Messages in this thread | | | From | Matteo Croce <> | Date | Sun, 8 Nov 2009 19:42:48 +0100 | Subject | Re: i686 quirk for AMD Geode |
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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. > >
There is a small advantage, but considering that GCC isn't much geode aware yet there is stil room for improvement IMHO:
root@alix:/usr/src/dist# ll totale 257M -rwxr-xr-x 1 1000 src 93K 8 nov 2009 bzip2-i586 -rwxr-xr-x 1 1000 src 93K 8 nov 2009 bzip2-i686 -rwxr-xr-x 1 1000 src 60K 8 nov 2009 gzip-i586 -rwxr-xr-x 1 1000 src 60K 8 nov 2009 gzip-i686 -rw-r--r-- 1 1000 src 256M 8 nov 2009 linux-2.6.31.5.tar -rwxr-xr-x 1 1000 src 90K 8 nov 2009 lzma-i586 -rwxr-xr-x 1 1000 src 94K 8 nov 2009 lzma-i686 root@alix:/usr/src/dist# time cat linux-2.6.31.5.tar >/dev/null
real 0m10.168s user 0m0.030s sys 0m1.390s root@alix:/usr/src/dist# time ./gzip-i586 -9 < linux-2.6.31.5.tar >/dev/null
real 5m22.331s user 5m10.820s sys 0m11.170s root@alix:/usr/src/dist# time ./gzip-i686 -9 < linux-2.6.31.5.tar >/dev/null
real 5m3.737s user 4m51.880s sys 0m11.510s root@alix:/usr/src/dist# time ./bzip2-i586 -9 < linux-2.6.31.5.tar >/dev/null
real 9m16.539s user 9m4.410s sys 0m11.760s root@alix:/usr/src/dist# time ./bzip2-i686 -9 < linux-2.6.31.5.tar >/dev/null
real 8m48.682s user 8m34.950s sys 0m13.260s -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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