RFR: 8338546: Speed up ConstantPoolBuilder::classEntry(ClassDesc) [v3]

[Chen Liang]

On Tue, 17 Sep 2024 02:04:51 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Speed up `ConstantPoolBuilder::classEntry(ClassDesc)` by going through `ClassDesc` comparison and reusing descriptor hash to calculate internal name hash if possible. No suitable device to run benchmarks so need to find something to run the new benchmark to ensure things work as intended.
>
> Chen Liang has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:
> 
>  - Fix build
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - Buggy 2nd attempt - crashes hotspot
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - More conflicts
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - Merge branch 'master' of https://github.com/openjdk/jdk into feature/classentry-speedup
>  - Another bug in benchmark
>  - ... and 5 more: https://git.openjdk.org/jdk/compare/996790c7...6117a5bd

I think I can add a benchmark to measure first-time insertion cost with already-hashed ClassDesc and internal name/array descriptors.

For your request of a table for smaller power exponents, I wish to delay it a bit, maybe in another patch - this patch is almost exclusively functional additions.

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PR Comment: https://git.openjdk.org/jdk/pull/20667#issuecomment-2361435817