JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / bytecode / DataFormat.h

diff --git a/bytecode/DataFormat.h b/bytecode/DataFormat.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 DataFormat_h
+#define DataFormat_h
+
+#include <wtf/Assertions.h>
+
+namespace JSC {
+
+// === DataFormat ===
+//
+// This enum tracks the current representation in which a value is being held.
+// Values may be unboxed primitives (int32, double, or cell), or boxed as a JSValue.
+// For boxed values, we may know the type of boxing that has taken place.
+// (May also need bool, array, object, string types!)
+enum DataFormat {
+    DataFormatNone = 0,
+    DataFormatInteger = 1,
+    DataFormatDouble = 2,
+    DataFormatBoolean = 3,
+    DataFormatCell = 4,
+    DataFormatStorage = 5,
+    DataFormatJS = 8,
+    DataFormatJSInteger = DataFormatJS | DataFormatInteger,
+    DataFormatJSDouble = DataFormatJS | DataFormatDouble,
+    DataFormatJSCell = DataFormatJS | DataFormatCell,
+    DataFormatJSBoolean = DataFormatJS | DataFormatBoolean
+};
+
+inline const char* dataFormatToString(DataFormat dataFormat)
+{
+    switch (dataFormat) {
+    case DataFormatNone:
+        return "None";
+    case DataFormatInteger:
+        return "Integer";
+    case DataFormatDouble:
+        return "Double";
+    case DataFormatCell:
+        return "Cell";
+    case DataFormatBoolean:
+        return "Boolean";
+    case DataFormatStorage:
+        return "Storage";
+    case DataFormatJS:
+        return "JS";
+    case DataFormatJSInteger:
+        return "JSInteger";
+    case DataFormatJSDouble:
+        return "JSDouble";
+    case DataFormatJSCell:
+        return "JSCell";
+    case DataFormatJSBoolean:
+        return "JSBoolean";
+    default:
+        return "Unknown";
+    }
+}
+
+#if USE(JSVALUE64)
+inline bool needDataFormatConversion(DataFormat from, DataFormat to)
+{
+    ASSERT(from != DataFormatNone);
+    ASSERT(to != DataFormatNone);
+    switch (from) {
+    case DataFormatInteger:
+    case DataFormatDouble:
+        return to != from;
+    case DataFormatCell:
+    case DataFormatJS:
+    case DataFormatJSInteger:
+    case DataFormatJSDouble:
+    case DataFormatJSCell:
+    case DataFormatJSBoolean:
+        switch (to) {
+        case DataFormatInteger:
+        case DataFormatDouble:
+            return true;
+        case DataFormatCell:
+        case DataFormatJS:
+        case DataFormatJSInteger:
+        case DataFormatJSDouble:
+        case DataFormatJSCell:
+        case DataFormatJSBoolean:
+            return false;
+        default:
+            // This captures DataFormatBoolean, which is currently unused.
+            ASSERT_NOT_REACHED();
+        }
+    case DataFormatStorage:
+        ASSERT(to == DataFormatStorage);
+        return false;
+    default:
+        // This captures DataFormatBoolean, which is currently unused.
+        ASSERT_NOT_REACHED();
+    }
+    return true;
+}
+
+#elif USE(JSVALUE32_64)
+inline bool needDataFormatConversion(DataFormat from, DataFormat to)
+{
+    ASSERT(from != DataFormatNone);
+    ASSERT(to != DataFormatNone);
+    switch (from) {
+    case DataFormatInteger:
+    case DataFormatCell:
+    case DataFormatBoolean:
+        return ((to & DataFormatJS) || to == DataFormatDouble);
+    case DataFormatDouble:
+    case DataFormatJSDouble:
+        return (to != DataFormatDouble && to != DataFormatJSDouble);
+    case DataFormatJS:
+    case DataFormatJSInteger:
+    case DataFormatJSCell:
+    case DataFormatJSBoolean:
+        return (!(to & DataFormatJS) || to == DataFormatJSDouble);
+    case DataFormatStorage:
+        ASSERT(to == DataFormatStorage);
+        return false;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    return true;
+}
+#endif
+
+inline bool isJSFormat(DataFormat format, DataFormat expectedFormat)
+{
+    ASSERT(expectedFormat & DataFormatJS);
+    return (format | DataFormatJS) == expectedFormat;
+}
+
+inline bool isJSInteger(DataFormat format)
+{
+    return isJSFormat(format, DataFormatJSInteger);
+}
+
+inline bool isJSDouble(DataFormat format)
+{
+    return isJSFormat(format, DataFormatJSDouble);
+}
+
+inline bool isJSCell(DataFormat format)
+{
+    return isJSFormat(format, DataFormatJSCell);
+}
+
+inline bool isJSBoolean(DataFormat format)
+{
+    return isJSFormat(format, DataFormatJSBoolean);
+}
+
+}
+
+#endif // DataFormat_h