On Thu, 19 Sep 2024 14:08:04 GMT, Claes Redestad <redes...@openjdk.org> wrote:
> This PR changes proxy code gen to avoid generating
> `Class.forName("java.lang.Object")`, instead emitting an ldc for the class
> literal, `ldc(CD_Object)`, java code equivalent `Object.class`.
>
> More types could profitably use `ldc(ClassDesc/-Entry)`, taking cues from
> `InvokerBytecodeGenerator.isStaticallyInvocable`, but just addressing the
> `Object` methods gets rid of most `Class.forName` emits. It's not terribly
> important for throughput performance since these are called in the generated
> `clinit`, so getting a quick win with few additional checks is a good
> starting point.
>
> Added a few unrelated minor refactors/improvements, guided by diagnostic runs
> of the now fixed microbenchmark.
src/java.base/share/classes/java/lang/reflect/ProxyGenerator.java line 833:
> 831: cob.ldc(objectCE);
> 832: } else {
> 833: cob.ldc(cl.getName())
This `Class.forName` is only necessary in a very small number of cases, namely
when the overridden interface method has an unaccessible parameter type,
usually a package-private type not accessible to the implementing class. Maybe
we can always directly ldc if the class is `public`.
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PR Review Comment: https://git.openjdk.org/jdk/pull/21090#discussion_r1766920897
