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From: khb@fatcity.Sun.COM (Keith Bierman Sun Tactical Engineering)
Newsgroups: comp.arch
Subject: Re: SUN procedure inlining(was i860 Dhrystones)
Message-ID: <97750@sun.Eng.Sun.COM>
Date: 6 Apr 89 09:26:41 GMT
References: <39388@oliveb.olivetti.com> <15475@winchester.mips.COM> <95013@sun.Eng.Sun.COM> <13641@jumbo.dec.com> <95215@sun.Eng.Sun.COM> <4614@pt.cs.cmu.edu> <1356@auspex.auspex.com> <4641@pt.cs.cmu.edu>
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In article <4641@pt.cs.cmu.edu> schmitz@fas.ri.cmu.edu (Donald Schmitz) writes:


>an error, as far as I know there is only one -O switch for the SUN3 family.

No. -O1, -O2, -O3, and -O4 all exist. -O means -O3. -O4 works, but is
not supported for f77 (meaning try it on your most expensive
procedures, but don't be surprised if something breaks). cc and f77 do
slightly different things with the optimizer... so it is NOT the case
that cc -O4 is really more optimized that f77 at -O3.

>However, even the crude inlining capability available on the SUN can be used
>to speed up Dhrystone.  Those magic .il files are just assembler with some

The question wasn't COULD it be done; the orginal posting said that
the optimizer was not turned all the way on because -O4 would have
resulted in strcpy being inlined. This is, with current compilers,
simply not true. No way. No how. If you want strcpy inlined, you'd
have to code your own .il (nothing up the sleeve, etc.).

>loose with the Dhrystone rules, this seemed like a very possible way it
>could have been done.

Greenhills does this silently. This is not currently done by any sun
compiler. Considering how totally stupid the Dhrystone benchmark is,
but how important it is in the minds of so many customers, it could be
that MIPS and SUN are missing the boat here. It would appear that
several vendors have been publishing "aggresive" Dhry. figures, and
our insistance on "playing by the rules" allows certain vendors to
claim their chips are unnaturally hot...

cheers all,

Keith H. Bierman
It's Not My Fault ---- I Voted for Bill & Opus