Date: Wed, 9 May 2001 01:35:15 +0200 From: Erik Trulsson <ertr1013@student.uu.se> To: freebsd-stable@FreeBSD.ORG Subject: Re: CFLAGS Optimization Message-ID: <20010509013515.A2725@student.uu.se> In-Reply-To: <KPECIILENDDLPCNIMLOFAEONCDAA.juha@saarinen.org>; from juha@saarinen.org on Wed, May 09, 2001 at 11:23:07AM %2B1200 References: <200105082305.QAA04771@freeway.dcfinc.com> <KPECIILENDDLPCNIMLOFAEONCDAA.juha@saarinen.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, May 09, 2001 at 11:23:07AM +1200, Juha Saarinen wrote: > :: Perhaps you'd be more comfortable if we changed the documentation to > :: remove all references to any -O switch with a number attached? > > Dunno. In my experience, any -O switch with a number attached creates > problems when compiling the kernel/userland on FreeBSD, so it seems > pointless to have those options. OTOH Jordan pointed out that there are some > instances for which the optflags can be useful. I have had both userland and kernel compiled using -O2 without noticing any problems. On the other hand I didn't notice much of a performance gain either so I decided that the extra compile time wasn't worth it. I would say that most programs work just fine when compiled with -O2/-O3 but not all and not all of the time. Although I am sure there are bugs gcc's optimization code I think that most of the time when programs work when compiled with -O but break when compiler with -O2 this is actually due to bugs in the program that only exposed when using high levels of optimization. > > I don't know why the optflags produce broken code on FreeBSD, but not with > Linux. Are you sure it doesn't produce bad code on Linux? Anyway, it might be that the bugs only trigger on certain code-sequences which occur in FreeBSD but not in Linux. (Or maybe not.) > > Aren't we sick of this thread yet? > Yes, we are. -- <Insert your favourite quote here.> Erik Trulsson ertr1013@student.uu.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010509013515.A2725>