RFR: 8322770: Implement C2 VectorizedHashCode on AArch64 [v9]

[Andrew Haley]

On Wed, 18 Sep 2024 12:10:43 GMT, Mikhail Ablakatov <duke at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5563:
>> 
>>> 5561:     }
>>> 5562: 
>>> 5563:     start = __ offset();
>> 
>> What does this logic from 5552 onwards do? It at least deserves a comment.
>> Can we not simply delete it?
>
> It's here to make sure the loop takes the smallest number of aligned 32-byte instruction memory regions possible.

Does that make a significant measurable difference?
Why not simply 32-align the region? Then we can get rid of this `large_loop_size` calculation.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18487#discussion_r1764966177