RFR: 8374349: [VectorAPI]: AArch64: Prefer merging mode SVE CPY instruction

[Andrew Haley]

On Wed, 28 Jan 2026 04:05:15 GMT, Eric Fang <erfang at openjdk.org> wrote:

> Therefore, when you test this change using the C case, you will see a significant performance improvement.
> 
> > I see 2% uplift on these numbers.
> 
> @theRealAph And I think this also explains your question on these numbers.

Not at all.

The performance claim above was:

> Microbenchmarks show this change brings performance uplift ranging from 11% to 33%, depending on the specific operation and data types.

But the real performance uplift, as measured in Java microbenchmarks, is 2%.

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PR Comment: https://git.openjdk.org/jdk/pull/29359#issuecomment-3810374167