[lworld] RFR: 8363846: [lworld] Make Class.isIdentityClass() non-native

[Coleen Phillimore]

On Tue, 22 Jul 2025 23:39:09 GMT, Chen Liang <liach at openjdk.org> wrote:

>> src/java.base/share/classes/java/lang/Class.java line 634:
>> 
>>> 632:         } else {
>>> 633:             return !isInterface();
>>> 634:         }
>> 
>> Isn't this going to take a performance hit?
>
> Where is the hit at?
> 
> Moving this method to Java should be friendly to both interpreter (no more jni context switch) and C2 (no more opacity). We can further simplify these to be  modifier checks later on.

Yes this is better performance because C2 now doesn't have to intrinsify this native call.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1514#discussion_r2225287655