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On Mon, Dec 19, 2011 at 12:15 AM, Dale <rdalek1967@×××××.com> wrote: |
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> Pandu Poluan wrote: |
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>> |
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>> |
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>> Kind of like what I always do when I switch from -march=nocona to |
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>> -march=native. (Usually I use -march=nocona to ensure seamless VM migration |
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>> on my XenServer-equipped boxen, but for some VMs, i.e., those requiring me |
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>> to wring out every last drop of performance, I go native.) |
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>> |
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>> That said, if you want to experience fully the "GCC Graphite" |
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>> optimizations, you'll also want to do emerge -ev ;-) |
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>> |
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>> Rgds, |
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>> |
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> |
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> |
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> Is Graphite worthwhile on a desktop system or is it better suited for |
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> servers or both? I found this but still not sure what it is intended for: |
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> |
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> http://gcc.gnu.org/wiki/Graphite/4.5 |
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> |
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> Are there any reasons to leave this be for a while? You know, bugs or |
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> packages that don't work with it? |
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|
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I used it for @world and ran into a couple times when things were |
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broken with it enabled... Don't really remember specifics. I didn't |
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notice any perceivable speed difference, so I stopped using it just to |
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simplify things in the future. :) |
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|
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In general,I have changed my CFLAGS to be less aggressive over the |
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past years. I started with the most aggressive optimizations, and |
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using -march=whatever... At some point I researched compile times for |
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different optimizations and realized some packages were taking tens of |
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minutes longer to compile! Surely whatever potential speed increase of |
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-O3 vs -O2 was not going to give me tens of minutes cumulatively. If |
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there is a package that really benefits from some specific |
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optimization (and doesn't already set those flags itself in the |
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ebuild), I'll set the CFLAGS for that individual package but leave the |
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rest of world very simplistic. |
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|
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Same with -march, I've gone to using -mtune instead, after having to |
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move hard drives into a system with different CPU feature set. And for |
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virtual machines (in hosts I don't control, especially), they could be |
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migrated to some other machine without my knowledge, and i don't want |
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it to stop working if that happens. |
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