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