On Fri, 2012-08-03 at 09:26 +0900, Yasumasa Suenaga wrote: > Testcase is also attached. Please run Simple.java and test.stp . Thanks. I see why it wasn't triggering on my setup. Even with CompressedOops on both _base and _shift are zero. Is there a way to force the heap somewhere that needs a base/shift? Cheers, Mark