--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/ControlFlowGraph.java	Thu Oct 31 14:23:06 2019 -0700
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/cfg/ControlFlowGraph.java	Thu Oct 31 16:54:16 2019 -0700
@@ -38,6 +38,7 @@
 import org.graalvm.compiler.debug.GraalError;
 import org.graalvm.compiler.graph.Node;
 import org.graalvm.compiler.graph.NodeMap;
+import org.graalvm.compiler.graph.iterators.NodeIterable;
 import org.graalvm.compiler.nodes.AbstractBeginNode;
 import org.graalvm.compiler.nodes.AbstractEndNode;
 import org.graalvm.compiler.nodes.ControlSinkNode;
@@ -416,6 +417,15 @@
         return nodeToBlock.get(node);
     }
 
+    public Block commonDominatorFor(NodeIterable<? extends Node> nodes) {
+        Block commonDom = null;
+        for (Node n : nodes) {
+            Block b = blockFor(n);
+            commonDom = (Block) AbstractControlFlowGraph.commonDominator(commonDom, b);
+        }
+        return commonDom;
+    }
+
     @Override
     public List<Loop<Block>> getLoops() {
         return loops;