RFR: 8160821: VarHandle accesses are penalized when argument conversion is required [v13]

[John R Rose]

On Fri, 23 Jan 2026 20:08:58 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Since access descriptor is created for each VH operation site, we can optimistically cache the adapted method handle in a site if the site operates on a constant VH.  Used a C2 IR test to verify such a setup through an inexact VarHandle invocation can be constant folded through (previously, it was blocked by `asType`)
>
> Chen Liang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Wording update, thanks Jorn

src/java.base/share/classes/java/lang/invoke/VarHandle.java line 2014:

> 2012:     // Exists for the adaption mechanism of AccessDescriptor
> 2013:     // Each VH should report its explicitly (receiver, coordinates) and
> 2014:     // implicitly (static declaring class) used class to MethodHandle.isReachableFrom

Perhaps add a comment:  "Classes which define this abstract method should themselves be final or locally sealed, to make it possible to ensure that all relevant classes are taken into account."

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PR Review Comment: https://git.openjdk.org/jdk/pull/28585#discussion_r2723365226