2 files changed, 32 insertions, 0 deletions
diff --git a/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp b/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
index 41b5c39..04dae15 100644
--- a/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
+++ b/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
@@ -1281,6 +1281,19 @@ RegisterID* BytecodeGenerator::emitDeleteById(RegisterID* dst, RegisterID* base,
 
 RegisterID* BytecodeGenerator::emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
 {
+    for (size_t i = m_forInContextStack.size(); i > 0; i--) {
+        ForInContext& context = m_forInContextStack[i - 1];
+        if (context.propertyRegister == property) {
+            emitOpcode(op_get_by_pname);
+            instructions().append(dst->index());
+            instructions().append(base->index());
+            instructions().append(property->index());
+            instructions().append(context.expectedSubscriptRegister->index());
+            instructions().append(context.iterRegister->index());
+            instructions().append(context.indexRegister->index());
+            return dst;
+        }
+    }
     emitOpcode(op_get_by_val);
     instructions().append(dst->index());
     instructions().append(base->index());
diff --git a/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.h
index 61de173..4648fb5 100644
--- a/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.h
+++ b/src/3rdparty/webkit/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -61,6 +61,13 @@ namespace JSC {
         FinallyContext finallyContext;
     };
 
+    struct ForInContext {
+        RefPtr<RegisterID> expectedSubscriptRegister;
+        RefPtr<RegisterID> iterRegister;
+        RefPtr<RegisterID> indexRegister;
+        RefPtr<RegisterID> propertyRegister;
+    };
+
     class BytecodeGenerator : public FastAllocBase {
     public:
         typedef DeclarationStacks::VarStack VarStack;
@@ -331,6 +338,17 @@ namespace JSC {
         void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
         void popFinallyContext();
 
+        void pushOptimisedForIn(RegisterID* expectedBase, RegisterID* iter, RegisterID* index, RegisterID* propertyRegister)
+        {
+            ForInContext context = { expectedBase, iter, index, propertyRegister };
+            m_forInContextStack.append(context);
+        }
+
+        void popOptimisedForIn()
+        {
+            m_forInContextStack.removeLast();
+        }
+
         LabelScope* breakTarget(const Identifier&);
         LabelScope* continueTarget(const Identifier&);
 
@@ -467,6 +485,7 @@ namespace JSC {
 
         Vector<ControlFlowContext> m_scopeContextStack;
         Vector<SwitchInfo> m_switchContextStack;
+        Vector<ForInContext> m_forInContextStack;
 
         int m_nextGlobalIndex;
         int m_nextParameterIndex;