1 files changed, 104 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/bytecode/ArrayProfile.h b/Source/JavaScriptCore/bytecode/ArrayProfile.h
new file mode 100644
index 000000000..5a656e2dd
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/ArrayProfile.h
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2012 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 ArrayProfile_h
+#define ArrayProfile_h
+
+#include "JSArray.h"
+#include "Structure.h"
+#include <wtf/HashMap.h>
+#include <wtf/SegmentedVector.h>
+
+namespace JSC {
+
+class LLIntOffsetsExtractor;
+
+typedef unsigned ArrayModes;
+
+static const unsigned IsNotArray = 1;
+static const unsigned IsJSArray  = 2;
+
+inline ArrayModes arrayModeFromStructure(Structure* structure)
+{
+    if (structure->classInfo() == &JSArray::s_info)
+        return IsJSArray;
+    return IsNotArray;
+}
+
+class ArrayProfile {
+public:
+    ArrayProfile()
+        : m_bytecodeOffset(std::numeric_limits<unsigned>::max())
+        , m_lastSeenStructure(0)
+        , m_expectedStructure(0)
+        , m_structureIsPolymorphic(false)
+        , m_observedArrayModes(0)
+    {
+    }
+    
+    ArrayProfile(unsigned bytecodeOffset)
+        : m_bytecodeOffset(bytecodeOffset)
+        , m_lastSeenStructure(0)
+        , m_expectedStructure(0)
+        , m_structureIsPolymorphic(false)
+        , m_observedArrayModes(0)
+    {
+    }
+    
+    unsigned bytecodeOffset() const { return m_bytecodeOffset; }
+    
+    Structure** addressOfLastSeenStructure() { return &m_lastSeenStructure; }
+    
+    void observeStructure(Structure* structure)
+    {
+        m_lastSeenStructure = structure;
+    }
+    
+    void computeUpdatedPrediction(OperationInProgress operation = NoOperation);
+    
+    Structure* expectedStructure() const { return m_expectedStructure; }
+    bool structureIsPolymorphic() const { return m_structureIsPolymorphic; }
+    bool hasDefiniteStructure() const
+    {
+        return !structureIsPolymorphic() && m_expectedStructure;
+    }
+    ArrayModes observedArrayModes() const { return m_observedArrayModes; }
+    
+private:
+    friend class LLIntOffsetsExtractor;
+    
+    unsigned m_bytecodeOffset;
+    Structure* m_lastSeenStructure;
+    Structure* m_expectedStructure;
+    bool m_structureIsPolymorphic;
+    ArrayModes m_observedArrayModes;
+};
+
+typedef SegmentedVector<ArrayProfile, 4, 0> ArrayProfileVector;
+
+} // namespace JSC
+
+#endif // ArrayProfile_h
+