src/share/vm/opto/phaseX.cpp

*** 981,990 ****
--- 981,1001 ----
    _table.hash_delete(n);
    if( VerifyIterativeGVN ) {
     assert( !_table.find_index(n->_idx), "found duplicate entry in table");
    }
  
+   // If n computes a constant, replace it with a constant now to skip unneeded
+   // ideal transformations
+   const Type* t_n = type_or_null(n);
+   if( t_n != NULL && t_n->singleton() && !n->is_Con() ) {
+     NOT_PRODUCT( set_progress(); )
+     Node *con = makecon(t_n);     // Make a constant
+     add_users_to_worklist( n );
+     subsume_node( n, con );     // Everybody using n now uses con
+     return con;
+   }
+ 
    // Apply the Ideal call in a loop until it no longer applies
    Node *k = n;
    DEBUG_ONLY(dead_loop_check(k);)
    DEBUG_ONLY(bool is_new = (k->outcnt() == 0);)
    Node *i = k->Ideal(this, /*can_reshape=*/true);
*** 1620,1632 ****
    set_req(i, n);
  
    // old goes dead?
    if( old ) {
      switch (old->outcnt()) {
!     case 0:      // Kill all his inputs, and recursively kill other dead nodes.
        if (!old->is_top())
!         igvn->remove_dead_node( old );
        break;
      case 1:
        if( old->is_Store() || old->has_special_unique_user() )
          igvn->add_users_to_worklist( old );
        break;
--- 1631,1645 ----
    set_req(i, n);
  
    // old goes dead?
    if( old ) {
      switch (old->outcnt()) {
!     case 0:
!       // Put into the worklist to kill later. We do not kill it now because the
!       // recursive kill will delete the current node (this) if dead-loop exists
        if (!old->is_top())
!         igvn->_worklist.push( old );
        break;
      case 1:
        if( old->is_Store() || old->has_special_unique_user() )
          igvn->add_users_to_worklist( old );
        break;