RFR: 8322770: Implement C2 VectorizedHashCode on AArch64 [v14]

[Andrew Dinn]

On Wed, 25 Sep 2024 10:31:11 GMT, Mikhail Ablakatov <duke at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 5439:
>> 
>>> 5437:     case Assembler::T8B:
>>> 5438:     case Assembler::T4H:
>>> 5439:     case Assembler::T8H:
>> 
>> With the current code we should never see T4H as a value for load_arrangement. Is there a reason why you are folding it into the same case handling block as T8B and T8H rather than into the default block? If not then best to remove that case here and below.
>
> The reason was to make the implementation handle all possible values of `load_arrangement` should it change. And it did while I was tuning the performance of the algorithm. The code is valid and I'd argue there's no mistake if we leave this line here. But I'm comfortable with removing it in order to make the current implementation less error-prone.

Please remove it then as it can only serve to confuse maintainers. The code should visibly display consistent assumptions wherever possible.

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

PR Review Comment: https://git.openjdk.org/jdk/pull/18487#discussion_r1775012965