JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / dfg / DFGPredictionPropagationPhase.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 DFGPredictionPropagationPhase_h
+#define DFGPredictionPropagationPhase_h
+
+#include <wtf/Platform.h>
+
+#if ENABLE(DFG_JIT)
+
+namespace JSC { namespace DFG {
+
+class Graph;
+
+// Propagate predictions gathered at heap load sites by the value profiler, and
+// from slow path executions, to generate a prediction for each node in the graph.
+// This is a crucial phase of compilation, since before running this phase, we
+// have no idea what types any node (or most variables) could possibly have, unless
+// that node is either a heap load, a call, a GetLocal for an argument, or an
+// arithmetic op that had definitely taken slow path. Most nodes (even most
+// arithmetic nodes) do not qualify for any of these categories. But after running
+// this phase, we'll have full information for the expected type of each node.
+
+void performPredictionPropagation(Graph&);
+
+} } // namespace JSC::DFG::Phase
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGPredictionPropagationPhase_h