1/*
2 * Copyright (C) 2008 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef RegisterID_h
30#define RegisterID_h
31
32#include "VirtualRegister.h"
33
34#include <wtf/Assertions.h>
35#include <wtf/VectorTraits.h>
36
37namespace JSC {
38
39    class RegisterID {
40        WTF_MAKE_NONCOPYABLE(RegisterID);
41    public:
42        RegisterID()
43            : m_refCount(0)
44            , m_isTemporary(false)
45#ifndef NDEBUG
46            , m_didSetIndex(false)
47#endif
48        {
49        }
50
51        RegisterID(VirtualRegister virtualRegister)
52            : m_refCount(0)
53            , m_virtualRegister(virtualRegister)
54            , m_isTemporary(false)
55#ifndef NDEBUG
56            , m_didSetIndex(true)
57#endif
58        {
59        }
60
61        explicit RegisterID(int index)
62            : m_refCount(0)
63            , m_virtualRegister(VirtualRegister(index))
64            , m_isTemporary(false)
65#ifndef NDEBUG
66            , m_didSetIndex(true)
67#endif
68        {
69        }
70
71        void setIndex(int index)
72        {
73            ASSERT(!m_refCount);
74#ifndef NDEBUG
75            m_didSetIndex = true;
76#endif
77            m_virtualRegister = VirtualRegister(index);
78        }
79
80        void setTemporary()
81        {
82            m_isTemporary = true;
83        }
84
85        int index() const
86        {
87            ASSERT(m_didSetIndex);
88            return m_virtualRegister.offset();
89        }
90
91        VirtualRegister virtualRegister() const
92        {
93            ASSERT(m_virtualRegister.isValid());
94            return m_virtualRegister;
95        }
96
97        bool isTemporary()
98        {
99            return m_isTemporary;
100        }
101
102        void ref()
103        {
104            ++m_refCount;
105        }
106
107        void deref()
108        {
109            --m_refCount;
110            ASSERT(m_refCount >= 0);
111        }
112
113        int refCount() const
114        {
115            return m_refCount;
116        }
117
118    private:
119
120        int m_refCount;
121        VirtualRegister m_virtualRegister;
122        bool m_isTemporary;
123#ifndef NDEBUG
124        bool m_didSetIndex;
125#endif
126    };
127
128} // namespace JSC
129
130namespace WTF {
131
132    template<> struct VectorTraits<JSC::RegisterID> : VectorTraitsBase<true, JSC::RegisterID> {
133        static const bool needsInitialization = true;
134        static const bool canInitializeWithMemset = true; // Default initialization just sets everything to 0 or false, so this is safe.
135    };
136
137} // namespace WTF
138
139#endif // RegisterID_h
140