1/*
2 * Copyright (C) 2013, 2015 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 "DFGUnificationPhase.h"
28
29#if ENABLE(DFG_JIT)
30
31#include "DFGBasicBlockInlines.h"
32#include "DFGGraph.h"
33#include "DFGPhase.h"
34#include "JSCInlines.h"
35
36namespace JSC { namespace DFG {
37
38class UnificationPhase : public Phase {
39public:
40 UnificationPhase(Graph& graph)
41 : Phase(graph, "unification")
42 {
43 }
44
45 bool run()
46 {
47 ASSERT(m_graph.m_form == ThreadedCPS);
48 ASSERT(m_graph.m_unificationState == LocallyUnified);
49
50 // Ensure that all Phi functions are unified.
51 for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
52 BasicBlock* block = m_graph.block(blockIndex);
53 if (!block)
54 continue;
55 ASSERT(block->isReachable);
56
57 for (unsigned phiIndex = block->phis.size(); phiIndex--;) {
58 Node* phi = block->phis[phiIndex];
59 for (unsigned childIdx = 0; childIdx < AdjacencyList::Size; ++childIdx) {
60 if (!phi->children.child(childIdx))
61 break;
62
63 // FIXME: Consider reversing the order of this unification, since the other
64 // order will reveal more bugs. https://bugs.webkit.org/show_bug.cgi?id=154368
65 phi->variableAccessData()->unify(phi->children.child(childIdx)->variableAccessData());
66 }
67 }
68 }
69
70 // Ensure that all predictions are fixed up based on the unification.
71 for (unsigned i = 0; i < m_graph.m_variableAccessData.size(); ++i) {
72 VariableAccessData* data = &m_graph.m_variableAccessData[i];
73 data->find()->predict(data->nonUnifiedPrediction());
74 data->find()->mergeStructureCheckHoistingFailed(data->structureCheckHoistingFailed());
75 data->find()->mergeCheckArrayHoistingFailed(data->checkArrayHoistingFailed());
76 data->find()->mergeShouldNeverUnbox(data->shouldNeverUnbox());
77 data->find()->mergeIsLoadedFrom(data->isLoadedFrom());
78 data->find()->mergeIsProfitableToUnbox(data->isProfitableToUnbox());
79 }
80
81 m_graph.m_unificationState = GloballyUnified;
82 return true;
83 }
84};
85
86bool performUnification(Graph& graph)
87{
88 return runPhase<UnificationPhase>(graph);
89}
90
91} } // namespace JSC::DFG
92
93#endif // ENABLE(DFG_JIT)
94
95