src/share/vm/opto/compile.cpp

*** 2881,2893 ****
      }
  #endif
      break;
    }
  
- #ifdef _LP64
    case Op_CastPP:
!     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
        Node* in1 = n->in(1);
        const Type* t = n->bottom_type();
        Node* new_in1 = in1->clone();
        new_in1->as_DecodeN()->set_type(t);
  
--- 2881,2923 ----
      }
  #endif
      break;
    }
  
    case Op_CastPP:
!   {
!     // Remove CastPP nodes to gain more freedom during scheduling but
!     // keep the dependency they encode as control or precedence edges
!     // (if control is set already) on memory operations. Some CastPP
!     // nodes don't have a control (don't carry a dependency): skip
!     // those.
!     if (n->in(0) != NULL) {
!       ResourceMark rm;
!       Unique_Node_List wq;
!       wq.push(n);
!       for (uint next = 0; next < wq.size(); ++next) {
!         Node *m = wq.at(next);
!         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
!           Node* use = m->fast_out(i);
!           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
!             use->ensure_control_or_add_prec(n->in(0));
!           } else if (use->in(0) == NULL) {
!             switch(use->Opcode()) {
!             case Op_AddP:
!             case Op_DecodeN:
!             case Op_DecodeNKlass:
!             case Op_CheckCastPP:
!             case Op_CastPP:
!               wq.push(use);
!               break;
!             }
!           }
!         }
!       }
!     }
!     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
!     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
        Node* in1 = n->in(1);
        const Type* t = n->bottom_type();
        Node* new_in1 = in1->clone();
        new_in1->as_DecodeN()->set_type(t);
  
*** 2916,2928 ****
  
        n->subsume_by(new_in1, this);
        if (in1->outcnt() == 0) {
          in1->disconnect_inputs(NULL, this);
        }
      }
      break;
! 
    case Op_CmpP:
      // Do this transformation here to preserve CmpPNode::sub() and
      // other TypePtr related Ideal optimizations (for example, ptr nullness).
      if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
        Node* in1 = n->in(1);
--- 2946,2964 ----
  
        n->subsume_by(new_in1, this);
        if (in1->outcnt() == 0) {
          in1->disconnect_inputs(NULL, this);
        }
+     } else {
+       n->subsume_by(n->in(1), this);
+       if (n->outcnt() == 0) {
+         n->disconnect_inputs(NULL, this);
+       }
      }
      break;
!   }
! #ifdef _LP64
    case Op_CmpP:
      // Do this transformation here to preserve CmpPNode::sub() and
      // other TypePtr related Ideal optimizations (for example, ptr nullness).
      if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
        Node* in1 = n->in(1);