JDK-8307058 has introduced code to optimize out unnecessary GC barriers based on analyzing dominating barriers. There's a new test "TestZGCBarrierElision.java" which tests the effectiveness of the barrier elision on some platforms, but not on PPC64. We could extend the test and make sure all the optimization patterns work on PPC64 as well.
In addition,
JDK-8348562 shows a pattern in which an allocation node is not found on PPC64. Maybe the analysis code could be extended for that.
Barrier elision will also be used with G1 after
JDK-8346280.
JDK-8346280 C2: implement late barrier elision for G1
JDK-8307058 Implementation of Generational ZGC
JDK-8348562 ZGC: segmentation fault due to missing node type check in barrier elision analysis
