Thanks to all. I'll try -O2 or -O3 and see what is better Sergey Berezka
----- Original Message ----- From: "Brendan Sullivan" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, January 20, 2004 10:00 PM Subject: Re: [gentoo-user] CFLAGS > I can't help you find that info...but i do know (at least in laymans > terms) what the basic differences of -O2 and -O3 are. > > The -O2 option when compiling, puts references to header files in the > locations where they are called. > > The -O3 option, actually pulls the sections out of the header files, and > inserts them into the executable code. > > Thus, advantage of the -O2 option is that your file sizes stay smaller > giving you faster load times and conserving hd space. Disadvantage is in > actual application speed, where you trade off the ability to execute > code line by line, in order to save space (good for people like me w/ > only 256Mb of RDram) > > Advantage of the -O3 option is that the code can just execute > line-by-line, and not have to reference back to other files to get > needed code. Makes for faster application speed, but you end up with > larger files and need for more hd space and memory to efficiently run > the programs. > > Someone correct me if i'm wrong, but that's how it was explained to me. > > Brendan > > On Tue, 2004-01-20 at 13:40, Michael W. Holdeman wrote: > > I saw that somewhere too. > > > > Can't find it either! > > > > Mike > > > > > > On Tuesday 20 January 2004 01:13 pm, Alan wrote: > > > On Tue, Jan 20, 2004 at 05:33:09PM +0200, Sergey Berezka wrote: > > > > I have Athlon XP+ 1800 CPU. I type flags : -march=athlon-xp -03 -pipe > > > > -fomit-frame-pointer in the make.conf. Now, when i compile any program , > > > > all the time line : unrecognized option '-03' shows up. What is the > > > > problem ? > > > > > > As mentioned by others, it's letter O not number 0. > > > > > > As an aside though, I've heard that -O2 works better than -O3, produces > > > faster/better code. Search for it in the forums or google, I don't > > > remember where I saw it right now. One of the cases where > > > over-optimization doesn't help. I think it might have been a > > > comparision of adding cflags and testing the results of each. > > > > > > alan > -- > Brendan Sullivan > <[EMAIL PROTECTED]> > > -- > [EMAIL PROTECTED] mailing list > > -- [EMAIL PROTECTED] mailing list
