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

[Chen Liang]

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.

Yeah, this is visible if a condy is used due to that updated site in StackMapGenerator - it required a symbolic expansion. Thanks for the reviews!

-------------

PR Comment: https://git.openjdk.org/jdk/pull/24938#issuecomment-2858740354