Date: Thu, 23 Mar 2000 11:15:27 -0800 (PST) From: Charles Cox <cscox@stanford.edu> To: Cy Schubert - ITSD Open Systems Group <Cy.Schubert@uumail.gov.bc.ca> Cc: 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: <Pine.GSO.4.21.0003231108220.4480-100000@cardinal0.Stanford.EDU> In-Reply-To: <200003231425.GAA01222@cwsys.cwsent.com>
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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 On Thu, 23 Mar 2000, Cy Schubert - ITSD Open Systems Group wrote: > In message <14553.19348.115781.273817@grasshopper.cs.duke.edu>, Andrew > Gallatin > writes: > > > > David O'Brien writes: > > > On Wed, Mar 22, 2000 at 03:03:09PM -0500, Howard Leadmon wrote: > > > > want to avoid, or at least note the problem with -O2 as I have been usin > > g > > > > that when making software on my Intel machines for a long time, so just > > > > assumed it was OK to do the same on the Alpha.. > > > > > > It isn't officially OK from the perspective of the FreeBSD Project. "-O2" > > > has been the cause of problems on the i386 arch too. Thus my constant > > > yelling about it that nobody pays attention to. > > > > > > I'm on the virge of turning off "-O2" on both Alpha and i386. > > > > You certainly have my vote. > > > > I take it the O2 bugs are not unique to us, but rather they are > > generic across all OSes that gcc version 2.95.2 runs on? Do the gcc > > people know these problems exist? > > How about a compromise? Just print a nasty message every time -O2 is > specified: > > BEWARE: -O2 may cause some applications to break or may cause your > system to fail to boot. Be sure you absolutely know what you are doing > before using -O2 optimisation. > > Then enclose it in stars (*) or bangs (!). > > > Regards, Phone: (250)387-8437 > Cy Schubert Fax: (250)387-5766 > Team Leader, Sun/DEC Team Internet: Cy.Schubert@osg.gov.bc.ca > Open Systems Group, ITSD, ISTA > Province of BC > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-stable" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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