On Thursday 03 July 2003 06:50, drewbian wrote: > On Thu, 2003-07-03 at 18:28, Eric Ball wrote: > > On Thu, 3 Jul 2003 12:42 pm, drewbian wrote to gentoo-user: > > > > After looking through the huge array of optimizations people > > > > have posted on the discussion forum's I'm rather confused as to > > > > what the hey to put in there. Particularly as most posters seem > > > > to use Pent 4's or Athlon XP's, > > > > > > > > Also would -march=athlon be the most suitable for a Duron 1.3? > > > > I understand that Morgan-core Durons (the >1GHz ones I believe) are > > just Athlon-XP's with less cache, so you can use -march=athlon-xp > > which will be (slightly) faster. > > > > My CFLAGS for an Athlon XP 1800+ are: > > > > CFLAGS="-march=athlon-xp -O3 -pipe -mcpu=athlon-xp -m3dnow -mmmx > > -msse -mfpmath=sse,387 -finline-functions -fmerge-all-constants > > -fthread-jumps -fomit-frame-pointer -fexpensive-optimizations > > -ffast-math -fforce-addr -falign-functions=64 -falign-jumps=4 > > -falign-loops=4 -frerun-cse-after-loop -frerun-loop-opt > > -fprefetch-loop-arrays -maccumulate-outgoing-args" > > > > Which contains some duplications but _seems_ to work perfectly. > > Note this will probably make people cry "Are you crazy and/or > > stupid!?" and developers will likely refuse to do troubleshooting > > on any problems you may have. > > > > -Eric > > Thanks for replying, > > Man, that's a lot of cflags ;) I"m going to try err toward the > conservative but this will give me lots to muck around with. > > The -march=athlon-xp bit is particularly interesting. I only had > -mach=athlon in make.conf before.
And because you have duron stay away from unroll optimizations this simply overloads the caching and thus code runs slower. So a basic "-march=athlon-xp -O2 -pipe" Should be on the fastest optimizations in general on your setup. I use -O2 in my P4 because of the same reason (well small L2 cache not cache in general) -- [EMAIL PROTECTED] mailing list
