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      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 
     41 namespace 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 
    179 namespace WTF {
    180 
    181     template<> struct VectorTraits<JSC::Instruction> : VectorTraitsBase<true, JSC::Instruction> { };
    182 
    183 } // namespace WTF
    184 
    185 #endif // Instruction_h
    186