--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/DefaultJavaLoweringProvider.java	Tue Sep 24 08:54:08 2019 -0700
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.replacements/src/org/graalvm/compiler/replacements/DefaultJavaLoweringProvider.java	Tue Sep 24 12:47:15 2019 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2019, 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
@@ -43,11 +43,13 @@
 import java.util.BitSet;
 import java.util.List;
 
+import jdk.vm.ci.meta.JavaConstant;
 import org.graalvm.compiler.api.directives.GraalDirectives;
 import org.graalvm.compiler.api.replacements.Snippet;
 import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;
 import org.graalvm.compiler.core.common.LIRKind;
 import org.graalvm.compiler.core.common.spi.ForeignCallsProvider;
+import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
 import org.graalvm.compiler.core.common.type.IntegerStamp;
 import org.graalvm.compiler.core.common.type.ObjectStamp;
 import org.graalvm.compiler.core.common.type.Stamp;
@@ -60,14 +62,20 @@
 import org.graalvm.compiler.nodeinfo.InputType;
 import org.graalvm.compiler.nodes.CompressionNode.CompressionOp;
 import org.graalvm.compiler.nodes.ConstantNode;
+import org.graalvm.compiler.nodes.EndNode;
 import org.graalvm.compiler.nodes.FieldLocationIdentity;
 import org.graalvm.compiler.nodes.FixedNode;
+import org.graalvm.compiler.nodes.FixedWithNextNode;
+import org.graalvm.compiler.nodes.IfNode;
 import org.graalvm.compiler.nodes.LogicNode;
+import org.graalvm.compiler.nodes.MergeNode;
 import org.graalvm.compiler.nodes.NamedLocationIdentity;
 import org.graalvm.compiler.nodes.NodeView;
+import org.graalvm.compiler.nodes.PhiNode;
 import org.graalvm.compiler.nodes.PiNode;
 import org.graalvm.compiler.nodes.StructuredGraph;
 import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.ValuePhiNode;
 import org.graalvm.compiler.nodes.calc.AddNode;
 import org.graalvm.compiler.nodes.calc.ConditionalNode;
 import org.graalvm.compiler.nodes.calc.IntegerBelowNode;
@@ -91,6 +99,7 @@
 import org.graalvm.compiler.nodes.extended.JavaWriteNode;
 import org.graalvm.compiler.nodes.extended.LoadArrayComponentHubNode;
 import org.graalvm.compiler.nodes.extended.LoadHubNode;
+import org.graalvm.compiler.nodes.extended.LoadHubOrNullNode;
 import org.graalvm.compiler.nodes.extended.MembarNode;
 import org.graalvm.compiler.nodes.extended.RawLoadNode;
 import org.graalvm.compiler.nodes.extended.RawStoreNode;
@@ -210,6 +219,8 @@
                 lowerArrayLengthNode((ArrayLengthNode) n, tool);
             } else if (n instanceof LoadHubNode) {
                 lowerLoadHubNode((LoadHubNode) n, tool);
+            } else if (n instanceof LoadHubOrNullNode) {
+                lowerLoadHubOrNullNode((LoadHubOrNullNode) n, tool);
             } else if (n instanceof LoadArrayComponentHubNode) {
                 lowerLoadArrayComponentHubNode((LoadArrayComponentHubNode) n);
             } else if (n instanceof MonitorEnterNode) {
@@ -558,6 +569,36 @@
         loadHub.replaceAtUsagesAndDelete(hub);
     }
 
+    protected void lowerLoadHubOrNullNode(LoadHubOrNullNode loadHubOrNullNode, LoweringTool tool) {
+        StructuredGraph graph = loadHubOrNullNode.graph();
+        if (tool.getLoweringStage() != LoweringTool.StandardLoweringStage.LOW_TIER) {
+            return;
+        }
+        if (graph.getGuardsStage().allowsFloatingGuards()) {
+            return;
+        }
+        final FixedWithNextNode predecessor = tool.lastFixedNode();
+        final ValueNode value = loadHubOrNullNode.getValue();
+        AbstractPointerStamp stamp = (AbstractPointerStamp) value.stamp(NodeView.DEFAULT);
+        final LogicNode isNull = graph.addOrUniqueWithInputs(IsNullNode.create(value));
+        final EndNode trueEnd = graph.add(new EndNode());
+        final EndNode falseEnd = graph.add(new EndNode());
+        final IfNode ifNode = graph.add(new IfNode(isNull, trueEnd, falseEnd, 0.5));
+        final MergeNode merge = graph.add(new MergeNode());
+        merge.addForwardEnd(trueEnd);
+        merge.addForwardEnd(falseEnd);
+        final AbstractPointerStamp hubStamp = (AbstractPointerStamp) loadHubOrNullNode.stamp(NodeView.DEFAULT);
+        ValueNode nullHub = ConstantNode.forConstant(hubStamp.asAlwaysNull(), JavaConstant.NULL_POINTER, tool.getMetaAccess(), graph);
+        final ValueNode nonNullValue = graph.addOrUniqueWithInputs(PiNode.create(value, stamp.asNonNull(), ifNode.falseSuccessor()));
+        ValueNode hub = createReadHub(graph, nonNullValue, tool);
+        ValueNode[] values = new ValueNode[]{nullHub, hub};
+        final PhiNode hubPhi = graph.unique(new ValuePhiNode(hubStamp, merge, values));
+        final FixedNode oldNext = predecessor.next();
+        predecessor.setNext(ifNode);
+        merge.setNext(oldNext);
+        loadHubOrNullNode.replaceAtUsagesAndDelete(hubPhi);
+    }
+
     protected void lowerLoadArrayComponentHubNode(LoadArrayComponentHubNode loadHub) {
         StructuredGraph graph = loadHub.graph();
         ValueNode hub = createReadArrayComponentHub(graph, loadHub.getValue(), loadHub);