1/*
2 * Copyright (C) 2014 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 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef Reg_h
27#define Reg_h
28
29#if ENABLE(JIT)
30
31#include "MacroAssembler.h"
32
33namespace JSC {
34
35// Reg is a polymorphic register class. It can refer to either integer or float registers.
36// Here are some use cases:
37//
38// GPRReg gpr;
39// Reg reg = gpr;
40// reg.isSet() == true
41// reg.isGPR() == true
42// reg.isFPR() == false
43//
44// for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
45//     if (reg.isGPR()) {
46//     } else /* reg.isFPR() */ {
47//     }
48// }
49//
50// The above loop could have also used !!reg or reg.isSet() as a condition.
51
52class Reg {
53public:
54    Reg()
55        : m_index(invalid())
56    {
57    }
58
59    Reg(MacroAssembler::RegisterID reg)
60        : m_index(MacroAssembler::registerIndex(reg))
61    {
62    }
63
64    Reg(MacroAssembler::FPRegisterID reg)
65        : m_index(MacroAssembler::registerIndex(reg))
66    {
67    }
68
69    static Reg fromIndex(unsigned index)
70    {
71        Reg result;
72        result.m_index = index;
73        return result;
74    }
75
76    static Reg first()
77    {
78        Reg result;
79        result.m_index = 0;
80        return result;
81    }
82
83    static Reg last()
84    {
85        Reg result;
86        result.m_index = MacroAssembler::numberOfRegisters() + MacroAssembler::numberOfFPRegisters() - 1;
87        return result;
88    }
89
90    Reg next() const
91    {
92        ASSERT(!!*this);
93        if (*this == last())
94            return Reg();
95        Reg result;
96        result.m_index = m_index + 1;
97        return result;
98    }
99
100    unsigned index() const { return m_index; }
101
102    bool isSet() const { return m_index != invalid(); }
103    bool operator!() const { return !isSet(); }
104
105    bool isGPR() const
106    {
107        return m_index < MacroAssembler::numberOfRegisters();
108    }
109
110    bool isFPR() const
111    {
112        return (m_index - MacroAssembler::numberOfRegisters()) < MacroAssembler::numberOfFPRegisters();
113    }
114
115    MacroAssembler::RegisterID gpr() const
116    {
117        ASSERT(isGPR());
118        return static_cast<MacroAssembler::RegisterID>(MacroAssembler::firstRegister() + m_index);
119    }
120
121    MacroAssembler::FPRegisterID fpr() const
122    {
123        ASSERT(isFPR());
124        return static_cast<MacroAssembler::FPRegisterID>(
125            MacroAssembler::firstFPRegister() + (m_index - MacroAssembler::numberOfRegisters()));
126    }
127
128    bool operator==(const Reg& other) const
129    {
130        return m_index == other.m_index;
131    }
132
133    bool operator!=(const Reg& other) const
134    {
135        return m_index != other.m_index;
136    }
137
138    bool operator<(const Reg& other) const
139    {
140        return m_index < other.m_index;
141    }
142
143    bool operator>(const Reg& other) const
144    {
145        return m_index > other.m_index;
146    }
147
148    bool operator<=(const Reg& other) const
149    {
150        return m_index <= other.m_index;
151    }
152
153    bool operator>=(const Reg& other) const
154    {
155        return m_index >= other.m_index;
156    }
157
158    unsigned hash() const
159    {
160        return m_index;
161    }
162
163    void dump(PrintStream&) const;
164
165private:
166    static uint8_t invalid() { return 0xff; }
167
168    uint8_t m_index;
169};
170
171} // namespace JSC
172
173#endif // ENABLE(JIT)
174
175#endif // Reg_h
176
177