RFR: 8341013: Optimize x86/aarch64 MD5 intrinsics by reducing data dependency [v2]

[Oli Gillespie]

On Fri, 27 Sep 2024 10:42:04 GMT, Hamlin Li <mli at openjdk.org> wrote:

>> Oli Gillespie has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix aarch64 bug
>
> src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp line 3422:
> 
>> 3420:     reg_cache.extract_u32(rscratch1, k);
>> 3421:     __ movw(rscratch2, t);
>> 3422:     __ addw(rscratch4, r1, rscratch2);
> 
> Can you try to replace these 2 lines (3421-3422) with following?
> 
>     __ movw(rscratch4, t);
>     __ addw(rscratch4, r1, rscratch4);
> 
> 
> I expect it could bring more performance gain, but not sure.

Thanks! I can't measure any difference at all with that change, seems to perform identically.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21203#discussion_r1778488350