hotspot/test/compiler/onSpinWait/TestOnSpinWait.java checks that Thread::onSpinWait is intrinsified on x86, we need tests which checks that Thread::onSpinWait works fine on non-x86 platforms. there is a test proposed by [~psandoz]:

On Mar 29, 2016, at 10:40 AM, Paul Sandoz wrote:
...
We can add another test to the webrev e.g. TestOnSpinWaitBasic:

// Test Thread.OnSpingWait can be called
public class TestOnSpinWaitBasic {

  public static void main(String[] args) {
    for (int i = 0; i < 50_000; i++) {
      java.lang.Thread.onSpinWait();
    }
  }
}

And we can run that with the intrinsic enabled and disabled.

Paul.