src/share/vm/opto/cfgnode.cpp

@@ -1887,10 +1887,16 @@
     // see if this phi should be sliced
     uint merge_width = 0;
     bool saw_self = false;
     for( uint i=1; i<req(); ++i ) {// For all paths in
       Node *ii = in(i);
+      // TOP inputs should not be counted as safe inputs because if the
+      // Phi references itself through all other inputs then splitting the
+      // Phi through memory merges would create dead loop at later stage.
+      if (ii == top) {
+        return NULL; // Delay optimization until graph is cleaned.
+      }
       if (ii->is_MergeMem()) {
         MergeMemNode* n = ii->as_MergeMem();
         merge_width = MAX2(merge_width, n->req());
         saw_self = saw_self || phase->eqv(n->base_memory(), this);
       }