RFR: 8363996: Obsolete UseCompressedClassPointers [v3]

[Thomas Stuefe]

On Thu, 4 Dec 2025 04:59:51 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Thomas Stuefe has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Apply suggestion from @theRealAph
>>   
>>   Co-authored-by: Andrew Haley <aph-open at littlepinkcloud.com>
>
> src/hotspot/share/cds/archiveBuilder.cpp line 671:
> 
>> 669:       dump_region->allocate(sizeof(address));
>> 670:     }
>> 671: #ifdef _LP64
> 
> Not obvious this isn't still needed.

That is a small simplification that should have been part of https://bugs.openjdk.org/browse/JDK-8363998. The test


alignment = nth_bit(ArchiveBuilder::precomputed_narrow_klass_shift());


can be applied to 32-bit, too. There, precomputed_narrow_klass_shift() is zero.

> src/hotspot/share/cds/archiveBuilder.cpp line 1140:
> 
>> 1138: };
>> 1139: 
>> 1140: #ifdef _LP64
> 
> Again not clear why this can be removed.

Same reasoning. 32-bit now also uses narrow Klass pointers, so that code can be made unconditionally compilable.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28366#discussion_r2587823782
PR Review Comment: https://git.openjdk.org/jdk/pull/28366#discussion_r2587825926