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