1/*
2 * Copyright (C) 2014, 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 "DFGCleanUpPhase.h"
28
29#if ENABLE(DFG_JIT)
30
31#include "DFGGraph.h"
32#include "DFGInsertionSet.h"
33#include "DFGPhase.h"
34#include "DFGPredictionPropagationPhase.h"
35#include "DFGVariableAccessDataDump.h"
36#include "JSCInlines.h"
37
38namespace JSC { namespace DFG {
39
40class CleanUpPhase : public Phase {
41public:
42 CleanUpPhase(Graph& graph)
43 : Phase(graph, "clean up")
44 {
45 }
46
47 bool run()
48 {
49 bool changed = false;
50
51 for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
52 unsigned sourceIndex = 0;
53 unsigned targetIndex = 0;
54 while (sourceIndex < block->size()) {
55 Node* node = block->at(sourceIndex++);
56 bool kill = false;
57
58 if (node->op() == Check)
59 node->children = node->children.justChecks();
60
61 switch (node->op()) {
62 case Phantom:
63 case Check:
64 if (node->children.isEmpty())
65 kill = true;
66 break;
67 case CheckVarargs:
68 kill = true;
69 m_graph.doToChildren(node, [&] (Edge edge) {
70 kill &= !edge;
71 });
72 break;
73 default:
74 break;
75 }
76
77 if (kill)
78 m_graph.deleteNode(node);
79 else
80 block->at(targetIndex++) = node;
81 }
82 block->resize(targetIndex);
83 }
84
85 return changed;
86 }
87};
88
89bool performCleanUp(Graph& graph)
90{
91 return runPhase<CleanUpPhase>(graph);
92}
93
94} } // namespace JSC::DFG
95
96#endif // ENABLE(DFG_JIT)
97
98