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 Computer, 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 Instruction_h
30#define Instruction_h
31
32#include "MacroAssembler.h"
33#include "Opcode.h"
34#include "Structure.h"
35#include "StructureChain.h"
36#include <wtf/VectorTraits.h>
37
38#define POLYMORPHIC_LIST_CACHE_SIZE 8
39
40namespace JSC {
41
42 // *Sigh*, If the JIT is enabled we need to track the stubRountine (of type CodeLocationLabel),
43 // If the JIT is not in use we don't actually need the variable (that said, if the JIT is not in use we don't
44 // curently actually use PolymorphicAccessStructureLists, which we should). Anyway, this seems like the best
45 // solution for now - will need to something smarter if/when we actually want mixed-mode operation.
46#if ENABLE(JIT)
47 typedef CodeLocationLabel PolymorphicAccessStructureListStubRoutineType;
48#else
49 typedef void* PolymorphicAccessStructureListStubRoutineType;
50#endif
51
52 class JSCell;
53 class Structure;
54 class StructureChain;
55
56 // Structure used by op_get_by_id_self_list and op_get_by_id_proto_list instruction to hold data off the main opcode stream.
57 struct PolymorphicAccessStructureList : FastAllocBase {
58 struct PolymorphicStubInfo {
59 bool isChain;
60 PolymorphicAccessStructureListStubRoutineType stubRoutine;
61 Structure* base;
62 union {
63 Structure* proto;
64 StructureChain* chain;
65 } u;
66
67 void set(PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base)
68 {
69 stubRoutine = _stubRoutine;
70 base = _base;
71 u.proto = 0;
72 isChain = false;
73 }
74
75 void set(PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, Structure* _proto)
76 {
77 stubRoutine = _stubRoutine;
78 base = _base;
79 u.proto = _proto;
80 isChain = false;
81 }
82
83 void set(PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, StructureChain* _chain)
84 {
85 stubRoutine = _stubRoutine;
86 base = _base;
87 u.chain = _chain;
88 isChain = true;
89 }
90 } list[POLYMORPHIC_LIST_CACHE_SIZE];
91
92 PolymorphicAccessStructureList(PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase)
93 {
94 list[0].set(stubRoutine: stubRoutine, base: firstBase);
95 }
96
97 PolymorphicAccessStructureList(PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, Structure* firstProto)
98 {
99 list[0].set(stubRoutine: stubRoutine, base: firstBase, proto: firstProto);
100 }
101
102 PolymorphicAccessStructureList(PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, StructureChain* firstChain)
103 {
104 list[0].set(stubRoutine: stubRoutine, base: firstBase, chain: firstChain);
105 }
106
107 void derefStructures(int count)
108 {
109 for (int i = 0; i < count; ++i) {
110 PolymorphicStubInfo& info = list[i];
111
112 ASSERT(info.base);
113 info.base->deref();
114
115 if (info.u.proto) {
116 if (info.isChain)
117 info.u.chain->deref();
118 else
119 info.u.proto->deref();
120 }
121 }
122 }
123 };
124
125 struct Instruction {
126 Instruction(Opcode opcode)
127 {
128#if !HAVE(COMPUTED_GOTO)
129 // We have to initialize one of the pointer members to ensure that
130 // the entire struct is initialized, when opcode is not a pointer.
131 u.jsCell = 0;
132#endif
133 u.opcode = opcode;
134 }
135
136 Instruction(int operand)
137 {
138 // We have to initialize one of the pointer members to ensure that
139 // the entire struct is initialized in 64-bit.
140 u.jsCell = 0;
141 u.operand = operand;
142 }
143
144 Instruction(Structure* structure) { u.structure = structure; }
145 Instruction(StructureChain* structureChain) { u.structureChain = structureChain; }
146 Instruction(JSCell* jsCell) { u.jsCell = jsCell; }
147 Instruction(PolymorphicAccessStructureList* polymorphicStructures) { u.polymorphicStructures = polymorphicStructures; }
148
149 union {
150 Opcode opcode;
151 int operand;
152 Structure* structure;
153 StructureChain* structureChain;
154 JSCell* jsCell;
155 PolymorphicAccessStructureList* polymorphicStructures;
156 } u;
157 };
158
159} // namespace JSC
160
161namespace WTF {
162
163 template<> struct VectorTraits<JSC::Instruction> : VectorTraitsBase<true, JSC::Instruction> { };
164
165} // namespace WTF
166
167#endif // Instruction_h
168

source code of qtscript/src/3rdparty/javascriptcore/JavaScriptCore/bytecode/Instruction.h