1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_OPTO_ROOTNODE_HPP
  26 #define SHARE_VM_OPTO_ROOTNODE_HPP
  27 
  28 #include "opto/loopnode.hpp"
  29 
  30 //------------------------------RootNode---------------------------------------
  31 // The one-and-only before-all-else and after-all-else RootNode.  The RootNode
  32 // represents what happens if the user runs the whole program repeatedly.  The
  33 // RootNode produces the initial values of I/O and memory for the program or
  34 // procedure start.
  35 class RootNode : public LoopNode {
  36 public:
  37   RootNode( ) : LoopNode(0,0) {
  38     init_class_id(Class_Root);
  39     del_req(2);
  40     del_req(1);
  41   }
  42   virtual int   Opcode() const;
  43   virtual const Node *is_block_proj() const { return this; }
  44   virtual const Type *bottom_type() const { return Type::BOTTOM; }
  45   virtual Node* Identity(PhaseGVN* phase) { return this; }
  46   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  47   virtual const Type* Value(PhaseGVN* phase) const { return Type::BOTTOM; }
  48 };
  49 
  50 //------------------------------HaltNode---------------------------------------
  51 // Throw an exception & die
  52 class HaltNode : public Node {
  53 public:
  54   HaltNode( Node *ctrl, Node *frameptr );
  55   virtual int Opcode() const;
  56   virtual bool  pinned() const { return true; };
  57   virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
  58   virtual const Type* Value(PhaseGVN* phase) const;
  59   virtual const Type *bottom_type() const;
  60   virtual bool  is_CFG() const { return true; }
  61   virtual uint hash() const { return NO_HASH; }  // CFG nodes do not hash
  62   virtual bool depends_only_on_test() const { return false; }
  63   virtual const Node *is_block_proj() const { return this; }
  64   virtual const RegMask &out_RegMask() const;
  65   virtual uint ideal_reg() const { return NotAMachineReg; }
  66   virtual uint match_edge(uint idx) const { return 0; }
  67 
  68 #ifndef PRODUCT
  69   virtual void related(GrowableArray<Node*> *in_rel, GrowableArray<Node*> *out_rel, bool compact) const;
  70 #endif
  71 };
  72 
  73 #endif // SHARE_VM_OPTO_ROOTNODE_HPP