RFR (S): 8199567: [Nestmates] Cleanup instanceKlass.cpp

[Lois Foltan]

On 10/22/2018 11:43 PM, David Holmes wrote:

> Bug: https://bugs.openjdk.java.net/browse/JDK-8199567
> Webrev: http://cr.openjdk.java.net/~dholmes/8199567/webrev/
>
> This is a simple "cleanup" previously suggested by John Rose for 
> checking nest membership. Rather than checking for name equality and 
> then checking the loaded class, we check if there's a loaded class 
> first and if not fallback to the name check. This favours the case 
> where the nestmate classes are already resolved and loaded.

Hi David,

Looks good.  One comment:

oops/instanceKlass.cpp:
- line #173: Consider changing the if conditional to "if 
(_constants->tag_at(cp_index).is_klass())"

I believe the "is_klass()" method is the preferred way to compare a tag 
to JVM_CONSTANT_Class.

Thanks,
Lois

>
> There was no observable performance difference.
>
> Testing: mach5 tiers 1-3 including nestmate tests
>
> Thanks,
> David