Am Montag, 12. Dezember 2011, 13:28:39 schrieb Joseph: > On 12/12/11 20:32, Michael Hampicke wrote: > >> Configuring source in > >> /var/tmp/portage/media-video/ffmpeg-0.7.8/work/ffmpeg-0.7.8 ... > >> x86_64-pc-linux-gnu-gcc is unable to create an executable file. > >> If x86_64-pc-linux-gnu-gcc is a cross-compiler, use the > >> --enable-cross-compile option. > >> Only do this if you know what cross compiling means. > >> C compiler test failed. > > > >Do you have enabled the "cpudetection" and/or "custom-cflags" use flags? > >Or do you use some crazy CFLAGS? > >ffmpeg 0.7.8 compiles just fine on my amd64 box. > > No nothing crazy: > CFLAGS="-Os -pipe -mtune=i686"
i686? That's not amd64. You need something 64bit. Just use march=native instead of mtune=i686. > I'm not even sure if these flags are correct for my CPU: > AMD FX(tm)-8150 Eight-Core Processor :) They are not. > The flags suggestion I found on gentoo wiki are crazy: > http://en.gentoo-wiki.com/wiki/Safe_Cflags/AMD#AMD_FX-8xxx.2F6xxx.2F4xxx_.28 > Bulldozer.29 > > CFLAGS="-O2 -pipe -fomit-frame-pointer -march=bdver1 -mtune=bdver1 -mcx16 > -msahf -maes -mpclmul -mpopcnt -mabm -mlwp -mavx" > Whoever suggested these flags must have been on some drugs :-/ Could well be, that this is what march=native gives for bdver1. Best, Michael
