DFG optimizes out strict mode arguments tear off

[WebKit-https.git] / Source / JavaScriptCore / dfg / DFGArgumentsSimplificationPhase.cpp

diff --git a/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp b/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
index 1972c97..8022b52 100644 (file)
--- a/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
@@ -122,12 +122,9 @@ public:
         bool changed = false;
         
         // Record which arguments are known to escape no matter what.
-        for (unsigned i = codeBlock()->inlineCallFrames().size(); i--;) {
-            InlineCallFrame* inlineCallFrame = &codeBlock()->inlineCallFrames()[i];
-            if (m_graph.m_executablesWhoseArgumentsEscaped.contains(
-                    m_graph.executableFor(inlineCallFrame)))
-                m_createsArguments.add(inlineCallFrame);
-        }
+        for (unsigned i = codeBlock()->inlineCallFrames().size(); i--;)
+            pruneObviousArgumentCreations(&codeBlock()->inlineCallFrames()[i]);
+        pruneObviousArgumentCreations(0); // the machine call frame.
         
         // Create data for variable access datas that we will want to analyze.
         for (unsigned i = m_graph.m_variableAccessData.size(); i--;) {
@@ -694,6 +691,14 @@ private:
             NullableHashTraits<VariableAccessData*> > m_argumentsAliasing;
     HashSet<VariableAccessData*> m_isLive;
 
+    void pruneObviousArgumentCreations(InlineCallFrame* inlineCallFrame)
+    {
+        ScriptExecutable* executable = m_graph.executableFor(inlineCallFrame);
+        if (m_graph.m_executablesWhoseArgumentsEscaped.contains(executable)
+            || executable->isStrictMode())
+            m_createsArguments.add(inlineCallFrame);
+    }
+    
     void observeBadArgumentsUse(Node* node)
     {
         if (!node)