1/*
2 * Copyright (C) 2011, 2015 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 VirtualRegister_h
27#define VirtualRegister_h
28
29#include "CallFrame.h"
30
31#include <wtf/PrintStream.h>
32
33namespace JSC {
34
35inline bool operandIsLocal(int operand)
36{
37 return operand < 0;
38}
39
40inline bool operandIsArgument(int operand)
41{
42 return operand >= 0;
43}
44
45
46class VirtualRegister {
47public:
48 friend VirtualRegister virtualRegisterForLocal(int);
49 friend VirtualRegister virtualRegisterForArgument(int, int);
50
51 VirtualRegister()
52 : m_virtualRegister(s_invalidVirtualRegister)
53 { }
54
55 explicit VirtualRegister(int virtualRegister)
56 : m_virtualRegister(virtualRegister)
57 { }
58
59 bool isValid() const { return (m_virtualRegister != s_invalidVirtualRegister); }
60 bool isLocal() const { return operandIsLocal(m_virtualRegister); }
61 bool isArgument() const { return operandIsArgument(m_virtualRegister); }
62 bool isHeader() const { return m_virtualRegister >= 0 && m_virtualRegister < JSStack::ThisArgument; }
63 bool isConstant() const { return m_virtualRegister >= s_firstConstantRegisterIndex; }
64 int toLocal() const { ASSERT(isLocal()); return operandToLocal(m_virtualRegister); }
65 int toArgument() const { ASSERT(isArgument()); return operandToArgument(m_virtualRegister); }
66 int toConstantIndex() const { ASSERT(isConstant()); return m_virtualRegister - s_firstConstantRegisterIndex; }
67 int offset() const { return m_virtualRegister; }
68 int offsetInBytes() const { return m_virtualRegister * sizeof(Register); }
69
70 bool operator==(VirtualRegister other) const { return m_virtualRegister == other.m_virtualRegister; }
71 bool operator!=(VirtualRegister other) const { return m_virtualRegister != other.m_virtualRegister; }
72 bool operator<(VirtualRegister other) const { return m_virtualRegister < other.m_virtualRegister; }
73 bool operator>(VirtualRegister other) const { return m_virtualRegister > other.m_virtualRegister; }
74 bool operator<=(VirtualRegister other) const { return m_virtualRegister <= other.m_virtualRegister; }
75 bool operator>=(VirtualRegister other) const { return m_virtualRegister >= other.m_virtualRegister; }
76
77 VirtualRegister operator+(int value) const
78 {
79 return VirtualRegister(offset() + value);
80 }
81 VirtualRegister operator-(int value) const
82 {
83 return VirtualRegister(offset() - value);
84 }
85 VirtualRegister operator+(VirtualRegister value) const
86 {
87 return VirtualRegister(offset() + value.offset());
88 }
89 VirtualRegister operator-(VirtualRegister value) const
90 {
91 return VirtualRegister(offset() - value.offset());
92 }
93 VirtualRegister& operator+=(int value)
94 {
95 return *this = *this + value;
96 }
97 VirtualRegister& operator-=(int value)
98 {
99 return *this = *this - value;
100 }
101
102 void dump(PrintStream& out) const;
103
104private:
105 static const int s_invalidVirtualRegister = 0x3fffffff;
106 static const int s_firstConstantRegisterIndex = 0x40000000;
107
108 static int localToOperand(int local) { return -1 - local; }
109 static int operandToLocal(int operand) { return -1 - operand; }
110 static int operandToArgument(int operand) { return operand - CallFrame::thisArgumentOffset(); }
111 static int argumentToOperand(int argument) { return argument + CallFrame::thisArgumentOffset(); }
112
113 int m_virtualRegister;
114};
115
116COMPILE_ASSERT(sizeof(VirtualRegister) == sizeof(int), VirtualRegister_is_32bit);
117
118inline VirtualRegister virtualRegisterForLocal(int local)
119{
120 return VirtualRegister(VirtualRegister::localToOperand(local));
121}
122
123inline VirtualRegister virtualRegisterForArgument(int argument, int offset = 0)
124{
125 return VirtualRegister(VirtualRegister::argumentToOperand(argument) + offset);
126}
127
128} // namespace JSC
129
130#endif // VirtualRegister_h
131