gcc 3.3 that Apple will ship with Darwin 7.0/Panther?
Apple's GCC 3.3-based compiler uses the DFA scheduling model, but
it is not in the FSF release of GCC.
Jack> ps Are there supposed to be any particular improvements in
Jack> execution speed from switching to DFA or does it just
Jack> provide a more maintainable framwork to do instruction
Jack> scheduling? My brief benchmarking suggests that it doesn't
Jack> really do much for g77 at -O3 compared to stock gcc 3.3.2.
There are numerous changes between GCC 3.3 and GCC 3.4, so I do
not know how you are testing that one change in isolation to compare just
the benefit of a DFA model.
David