diff -r 8b0a4867acf0 -r 5e990493719e src/share/vm/opto/loopnode.cpp
--- a/src/share/vm/opto/loopnode.cpp	Tue Jun 12 14:31:44 2012 -0700
+++ b/src/share/vm/opto/loopnode.cpp	Tue Jun 12 16:23:31 2012 -0700
@@ -1129,8 +1129,7 @@
         // I'm mid-iteration over the Region's uses.
         for (DUIterator_Last imin, i = old_phi->last_outs(imin); i >= imin; ) {
           Node* use = old_phi->last_out(i);
-          igvn.hash_delete(use);
-          igvn._worklist.push(use);
+          igvn.rehash_node_delayed(use);
           uint uses_found = 0;
           for (uint j = 0; j < use->len(); j++) {
             if (use->in(j) == old_phi) {
@@ -1186,10 +1185,8 @@
       phi->init_req(LoopNode::LoopBackControl, old_phi->in(outer_idx));
       phi = igvn.register_new_node_with_optimizer(phi, old_phi);
       // Make old Phi point to new Phi on the fall-in path
-      igvn.hash_delete(old_phi);
-      old_phi->set_req(LoopNode::EntryControl, phi);
+      igvn.replace_input_of(old_phi, LoopNode::EntryControl, phi);
       old_phi->del_req(outer_idx);
-      igvn._worklist.push(old_phi);
     }
   }
 
@@ -1992,9 +1989,7 @@
     // we do it here.
     for( uint i = 1; i < C->root()->req(); i++ ) {
       if( !_nodes[C->root()->in(i)->_idx] ) {    // Dead path into Root?
-        _igvn.hash_delete(C->root());
-        C->root()->del_req(i);
-        _igvn._worklist.push(C->root());
+        _igvn.delete_input_of(C->root(), i);
         i--;                      // Rerun same iteration on compressed edges
       }
     }