cflags

exodist · 01-14-2005, 06:22 PM

I have been using gentoo for a while, so I compile everything with my own cflags. There is onl one thing I wonder about.

the -O flag, it takes s 0 1 2 or 3

I know s means optimise for Size of binaries. and I know a higher number is more optimisation. So why do most places recommend -O2 instead of O3? isn't more optimisation good? what advantages would there be in using O2 over O3?

jtshaw · 01-14-2005, 06:27 PM

The only advantage of using -02 instead of -03 is some things won't compile with -O3 because the optimizations are too aggressive.

I've noticed that most applications that have problems with -O3 in Gentoo have ebuilds that automatically lower your optimization level. So I just leave my make.conf CFLAGS set to -O3 and it has been quite some time since I've a problem because of that.

exodist · 01-14-2005, 07:44 PM

thanx, that makes clear and perfect sence :-D