Ensure we can reliably check the cell for validity of global property

src/ic/x64/handler-compiler-x64.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/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/ic/call-optimization.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 483 matching lines @@
     // Go to the next object in the prototype chain.
     current = prototype;
     current_map = handle(current->map());
   }
 
   DCHECK(!current_map->IsJSGlobalProxyMap());
 
   // Log the check depth.
   LOG(isolate(), IntEvent("check-maps-depth", depth + 1));
 
-  if (depth != 0 || check == CHECK_ALL_MAPS) {
+  if (!current_map->IsJSGlobalObjectMap() &&
+      (depth != 0 || check == CHECK_ALL_MAPS)) {
     __ movp(scratch1, FieldOperand(reg, HeapObject::kMapOffset));
     Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
     __ CmpWeakValue(scratch1, cell, scratch2);
     __ j(not_equal, miss);
   }
 
   // Return the register containing the holder.
   return reg;
 }
 
@@ skipping 204 matching lines @@
   return GetCode(kind(), Code::FAST, name);
 }
 
 
 Register NamedStoreHandlerCompiler::value() {
   return StoreDescriptor::ValueRegister();
 }
 
 
 Handle<Code> NamedLoadHandlerCompiler::CompileLoadGlobal(
-    Handle<PropertyCell> cell, Handle<Name> name, bool is_configurable) {
+    Handle<PropertyCell> cell, Handle<Name> name) {
   Label miss;
   if (IC::ICUseVector(kind())) {
     PushVectorAndSlot();
   }
   FrontendHeader(receiver(), name, &miss);
 
   // Get the value from the cell.
   Register result = StoreDescriptor::ValueRegister();
   Handle<WeakCell> weak_cell = factory()->NewWeakCell(cell);
   __ LoadWeakValue(result, weak_cell, &miss);
   __ movp(result, FieldOperand(result, PropertyCell::kValueOffset));
 
-  // Check for deleted property if property can actually be deleted.
-  if (is_configurable) {
-    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
-    __ j(equal, &miss);
-  } else if (FLAG_debug_code) {
-    __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
-    __ Check(not_equal, kDontDeleteCellsCannotContainTheHole);
-  }
+  __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
+  __ j(equal, &miss);
 
   Counters* counters = isolate()->counters();
   __ IncrementCounter(counters->named_load_global_stub(), 1);
   if (IC::ICUseVector(kind())) {
     DiscardVectorAndSlot();
   }
   __ ret(0);
 
   FrontendFooter(name, &miss);
 
   // Return the generated code.
   return GetCode(kind(), Code::NORMAL, name);
 }
 
 
 #undef __
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64