diff -r 56d9fd74b7e8 -r 3eb521896836 hotspot/src/share/vm/opto/loopnode.hpp
--- a/hotspot/src/share/vm/opto/loopnode.hpp	Mon Feb 11 14:47:04 2013 -0800
+++ b/hotspot/src/share/vm/opto/loopnode.hpp	Tue Feb 12 12:56:11 2013 +0100
@@ -263,9 +263,18 @@
   bool stride_is_con() const        { Node *tmp = stride  (); return (tmp != NULL && tmp->is_Con()); }
   BoolTest::mask test_trip() const  { return in(TestValue)->as_Bool()->_test._test; }
   CountedLoopNode *loopnode() const {
+    // The CountedLoopNode that goes with this CountedLoopEndNode may
+    // have been optimized out by the IGVN so be cautious with the
+    // pattern matching on the graph
+    if (phi() == NULL) {
+      return NULL;
+    }
     Node *ln = phi()->in(0);
-    assert( ln->Opcode() == Op_CountedLoop, "malformed loop" );
-    return (CountedLoopNode*)ln; }
+    if (ln->is_CountedLoop() && ln->as_CountedLoop()->loopexit() == this) {
+      return (CountedLoopNode*)ln;
+    }
+    return NULL;
+  }
 
 #ifndef PRODUCT
   virtual void dump_spec(outputStream *st) const;
@@ -598,6 +607,7 @@
   // check if transform created new nodes that need _ctrl recorded
   Node *get_late_ctrl( Node *n, Node *early );
   Node *get_early_ctrl( Node *n );
+  Node *get_early_ctrl_for_expensive(Node *n, Node* earliest);
   void set_early_ctrl( Node *n );
   void set_subtree_ctrl( Node *root );
   void set_ctrl( Node *n, Node *ctrl ) {
@@ -905,6 +915,16 @@
   void collect_potentially_useful_predicates(IdealLoopTree *loop, Unique_Node_List &predicate_opaque1);
   void eliminate_useless_predicates();
 
+  // Change the control input of expensive nodes to allow commoning by
+  // IGVN when it is guaranteed to not result in a more frequent
+  // execution of the expensive node. Return true if progress.
+  bool process_expensive_nodes();
+
+  // Check whether node has become unreachable
+  bool is_node_unreachable(Node *n) const {
+    return !has_node(n) || n->is_unreachable(_igvn);
+  }
+
   // Eliminate range-checks and other trip-counter vs loop-invariant tests.
   void do_range_check( IdealLoopTree *loop, Node_List &old_new );
 
@@ -1043,7 +1063,7 @@
   void register_new_node( Node *n, Node *blk );
 
 #ifdef ASSERT
-void dump_bad_graph(Node* n, Node* early, Node* LCA);
+  void dump_bad_graph(const char* msg, Node* n, Node* early, Node* LCA);
 #endif
 
 #ifndef PRODUCT