Array constructor can be simplified by loading context from JSFunction.

src/code-stubs-hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * 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
@@ skipping 63 matching lines @@
   HValue* GetArgumentsLength() {
     // This is initialized in BuildGraph()
     ASSERT(arguments_length_ != NULL);
     return arguments_length_;
   }
   CompilationInfo* info() { return &info_; }
   HydrogenCodeStub* stub() { return info_.code_stub(); }
   HContext* context() { return context_; }
   Isolate* isolate() { return info_.isolate(); }
 
-  class ArrayContextChecker {
-   public:
-    ArrayContextChecker(HGraphBuilder* builder, HValue* constructor,
-                        HValue* array_function)
-        : checker_(builder) {
-      checker_.If<HCompareObjectEqAndBranch, HValue*>(constructor,
-                                                      array_function);
-      checker_.Then();
-    }
-
-    ~ArrayContextChecker() {
-      checker_.ElseDeopt("Array constructor called from different context");
-      checker_.End();
-    }
-   private:
-    IfBuilder checker_;
-  };
-
   enum ArgumentClass {
     NONE,
     SINGLE,
     MULTIPLE
   };
 
   HValue* BuildArrayConstructor(ElementsKind kind,
-                                ContextCheckMode context_mode,
                                 AllocationSiteOverrideMode override_mode,
                                 ArgumentClass argument_class);
   HValue* BuildInternalArrayConstructor(ElementsKind kind,
                                         ArgumentClass argument_class);
 
   void BuildInstallOptimizedCode(HValue* js_function, HValue* native_context,
                                  HValue* code_object);
   void BuildInstallCode(HValue* js_function, HValue* shared_info);
   void BuildInstallFromOptimizedCodeMap(HValue* js_function,
                                         HValue* shared_info,
@@ skipping 545 matching lines @@
   return GetParameter(0);
 }
 
 
 Handle<Code> TransitionElementsKindStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 HValue* CodeStubGraphBuilderBase::BuildArrayConstructor(
     ElementsKind kind,
-    ContextCheckMode context_mode,
     AllocationSiteOverrideMode override_mode,
     ArgumentClass argument_class) {
   HValue* constructor = GetParameter(ArrayConstructorStubBase::kConstructor);
-  if (context_mode == CONTEXT_CHECK_REQUIRED) {
-    HInstruction* array_function = BuildGetArrayFunction();
-    ArrayContextChecker checker(this, constructor, array_function);
-  }
-
   HValue* property_cell = GetParameter(ArrayConstructorStubBase::kPropertyCell);
   // Walk through the property cell to the AllocationSite
   HValue* alloc_site = Add<HLoadNamedField>(property_cell,
                                             HObjectAccess::ForCellValue());
   JSArrayBuilder array_builder(this, kind, alloc_site, constructor,
                                override_mode);
   HValue* result = NULL;
   switch (argument_class) {
     case NONE:
       result = array_builder.AllocateEmptyArray();
@@ skipping 86 matching lines @@
 
   Add<HStoreKeyed>(elements, key, argument, kind);
   builder.EndBody();
   return new_object;
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<ArrayNoArgumentConstructorStub>::BuildCodeStub() {
   ElementsKind kind = casted_stub()->elements_kind();
-  ContextCheckMode context_mode = casted_stub()->context_mode();
   AllocationSiteOverrideMode override_mode = casted_stub()->override_mode();
-  return BuildArrayConstructor(kind, context_mode, override_mode, NONE);
+  return BuildArrayConstructor(kind, override_mode, NONE);
 }
 
 
 Handle<Code> ArrayNoArgumentConstructorStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<ArraySingleArgumentConstructorStub>::
     BuildCodeStub() {
   ElementsKind kind = casted_stub()->elements_kind();
-  ContextCheckMode context_mode = casted_stub()->context_mode();
   AllocationSiteOverrideMode override_mode = casted_stub()->override_mode();
-  return BuildArrayConstructor(kind, context_mode, override_mode, SINGLE);
+  return BuildArrayConstructor(kind, override_mode, SINGLE);
 }
 
 
 Handle<Code> ArraySingleArgumentConstructorStub::GenerateCode(
     Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<ArrayNArgumentsConstructorStub>::BuildCodeStub() {
   ElementsKind kind = casted_stub()->elements_kind();
-  ContextCheckMode context_mode = casted_stub()->context_mode();
   AllocationSiteOverrideMode override_mode = casted_stub()->override_mode();
-  return BuildArrayConstructor(kind, context_mode, override_mode, MULTIPLE);
+  return BuildArrayConstructor(kind, override_mode, MULTIPLE);
 }
 
 
 Handle<Code> ArrayNArgumentsConstructorStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<InternalArrayNoArgumentConstructorStub>::
@@ skipping 541 matching lines @@
   return BuildUncheckedDictionaryElementLoad(receiver, key);
 }
 
 
 Handle<Code> KeyedLoadDictionaryElementStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 } }  // namespace v8::internal