--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/nodes/ClassGetClassLoader0Node.java	Tue Jun 17 12:50:22 2014 -0700
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.graal.hotspot.nodes;
+
+import com.oracle.graal.graph.*;
+import com.oracle.graal.graph.spi.*;
+import com.oracle.graal.hotspot.meta.*;
+import com.oracle.graal.hotspot.replacements.*;
+import com.oracle.graal.nodes.*;
+import com.oracle.graal.replacements.nodes.*;
+
+/**
+ * {@link MacroNode Macro node} for {@link Class#getClassLoader0()}.
+ *
+ * @see ClassSubstitutions#getClassLoader0(Class)
+ */
+@SuppressWarnings("javadoc")
+public class ClassGetClassLoader0Node extends MacroNode implements Canonicalizable {
+
+    public ClassGetClassLoader0Node(Invoke invoke) {
+        super(invoke);
+    }
+
+    private ValueNode getJavaClass() {
+        return arguments.get(0);
+    }
+
+    @Override
+    public Node canonical(CanonicalizerTool tool) {
+        ValueNode javaClass = getJavaClass();
+        if (javaClass.isConstant()) {
+            Class<?> c = (Class<?>) HotSpotObjectConstant.asObject(javaClass.asConstant());
+            if (c != null) {
+                /*
+                 * This is an intrinsic for getClassLoader0, which occurs after any security checks.
+                 * We can't call that directly so just call getClassLoader.
+                 */
+                ClassLoader classLoader = c.getClassLoader();
+                return ConstantNode.forConstant(HotSpotObjectConstant.forObject(classLoader), tool.getMetaAccess(), graph());
+            }
+        }
+        return this;
+    }
+}

--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ClassSubstitutions.java	Tue Jun 17 12:48:20 2014 -0700
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ClassSubstitutions.java	Tue Jun 17 12:50:22 2014 -0700
@@ -82,6 +82,9 @@
         return klass.equal(0);
     }
 
+    @MacroSubstitution(macro = ClassGetClassLoader0Node.class, isStatic = false)
+    public static native ClassLoader getClassLoader0(Class<?> thisObj);
+
     @MacroSubstitution(macro = ClassGetSuperclassNode.class, isStatic = false)
     @MethodSubstitution(isStatic = false)
     public static Class<?> getSuperclass(final Class<?> thisObj) {

--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ObjectGetClassNode.java	Tue Jun 17 12:48:20 2014 -0700
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ObjectGetClassNode.java	Tue Jun 17 12:50:22 2014 -0700
@@ -67,11 +67,19 @@
         if (usages().isEmpty()) {
             return null;
         } else {
+            ResolvedJavaType type = StampTool.typeOrNull(getObject());
             if (StampTool.isExactType(getObject())) {
-                ResolvedJavaType type = StampTool.typeOrNull(getObject());
                 Constant clazz = type.getEncoding(Representation.JavaClass);
                 return ConstantNode.forConstant(clazz, tool.getMetaAccess(), graph());
             }
+            if (type != null && tool.assumptions().useOptimisticAssumptions()) {
+                ResolvedJavaType exactType = type.findUniqueConcreteSubtype();
+                if (exactType != null) {
+                    tool.assumptions().recordConcreteSubtype(type, exactType);
+                    Constant clazz = exactType.getEncoding(Representation.JavaClass);
+                    return ConstantNode.forConstant(clazz, tool.getMetaAccess(), graph());
+                }
+            }
             return this;
         }
     }