rootnode.hpp revision 1879:f95d63e2154a 
1/*
2 * Copyright (c) 1997, 2010, 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
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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.
35class RootNode : public LoopNode {
36public:
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( PhaseTransform *phase ) { return this; }
46  virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
47  virtual const Type *Value( PhaseTransform *phase ) const { return Type::BOTTOM; }
48};
49
50//------------------------------HaltNode---------------------------------------
51// Throw an exception & die
52class HaltNode : public Node {
53public:
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( PhaseTransform *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
69#endif // SHARE_VM_OPTO_ROOTNODE_HPP
70