Re: Submission of pa8000 changes?

[Jeffrey A Law <law at cygnus dot com>]

  In message <365DD8CB.41DA2F86@americasm01.nt.com>you write:
  > I've added support for -mschedule= 8000, 8200, and 8500 for hppa to
  > egcs.  They're all the same and are clones of the machine description
  > for pa7200 except doubling available function units.  I haven't modified
  > the configure scripts to default to pa2.0 yet.  The patch file has about
  > 90 !'s and 113 +'s.  Does this count as a small submission or does it
  > need a disclaimer form?
Actually, I doubt this is going to help scheduling anyway.

Most of the papers I've read on the PA8000 discourage latency scheduling for
everything except a few FP ops where they encourage an inaccurate description
of latencies.

Did you benchmark after your changes?  If so, what did you benchmark and what
were the results of those benchmarks.

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.

And yes, your patch would need a copyright assignment in its current form.

jeff