bytecode/PolymorphicGetByIdList.cpp

   1 /*
   2  * Copyright (C) 2014 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  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "PolymorphicGetByIdList.h"
  28
  29 #if ENABLE(JIT)
  30
  31 #include "CodeBlock.h"
  32 #include "Heap.h"
  33 #include "JSCInlines.h"
  34 #include "StructureStubInfo.h"
  35
  36 namespace JSC {
  37
  38 GetByIdAccess::GetByIdAccess(
  39     VM& vm, JSCell* owner, AccessType type, PassRefPtr<JITStubRoutine> stubRoutine,
  40     Structure* structure, StructureChain* chain, unsigned chainCount)
  41     : m_type(type)
  42     , m_chainCount(chainCount)
  43     , m_structure(vm, owner, structure)
  44     , m_stubRoutine(stubRoutine)
  45 {
  46     if (chain)
  47         m_chain.set(vm, owner, chain);
  48 }
  49
  50 GetByIdAccess::~GetByIdAccess()
  51 {
  52 }
  53
  54 GetByIdAccess GetByIdAccess::fromStructureStubInfo(StructureStubInfo& stubInfo)
  55 {
  56     MacroAssemblerCodePtr initialSlowPath =
  57         stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToSlowCase);
  58
  59     GetByIdAccess result;
  60
  61     switch (stubInfo.accessType) {
  62     case access_get_by_id_self:
  63         result.m_type = SimpleInline;
  64         result.m_structure.copyFrom(stubInfo.u.getByIdSelf.baseObjectStructure);
  65         result.m_stubRoutine = JITStubRoutine::createSelfManagedRoutine(initialSlowPath);
  66         break;
  67
  68     case access_get_by_id_chain:
  69         result.m_structure.copyFrom(stubInfo.u.getByIdChain.baseObjectStructure);
  70         result.m_chain.copyFrom(stubInfo.u.getByIdChain.chain);
  71         result.m_chainCount = stubInfo.u.getByIdChain.count;
  72         result.m_stubRoutine = stubInfo.stubRoutine;
  73         if (stubInfo.u.getByIdChain.isDirect)
  74             result.m_type = SimpleStub;
  75         else
  76             result.m_type = Getter;
  77         break;
  78
  79     default:
  80         RELEASE_ASSERT_NOT_REACHED();
  81     }
  82
  83     return result;
  84 }
  85
  86 bool GetByIdAccess::visitWeak(RepatchBuffer& repatchBuffer) const
  87 {
  88     if (m_structure && !Heap::isMarked(m_structure.get()))
  89         return false;
  90     if (m_chain && !Heap::isMarked(m_chain.get()))
  91         return false;
  92     if (!m_stubRoutine->visitWeak(repatchBuffer))
  93         return false;
  94     return true;
  95 }
  96
  97 PolymorphicGetByIdList::PolymorphicGetByIdList(StructureStubInfo& stubInfo)
  98 {
  99     if (stubInfo.accessType == access_unset)
 100         return;
 101
 102     m_list.append(GetByIdAccess::fromStructureStubInfo(stubInfo));
 103 }
 104
 105 PolymorphicGetByIdList* PolymorphicGetByIdList::from(StructureStubInfo& stubInfo)
 106 {
 107     if (stubInfo.accessType == access_get_by_id_list)
 108         return stubInfo.u.getByIdList.list;
 109
 110     ASSERT(
 111         stubInfo.accessType == access_get_by_id_self
 112         || stubInfo.accessType == access_get_by_id_chain
 113         || stubInfo.accessType == access_unset);
 114
 115     PolymorphicGetByIdList* result = new PolymorphicGetByIdList(stubInfo);
 116
 117     stubInfo.initGetByIdList(result);
 118
 119     return result;
 120 }
 121
 122 PolymorphicGetByIdList::~PolymorphicGetByIdList() { }
 123
 124 MacroAssemblerCodePtr PolymorphicGetByIdList::currentSlowPathTarget(
 125     StructureStubInfo& stubInfo) const
 126 {
 127     if (isEmpty())
 128         return stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToSlowCase);
 129     return m_list.last().stubRoutine()->code().code();
 130 }
 131
 132 void PolymorphicGetByIdList::addAccess(const GetByIdAccess& access)
 133 {
 134     ASSERT(!isFull());
 135     // Make sure that the resizing optimizes for space, not time.
 136     m_list.resize(m_list.size() + 1);
 137     m_list.last() = access;
 138 }
 139
 140 bool PolymorphicGetByIdList::isFull() const
 141 {
 142     ASSERT(size() <= POLYMORPHIC_LIST_CACHE_SIZE);
 143     return size() == POLYMORPHIC_LIST_CACHE_SIZE;
 144 }
 145
 146 bool PolymorphicGetByIdList::isAlmostFull() const
 147 {
 148     ASSERT(size() <= POLYMORPHIC_LIST_CACHE_SIZE);
 149     return size() >= POLYMORPHIC_LIST_CACHE_SIZE - 1;
 150 }
 151
 152 bool PolymorphicGetByIdList::didSelfPatching() const
 153 {
 154     for (unsigned i = size(); i--;) {
 155         if (at(i).type() == GetByIdAccess::SimpleInline)
 156             return true;
 157     }
 158     return false;
 159 }
 160
 161 bool PolymorphicGetByIdList::visitWeak(RepatchBuffer& repatchBuffer) const
 162 {
 163     for (unsigned i = size(); i--;) {
 164         if (!at(i).visitWeak(repatchBuffer))
 165             return false;
 166     }
 167     return true;
 168 }
 169
 170 } // namespace JSC
 171
 172 #endif // ENABLE(JIT)
 173
 174