Revert of [runtime] Replace global object link with native context link in all contexts.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 296 matching lines @@
 
 
 void JSGenericLowering::LowerJSLoadGlobal(Node* node) {
   Node* context = NodeProperties::GetContextInput(node);
   Node* effect = NodeProperties::GetEffectInput(node);
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   const LoadGlobalParameters& p = LoadGlobalParametersOf(node->op());
   Callable callable = CodeFactory::LoadICInOptimizedCode(
       isolate(), p.typeof_mode(), SLOPPY, UNINITIALIZED);
   // Load global object from the context.
-  Node* native_context =
-      graph()->NewNode(machine()->Load(kMachAnyTagged), context,
-                       jsgraph()->IntPtrConstant(
-                           Context::SlotOffset(Context::NATIVE_CONTEXT_INDEX)),
-                       effect, graph()->start());
-  Node* global = graph()->NewNode(
-      machine()->Load(kMachAnyTagged), native_context,
-      jsgraph()->IntPtrConstant(Context::SlotOffset(Context::EXTENSION_INDEX)),
-      effect, graph()->start());
+  Node* global = graph()->NewNode(machine()->Load(kMachAnyTagged), context,
+                                  jsgraph()->IntPtrConstant(Context::SlotOffset(
+                                      Context::GLOBAL_OBJECT_INDEX)),
+                                  effect, graph()->start());
   node->InsertInput(zone(), 0, global);
   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
   node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
   ReplaceWithStubCall(node, callable, flags);
 }
 
 
 void JSGenericLowering::LowerJSStoreProperty(Node* node) {
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   PropertyAccess const& p = PropertyAccessOf(node->op());
@@ skipping 21 matching lines @@
 
 
 void JSGenericLowering::LowerJSStoreGlobal(Node* node) {
   Node* context = NodeProperties::GetContextInput(node);
   Node* effect = NodeProperties::GetEffectInput(node);
   CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
   const StoreGlobalParameters& p = StoreGlobalParametersOf(node->op());
   Callable callable = CodeFactory::StoreICInOptimizedCode(
       isolate(), p.language_mode(), UNINITIALIZED);
   // Load global object from the context.
-  Node* native_context =
-      graph()->NewNode(machine()->Load(kMachAnyTagged), context,
-                       jsgraph()->IntPtrConstant(
-                           Context::SlotOffset(Context::NATIVE_CONTEXT_INDEX)),
-                       effect, graph()->start());
-  Node* global = graph()->NewNode(
-      machine()->Load(kMachAnyTagged), native_context,
-      jsgraph()->IntPtrConstant(Context::SlotOffset(Context::EXTENSION_INDEX)),
-      effect, graph()->start());
+  Node* global = graph()->NewNode(machine()->Load(kMachAnyTagged), context,
+                                  jsgraph()->IntPtrConstant(Context::SlotOffset(
+                                      Context::GLOBAL_OBJECT_INDEX)),
+                                  effect, graph()->start());
   node->InsertInput(zone(), 0, global);
   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
   DCHECK(p.feedback().index() != -1);
   node->InsertInput(zone(), 3, jsgraph()->SmiConstant(p.feedback().index()));
   ReplaceWithStubCall(node, callable,
                       CallDescriptor::kPatchableCallSite | flags);
 }
 
 
 void JSGenericLowering::LowerJSDeleteProperty(Node* node) {
@@ skipping 46 matching lines @@
                             graph()->start()));
   }
   node->ReplaceInput(2, NodeProperties::GetValueInput(node, 1));
   node->ReplaceInput(1, jsgraph()->Int32Constant(Context::SlotOffset(
                             static_cast<int>(access.index()))));
   NodeProperties::ChangeOp(node, machine()->Store(StoreRepresentation(
                                      kMachAnyTagged, kFullWriteBarrier)));
 }
 
 
+void JSGenericLowering::LowerJSLoadNativeContext(Node* node) {
+  node->ReplaceInput(
+      1, jsgraph()->IntPtrConstant(JSGlobalObject::kNativeContextOffset -
+                                   kHeapObjectTag));
+  node->AppendInput(zone(), graph()->start());
+  NodeProperties::ChangeOp(node, machine()->Load(kMachAnyTagged));
+}
+
+
 void JSGenericLowering::LowerJSLoadDynamic(Node* node) {
   const DynamicAccess& access = DynamicAccessOf(node->op());
   Runtime::FunctionId function_id =
       (access.typeof_mode() == NOT_INSIDE_TYPEOF)
           ? Runtime::kLoadLookupSlot
           : Runtime::kLoadLookupSlotNoReferenceError;
   Node* projection = graph()->NewNode(common()->Projection(0), node);
   NodeProperties::ReplaceUses(node, projection, node, node, node);
   node->RemoveInput(NodeProperties::FirstValueIndex(node));
   node->InsertInput(zone(), 1, jsgraph()->Constant(access.name()));
@@ skipping 438 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8