The barrier elision test set added by JDK-8301584 and extended by JDK-8301769 interleave correctness tests (do not elide necessary barriers) and effectiveness tests (do elide unnecessary barriers). These two subsets can be split in order to enable the former on all platforms that support ZGC, see discussion with PPC and RISCV maintainers on https://github.com/openjdk/zgc/pull/13.