Le 25/11/2012 23:38, Ken Moffat a écrit : > On Sun, Nov 25, 2012 at 11:04:01PM +0100, Pierre Labastie wrote: > >> At this place in the book, everything should be independant on what is >> on the host, shouldn't it ? librt and libpthread are both from glibc. I >> more suspect the optimization, as pointed out by Armin. Trying again >> without optimization and I'll let you know (build takes much longer). >> >> Regards, >> Pierre > Are you sure it takes longer ? Most packages default their CFLAGS, > CXXFLAGS to '-O2 -g' : using -O3 is *expected* to take longer. > > To be clear, don't set CFLAGS, CXXFLAGS if you want to avoid > problematic optimisations, just let the packages use their own > defaults. Building with "CFLAGS= " and the same for CXXFLAGS will > turn off all optimisations (if a package accepts that from its > environment), but for e.g. gcc I *would* expect the resulting > compilers to be *slow*. > > ĸen Hi,
First, I confirm that without any flag, everything went well. You are right that -O3 is expected to take longer. I wrote to rapidly. I suppressed all the optimization, even the -j flag in make. That's what makes it longer. Marginally, -pipe is supposed to increase speed too. I guess it was that flag that was wrong in the present case. I need more testing to confirm that. Sorry for the noise, but I had been building with these optimizations (-O3 -march=native -pipe) for years and they seemed innocuous. I had forgotten about them. Pierre -- http://linuxfromscratch.org/mailman/listinfo/lfs-dev FAQ: http://www.linuxfromscratch.org/faq/ Unsubscribe: See the above information page
