make.conf CFLAGS

Quitch · Apprentice Joined: 04 Jun 2003 Posts: 151

I have the CFLAGS -03 (or -O3) -pipe -march=i386 because it's already there.

Now, the comments explain the last part, but what does the rest mean?

Also, I notice that in the FAQ there appear to be a lot of different CFLAG settings. Where should I go to find what settings there are, and what they do?

Earthwings · Posted: Thu Aug 21, 2003 3:53 pm Post subject:

You'll find explanations using 'man g++'. There's also some information on the web, I don't remember any good source at the moment.

If you want to try some more optimization, you can have a look at
http://www.freehackers.org/gentoo/gccflags/flag_gcc3.html

There is also a list of experimental flags.
http://www.freehackers.org/gentoo/gccflags/flag_gcc3opt.html

pYrania · Posted: Thu Aug 21, 2003 3:59 pm Post subject:

it's supposed to be -O3 as in Optimisation.

for cflags that fit to your cpu, have a look at http://www.freehackers.org/gentoo/gccflags/

the gcc man page provides explanations for every single flag you can select.

EDIT: i should refresh before posting

_________________
Markus Nigbur

Quitch · Apprentice Joined: 04 Jun 2003 Posts: 151

Thanks for the advice guys. I'll check that site out.

Quitch · Apprentice Joined: 04 Jun 2003 Posts: 151

Looking at the Gentoo 1.4 section, it says for the Pentium 4 use march=pentium4... yet the install guide says there is no such entry, and you should use pentium3.

Which is right?

Earthwings · Posted: Fri Aug 22, 2003 9:20 am Post subject:

Quitch · Apprentice Joined: 04 Jun 2003 Posts: 151

Ah, I see, thanks for that.

pYrania · Posted: Fri Aug 22, 2003 11:27 am Post subject:

it was buggy in earlier versions of gcc. you can use it without fear nowadays.
_________________
Markus Nigbur

Quitch · Apprentice Joined: 04 Jun 2003 Posts: 151

Ah, I see... I have already done emerge system, if I changed make.conf now, what command would I need to use for the change to take effect?

pYrania · Posted: Fri Aug 22, 2003 3:44 pm Post subject:

if you do nothin, after you changed your cfalgs, your system will compile all new packages with the changed flags, so old packages will get the new cflags only just, if you update those.

however, it is possible to recompile your complete system, in order to compile it with the new settings, but the gain isn't worse the hassle.
anyway, if you want to do it, type: