RFR: 8342601: AArch64: Micro-optimize bit shift in copy_memory

[Andrew Haley]

On Mon, 21 Oct 2024 08:34:38 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Looking at this differently: if I wrote the `copy_memory` stub from scratch today, would I do this optimization? Answering personally, I probably would.

I wonder if that's too low a bar for whether we should change it now, though. If we adopt "would I have done it this way, first time around?" as an appropriate threshold for a change, it gives permission for endless churn with tiny issues. Churn _in itself_ is bad.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/21589#issuecomment-2426401929