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diff --git a/Source/JavaScriptCore/dfg/DFGLoopPreHeaderCreationPhase.h b/Source/JavaScriptCore/dfg/DFGLoopPreHeaderCreationPhase.h
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+/*
+ * Copyright (C) 2013 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 DFGLoopPreHeaderCreationPhase_h
+#define DFGLoopPreHeaderCreationPhase_h
+
+#if ENABLE(DFG_JIT)
+
+namespace JSC { namespace DFG {
+
+class BlockInsertionSet;
+class Graph;
+struct BasicBlock;
+
+// Inserts dummy basic blocks before any loop headers that don't already have
+// a single non-loop predecessor.
+
+bool performLoopPreHeaderCreation(Graph&);
+
+// Creates a new basic block (a pre-header) that jumps to the given block. All
+// predecessors of the given block that aren't dominated by it are rerouted to
+// the pre-header.
+//
+// This function is used internally and it's used in a surgical fashion by
+// OSREntrypointCreationPhase.
+//
+// Note that executing this function requires having an intact dominators
+// analysis. You should run that analysis before doing damage to the CFG, even
+// if said damage is done before you call this.
+BasicBlock* createPreHeader(Graph&, BlockInsertionSet&, BasicBlock*);
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGLoopPreHeaderCreationPhase_h
+