Aaron J. Seigo said: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Monday 16 June 2003 03:41, Jesse Kline wrote: >> packages of the apps I compile. I know that when building a src.rpm you >> can target a specific architecture, but I'm not sure how to do that when >> you compile a tarball. > > you usually use the gcc arch flags... i usually use -march=pentiumpro > since i > have Pentium based systems (pro, II, III... doesn't matter)... gcc's > man/info > pages list all the different arch options; you can also use the -mcpu and > related flags, but i find -march nice and convenient...
-mcpu= will optimize for a particular type of CPU without breaking compatibility with other types of CPUs. -march= will take full advantage of your CPU but will also break compatibility with older CPUs So: -mcpu=pentium2 will produce binary files that will run better on a Pentium 2 then -mcpu=i386 will but it *will* also run on anything like a 386 or Pentium 4 -march=pentium2 will produce binary files that will run better on a Pentium 2 then -march=i386 will but it *will not* run on a 386 or Pentium Pro or anything else older then a Pentium 2. So if you have compiled something using -march=pentium3 and your friend has a Pentium 2, he would not be able to run that binary if you copied it onto his computer. Don't use -march=pentium4 or -march=althon-4, they both generate invalid instructions and cause problems. Even things you might pass off as bugs in the software might actually be a result of using those flags. (Unless they fixed that bug in GCC 3.3, can anyone confirm that?) You can also mix and match the flags, for example I use -march=pentium3 -mcpu=pentium4 -O3 -pipe. That way it will run on Pentium 3 and higher but still be somewhat optimized for a Pentium 4 without generating invalid instructions. Cheers, -- Trevor Lauder Web: http://www.thelauders.net E-Mail: [EMAIL PROTECTED] Resume: http://www.thelauders.net/resume/ Gentoo Linux Powered "Any intelligent fool can make things bigger and more complex... It takes a touch of genius -- and a lot of courage to move in the opposite direction." -- Albert Einstein
