dfg/DFGClobberSet.h

   1 /*
   2  * Copyright (C) 2013 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
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   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,
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  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef DFGClobberSet_h
  27 #define DFGClobberSet_h
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "DFGAbstractHeap.h"
  32 #include <wtf/HashMap.h>
  33 #include <wtf/HashSet.h>
  34 #include <wtf/PrintStream.h>
  35
  36 namespace JSC { namespace DFG {
  37
  38 class Graph;
  39 struct Node;
  40
  41 // FIXME: If we ever want to compare if two nodes clobber each other, we should
  42 // have a SmallClobberSet, which just keeps an array of the AbstractHeaps and
  43 // satisfies overlaps() requests by looping over all of them. This will probably
  44 // be faster than a full HashMap in a lot of cases. Or, maybe, we could have
  45 // ClobberSet be smart and use a vector so long as it was small.
  46
  47 class ClobberSet {
  48 public:
  49     ClobberSet();
  50     ~ClobberSet();
  51
  52     bool isEmpty() const { return m_clobbers.isEmpty(); }
  53
  54     void add(AbstractHeap);
  55     void addAll(const ClobberSet&);
  56     bool contains(AbstractHeap) const;
  57     bool overlaps(AbstractHeap) const;
  58     void clear();
  59
  60     // Calls useful for debugging the ClobberSet.
  61
  62     HashSet<AbstractHeap> direct() const;
  63     HashSet<AbstractHeap> super() const;
  64
  65     void dump(PrintStream&) const;
  66
  67 private:
  68     HashSet<AbstractHeap> setOf(bool direct) const;
  69
  70     // Maps heap to:
  71     // true --> it's a direct clobber
  72     // false --> it's just a supertype of a direct clobber
  73     HashMap<AbstractHeap, bool> m_clobbers;
  74 };
  75
  76 class ClobberSetAdd {
  77 public:
  78     ClobberSetAdd(ClobberSet& set)
  79         : m_set(set)
  80     {
  81     }
  82
  83     void operator()(AbstractHeap heap)
  84     {
  85         m_set.add(heap);
  86     }
  87 private:
  88     ClobberSet& m_set;
  89 };
  90
  91 class ClobberSetOverlaps {
  92 public:
  93     ClobberSetOverlaps(const ClobberSet& set)
  94         : m_set(set)
  95         , m_result(false)
  96     {
  97     }
  98
  99     void operator()(AbstractHeap heap)
 100     {
 101         m_result |= m_set.overlaps(heap);
 102     }
 103
 104     bool result() const { return m_result; }
 105
 106 private:
 107     const ClobberSet& m_set;
 108     bool m_result;
 109 };
 110
 111 void addReads(Graph&, Node*, ClobberSet&);
 112 void addWrites(Graph&, Node*, ClobberSet&);
 113 void addReadsAndWrites(Graph&, Node*, ClobberSet& reads, ClobberSet& writes);
 114
 115 bool readsOverlap(Graph&, Node*, ClobberSet&);
 116 bool writesOverlap(Graph&, Node*, ClobberSet&);
 117
 118 } } // namespace JSC::DFG
 119
 120 #endif // ENABLE(DFG_JIT)
 121
 122 #endif // DFGClobberSet_h
 123