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
21 * questions.
22 *
23 */
24
25#ifndef SHARE_VM_RUNTIME_STACKVALUE_HPP
26#define SHARE_VM_RUNTIME_STACKVALUE_HPP
27
28#include "code/location.hpp"
29#include "runtime/handles.hpp"
30
31class StackValue : public ResourceObj {
32 private:
33  BasicType _type;
34  intptr_t  _i; // Blank java stack slot value
35  Handle    _o; // Java stack slot value interpreted as a Handle
36 public:
37
38  StackValue(intptr_t value) {
39    _type  = T_INT;
40    _i     = value;
41  }
42
43  StackValue(Handle value, intptr_t scalar_replaced = 0) {
44    _type    = T_OBJECT;
45    _i       = scalar_replaced;
46    _o       = value;
47    assert(_i == 0 || _o.is_null(), "not null object should not be marked as scalar replaced");
48  }
49
50  StackValue() {
51    _type   = T_CONFLICT;
52    _i      = 0;
53  }
54
55  // Only used during deopt- preserve object type.
56  StackValue(intptr_t o, BasicType t) {
57    assert(t == T_OBJECT, "should not be used");
58    _type   = t;
59    _i      = o;
60  }
61
62  Handle get_obj() const {
63    assert(type() == T_OBJECT, "type check");
64    return _o;
65  }
66
67  bool obj_is_scalar_replaced() const {
68    assert(type() == T_OBJECT, "type check");
69    return _i != 0;
70  }
71
72  void set_obj(Handle value) {
73    assert(type() == T_OBJECT, "type check");
74    _o = value;
75  }
76
77  intptr_t get_int() const {
78    assert(type() == T_INT, "type check");
79    return _i;
80  }
81
82  // For special case in deopt.
83  intptr_t get_int(BasicType t) const {
84    assert(t == T_OBJECT && type() == T_OBJECT, "type check");
85    return _i;
86  }
87
88  void set_int(intptr_t value) {
89    assert(type() == T_INT, "type check");
90    _i = value;
91  }
92
93  BasicType type() const { return  _type; }
94
95  bool equal(StackValue *value) {
96    if (_type != value->_type) return false;
97    if (_type == T_OBJECT)
98      return (_o == value->_o);
99    else {
100      assert(_type == T_INT, "sanity check");
101      // [phh] compare only low addressed portions of intptr_t slots
102      return (*(int *)&_i == *(int *)&value->_i);
103    }
104  }
105
106  static StackValue* create_stack_value(const frame* fr, const RegisterMap* reg_map, ScopeValue* sv);
107  static BasicLock*  resolve_monitor_lock(const frame* fr, Location location);
108
109#ifndef PRODUCT
110 public:
111  // Printing
112  void print_on(outputStream* st) const;
113#endif
114};
115
116#endif // SHARE_VM_RUNTIME_STACKVALUE_HPP
117