bytecode-traits.h revision f2e3994fa5148cc3d9946666f0b0596290192b0e 
1// Copyright 2015 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_INTERPRETER_BYTECODE_TRAITS_H_
6#define V8_INTERPRETER_BYTECODE_TRAITS_H_
7
8#include "src/interpreter/bytecodes.h"
9
10namespace v8 {
11namespace internal {
12namespace interpreter {
13
14// TODO(rmcilroy): consider simplifying this to avoid the template magic.
15
16// Template helpers to deduce the number of operands each bytecode has.
17#define OPERAND_TERM OperandType::kNone, OperandType::kNone, OperandType::kNone
18
19template <OperandType>
20struct OperandTraits {};
21
22#define DECLARE_OPERAND_SIZE(Name, Size)             \
23  template <>                                        \
24  struct OperandTraits<OperandType::k##Name> {       \
25    static const OperandSize kSizeType = Size;       \
26    static const int kSize = static_cast<int>(Size); \
27  };
28OPERAND_TYPE_LIST(DECLARE_OPERAND_SIZE)
29#undef DECLARE_OPERAND_SIZE
30
31
32template <OperandType... Args>
33struct BytecodeTraits {};
34
35template <OperandType operand_0, OperandType operand_1, OperandType operand_2,
36          OperandType operand_3>
37struct BytecodeTraits<operand_0, operand_1, operand_2, operand_3,
38                      OPERAND_TERM> {
39  static OperandType GetOperandType(int i) {
40    DCHECK(0 <= i && i < kOperandCount);
41    const OperandType kOperands[] = {operand_0, operand_1, operand_2,
42                                     operand_3};
43    return kOperands[i];
44  }
45
46  static inline OperandSize GetOperandSize(int i) {
47    DCHECK(0 <= i && i < kOperandCount);
48    const OperandSize kOperandSizes[] =
49        {OperandTraits<operand_0>::kSizeType,
50         OperandTraits<operand_1>::kSizeType,
51         OperandTraits<operand_2>::kSizeType,
52         OperandTraits<operand_3>::kSizeType};
53    return kOperandSizes[i];
54  }
55
56  static inline int GetOperandOffset(int i) {
57    DCHECK(0 <= i && i < kOperandCount);
58    const int kOffset0 = 1;
59    const int kOffset1 = kOffset0 + OperandTraits<operand_0>::kSize;
60    const int kOffset2 = kOffset1 + OperandTraits<operand_1>::kSize;
61    const int kOffset3 = kOffset2 + OperandTraits<operand_2>::kSize;
62    const int kOperandOffsets[] = {kOffset0, kOffset1, kOffset2, kOffset3};
63    return kOperandOffsets[i];
64  }
65
66  static const int kOperandCount = 4;
67  static const int kSize =
68      1 + OperandTraits<operand_0>::kSize + OperandTraits<operand_1>::kSize +
69      OperandTraits<operand_2>::kSize + OperandTraits<operand_3>::kSize;
70};
71
72
73template <OperandType operand_0, OperandType operand_1, OperandType operand_2>
74struct BytecodeTraits<operand_0, operand_1, operand_2, OPERAND_TERM> {
75  static inline OperandType GetOperandType(int i) {
76    DCHECK(0 <= i && i <= 2);
77    const OperandType kOperands[] = {operand_0, operand_1, operand_2};
78    return kOperands[i];
79  }
80
81  static inline OperandSize GetOperandSize(int i) {
82    DCHECK(0 <= i && i < kOperandCount);
83    const OperandSize kOperandSizes[] =
84        {OperandTraits<operand_0>::kSizeType,
85         OperandTraits<operand_1>::kSizeType,
86         OperandTraits<operand_2>::kSizeType};
87    return kOperandSizes[i];
88  }
89
90  static inline int GetOperandOffset(int i) {
91    DCHECK(0 <= i && i < kOperandCount);
92    const int kOffset0 = 1;
93    const int kOffset1 = kOffset0 + OperandTraits<operand_0>::kSize;
94    const int kOffset2 = kOffset1 + OperandTraits<operand_1>::kSize;
95    const int kOperandOffsets[] = {kOffset0, kOffset1, kOffset2};
96    return kOperandOffsets[i];
97  }
98
99  static const int kOperandCount = 3;
100  static const int kSize =
101      1 + OperandTraits<operand_0>::kSize + OperandTraits<operand_1>::kSize +
102      OperandTraits<operand_2>::kSize;
103};
104
105template <OperandType operand_0, OperandType operand_1>
106struct BytecodeTraits<operand_0, operand_1, OPERAND_TERM> {
107  static inline OperandType GetOperandType(int i) {
108    DCHECK(0 <= i && i < kOperandCount);
109    const OperandType kOperands[] = {operand_0, operand_1};
110    return kOperands[i];
111  }
112
113  static inline OperandSize GetOperandSize(int i) {
114    DCHECK(0 <= i && i < kOperandCount);
115    const OperandSize kOperandSizes[] =
116        {OperandTraits<operand_0>::kSizeType,
117         OperandTraits<operand_1>::kSizeType};
118    return kOperandSizes[i];
119  }
120
121  static inline int GetOperandOffset(int i) {
122    DCHECK(0 <= i && i < kOperandCount);
123    const int kOffset0 = 1;
124    const int kOffset1 = kOffset0 + OperandTraits<operand_0>::kSize;
125    const int kOperandOffsets[] = {kOffset0, kOffset1};
126    return kOperandOffsets[i];
127  }
128
129  static const int kOperandCount = 2;
130  static const int kSize =
131      1 + OperandTraits<operand_0>::kSize + OperandTraits<operand_1>::kSize;
132};
133
134template <OperandType operand_0>
135struct BytecodeTraits<operand_0, OPERAND_TERM> {
136  static inline OperandType GetOperandType(int i) {
137    DCHECK(i == 0);
138    return operand_0;
139  }
140
141  static inline OperandSize GetOperandSize(int i) {
142    DCHECK(i == 0);
143    return OperandTraits<operand_0>::kSizeType;
144  }
145
146  static inline int GetOperandOffset(int i) {
147    DCHECK(i == 0);
148    return 1;
149  }
150
151  static const int kOperandCount = 1;
152  static const int kSize = 1 + OperandTraits<operand_0>::kSize;
153};
154
155template <>
156struct BytecodeTraits<OperandType::kNone, OPERAND_TERM> {
157  static inline OperandType GetOperandType(int i) {
158    UNREACHABLE();
159    return OperandType::kNone;
160  }
161
162  static inline OperandSize GetOperandSize(int i) {
163    UNREACHABLE();
164    return OperandSize::kNone;
165  }
166
167  static inline int GetOperandOffset(int i) {
168    UNREACHABLE();
169    return 1;
170  }
171
172  static const int kOperandCount = 0;
173  static const int kSize = 1 + OperandTraits<OperandType::kNone>::kSize;
174};
175
176}  // namespace interpreter
177}  // namespace internal
178}  // namespace v8
179
180#endif  // V8_INTERPRETER_BYTECODE_TRAITS_H_
181