P4
We have at least three ways to check the type of a given Klass*:
1) Using the Klass::_id field
2) Using the layout helper
3) Using the InstanceKlass::_kind field
The Klass::_id field was something that was added when we rewrote the oop_oop_iterate dispatch mechanism, but the other mechanisms where left in place.
The current Loom code uses both (2) and (3) every time a the code checks if an object is of type InstanceStackChunkKlass. In the Loom repository I intend to reduce that check to be a single test against the (1) field. To keep the code unified, and simpler, I changed all C++ Klass type checks to use (1).
I propose that we upstream this change to the mainline, to slightly reduce the Loom diff.
1) Using the Klass::_id field
2) Using the layout helper
3) Using the InstanceKlass::_kind field
The Klass::_id field was something that was added when we rewrote the oop_oop_iterate dispatch mechanism, but the other mechanisms where left in place.
The current Loom code uses both (2) and (3) every time a the code checks if an object is of type InstanceStackChunkKlass. In the Loom repository I intend to reduce that check to be a single test against the (1) field. To keep the code unified, and simpler, I changed all C++ Klass type checks to use (1).
I propose that we upstream this change to the mainline, to slightly reduce the Loom diff.
