Date: Thu, 27 Feb 2003 05:49:47 -0500 (EST) From: Geoffrey <geoffrey@reptiles.org> To: Bruce Cran <bruce@cran.org.uk> Cc: current@freebsd.org Subject: Re: -O2 considered harmful Message-ID: <20030227054508.V28626-100000@iguana.reptiles.org> In-Reply-To: <20030227083800.GA96372@fourtytwo.brucec.backnet>
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On Thu, 27 Feb 2003, Bruce Cran wrote: > On Wed, Feb 26, 2003 at 06:51:55PM -0800, Rhett Monteg Hollander wrote: > > I'm afraid you're wrong - the V2SI datatype and MMX functions automatically > become available after -march=pentium2, while with other processor types > you've got to explicitly add -mmmx. -msse is presumed with -march=pentium3 > and up. It's far from absurd to use mmx for everyday applications - sure, > only a few applications may take advantage of it, but I've seen code which > runs 40x faster when compiled for athlon-xp than for i386, and I would guess > that a lot of that is because of clever use of sse and mmx. That wasn't > an audio/video program, it was the libgmp arbitrary precision maths > package. Also, I'm sure > most people wouldn't say no to 50% more processing speed for free! > So, if you've got a pentium, k6 or pentiumpro which supports MMX, you _do_ > need to explicitly add -mmmx, but for other processors it's implied. > This is fine and good, but make.conf appears to be hiding in 5.0 (or at least in the various installs/cvsups I've encountered to date). What flags are accepted is a bit of a guessing game without a template in /etc/defaults (yes, I could wade through man pages but with the rate of change on release, those recommendations aren't a given either). Cheers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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