Merged r11907 into 3.11 branch.

src/x64/lithium-codegen-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2217 matching lines @@
       current =
           Handle<HeapObject>(HeapObject::cast(current->map()->prototype()));
     }
     __ LoadRoot(result, Heap::kUndefinedValueRootIndex);
   }
 }
 
 
 // Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
 // prototype chain, which causes unbounded code generation.
-static bool CompactEmit(
-    SmallMapList* list, Handle<String> name, int i, Isolate* isolate) {
+static bool CompactEmit(SmallMapList* list,
+                        Handle<String> name,
+                        int i,
+                        Isolate* isolate) {
+  Handle<Map> map = list->at(i);
+  // If the map has ElementsKind transitions, we will generate map checks
+  // for each kind in __ CompareMap(..., ALLOW_ELEMENTS_TRANSITION_MAPS).
+  if (map->elements_transition_map() != NULL) return false;
   LookupResult lookup(isolate);
-  Handle<Map> map = list->at(i);
   map->LookupInDescriptors(NULL, *name, &lookup);
   return lookup.IsFound() &&
       (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION);
 }
 
 
 void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
   Register object = ToRegister(instr->object());
   Register result = ToRegister(instr->result());
 
@@ skipping 2693 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64