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.