Constant pools (and their caches) are costly:

 - they are not strongly typed
 - they are subject to subtle race conditions (especially in the tags and CP cache)
 - their access API is confusing and hard to maintain
 - indexes come in many flavors and are hard to keep straight
 - they are hard to inspect in a debugger, despite modern C++ support
 - they are intricately coupled to assembly code, and so hard to improve
 - they mix hot and cold (mutable and immutable) data, costing bandwidth and density
 - they will be difficult to extend in planned future directions, such as the Parametric VM

The solution is to remove the current two-array constant pool design in the Hotspot JVM, replacing it with a design based on bundles of strongly-typed linkage tables.

See this memo for details:
https://cr.openjdk.org/~jrose/jvm/linkage-table.html