Assign less environments in StoreNamedField

src/x64/lithium-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 2276 matching lines @@
   } else {
     val = UseRegister(instr->value());
   }
 
   // We only need a scratch register if we have a write barrier or we
   // have a store into the properties array (not in-object-property).
   LOperand* temp = (!is_in_object || needs_write_barrier ||
       needs_write_barrier_for_map) ? TempRegister() : NULL;
 
   LStoreNamedField* result = new(zone()) LStoreNamedField(obj, val, temp);
-  if ((FLAG_track_fields && instr->field_representation().IsSmi()) ||
-      (FLAG_track_heap_object_fields &&
-       instr->field_representation().IsHeapObject())) {
-    return AssignEnvironment(result);
+  if (FLAG_track_heap_object_fields &&
+      instr->field_representation().IsHeapObject()) {
+    if (!instr->value()->type().IsHeapObject()) {
+      return AssignEnvironment(result);
+    }
   }
   return result;
 }
 
 
 LInstruction* LChunkBuilder::DoStoreNamedGeneric(HStoreNamedGeneric* instr) {
   LOperand* object = UseFixed(instr->object(), rdx);
   LOperand* value = UseFixed(instr->value(), rax);
 
   LStoreNamedGeneric* result = new(zone()) LStoreNamedGeneric(object, value);
@@ skipping 263 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64