How to switch to GCC 3.1? Which optimisations?

hanno · n00b Joined: 28 Apr 2002 Posts: 15

I noticed that GCC 3.1 is now in Gentoo. How can I switch to it? Any known problems?
Which further optimisations (beside -march= and -O3) can I turn on safely (without making my system unstable - I don't care about debugging info or things like that).

Guest · Posted: Sat May 18, 2002 9:27 am Post subject:

If your code uses much floating point arithmetic, -mfpmath=sse could bring some considerable performance increase. But of course your CPU must support the SSE instruction set (Athlon XP and Pentium IV does, I don't know about others). I also use -mmmx -msse -m3dnow but those seem to be 0.0001% range.

katakombi · n00b Joined: 03 May 2002 Posts: 27

my attempts to emerge it failed.
i took a look into package.mask and commented it out.
Still, it won't emerge, saying:

emerge -p gcc-3.1.ebuild

These are the packages that I would merge, in order.

Calculating dependencies \

!!! ebuild sys-devel/gcc-3.1 not found (possibly blocked by package.mask)

what do we have to do else?

Pablo · n00b Joined: 03 May 2002 Posts: 15

If you really want to try it, you could do an

katakombi · n00b Joined: 03 May 2002 Posts: 27

thanks,

this one did it for me!
Now i am able to compile with gcc 3.1.
C++ code is processed considerabely faster (without optimization) and that's worth using it for my own projects.

i wouldn't try to reemerge my entire system.... >8^)

keep it up,
katakombi