On Thu, Aug 21, 2008 at 08:03:27PM +0200, Kris Kennaway wrote: > Rohit Tripathi wrote: >> I have a core2duo laptop on which out of curiosity I decided to >> recompile x11 and gnome2. After a few hours when it was ready, I found >> gnome crawling painfully slow. I'd click a menu and it'll take 2 >> seconds to appear, I try running terminal, and it take 10 seconds to >> come up, try typing and keyboard lags by 5-6 seconds.....what I find >> is really cool is that the ports installed by FreeBSD release are >> waaaay faster....here's my make.conf: (do you see a culprit?) >> ARCH=core2 #nocona >> MACHINE=core2 #nocona >> MACHINE_ARCH=core2 #nocona >> CFLAGS= -O3 -pipe -mtune=core2 -m128bit-long-double -mfpmath=sse >> -ftree-vectorize >> CXXFLAGS+= -fconserve-space >> COPTFLAGS = -O -pipe -mtune=core2 -m128bit-long-double > -mfpmath=sse > > Revert all this rampant craziness, you broke something. CPUTYPE sets -march=, which is also an implicit -mtune=. The purpose of -march= is largely to tell gcc what cpu features are available so that it doesn't do things like scheduling and sse3 on platforms that can't support it. Of course, this means nothing at all unless you also tell gcc to use those features with -msse3 and the like. There are places where such features are not desired and CPUTYPE is overridden when allowed (CPUTYPE?=), but otherwise just breaks stuff when forced (CUPTYPE=). Another clue, is that -Werror is normally set for a reason. Reverting this may reveal some breakage. I would personally suggest scrapping all of it, setting nothing more 'CPUTYPE?=native' to start ("core2" doesn't appear to be a valid value for gcc 4.2.1), adding optimizations a little at a time while reading the gcc manual at every step. This way you can easily find what broke it. Try stating with the gcc manual page here: http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/i386-and-x86_002d64-Options.html Finally, I will give the standard disclaimer that it's probably not wise to use any optimization at all, since even if it seems to work, there can be subtle breakage that isn't immediately traceable. (Google for firefox with ffast-math for an example)Received on Thu Aug 21 2008 - 18:09:50 UTC
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