Move back primary header includes next to config.h
[WebKit-https.git] / Source / JavaScriptCore / dfg / DFGOSRAvailabilityAnalysisPhase.cpp
1 /*
2  * Copyright (C) 2013 Apple Inc. All rights reserved.
3  *
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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,
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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 "DFGOSRAvailabilityAnalysisPhase.h"
28
29 #if ENABLE(DFG_JIT)
30
31 #include "DFGBasicBlockInlines.h"
32 #include "DFGGraph.h"
33 #include "DFGInsertionSet.h"
34 #include "DFGPhase.h"
35 #include "JSCInlines.h"
36
37 namespace JSC { namespace DFG {
38
39 class OSRAvailabilityAnalysisPhase : public Phase {
40 public:
41     OSRAvailabilityAnalysisPhase(Graph& graph)
42         : Phase(graph, "OSR availability analysis")
43     {
44     }
45     
46     bool run()
47     {
48         ASSERT(m_graph.m_form == SSA);
49         
50         for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
51             BasicBlock* block = m_graph.block(blockIndex);
52             if (!block)
53                 continue;
54             block->ssa->availabilityAtHead.fill(Availability());
55             block->ssa->availabilityAtTail.fill(Availability());
56         }
57         
58         BasicBlock* root = m_graph.block(0);
59         for (unsigned argument = root->ssa->availabilityAtHead.numberOfArguments(); argument--;) {
60             root->ssa->availabilityAtHead.argument(argument) =
61                 Availability::unavailable().withFlush(
62                     FlushedAt(FlushedJSValue, virtualRegisterForArgument(argument)));
63         }
64
65         if (m_graph.m_plan.mode == FTLForOSREntryMode) {
66             for (unsigned local = m_graph.m_profiledBlock->m_numCalleeRegisters; local--;)
67                 root->ssa->availabilityAtHead.local(local) = Availability::unavailable();
68         } else {
69             for (unsigned local = root->ssa->availabilityAtHead.numberOfLocals(); local--;)
70                 root->ssa->availabilityAtHead.local(local) = Availability::unavailable();
71         }
72         
73         // This could be made more efficient by processing blocks in reverse postorder.
74         Operands<Availability> availability;
75         bool changed;
76         do {
77             changed = false;
78             
79             for (BlockIndex blockIndex = 0; blockIndex < m_graph.numBlocks(); ++blockIndex) {
80                 BasicBlock* block = m_graph.block(blockIndex);
81                 if (!block)
82                     continue;
83                 
84                 availability = block->ssa->availabilityAtHead;
85                 
86                 for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
87                     Node* node = block->at(nodeIndex);
88                     
89                     switch (node->op()) {
90                     case SetLocal: {
91                         VariableAccessData* variable = node->variableAccessData();
92                         availability.operand(variable->local()) =
93                             Availability(node->child1().node(), variable->flushedAt());
94                         break;
95                     }
96                         
97                     case GetArgument: {
98                         VariableAccessData* variable = node->variableAccessData();
99                         availability.operand(variable->local()) =
100                             Availability(node, variable->flushedAt());
101                         break;
102                     }
103                         
104                     case MovHint: {
105                         availability.operand(node->unlinkedLocal()) =
106                             Availability(node->child1().node());
107                         break;
108                     }
109                         
110                     case ZombieHint: {
111                         availability.operand(node->unlinkedLocal()) =
112                             Availability::unavailable();
113                         break;
114                     }
115                         
116                     default:
117                         break;
118                     }
119                 }
120                 
121                 if (availability == block->ssa->availabilityAtTail)
122                     continue;
123                 
124                 block->ssa->availabilityAtTail = availability;
125                 changed = true;
126                 
127                 for (unsigned successorIndex = block->numSuccessors(); successorIndex--;) {
128                     BasicBlock* successor = block->successor(successorIndex);
129                     for (unsigned i = availability.size(); i--;) {
130                         successor->ssa->availabilityAtHead[i] = availability[i].merge(
131                             successor->ssa->availabilityAtHead[i]);
132                     }
133                 }
134             }
135         } while (changed);
136         
137         return true;
138     }
139 };
140
141 bool performOSRAvailabilityAnalysis(Graph& graph)
142 {
143     SamplingRegion samplingRegion("DFG OSR Availability Analysis Phase");
144     return runPhase<OSRAvailabilityAnalysisPhase>(graph);
145 }
146
147 } } // namespace JSC::DFG
148
149 #endif // ENABLE(DFG_JIT)
150