RFR: 8355775: Improve symbolic sharing in dynamic constant pool entries

[Adam Sotona]

On Mon, 28 Apr 2025 20:50:58 GMT, Chen Liang <liach at openjdk.org> wrote:

> Some dynamic constant pool entries with heavy symbolic descriptors currently don't share them, yet they are used by stack map generation, and computing a new descriptor every time introduces a heavy cost.
> 
> This cost is obvious if bytecode generation uses constant dynamic - the stack map generator parses the whole dynamic constant symbol to interpret the return type of an ldc condy, such as in FFM downcalls.
> 
> Both the lack of expensive symbol caching in dynamic cp entries and the incorrect query in StackMapGenerator should be fixed.

Looks reasonable to me.
Is it visible in some benchmark numbers?

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Marked as reviewed by asotona (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24938#pullrequestreview-2820956106