gentoo optimization

borkes · n00b Joined: 15 Jul 2007 Posts: 5

Hi, gurus!

I am interested in how optimization of source code compiling under certain architecture works. What is going on the level of compiler?
Are there real benefits of doing this? What is the achieved gain in performance?
Can you pls provide me with some benchmarks/articles about subj..

And another question is abt -Ox flags in make.conf. Are they worth using if X is higher than 2? Any examples would be appreciated!

button · n00b Joined: 24 Dec 2007 Posts: 65 Location: Croatia

I don't know the answers to all questions, but I can tell you the following (somebody correct me if I'm wrong):

The performance gain from compiling is, AFAIK, only 3-5%. You get also get some benefit from USE flags which allow you to install only what you really need (again, this affects disk space rather than performance).

The highest level is -O3. Any higher number is interpreted as 3.
For details refer to
$ man gcc

gentoo-dev · Apprentice Joined: 24 Jan 2006 Posts: 172

http://www.gentoo.org/doc/en/gcc-optimization.xml

muhsinzubeir · l33t Joined: 29 Sep 2007 Posts: 948 Location: /home/muhsin

next time search first b4 you post....i mean in a good way :wink:

_________________
~x86
p5k-se
Intel Core 2 Duo
Nvidia GT200
http://www.zanbytes.com

nixnut · Posted: Fri May 30, 2008 5:37 pm Post subject:

Moved from Kernel & Hardware to Duplicate Threads.

See here, here, here, definitely here, here, and here.
_________________
Please add [solved] to the initial post's subject line if you feel your problem is resolved. Help answer the unanswered

talk is cheap. supply exceeds demand