On Monday 19 November 2001 18:00, Magnus von Koeller wrote: > On Saturday 20 October 2001 10:54, Allan Sandfeld Jensen wrote: > > If you have the time and skills it is always a good idea to compile > > K-packages yourself. It turned out recently that adding > > architecture specific optimization makes a big performance > > difference, becouse of the amount of byteoperations. So get the > > source and compile it with '-march=<myArch>' :-) (I can also > > recommend -ffast-math and -finline-functions for good standard > > optimizations that arent included in -O2) > > How do I do this? Is doing > > # export CXXFLAGS="-O3 -march=i686" > # export CPPFLAGS="-O3 -march=i686" > # export CFLAGS="-O3 -march=i686" > # dpkg-buildpackage > > enough? > > Is -O3 a good idea? Or should I rather use "-O2 --ffast-math > -finline-functions"?
Change the debian/rules file, it might/does set some flags on its own. If not using deb packages, you would simple write: CFLAGS='-march=i686 -O2' CXXFLAGS='-march=i686 -O2' ./configure The only importent flag is -march. The others are for "fun" or experiments, please try -O3 if you like, but I doubt it makes much of an impact. btw -ffast-math is not included i O3, becouse floating point operations might be changed in a way that changes the result, but which are still accurate. regards Allan
