--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java	Tue Oct 30 15:43:00 2018 +0530
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Type.java	Tue Nov 20 10:47:35 2018 +0530
@@ -317,6 +317,12 @@
         throw new AssertionError();
     }
 
+    /** Define a light weight nullable box type. Make sense only for for a value type.
+     */
+    public Type loxType() {
+        throw new AssertionError();
+    }
+
     /**
      * If this is a constant type, return its underlying type.
      * Otherwise, return the type itself.
@@ -331,7 +337,13 @@
      * it should not be used outside this class.
      */
     protected Type typeNoMetadata() {
-        return metadata == TypeMetadata.EMPTY ? this : baseType();
+        Type t = metadata == TypeMetadata.EMPTY ? this : baseType();
+        if (t.hasTag(CLASS)) {
+            ClassType ct = (ClassType) t;
+            if (ct.loxType != null && ct.loxType.tsym.isValue())
+                return ct.loxType;
+        }
+        return t;
     }
 
     /**
@@ -961,6 +973,12 @@
          */
         public List<Type> all_interfaces_field;
 
+        /** The light weight box type for this type - make sense only for value types
+         *  Perhaps this field should be elided by having this maintained in a side
+         *  data structure
+         *  */
+        private ClassType loxType;
+
         public ClassType(Type outer, List<Type> typarams, TypeSymbol tsym) {
             this(outer, typarams, tsym, TypeMetadata.EMPTY);
         }
@@ -1007,6 +1025,22 @@
                 };
         }
 
+        public Type loxType() {
+            Assert.check(tsym.isValue());
+            if (loxType == null) {
+                loxType = new ClassType(outer_field, typarams_field, null);
+                loxType.allparams_field = this.allparams_field;
+                loxType.supertype_field = this.supertype_field;
+                loxType.interfaces_field = this.interfaces_field;
+                loxType.all_interfaces_field = this.all_interfaces_field;
+                ClassSymbol ts = new ClassSymbol((tsym.flags() & ~VALUE), tsym.name, loxType, tsym.owner);
+                ts.members_field = tsym.members();
+                loxType.tsym = ts;
+                loxType.loxType = this;
+            }
+            return loxType;
+        }
+
         /** The Java source which this type represents.
          */
         @DefinedBy(Api.LANGUAGE_MODEL)

--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java	Tue Oct 30 15:43:00 2018 +0530
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Resolve.java	Tue Nov 20 10:47:35 2018 +0530
@@ -2171,6 +2171,16 @@
                     : new AccessError(env, site, sym);
             }
         }
+
+        if (c.isValue() && site.tsym == c) {
+            if (name == names.val) {
+                return c;
+            }
+            if (name == names.box) {
+                return site.loxType().tsym;
+            }
+        }
+
         return typeNotFound;
     }
 

--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java	Tue Oct 30 15:43:00 2018 +0530
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java	Tue Nov 20 10:47:35 2018 +0530
@@ -2141,7 +2141,7 @@
         if (!tree.clazz.type.isPrimitive() &&
            !types.isSameType(tree.expr.type, tree.clazz.type) &&
            types.asSuper(tree.expr.type, tree.clazz.type.tsym) == null) {
-            code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type));
+            code.emitop2(checkcast, makeRef(tree.pos(), tree.clazz.type, types.emitQtypes && types.isValue(tree.clazz.type)));
         }
     }
 

--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java	Tue Oct 30 15:43:00 2018 +0530
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java	Tue Nov 20 10:47:35 2018 +0530
@@ -197,6 +197,8 @@
     public final Name module_info;
     public final Name package_info;
     public final Name requireNonNull;
+    public final Name box;
+    public final Name val;
 
     // lambda-related
     public final Name lambda;
@@ -369,6 +371,8 @@
         module_info = fromString("module-info");
         package_info = fromString("package-info");
         requireNonNull = fromString("requireNonNull");
+        box = fromString("box");
+        val = fromString("val");
 
         //lambda-related
         lambda = fromString("lambda$");