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     RELEASE_ASSERT(stubInfo.accessType == access_get_by_id_self);
  62
  63     result.m_type = SimpleInline;
  64     result.m_structure.copyFrom(stubInfo.u.getByIdSelf.baseObjectStructure);
  65     result.m_stubRoutine = JITStubRoutine::createSelfManagedRoutine(initialSlowPath);
  66
  67     return result;
  68 }
  69
  70 bool GetByIdAccess::visitWeak(RepatchBuffer& repatchBuffer) const
  71 {
  72     if (m_structure && !Heap::isMarked(m_structure.get()))
  73         return false;
  74     if (m_chain && !Heap::isMarked(m_chain.get()))
  75         return false;
  76     if (!m_stubRoutine->visitWeak(repatchBuffer))
  77         return false;
  78     return true;
  79 }
  80
  81 PolymorphicGetByIdList::PolymorphicGetByIdList(StructureStubInfo& stubInfo)
  82 {
  83     if (stubInfo.accessType == access_unset)
  84         return;
  85
  86     m_list.append(GetByIdAccess::fromStructureStubInfo(stubInfo));
  87 }
  88
  89 PolymorphicGetByIdList* PolymorphicGetByIdList::from(StructureStubInfo& stubInfo)
  90 {
  91     if (stubInfo.accessType == access_get_by_id_list)
  92         return stubInfo.u.getByIdList.list;
  93
  94     ASSERT(
  95         stubInfo.accessType == access_get_by_id_self
  96         || stubInfo.accessType == access_unset);
  97
  98     PolymorphicGetByIdList* result = new PolymorphicGetByIdList(stubInfo);
  99
 100     stubInfo.initGetByIdList(result);
 101
 102     return result;
 103 }
 104
 105 PolymorphicGetByIdList::~PolymorphicGetByIdList() { }
 106
 107 MacroAssemblerCodePtr PolymorphicGetByIdList::currentSlowPathTarget(
 108     StructureStubInfo& stubInfo) const
 109 {
 110     if (isEmpty())
 111         return stubInfo.callReturnLocation.labelAtOffset(stubInfo.patch.deltaCallToSlowCase);
 112     return m_list.last().stubRoutine()->code().code();
 113 }
 114
 115 void PolymorphicGetByIdList::addAccess(const GetByIdAccess& access)
 116 {
 117     ASSERT(!isFull());
 118     // Make sure that the resizing optimizes for space, not time.
 119     m_list.resizeToFit(m_list.size() + 1);
 120     m_list.last() = access;
 121 }
 122
 123 bool PolymorphicGetByIdList::isFull() const
 124 {
 125     ASSERT(size() <= POLYMORPHIC_LIST_CACHE_SIZE);
 126     return size() == POLYMORPHIC_LIST_CACHE_SIZE;
 127 }
 128
 129 bool PolymorphicGetByIdList::isAlmostFull() const
 130 {
 131     ASSERT(size() <= POLYMORPHIC_LIST_CACHE_SIZE);
 132     return size() >= POLYMORPHIC_LIST_CACHE_SIZE - 1;
 133 }
 134
 135 bool PolymorphicGetByIdList::didSelfPatching() const
 136 {
 137     for (unsigned i = size(); i--;) {
 138         if (at(i).type() == GetByIdAccess::SimpleInline)
 139             return true;
 140     }
 141     return false;
 142 }
 143
 144 bool PolymorphicGetByIdList::visitWeak(RepatchBuffer& repatchBuffer) const
 145 {
 146     for (unsigned i = size(); i--;) {
 147         if (!at(i).visitWeak(repatchBuffer))
 148             return false;
 149     }
 150     return true;
 151 }
 152
 153 } // namespace JSC
 154
 155 #endif // ENABLE(JIT)
 156
 157