Re: [PATCH RFC] [X86] performance improvement for memcpy_64.S by fast string.

Pavel Machek
2009-11-12T23:03:51Z

On Mon 2009-11-09 15:24:03, Ma, Ling wrote:
> Hi All
>
> Today we run our benchmark on Core2 and Sandy Bridge:
>
> 1. Retrieve result on Core2
> Speedup on Core2
> Len Alignement Speedup
> 1024, 0/ 0: 0.95x
> 2048, 0/ 0: 1.03x

Well, so you are running cache hot and it is only a win on huge
copies... how common are those?

> Application run through perf
> For (i= 1024; i < 1024 * 16; i = i + 64)
> do_memcpy(0, 0, i);

Pavel

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