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Re: Performance measurements
- To: Aubert Pierre <paubert at laninsa dot insa-lyon dot fr>
- Subject: Re: Performance measurements
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Sat, 27 Jun 1998 00:15:37 -0600
- cc: Martin Kahlert <martin dot kahlert at mchp dot siemens dot de>, egcs at cygnus dot com
- Reply-To: law at cygnus dot 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