--- old/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotMemoryAccessProvider.java	2017-04-03 16:03:51.000000000 +0200
+++ new/src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotMemoryAccessProvider.java	2017-04-03 16:03:51.000000000 +0200
@@ -31,6 +31,10 @@
  */
 public interface HotSpotMemoryAccessProvider extends MemoryAccessProvider {
 
+    /**
+     * @throws IllegalArgumentException if the address computed from {@code base} and
+     *             {@code displacement} does not denote a location holding a narrow oop
+     */
     JavaConstant readNarrowOopConstant(Constant base, long displacement);
 
     Constant readKlassPointerConstant(Constant base, long displacement);