Loads and stores to global vars are now made via property cell shortcuts installed into parent scri…

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index d04fc62c71dc060cc321b5cb8fe3f3c8ad08875a..6aae85bc9b4a76c8b58b8b683778e850374bcbc6 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -3264,9 +3264,23 @@ Node* AstGraphBuilder::BuildVariableLoad(Variable* variable,
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
       // Global var, const, or let variable.
+      Node* script_context = current_context();
+      int slot_index = -1;
+      if (variable->index() > 0) {
+        DCHECK(variable->IsStaticGlobalObjectProperty());
+        // Each var occupies two slots in the context: for reads and writes.
+        slot_index = variable->index();
+        int depth = current_scope()->ContextChainLength(variable->scope());
+        if (depth > 0) {
+          const Operator* op = javascript()->LoadContext(
+              depth - 1, Context::PREVIOUS_INDEX, true);
+          script_context = NewNode(op, current_context());
+        }
+      }
       Node* global = BuildLoadGlobalObject();
       Handle<Name> name = variable->name();
-      Node* value = BuildGlobalLoad(global, name, feedback, contextual_mode);
+      Node* value = BuildGlobalLoad(script_context, global, name, feedback,
+                                    contextual_mode, slot_index);
       states.AddToNode(value, bailout_id, combine);
       return value;
     }
@@ -3404,10 +3418,24 @@ Node* AstGraphBuilder::BuildVariableAssignment(
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED: {
       // Global var, const, or let variable.
+      Node* script_context = current_context();
+      int slot_index = -1;
+      if (variable->index() > 0) {
+        DCHECK(variable->IsStaticGlobalObjectProperty());
+        // Each var occupies two slots in the context: for reads and writes.
+        slot_index = variable->index();
+        int depth = current_scope()->ContextChainLength(variable->scope());
+        if (depth > 0) {
+          const Operator* op = javascript()->LoadContext(
+              depth - 1, Context::PREVIOUS_INDEX, true);
+          script_context = NewNode(op, current_context());
+        }
+      }
       Node* global = BuildLoadGlobalObject();
       Handle<Name> name = variable->name();
-      Node* store = BuildGlobalStore(global, name, value, feedback,
-                                     TypeFeedbackId::None());
+      Node* store =
+          BuildGlobalStore(script_context, global, name, value, feedback,
+                           TypeFeedbackId::None(), slot_index);
       states.AddToNode(store, bailout_id, combine);
       return store;
     }
@@ -3611,23 +3639,25 @@ Node* AstGraphBuilder::BuildNamedSuperStore(Node* receiver, Node* home_object,
 }
 
 
-Node* AstGraphBuilder::BuildGlobalLoad(Node* object, Handle<Name> name,
+Node* AstGraphBuilder::BuildGlobalLoad(Node* script_context, Node* global,
+                                       Handle<Name> name,
                                        const VectorSlotPair& feedback,
-                                       ContextualMode mode) {
+                                       ContextualMode mode, int slot_index) {
   const Operator* op =
-      javascript()->LoadGlobal(MakeUnique(name), feedback, mode);
-  Node* node = NewNode(op, object, BuildLoadFeedbackVector());
+      javascript()->LoadGlobal(MakeUnique(name), feedback, mode, slot_index);
+  Node* node = NewNode(op, script_context, global, BuildLoadFeedbackVector());
   return Record(js_type_feedback_, node, feedback.slot());
 }
 
 
-Node* AstGraphBuilder::BuildGlobalStore(Node* object, Handle<Name> name,
-                                        Node* value,
+Node* AstGraphBuilder::BuildGlobalStore(Node* script_context, Node* global,
+                                        Handle<Name> name, Node* value,
                                         const VectorSlotPair& feedback,
-                                        TypeFeedbackId id) {
-  const Operator* op =
-      javascript()->StoreGlobal(language_mode(), MakeUnique(name), feedback);
-  Node* node = NewNode(op, object, value, BuildLoadFeedbackVector());
+                                        TypeFeedbackId id, int slot_index) {
+  const Operator* op = javascript()->StoreGlobal(
+      language_mode(), MakeUnique(name), feedback, slot_index);
+  Node* node =
+      NewNode(op, script_context, global, value, BuildLoadFeedbackVector());
   if (FLAG_vector_stores) {
     return Record(js_type_feedback_, node, feedback.slot());
   }
@@ -3921,7 +3951,7 @@ Node** AstGraphBuilder::EnsureInputBufferSize(int size) {
 
 Node* AstGraphBuilder::MakeNode(const Operator* op, int value_input_count,
                                 Node** value_inputs, bool incomplete) {
-  DCHECK(op->ValueInputCount() == value_input_count);
+  DCHECK_EQ(op->ValueInputCount(), value_input_count);
 
   bool has_context = OperatorProperties::HasContextInput(op);
   int frame_state_count = OperatorProperties::GetFrameStateInputCount(op);