bytecode/Instruction.h

   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             PolymorphicStubInfo()
  71             {
  72                 u.proto.clear();
  73             }
  74
  75             void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base)
  76             {
  77                 stubRoutine = _stubRoutine;
  78                 base.set(globalData, owner, _base);
  79                 u.proto.clear();
  80                 isChain = false;
  81             }
  82
  83             void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, Structure* _proto)
  84             {
  85                 stubRoutine = _stubRoutine;
  86                 base.set(globalData, owner, _base);
  87                 u.proto.set(globalData, owner, _proto);
  88                 isChain = false;
  89             }
  90
  91             void set(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType _stubRoutine, Structure* _base, StructureChain* _chain)
  92             {
  93                 stubRoutine = _stubRoutine;
  94                 base.set(globalData, owner, _base);
  95                 u.chain.set(globalData, owner, _chain);
  96                 isChain = true;
  97             }
  98         } list[POLYMORPHIC_LIST_CACHE_SIZE];
  99
 100         PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase)
 101         {
 102             list[0].set(globalData, owner, stubRoutine, firstBase);
 103         }
 104
 105         PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, Structure* firstProto)
 106         {
 107             list[0].set(globalData, owner, stubRoutine, firstBase, firstProto);
 108         }
 109
 110         PolymorphicAccessStructureList(JSGlobalData& globalData, JSCell* owner, PolymorphicAccessStructureListStubRoutineType stubRoutine, Structure* firstBase, StructureChain* firstChain)
 111         {
 112             list[0].set(globalData, owner, stubRoutine, firstBase, firstChain);
 113         }
 114
 115         void visitAggregate(SlotVisitor& visitor, int count)
 116         {
 117             for (int i = 0; i < count; ++i) {
 118                 PolymorphicStubInfo& info = list[i];
 119                 if (!info.base) {
 120                     // We're being marked during initialisation of an entry
 121                     ASSERT(!info.u.proto);
 122                     continue;
 123                 }
 124
 125                 visitor.append(&info.base);
 126                 if (info.u.proto && !info.isChain)
 127                     visitor.append(&info.u.proto);
 128                 if (info.u.chain && info.isChain)
 129                     visitor.append(&info.u.chain);
 130             }
 131         }
 132     };
 133
 134     struct Instruction {
 135         Instruction(Opcode opcode)
 136         {
 137 #if !ENABLE(COMPUTED_GOTO_INTERPRETER)
 138             // We have to initialize one of the pointer members to ensure that
 139             // the entire struct is initialized, when opcode is not a pointer.
 140             u.jsCell.clear();
 141 #endif
 142             u.opcode = opcode;
 143         }
 144
 145         Instruction(int operand)
 146         {
 147             // We have to initialize one of the pointer members to ensure that
 148             // the entire struct is initialized in 64-bit.
 149             u.jsCell.clear();
 150             u.operand = operand;
 151         }
 152
 153         Instruction(JSGlobalData& globalData, JSCell* owner, Structure* structure)
 154         {
 155             u.structure.clear();
 156             u.structure.set(globalData, owner, structure);
 157         }
 158         Instruction(JSGlobalData& globalData, JSCell* owner, StructureChain* structureChain)
 159         {
 160             u.structureChain.clear();
 161             u.structureChain.set(globalData, owner, structureChain);
 162         }
 163         Instruction(JSGlobalData& globalData, JSCell* owner, JSCell* jsCell)
 164         {
 165             u.jsCell.clear();
 166             u.jsCell.set(globalData, owner, jsCell);
 167         }
 168         Instruction(PolymorphicAccessStructureList* polymorphicStructures) { u.polymorphicStructures = polymorphicStructures; }
 169         Instruction(PropertySlot::GetValueFunc getterFunc) { u.getterFunc = getterFunc; }
 170
 171         union {
 172             Opcode opcode;
 173             int operand;
 174             WriteBarrierBase<Structure> structure;
 175             WriteBarrierBase<StructureChain> structureChain;
 176             WriteBarrierBase<JSCell> jsCell;
 177             PolymorphicAccessStructureList* polymorphicStructures;
 178             PropertySlot::GetValueFunc getterFunc;
 179         } u;
 180
 181     private:
 182         Instruction(StructureChain*);
 183         Instruction(Structure*);
 184     };
 185
 186 } // namespace JSC
 187
 188 namespace WTF {
 189
 190     template<> struct VectorTraits<JSC::Instruction> : VectorTraitsBase<true, JSC::Instruction> { };
 191
 192 } // namespace WTF
 193
 194 #endif // Instruction_h