Re: Submission of pa8000 changes?

[N8TM at aol dot com]

In a message dated 11/28/98 5:33:23 PM Pacific Standard Time, law@cygnus.com
writes:

<< I think you'll find that altering some of the code generation choices wil
give
 you much better results.  For example, on the PA8000 it is wise to avoid
insns
 which have multiple outputs (like fmpyadd and fmpysub).  I also suspect that
 implementing fused multiply-add type sequences will be a big win.  My sources
 indicate that traditional latency scheduling is almost worthless on this
chip.
  >>
Yes, the fused multiply-add may double the performance in some cases, judging
by results with HPUX f90; this architecture is quite dependent on it.  The
out-of-order execution facility presumably reduces the importance of the
compiler predicting latencies.

  At my office, the hppa2.0 machines are slipping out of the role of
supporting locally built software, which may or may not be a reason for having
egcs working well.  In favor of egcs is that it seems easier to copy the
support libraries than to get access to the HPUX "native" compiler run-times
on machines which don't have those compilers licensed.