Messages in this thread |  | | | Date | Sun, 8 Nov 2009 18:37:08 +0100 | | From | Pavel Machek <> | | Subject | Re: i686 quirk for AMD Geode |
On Fri 2009-11-06 23:18:06, Matteo Croce wrote: > On Fri, Nov 6, 2009 at 5:44 PM, H. Peter Anvin <hpa@zytor.com> wrote: > > On 11/06/2009 06:59 AM, Matteo Croce wrote: > >> indeed it has MMX, MMXEXT and CMOV, just lacks the long NOP instruction (NOPL). > > > > MMX and MMXEXT are hardly hallmarks of i686, which leaves only cmov. > > I'm somewhat wondering about the general value of this patch; is i686 > > code really that much faster on Geode that it's worth it? > > > > ? ? ? ?-hpa > > > > -- > > H. Peter Anvin, Intel Open Source Technology Center > > I work for Intel. ?I don't speak on their behalf. > > > > > > yes, I did some test like gzip, bzip2, lame etc and they give more or less > the same results of dhrystone > > root@alix:/usr/src# CFLAGS='-march=i586' ./dry.c > Microseconds for one run through Dhrystone: 1.4 > Dhrystones per Second: 740741 ... > root@alix:/usr/src# CFLAGS='-march=i686' ./dry.c > Trying 5000000 runs through Dhrystone: > Microseconds for one run through Dhrystone: 1.2 > Dhrystones per Second: 841751
Teach gcc that geodelx exists? No need to break kernel for that... and you probably can gain even bigger gains. Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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