DFA and ppc?

[Jack Howarth]

    In building g77 from the latest gcc 3.4 snapshot I noticed
that DFA is now being set up on ppc. Does anyone know how
functional this is currently on ppc? Also is the ppc DFA 
support specific to gcc 3.4 only or does it exist in the
gcc 3.3 that Apple will ship with Darwin 7.0/Panther? 
                         Jack
ps Are there supposed to be any particular improvements in
execution speed from switching to DFA or does it just
provide a more maintainable framwork to do instruction
scheduling? My brief benchmarking suggests that it doesn't
really do much for g77 at -O3 compared to stock gcc 3.3.2.