JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / dfg / DFGEdge.h

diff --git a/dfg/DFGEdge.h b/dfg/DFGEdge.h
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+/*
+ * Copyright (C) 2011 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef DFGEdge_h
+#define DFGEdge_h
+
+#include <wtf/Platform.h>
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGCommon.h"
+
+namespace JSC { namespace DFG {
+
+class AdjacencyList;
+
+class Edge {
+public:
+    Edge()
+        : m_encodedWord(makeWord(NoNode, UntypedUse))
+    {
+    }
+    
+    explicit Edge(NodeIndex nodeIndex)
+        : m_encodedWord(makeWord(nodeIndex, UntypedUse))
+    {
+    }
+    
+    Edge(NodeIndex nodeIndex, UseKind useKind)
+        : m_encodedWord(makeWord(nodeIndex, useKind))
+    {
+    }
+    
+    NodeIndex indexUnchecked() const { return m_encodedWord >> shift(); }
+    NodeIndex index() const
+    {
+        ASSERT(isSet());
+        return m_encodedWord >> shift();
+    }
+    void setIndex(NodeIndex nodeIndex)
+    {
+        m_encodedWord = makeWord(nodeIndex, useKind());
+    }
+    
+    UseKind useKind() const
+    {
+        ASSERT(isSet());
+        unsigned masked = m_encodedWord & (((1 << shift()) - 1));
+        ASSERT(masked < LastUseKind);
+        return static_cast<UseKind>(masked);
+    }
+    void setUseKind(UseKind useKind)
+    {
+        ASSERT(isSet());
+        m_encodedWord = makeWord(index(), useKind);
+    }
+    
+    bool isSet() const { return indexUnchecked() != NoNode; }
+    bool operator!() const { return !isSet(); }
+    
+    bool operator==(Edge other) const
+    {
+        return m_encodedWord == other.m_encodedWord;
+    }
+    bool operator!=(Edge other) const
+    {
+        return m_encodedWord != other.m_encodedWord;
+    }
+
+private:
+    friend class AdjacencyList;
+    
+    static uint32_t shift() { return 4; }
+    
+    static int32_t makeWord(NodeIndex nodeIndex, UseKind useKind)
+    {
+        ASSERT(static_cast<uint32_t>(((static_cast<int32_t>(nodeIndex) << shift()) >> shift())) == nodeIndex);
+        ASSERT(useKind >= 0 && useKind < LastUseKind);
+        ASSERT(LastUseKind <= (1 << shift()));
+        return (nodeIndex << shift()) | useKind;
+    }
+    
+    int32_t m_encodedWord;
+};
+
+inline bool operator==(Edge nodeUse, NodeIndex nodeIndex)
+{
+    return nodeUse.indexUnchecked() == nodeIndex;
+}
+inline bool operator==(NodeIndex nodeIndex, Edge nodeUse)
+{
+    return nodeUse.indexUnchecked() == nodeIndex;
+}
+inline bool operator!=(Edge nodeUse, NodeIndex nodeIndex)
+{
+    return nodeUse.indexUnchecked() != nodeIndex;
+}
+inline bool operator!=(NodeIndex nodeIndex, Edge nodeUse)
+{
+    return nodeUse.indexUnchecked() != nodeIndex;
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGEdge_h
+