Messages in this thread | | | Date | Sun, 8 Nov 2009 18:35:37 +0100 | From | Pavel Machek <> | Subject | Re: i686 quirk for AMD Geode |
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Hi!
> The AMD Geode LX has an x86 id of 5 (i586) tought it's technically an i686:
It is not.
> root@alix:~# egrep '^(cpu family|model name|flags)' /proc/cpuinfo > cpu family : 5 > model name : Geode(TM) Integrated Processor by AMD PCS > flags : fpu de pse tsc msr cx8 sep pge cmov clflush mmx > mmxext 3dnowext 3dnow > > indeed it has MMX, MMXEXT and CMOV, just lacks the long NOP instruction (NOPL). > This patch adds a quirck to promote the Geode to an i686 and emulates > the NOPL in the do_invalid_op trap, so the userspace never notices. > Emulating the NOPL has minimum performance loss, emulating a NOPL > takes 0.5 usecs > and they are rarely used in x86
NOP should be fast, so this is bad idea. Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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