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

src/compiler/ast-graph-builder.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/compiler/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 3246 matching lines @@
                                          FrameStateBeforeAndAfter& states,
                                          const VectorSlotPair& feedback,
                                          OutputFrameStateCombine combine,
                                          ContextualMode contextual_mode) {
   Node* the_hole = jsgraph()->TheHoleConstant();
   VariableMode mode = variable->mode();
   switch (variable->location()) {
     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;
     }
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL: {
       // Local var, const, or let variable.
       Node* value = environment()->Lookup(variable);
       if (mode == CONST_LEGACY) {
         // Perform check for uninitialized legacy const variables.
         if (value->op() == the_hole->op()) {
@@ skipping 117 matching lines @@
 Node* AstGraphBuilder::BuildVariableAssignment(
     Variable* variable, Node* value, Token::Value op,
     const VectorSlotPair& feedback, BailoutId bailout_id,
     FrameStateBeforeAndAfter& states, OutputFrameStateCombine combine) {
   Node* the_hole = jsgraph()->TheHoleConstant();
   VariableMode mode = variable->mode();
   switch (variable->location()) {
     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;
     }
     case VariableLocation::PARAMETER:
     case VariableLocation::LOCAL:
       // Local var, const, or let variable.
       if (mode == CONST_LEGACY && op == Token::INIT_CONST_LEGACY) {
         // Perform an initialization check for legacy const variables.
         Node* current = environment()->Lookup(variable);
         if (current->op() != the_hole->op()) {
@@ skipping 183 matching lines @@
   Node* name_node = jsgraph()->Constant(name);
   Runtime::FunctionId function_id = is_strict(language_mode())
                                         ? Runtime::kStoreToSuper_Strict
                                         : Runtime::kStoreToSuper_Sloppy;
   const Operator* op = javascript()->CallRuntime(function_id, 4);
   Node* node = NewNode(op, receiver, home_object, name_node, value);
   return Record(js_type_feedback_, node, id);
 }
 
 
-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());
   }
   return Record(js_type_feedback_, node, id);
 }
 
 
 Node* AstGraphBuilder::BuildLoadObjectField(Node* object, int offset) {
   return NewNode(jsgraph()->machine()->Load(kMachAnyTagged), object,
                  jsgraph()->IntPtrConstant(offset - kHeapObjectTag));
@@ skipping 273 matching lines @@
     size = size + kInputBufferSizeIncrement + input_buffer_size_;
     input_buffer_ = local_zone()->NewArray<Node*>(size);
     input_buffer_size_ = size;
   }
   return input_buffer_;
 }
 
 
 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);
   bool has_control = op->ControlInputCount() == 1;
   bool has_effect = op->EffectInputCount() == 1;
 
   DCHECK(op->ControlInputCount() < 2);
   DCHECK(op->EffectInputCount() < 2);
 
   Node* result = NULL;
@@ skipping 270 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8