RFR: 8350607: Consolidate MethodHandles::zero into MethodHandles::constant [v2]

[John R Rose]

On Mon, 24 Feb 2025 23:45:37 GMT, Chen Liang <liach at openjdk.org> wrote:

>> LF editor spins classes, this avoids the spinning overhead and should speed up non-capturing lambdas too.
>> 
>> There may need to be additional intrinsic work for MH combinator lf bytecode generation.
>
> Chen Liang has updated the pull request incrementally with one additional commit since the last revision:
> 
>   We no longer load DelegateMH as we no longer rebind

I hope that the intrinsic mechanism can be further simplified, at some point.  But I defer to Jorn's comments about tableswitch.

Excellent cleanups.  Lots and lots of deleted code, and other code regularized.  Thank you!

src/java.base/share/classes/java/lang/invoke/SimpleMethodHandle.java line 36:

> 34:  * A method handle whose behavior is determined only by its LambdaForm.
> 35:  * Access to SimpleMethodHandle should ensure BoundMethodHandle is initialized
> 36:  * first.

Did you try factoring UNSAFE.ensureInit(BMH) into a static block in SimpleMethodHandle.java?
Sometimes that works.

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Marked as reviewed by jrose (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23706#pullrequestreview-2658926068
PR Review Comment: https://git.openjdk.org/jdk/pull/23706#discussion_r1980190604