RFR: 8256820: AArch64: Optimize vector rotate (immediate) with shift and insert instructions

[Andrew Haley]

On 14/12/2020 10:04, Andrew Haley wrote:
> I am seriously wondering if this change is worth doing. To find out,
> we'd have to test on all of the different AArch64 systems in use.

Just to explain a little more. We've never had many really processor-
microarchitecture-specific optimizations in AArch64 HotSpot. I'm not
very happy that we should do so, because the resulting complexity
would make the port hard to manage.

I wonder if this optimization would ever make a significant difference
to any workload other than one specifically written to test it. If you
know of any, please tell us.

-- 
Andrew Haley  (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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