JavaScriptCore-1218.tar.gz

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

diff --git a/dfg/DFGUnificationPhase.cpp b/dfg/DFGUnificationPhase.cpp
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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. 
+ */
+
+#include "config.h"
+#include "DFGUnificationPhase.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGBasicBlockInlines.h"
+#include "DFGGraph.h"
+#include "DFGPhase.h"
+#include "Operations.h"
+
+namespace JSC { namespace DFG {
+
+class UnificationPhase : public Phase {
+public:
+    UnificationPhase(Graph& graph)
+        : Phase(graph, "unification")
+    {
+    }
+    
+    bool run()
+    {
+        ASSERT(m_graph.m_form == ThreadedCPS);
+        ASSERT(m_graph.m_unificationState == LocallyUnified);
+        
+        // Ensure that all Phi functions are unified.
+        for (BlockIndex blockIndex = m_graph.m_blocks.size(); blockIndex--;) {
+            BasicBlock* block = m_graph.m_blocks[blockIndex].get();
+            if (!block)
+                continue;
+            ASSERT(block->isReachable);
+            
+            for (unsigned phiIndex = block->phis.size(); phiIndex--;) {
+                Node* phi = block->phis[phiIndex];
+                for (unsigned childIdx = 0; childIdx < AdjacencyList::Size; ++childIdx) {
+                    if (!phi->children.child(childIdx))
+                        break;
+                    
+                    phi->variableAccessData()->unify(
+                        phi->children.child(childIdx)->variableAccessData());
+                }
+            }
+        }
+        
+        // Ensure that all predictions are fixed up based on the unification.
+        for (unsigned i = 0; i < m_graph.m_variableAccessData.size(); ++i) {
+            VariableAccessData* data = &m_graph.m_variableAccessData[i];
+            data->find()->predict(data->nonUnifiedPrediction());
+            data->find()->mergeIsCaptured(data->isCaptured());
+            data->find()->mergeStructureCheckHoistingFailed(data->structureCheckHoistingFailed());
+            data->find()->mergeShouldNeverUnbox(data->shouldNeverUnbox());
+            data->find()->mergeIsLoadedFrom(data->isLoadedFrom());
+        }
+        
+        m_graph.m_unificationState = GloballyUnified;
+        return true;
+    }
+};
+
+bool performUnification(Graph& graph)
+{
+    SamplingRegion samplingRegion("DFG Unification Phase");
+    return runPhase<UnificationPhase>(graph);
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+