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Re: [PATCH] Improve string benchtest timing
On 22/05/19 6:08 PM, Anton Youdkevitch wrote:
> They were. The difference was up to 50% in some cases. But this is the
> data for bench-memcpy. Reports for bench-memcpy-walk and
> bench-memcpy-random do not have alignment info in them.
>
> So, unaligned accesses can be much slower that aligned ones. Or, at least,
> this is how the benchmarks measure them. We already know that the results
> are not very stable, though.
bench-memcpy-walk mixes in the misaligned sizes, but it shouldn't have a
big impact because 1) the source and destination are not mutually
misaligned and 2) the alignment code is usually a tiny portion of the
execution time and hence shouldn't show up in memcpy-walk.
Siddhesh