--- a/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedObjectTypeImpl.java	Thu Mar 31 10:21:27 2016 -0700
+++ b/jvmci/jdk.vm.ci.hotspot/src/jdk/vm/ci/hotspot/HotSpotResolvedObjectTypeImpl.java	Fri Apr 01 10:32:24 2016 -0700
@@ -169,6 +169,10 @@
 
     @Override
     public AssumptionResult<ResolvedJavaType> findLeafConcreteSubtype() {
+        if (isLeaf()) {
+            // No assumptions are required.
+            return new AssumptionResult<>(this);
+        }
         HotSpotVMConfig config = config();
         if (isArray()) {
             ResolvedJavaType elementalType = getElementalType();
@@ -206,8 +210,7 @@
                 }
                 return null;
             }
-
-            return new AssumptionResult<>(implementor, new LeafType(implementor), new ConcreteSubtype(this, implementor));
+            return concreteSubtype(implementor);
         } else {
             HotSpotResolvedObjectTypeImpl type = this;
             while (type.isAbstract()) {
@@ -221,7 +224,7 @@
                 return null;
             }
             if (this.isAbstract()) {
-                return new AssumptionResult<>(type, new LeafType(type), new ConcreteSubtype(this, type));
+                return concreteSubtype(type);
             } else {
                 assert this.equals(type);
                 return new AssumptionResult<>(type, new LeafType(type));
@@ -229,6 +232,14 @@
         }
     }
 
+    private AssumptionResult<ResolvedJavaType> concreteSubtype(HotSpotResolvedObjectTypeImpl type) {
+        if (type.isLeaf()) {
+            return new AssumptionResult<>(type, new ConcreteSubtype(this, type));
+        } else {
+            return new AssumptionResult<>(type, new LeafType(type), new ConcreteSubtype(this, type));
+        }
+    }
+
     /**
      * Returns if type {@code type} is a leaf class. This is the case if the
      * {@code Klass::_subklass} field of the underlying class is zero.

--- a/jvmci/jdk.vm.ci.meta/src/jdk/vm/ci/meta/Assumptions.java	Thu Mar 31 10:21:27 2016 -0700
+++ b/jvmci/jdk.vm.ci.meta/src/jdk/vm/ci/meta/Assumptions.java	Fri Apr 01 10:32:24 2016 -0700
@@ -44,7 +44,10 @@
 
     /**
      * A class for providing information that is only valid in association with a set of
-     * {@link Assumption}s.
+     * {@link Assumption}s. It is permissible for AssumptionResults to have no any assumptions at
+     * all. For instance, if {@link ResolvedJavaType#isLeaf()} returns true for a type
+     * {@link ResolvedJavaType#findLeafConcreteSubtype()} can return an AssumptionResult with no
+     * assumptions since the leaf information is statically true.
      *
      * @param <T>
      */
@@ -187,6 +190,7 @@
         public final ResolvedJavaType context;
 
         public LeafType(ResolvedJavaType context) {
+            assert !context.isLeaf() : "assumption isn't required for leaf types";
             this.context = context;
         }
 

--- a/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestResolvedJavaType.java	Thu Mar 31 10:21:27 2016 -0700
+++ b/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestResolvedJavaType.java	Fri Apr 01 10:32:24 2016 -0700
@@ -295,6 +295,7 @@
             } else {
                 assertTrue(leafConcreteSubtype.getResult().equals(expected));
             }
+            assertTrue(!type.isLeaf() || leafConcreteSubtype.isAssumptionFree());
         }
 
         if (!type.isArray()) {