1/*
2 * Copyright (C) 2011-2019 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#pragma once
27
28#include "BytecodeConventions.h"
29#include "CallFrame.h"
30#include <wtf/PrintStream.h>
31
32namespace JSC {
33
34inline bool operandIsLocal(int operand)
35{
36 return operand < 0;
37}
38
39inline bool operandIsArgument(int operand)
40{
41 return operand >= 0;
42}
43
44
45class RegisterID;
46
47class VirtualRegister {
48public:
49 friend VirtualRegister virtualRegisterForLocal(int);
50 friend VirtualRegister virtualRegisterForArgument(int, int);
51
52 VirtualRegister(RegisterID*);
53 VirtualRegister(RefPtr<RegisterID>);
54
55 VirtualRegister()
56 : m_virtualRegister(s_invalidVirtualRegister)
57 { }
58
59 explicit VirtualRegister(int virtualRegister)
60 : m_virtualRegister(virtualRegister)
61 { }
62
63 bool isValid() const { return (m_virtualRegister != s_invalidVirtualRegister); }
64 bool isLocal() const { return operandIsLocal(m_virtualRegister); }
65 bool isArgument() const { return operandIsArgument(m_virtualRegister); }
66 bool isHeader() const { return m_virtualRegister >= 0 && m_virtualRegister < CallFrameSlot::thisArgument; }
67 bool isConstant() const { return m_virtualRegister >= s_firstConstantRegisterIndex; }
68 int toLocal() const { ASSERT(isLocal()); return operandToLocal(m_virtualRegister); }
69 int toArgument() const { ASSERT(isArgument()); return operandToArgument(m_virtualRegister); }
70 int toConstantIndex() const { ASSERT(isConstant()); return m_virtualRegister - s_firstConstantRegisterIndex; }
71 int offset() const { return m_virtualRegister; }
72 int offsetInBytes() const { return m_virtualRegister * sizeof(Register); }
73
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 bool operator<(VirtualRegister other) const { return m_virtualRegister < other.m_virtualRegister; }
77 bool operator>(VirtualRegister other) const { return m_virtualRegister > other.m_virtualRegister; }
78 bool operator<=(VirtualRegister other) const { return m_virtualRegister <= other.m_virtualRegister; }
79 bool operator>=(VirtualRegister other) const { return m_virtualRegister >= other.m_virtualRegister; }
80
81 VirtualRegister operator+(int value) const
82 {
83 return VirtualRegister(offset() + value);
84 }
85 VirtualRegister operator-(int value) const
86 {
87 return VirtualRegister(offset() - value);
88 }
89 VirtualRegister operator+(VirtualRegister value) const
90 {
91 return VirtualRegister(offset() + value.offset());
92 }
93 VirtualRegister operator-(VirtualRegister value) const
94 {
95 return VirtualRegister(offset() - value.offset());
96 }
97 VirtualRegister& operator+=(int value)
98 {
99 return *this = *this + value;
100 }
101 VirtualRegister& operator-=(int value)
102 {
103 return *this = *this - value;
104 }
105
106 void dump(PrintStream& out) const;
107
108private:
109 static constexpr int s_invalidVirtualRegister = 0x3fffffff;
110 static constexpr int s_firstConstantRegisterIndex = FirstConstantRegisterIndex;
111
112 static int localToOperand(int local) { return -1 - local; }
113 static int operandToLocal(int operand) { return -1 - operand; }
114 static int operandToArgument(int operand) { return operand - CallFrame::thisArgumentOffset(); }
115 static int argumentToOperand(int argument) { return argument + CallFrame::thisArgumentOffset(); }
116
117 int m_virtualRegister;
118};
119
120COMPILE_ASSERT(sizeof(VirtualRegister) == sizeof(int), VirtualRegister_is_32bit);
121
122inline VirtualRegister virtualRegisterForLocal(int local)
123{
124 return VirtualRegister(VirtualRegister::localToOperand(local));
125}
126
127inline VirtualRegister virtualRegisterForArgument(int argument, int offset = 0)
128{
129 return VirtualRegister(VirtualRegister::argumentToOperand(argument) + offset);
130}
131
132} // namespace JSC
133