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-original message- |
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Subject: Re: [gentoo-user] CFlags for CPU |
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From: Andy Wilkinson <drukargin@×××××.com> |
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Date: 2011-07-27 21:09 |
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>Another good trick I've found on the forums is to run: |
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>$ gcc -### -e -v -march=native /usr/include/stdlib.h |
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>The last line of output will include the various CFLAGS that |
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>-march=native picks. In my case (Phenom II 955): |
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> "/usr/libexec/gcc/x86_64-pc-linux-gnu/4.4.5/cc1" "-quiet" |
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>"/usr/include/stdlib.h" "-D_FORTIFY_SOURCE=2" *"-march=amdfam10" |
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>"-mcx16" "-msahf" "-mpopcnt"* "--param" "l1-cache-size=64" "--param" |
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>"l1-cache-line-size=64" "--param" "l2-cache-size=512" "-mtune=amdfam10" |
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>"-quiet" "-dumpbase" "stdlib.h" "-auxbase" "stdlib" "-o" |
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>"/tmp/ccR1PlNZ.s" "--output-pch=/usr/include/stdlib.h.gch" |
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> |
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>I typically use -march=native when I don't need to worry about distcc, |
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>or the options from that output that start with "-m". |
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Hey, that's a nice trick! Thanks for re-sharing :) |
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That said, I usually *can't* use -march=native because all my Gentoo systems are virtualized servers, running on top of XenServer, which itself runs on heterogenous server boxes (all Intel). |
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So, I purposefully limit myself to "-march=nocona". |
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(I did raise an explicit point about -march parameter in my Gentoo-Wiki article) |
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Rgds, |
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-- |
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FdS Pandu E Poluan |
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~ IT Optimizer ~ |
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Sent from Nokia E72-1 |