Date: Thu, 23 Mar 2000 14:23:12 -0500 (EST) From: Andrew Gallatin <gallatin@cs.duke.edu> To: Charles Cox <cscox@stanford.edu> Cc: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca>, Andrew Gallatin <gallatin@cs.duke.edu>, obrien@FreeBSD.ORG, Howard Leadmon <howardl@account.abs.net>, freebsd-alpha@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG Subject: Re: Compiler problems with -O2 (was Re: CVS Trouble, even under 4.0-RELEASE (alpha) HELP!) Message-ID: <14554.28033.439748.801349@grasshopper.cs.duke.edu> In-Reply-To: <Pine.GSO.4.21.0003231108220.4480-100000@cardinal0.Stanford.EDU> References: <200003231425.GAA01222@cwsys.cwsent.com> <Pine.GSO.4.21.0003231108220.4480-100000@cardinal0.Stanford.EDU>
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Charles Cox writes: > I would like to add that some of us who do a lot of numerically intensive > programming, and that need to squeeze every last available cycle out of > our CPU's would really appreciate having -O2 available for userland > programs. To me, getting rid of the -O2+ switch would be like outlawing > cars because someone had a really bad car accident. Just like driving a > car, using gcc and the -O2 switch safely are the USER's > responsibility. Having said this though, I do fully support having > comments in make.conf, and documentation elsewhere that cautions against > compiling a kernel with -O2. > > CC You're missing the point almost entirely. FreeBSD's stock gcc -O2 is demonstrably __broken__ on the alpha. You cannot trust code it outputs. If you want to obtain results as quickly as possible & do not care if they are correct, it would be much faster to read them from /dev/zero. ;-) ------------------------------------------------------------------------------ Andrew Gallatin, Sr Systems Programmer http://www.cs.duke.edu/~gallatin Duke University Email: gallatin@cs.duke.edu Department of Computer Science Phone: (919) 660-6590 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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