On Tue, May 24, 2005 at 12:57:08PM +0000, James wrote > Well, I'm sure we all have different preferences, but, I've been > running "-O3" on 6 systems (PIII, (2)P4, P4 w/ HT, and (2)Athlons) > with no problems for 8 months. > > My Athlons use: > CFLAGS="-O3 -march=athlon-xp -fomit-frame-pointer -pipe" > stability has been rock solid...
Back in my Redhat days (don't laugh, I used Windoze before that) I got my feet wet in compiling/optimization thanks to Mozilla 0.9x. Let's just say that the standard i386 Mozilla binary was pa-a-a-a-a-ainfully slow on my 450 mhz Dell with 128 megs of RAM. That was where I started pulling cvs, tweaking CFLAGS, etc. I got Mozilla to the point where it was actually usable in its custom-built form. Most of the tweaks helped, but -O3 was *BAD NEWS*. If the compile didn't blow up, Mozilla would crash mysteriously all the time. A build with -O2 was much more stable. Since then, I've stayed with -O2. What I've read since then indicates that there is no point in -O3. One thing I've found out "the hard way" is that on a 400 mhz PII, even MAKEPTS="-j2" can be too aggressive. I was getting nowhere with an install, things mysteriously blowing up, until someone suggested trying MAKEPTS="-j1". It worked like a charm. One thing I haven't seen mentioned in this discussion is cpu-specific flags. Try doing a "cat /proc/cpuinfo" and see which of the flags are allowed in gcc. mmx, mmx2, sse, sse2, sse3 and various other stuff will speed things up. If you have any version of sse, remember "-mfpmath=sse". In addition to being valid CFLAGS, some of these items are valid USE flags as well. -- Walter Dnes <[EMAIL PROTECTED]> An infinite number of monkeys pounding away on keyboards will eventually produce a report showing that Windows is more secure, and has a lower TCO, than linux. -- gentoo-user@gentoo.org mailing list
