Date: Wed, 17 Dec 1997 08:42:33 -0700 From: "Russell L. Carter" <rcarter@consys.com> To: dyson@FreeBSD.ORG Cc: garbanzo@hooked.net (Alex), current@FreeBSD.ORG Subject: Re: Pentium optimizations Message-ID: <199712171542.IAA09962@dnstoo.consys.com> In-Reply-To: Your message of "Wed, 17 Dec 1997 01:23:22 EST." <199712170623.BAA00476@dyson.iquest.net>
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}Alex said:
}>
}> The response(s) I got to my "I'm a newbie, anyone know about this problem"
}> was basically met with "well no FreeBSD developers have contacted us, and
}> if they did we'd accept/commit/whatever some changes..".
}>
}I expected that they would be cooperative (the EGCS group appears to be
}culturally similar to us (modulo-GPL).) John Polstra is really our
}most active ELF/Compiler person, and so he would likely be a better
}"official FreeBSD" interface. He is also less politically likely to
}insert his foot into his eating orifice. I do have some PPro mods,
}and they appear to help performance on average. The PPro is a
}really wierd creature (like the K6.) The darned processor does so
}much optimization, it appears to be insensitive to code mods. There are
^^^^^^^^^^^^^^^^^^^^^^^^
Noticed that too, eh? Recently I hacked up some of the SSLeay asm
code and while I could improve P5 performance about 30%, the best
that I could do, with a lot of effort was maybe 4% for PII and PPro.
The out-of-order execution seems to help a lot. Oh, and the P5
specific asm actually makes the PPro slow down over the C source;
not good tidings for ye merry old tuners.
}areas of reasonable payoffs, and lots of "obvious" optimizations that
}end up being neutral.
Yep. I wouldn't worry too much about other people's claims about code
optimized for Pentium Pro.
Russell
}
}--
}John | Never try to teach a pig to sing,
}dyson@freebsd.org | it just makes you look stupid,
}jdyson@nc.com | and it irritates the pig.
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