c1e5e67584769c5ae23fc1453c15da4ae2c460ab
[WebKit-https.git] / Source / JavaScriptCore / 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