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pni means prescott new instructions and is the same as sse3, yeah |
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On 10/24/06, Conway S. Smith <beolach@×××××××.net> wrote: |
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> |
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> On Tue, 24 Oct 2006 15:49:31 +0200 |
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> Simon Stelling <blubb@g.o> wrote: |
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> > Hi all, |
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> > |
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> > Back in May 2005 we made the decision to not use the assembler USE |
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> > flags because AMD64 was not affected by the "lots of sub-arches" |
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> > problem and instead just enable SIMD code where possible. As a result |
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> > of this, the 3dnow, 3dnowext, mmx, mmxext, sse and sse2 USE flags got |
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> > masked. This decision turned out to be not the best. Intel's EM64T |
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> > processors don't support 3dnow and 3dnowext, there are AMD64s with |
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> > and without SSE3 support. The "one size fits all" idea simply is no |
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> > longer true. Starting with portage 2.1.2_pre3-r4, there is support to |
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> > force USE flags on or off on a per-package basis. This means less |
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> > ebuild hackery for us, and so I went and checked the ~50 packages |
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> > with mentioned USE flags. |
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> > |
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> > The result is that the assembler USE flags convey their actual |
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> > meaning again IF AND ONLY IF you use >=portage-2.1.2_pre3-r4. I |
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> > suggest you to stick at least "mmx mmxext sse sse2" into your USE |
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> > flags, as this is the common denominator of all AMD64s. If your |
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> > processor supports it, 3dnow and 3dnowext might be worth adding too. |
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> > |
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> > *For users of portage versions prior to 2.1.2_pre3-r4 nothing |
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> > changes*, but I'd still recommend to add the USE flags. They will |
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> > become effective as soon as you upgrade portage. |
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> > |
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> > In a nutshell: |
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> > |
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> > 1. add "mmx mmxext sse sse2" to your USE flags |
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> > 2. emerge -u portage |
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> > 3. emerge -NuD world |
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> > |
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> > If you experience any build failures, please file a bug report on |
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> > http://bugs.gentoo.org/ |
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> > |
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> > Thank you for your attention, the team wishes you a convenient flight. |
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> > |
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> |
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> We should be able to cat /proc/cpuinfo to find out which ones our CPUs |
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> support, right? Except IIRC SSE3 is called something else in |
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> /proc/cpuinfo... pni, is it? Any other caveats we should be aware of? |
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> |
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> |
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> Conway S. Smith |
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> |
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> |
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> |
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