RFR: 8331341: secondary_super_cache does not scale well: C1 and interpreter [v23]

[Andrew Haley]

On Wed, 9 Oct 2024 23:50:34 GMT, Dean Long <dlong at openjdk.org> wrote:

>> Andrew Haley has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 61 commits:
>> 
>>  - Merge from 4ff72dc57e65e99b129f0ba28196994edf402018
>>  - Fix s390
>>  - Use post-incrememnt RegSet operator.
>>  - Merge branch 'clean' into JDK-8331658-work
>>  - Fix merge
>>  - Merge branch 'clean' into JDK-8331658-work
>>  - Merge from JDK head.
>>  - Cleanup
>>  - Fix shared code
>>  - Fix shared code
>>  - ... and 51 more: https://git.openjdk.org/jdk/compare/4ff72dc5...a7612674
>
> src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp line 1863:
> 
>> 1861: 
>> 1862:   // Is there another entry to check? Consult the bitmap.
>> 1863:   eor(slot, slot, (u1)(Klass::SECONDARY_SUPERS_TABLE_SIZE - 1));
> 
> Can we remove this XOR if we don't destroy the original value at line 1820?

I don't think we have a spare register,

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PR Review Comment: https://git.openjdk.org/jdk/pull/19989#discussion_r1799131716