Re: Performance measurements

[Jeffrey A Law <law@cygnus.com>]

  > Just for information, on HP
  > 
  > PA7200: gcc-2.7.2.2              -O3  :  26.63 MFLOPS
  > PA7200: egcs-2.91.42             -O3  :  47.13 MFLOPS
  > PA7200: cc                   -Ae +O4  :  52.88 MFLOPS
  > 
  > PA8000: gcc-2.7.2.2              -O3  : 108.31 MFLOPS
  > PA8000: egcs-2.91.42             -O3  :  97.10 MFLOPS
  > PA8000: cc            +DA1.1 -Ae +O4  : 129.47 MFLOPS 
  > PA8000: cc            +DA2.0 -Ae +O4  : 216.62 MFLOPS
  > 
  > egcs faster on PA8000 and slower on PA7200 than gcc-2.7.2.
  > cc is faster du to a better support of special instructions.
Err, you got that backwards :-)  egcs is faster than gcc2 on
the PA7200, but slower on the PA8000 series.

Note that you can get about a 30% improvement in this code on a
PA8000 by disabling the fmpyadd/fmpysub instructions.  They're
reorder buffer killers.

In fact, if someone wanted to submit a patch which added flags for
PA2.0 scheduling and codegen I'd accept it -- even if it did nothing
at this point.   Just having the flags allows us to start experimenting
with the code gen issues.

  > Is there a planed support for PA2.0 on HP?
I'd like to do it, but I don't have the time.  I'd happily accept
contributions.

Note first you have to add PA2.0 support in bfd/binutils/gas if
you're going to use any of the new instructions.

jeff