src/share/vm/opto/phaseX.cpp

*** 381,390 ****
--- 381,392 ----
    // to each SafePointNode at a backward branch.  Inserted in add_safepoint().
    if( !UseLoopSafepoints || !OptoRemoveUseless ) return;
  
    // Identify nodes that are reachable from below, useful.
    C->identify_useful_nodes(_useful);
+   // Update dead node list
+   C->update_dead_node_list(_useful);
  
    // Remove all useless nodes from PhaseValues' recorded types
    // Must be done before disconnecting nodes to preserve hash-table-invariant
    gvn->remove_useless_nodes(_useful.member_set());
  
*** 1188,1206 ****
                  assert(!(i < imax), "sanity");
                }
              }
            }
          }
! 
          if (dead->is_macro()) {
            C->remove_macro_node(dead);
          }
  
          if (recurse) {
            continue;
          }
        }
      }
  
      // Aggressively kill globally dead uses
      // (Rather than pushing all the outs at once, we push one at a time,
      // plus the parent to resume later, because of the indefinite number
--- 1190,1213 ----
                  assert(!(i < imax), "sanity");
                }
              }
            }
          }
!         C->record_dead_node(dead->_idx);
          if (dead->is_macro()) {
            C->remove_macro_node(dead);
          }
  
          if (recurse) {
            continue;
          }
        }
+       // Constant node that has no out-edges and has only one in-edge from
+       // root is usually dead. However, sometimes reshaping walk makes
+       // it reachable by adding use edges. So, we will NOT count Con nodes
+       // as dead to be conservative about the dead node count at any
+       // given time.
      }
  
      // Aggressively kill globally dead uses
      // (Rather than pushing all the outs at once, we push one at a time,
      // plus the parent to resume later, because of the indefinite number