Messages in this thread | | | Date | Mon, 09 Nov 2009 08:41:36 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string. |
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On 11/09/2009 01:26 AM, Andi Kleen wrote: > "H. Peter Anvin" <hpa@zytor.com> writes: >> >> My personal opinion is that if we can show no significant slowdown on >> P4, K8, P-M/Core 1, Core 2, and Nehalem then we can simply use this code > > The issue is Core 2. > > P4 uses a different path, and Core 1 doesn't use the 64bit code. >
Ling's numbers didn't seem to show a significant slowdown on Core 2 (it was something like 0.95x baseline in the worst case, and most of the cases were positive) so Core 2 doesn't seem to have a problem.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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