JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / dfg / DFGCleanUpPhase.cpp

diff --git a/dfg/DFGCleanUpPhase.cpp b/dfg/DFGCleanUpPhase.cpp
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+/*
+ * Copyright (C) 2014, 2015 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. 
+ */
+
+#include "config.h"
+#include "DFGCleanUpPhase.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGGraph.h"
+#include "DFGInsertionSet.h"
+#include "DFGPhase.h"
+#include "DFGPredictionPropagationPhase.h"
+#include "DFGVariableAccessDataDump.h"
+#include "JSCInlines.h"
+
+namespace JSC { namespace DFG {
+
+class CleanUpPhase : public Phase {
+public:
+    CleanUpPhase(Graph& graph)
+        : Phase(graph, "clean up")
+    {
+    }
+    
+    bool run()
+    {
+        bool changed = false;
+        
+        for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+            unsigned sourceIndex = 0;
+            unsigned targetIndex = 0;
+            while (sourceIndex < block->size()) {
+                Node* node = block->at(sourceIndex++);
+                bool kill = false;
+                
+                if (node->op() == Check)
+                    node->children = node->children.justChecks();
+                
+                switch (node->op()) {
+                case Phantom:
+                case Check:
+                    if (node->children.isEmpty())
+                        kill = true;
+                    break;
+                default:
+                    break;
+                }
+                
+                if (kill)
+                    m_graph.m_allocator.free(node);
+                else
+                    block->at(targetIndex++) = node;
+            }
+            block->resize(targetIndex);
+        }
+        
+        return changed;
+    }
+};
+    
+bool performCleanUp(Graph& graph)
+{
+    SamplingRegion samplingRegion("DFG Clean Up Phase");
+    return runPhase<CleanUpPhase>(graph);
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+