gcc flags and USE dual p3

dcstimm · Guru Joined: 19 Jun 2002 Posts: 321

Hey all what would be the ideal set of flags for a dual p3 system? Also what USE variables should I have If I want to build my system optimized for a dual p3 system?

I know i should have sse and mmx in my use, but what else? (I will be reinstalling my system using 1.3b or the new gentoo release which includes gcc 3.1)

ALso I know that these flags are not optimized for dual p3s.

CHOST="i686-pc-linux-gnu"
CFLAGS="-mcpu=i686 -O3 -pipe"
CXXFLAGS="-mcpu=i686 -O3 -pipe"

Please reply and put the optimized flags in that format.

Pasoa2000 · n00b Joined: 06 Jul 2002 Posts: 29

This is what I have.....

# Build-time functionality

USE="3dfx voodoo3 sse mmx kde alsa xmms qt qtmt arts opengl"

# Pentium Pro/Pentium II/Pentium III+/Pentium 4/Athlon exclusive (binaries
# will use the P6 instruction set and only run on P6+ systems)
CHOST="i686-pc-linux-gnu"
CFLAGS="-march=i686 -O3 -pipe -fomit-frame-pointer"
CXXFLAGS="-march=i686 -O3 -pipe -fomit-frame-pointer"
MAKEOPTS="-j3"

Yeah I know you can get fancier with the CFLAGS, but I've only notice the frame pointer to make a difference.

MAKOPTS="-j3" will invoke three instances of gcc when compiling - typically the rulse is #procs+1 - although you can specify as many as you'd like.

delta407 · Posted: Tue Jul 23, 2002 4:39 am Post subject:

I also have a dual P3 running Gentoo, with the bare i686 optimizations and -fomit-frame-pointer under GCC 2.

Also, USE flags usually only determine what optional functionality a package has, not (usually) optimization. As far as "optimized for dual P3s" goes, optimize for a P3 and multithreaded apps will naturally use both CPUs; single threaded apps will only use one but there's not much you can do about that.
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StrCrssd · Posted: Tue Jul 23, 2002 6:52 am Post subject: CFLAGS and CXXFLAGS

I'm running 2 Pentium 3 CuMine's on GCC 3.1

flags are:

"-O3 -pipe -mcpu=pentium3 -fomit-frame-pointer -funroll-loops -fexpensive-optimizations -mmmx -msse -mfpmath=sse"

don't forget to set -j=3.

[edit -- that "o" should have been an "O"]
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klieber · Posted: Tue Jul 23, 2002 11:55 am Post subject:

This was double-posted why?

Locking thread in favor of this one.

--kurt
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