JavaScriptCore-521.tar.gz

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

diff --git a/bytecode/JumpTable.h b/bytecode/JumpTable.h
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+/*
+ * Copyright (C) 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
+ *
+ * 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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 JumpTable_h
+#define JumpTable_h
+
+#include "UString.h"
+#include <wtf/HashMap.h>
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+    struct OffsetLocation {
+        int32_t branchOffset;
+#if ENABLE(JIT)
+        void* ctiOffset;
+#endif
+    };
+
+    struct StringJumpTable {
+        typedef HashMap<RefPtr<UString::Rep>, OffsetLocation> StringOffsetTable;
+        StringOffsetTable offsetTable;
+#if ENABLE(JIT)
+        void* ctiDefault; // FIXME: it should not be necessary to store this.
+#endif
+
+        inline int32_t offsetForValue(UString::Rep* value, int32_t defaultOffset)
+        {
+            StringOffsetTable::const_iterator end = offsetTable.end();
+            StringOffsetTable::const_iterator loc = offsetTable.find(value);
+            if (loc == end)
+                return defaultOffset;
+            return loc->second.branchOffset;
+        }
+
+#if ENABLE(JIT)
+        inline void* ctiForValue(UString::Rep* value)
+        {
+            StringOffsetTable::const_iterator end = offsetTable.end();
+            StringOffsetTable::const_iterator loc = offsetTable.find(value);
+            if (loc == end)
+                return ctiDefault;
+            return loc->second.ctiOffset;
+        }
+#endif
+    };
+
+    struct SimpleJumpTable {
+        // FIXME: The two Vectors can be combind into one Vector<OffsetLocation>
+        Vector<int32_t> branchOffsets;
+        int32_t min;
+#if ENABLE(JIT)
+        Vector<void*> ctiOffsets;
+        void* ctiDefault;
+#endif
+
+        int32_t offsetForValue(int32_t value, int32_t defaultOffset);
+        void add(int32_t key, int32_t offset)
+        {
+            if (!branchOffsets[key])
+                branchOffsets[key] = offset;
+        }
+
+#if ENABLE(JIT)
+        inline void* ctiForValue(int32_t value)
+        {
+            if (value >= min && static_cast<uint32_t>(value - min) < ctiOffsets.size())
+                return ctiOffsets[value - min];
+            return ctiDefault;
+        }
+#endif
+    };
+
+} // namespace JSC
+
+#endif // JumpTable_h