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 "PropertySlot.h"
35#include "Structure.h"
36#include "StructureChain.h"
37#include <wtf/VectorTraits.h>
38
39#define POLYMORPHIC_LIST_CACHE_SIZE 8
40
41namespace JSC {
42
43    // *Sigh*, If the JIT is enabled we need to track the stubRountine (of type CodeLocationLabel),
44    // 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
45    // curently actually use PolymorphicAccessStructureLists, which we should).  Anyway, this seems like the best
46    // solution for now - will need to something smarter if/when we actually want mixed-mode operation.
47#if ENABLE(JIT)
48    typedef CodeLocationLabel PolymorphicAccessStructureListStubRoutineType;
49#else
50    typedef void* PolymorphicAccessStructureListStubRoutineType;
51#endif
52
53    class JSCell;
54    class Structure;
55    class StructureChain;
56
57    // 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.
58    struct PolymorphicAccessStructureList {
59        WTF_MAKE_FAST_ALLOCATED;
60    public:
61        struct PolymorphicStubInfo {
62            bool isChain;
63            PolymorphicAccessStructureListStubRoutineType stubRoutine;
64            WriteBarrier<Structure> base;
65            union {
66                WriteBarrierBase<Structure> proto;
67                WriteBarrierBase<StructureChain> chain;
68            } u;
69
70            void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base)
71            {
72                stubRoutine = _stubRoutine;
73                base.set(globalData, owner, _base);
74                u.proto.clear();
75                isChain = false;
76            }
77
78            void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, Structure* _proto)
79            {
80                stubRoutine = _stubRoutine;
81                base.set(globalData, owner, _base);
82                u.proto.set(globalData, owner, _proto);
83                isChain = false;
84            }
85
86            void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, StructureChain* _chain)
87            {
88                stubRoutine = _stubRoutine;
89                base.set(globalData, owner, _base);
90                u.chain.set(globalData, owner, _chain);
91                isChain = true;
92            }
93        } list[POLYMORPHIC_LIST_CACHE_SIZE];
94
95        PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase)
96        {
97            list[0].set(globalData, owner, stubRoutine, firstBase);
98        }
99
100        PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, Structure* firstProto)
101        {
102            list[0].set(globalData, owner, stubRoutine, firstBase, firstProto);
103        }
104
105        PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, StructureChain* firstChain)
106        {
107            list[0].set(globalData, owner, stubRoutine, firstBase, firstChain);
108        }
109
110        void markAggregate(MarkStack& markStack, int count)
111        {
112            for (int i = 0; i < count; ++i) {
113                PolymorphicStubInfo& info = list[i];
114                ASSERT(info.base);
115
116                markStack.append(&info.base);
117                if (info.u.proto && !info.isChain)
118                    markStack.append(&info.u.proto);
119                if (info.u.chain && info.isChain)
120                    markStack.append(&info.u.chain);
121            }
122        }
123    };
124
125    struct Instruction {
126        Instruction(Opcode opcode)
127        {
128#if !ENABLE(COMPUTED_GOTO_INTERPRETER)
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.clear();
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.clear();
141            u.operand = operand;
142        }
143
144        Instruction(JSGlobalData& globalData, JSCell* owner, Structure* structure)
145        {
146            u.structure.clear();
147            u.structure.set(globalData, owner, structure);
148        }
149        Instruction(JSGlobalData& globalData, JSCell* owner, StructureChain* structureChain)
150        {
151            u.structureChain.clear();
152            u.structureChain.set(globalData, owner, structureChain);
153        }
154        Instruction(JSGlobalData& globalData, JSCell* owner, JSCell* jsCell)
155        {
156            u.jsCell.clear();
157            u.jsCell.set(globalData, owner, jsCell);
158        }
159        Instruction(PolymorphicAccessStructureList* polymorphicStructures) { u.polymorphicStructures = polymorphicStructures; }
160        Instruction(PropertySlot::GetValueFunc getterFunc) { u.getterFunc = getterFunc; }
161
162        union {
163            Opcode opcode;
164            int operand;
165            WriteBarrierBase<Structure> structure;
166            WriteBarrierBase<StructureChain> structureChain;
167            WriteBarrierBase<JSCell> jsCell;
168            PolymorphicAccessStructureList* polymorphicStructures;
169            PropertySlot::GetValueFunc getterFunc;
170        } u;
171
172    private:
173        Instruction(StructureChain*);
174        Instruction(Structure*);
175    };
176
177} // namespace JSC
178
179namespace WTF {
180
181    template<> struct VectorTraits<JSC::Instruction> : VectorTraitsBase<true, JSC::Instruction> { };
182
183} // namespace WTF
184
185#endif // Instruction_h
186