dfg/DFGEdge.h

   1 /*
   2  * Copyright (C) 2011 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 #ifndef DFGEdge_h
  27 #define DFGEdge_h
  28
  29 #include <wtf/Platform.h>
  30
  31 #if ENABLE(DFG_JIT)
  32
  33 #include "DFGCommon.h"
  34
  35 namespace JSC { namespace DFG {
  36
  37 class AdjacencyList;
  38
  39 class Edge {
  40 public:
  41     Edge()
  42         : m_encodedWord(makeWord(NoNode, UntypedUse))
  43     {
  44     }
  45
  46     explicit Edge(NodeIndex nodeIndex)
  47         : m_encodedWord(makeWord(nodeIndex, UntypedUse))
  48     {
  49     }
  50
  51     Edge(NodeIndex nodeIndex, UseKind useKind)
  52         : m_encodedWord(makeWord(nodeIndex, useKind))
  53     {
  54     }
  55
  56     NodeIndex indexUnchecked() const { return m_encodedWord >> shift(); }
  57     NodeIndex index() const
  58     {
  59         ASSERT(isSet());
  60         return m_encodedWord >> shift();
  61     }
  62     void setIndex(NodeIndex nodeIndex)
  63     {
  64         m_encodedWord = makeWord(nodeIndex, useKind());
  65     }
  66
  67     UseKind useKind() const
  68     {
  69         ASSERT(isSet());
  70         unsigned masked = m_encodedWord & (((1 << shift()) - 1));
  71         ASSERT(masked < LastUseKind);
  72         return static_cast<UseKind>(masked);
  73     }
  74     void setUseKind(UseKind useKind)
  75     {
  76         ASSERT(isSet());
  77         m_encodedWord = makeWord(index(), useKind);
  78     }
  79
  80     bool isSet() const { return indexUnchecked() != NoNode; }
  81     bool operator!() const { return !isSet(); }
  82
  83     bool operator==(Edge other) const
  84     {
  85         return m_encodedWord == other.m_encodedWord;
  86     }
  87     bool operator!=(Edge other) const
  88     {
  89         return m_encodedWord != other.m_encodedWord;
  90     }
  91
  92 private:
  93     friend class AdjacencyList;
  94
  95     static uint32_t shift() { return 4; }
  96
  97     static int32_t makeWord(NodeIndex nodeIndex, UseKind useKind)
  98     {
  99         ASSERT(static_cast<uint32_t>(((static_cast<int32_t>(nodeIndex) << shift()) >> shift())) == nodeIndex);
 100         ASSERT(useKind >= 0 && useKind < LastUseKind);
 101         ASSERT(LastUseKind <= (1 << shift()));
 102         return (nodeIndex << shift()) | useKind;
 103     }
 104
 105     int32_t m_encodedWord;
 106 };
 107
 108 inline bool operator==(Edge nodeUse, NodeIndex nodeIndex)
 109 {
 110     return nodeUse.indexUnchecked() == nodeIndex;
 111 }
 112 inline bool operator==(NodeIndex nodeIndex, Edge nodeUse)
 113 {
 114     return nodeUse.indexUnchecked() == nodeIndex;
 115 }
 116 inline bool operator!=(Edge nodeUse, NodeIndex nodeIndex)
 117 {
 118     return nodeUse.indexUnchecked() != nodeIndex;
 119 }
 120 inline bool operator!=(NodeIndex nodeIndex, Edge nodeUse)
 121 {
 122     return nodeUse.indexUnchecked() != nodeIndex;
 123 }
 124
 125 } } // namespace JSC::DFG
 126
 127 #endif // ENABLE(DFG_JIT)
 128
 129 #endif // DFGEdge_h
 130