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Path: sserve!newshost.anu.edu.au!munnari.oz.au!ihnp4.ucsd.edu!sdd.hp.com!swrinde!cs.utexas.edu!howland.reston.ans.net!EU.net!ieunet!news.ieunet.ie!jkh From: jkh@whisker.hubbard.ie (Jordan K. Hubbard) Newsgroups: comp.os.386bsd.misc Subject: Re: Why uses /usr/src -O instead of -O2? Date: 16 Feb 1994 19:09:11 GMT Organization: Jordan Hubbard Lines: 18 Distribution: world Message-ID: <JKH.94Feb16190911@whisker.hubbard.ie> References: <1994Feb16.103448.6398@paramount.nikhefk.nikhef.nl> NNTP-Posting-Host: whisker.hubbard.ie In-reply-to: eloy@paramount.nikhefk.nikhef.nl's message of Wed, 16 Feb 1994 10:34:48 GMT In article <1994Feb16.103448.6398@paramount.nikhefk.nikhef.nl> eloy@paramount.nikhefk.nikhef.nl (Eloy Domingos) writes: When rebuilding the 'world' I noticed that the makefiles use -O instead of the better optimizing -O2. Is there a reason not to use the better optimization? I think in gcc 2.4.5 the -O2 optimizer is reliable. Just conservatism, mostly. If you want to go to higher levels of optimization, it's very easy indeed to just change /usr/share/mk/sys.mk. If you want to compile your kernels with more optimization as well (Linux uses -O6, so why not go for -O8 or -O9? :-), change /usr/src/sys/i386/conf/Makefile.i386 as well. [ Note: I'm just kidding - anything over -O3 is basically meaningless! ] Jordan -- Jordan K. Hubbard FreeBSD core team Electric Bivalves Anonymous On the net, no one can hear you scream.