[turbofan] Add fast path for cached property names.

src/compiler/js-global-object-specialization.cc

 // Copyright 2015 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/js-global-object-specialization.h"
 
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-graph.h"
@@ skipping 44 matching lines @@
   if (representation == MachineRepresentation::kTaggedSigned) {
     kind = kNoWriteBarrier;
   } else if (representation == MachineRepresentation::kTaggedPointer) {
     kind = kPointerWriteBarrier;
   }
   MachineType r = MachineType::TypeForRepresentation(representation);
   FieldAccess access = {
       kTaggedBase, PropertyCell::kValueOffset, name, map, type, r, kind};
   return access;
 }
+
 }  // namespace
 
 Reduction JSGlobalObjectSpecialization::ReduceJSLoadGlobal(Node* node) {
   DCHECK_EQ(IrOpcode::kJSLoadGlobal, node->opcode());
   Handle<Name> name = LoadGlobalParametersOf(node->op()).name();
   Node* effect = NodeProperties::GetEffectInput(node);
   Node* control = NodeProperties::GetControlInput(node);
 
   // Try to lookup the name on the script context table first (lexical scoping).
   ScriptContextTableLookupResult result;
   if (LookupInScriptContextTable(name, &result)) {
     if (result.context->is_the_hole(isolate(), result.index)) return NoChange();
     Node* context = jsgraph()->HeapConstant(result.context);
     Node* value = effect = graph()->NewNode(
         javascript()->LoadContext(0, result.index, result.immutable), context,
         effect);
     ReplaceWithValue(node, value, effect);
     return Replace(value);
   }
 
   // Lookup on the global object instead.  We only deal with own data
   // properties of the global object here (represented as PropertyCell).
   LookupIterator it(global_object(), name, LookupIterator::OWN);
+  it.TryLookupCachedProperty();
   if (it.state() != LookupIterator::DATA) return NoChange();
   if (!it.GetHolder<JSObject>()->IsJSGlobalObject()) return NoChange();
   Handle<PropertyCell> property_cell = it.GetPropertyCell();
   PropertyDetails property_details = property_cell->property_details();
   Handle<Object> property_cell_value(property_cell->value(), isolate());
 
   // Load from non-configurable, read-only data property on the global
   // object can be constant-folded, even without deoptimization support.
   if (!property_details.IsConfigurable() && property_details.IsReadOnly()) {
     Node* value = jsgraph()->Constant(property_cell_value);
@@ skipping 187 matching lines @@
   return jsgraph()->javascript();
 }
 
 SimplifiedOperatorBuilder* JSGlobalObjectSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8