Tag smi-constants as smi.

src/hydrogen-instructions.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 2147 matching lines @@
       boolean_value_(double_value != 0 && !std::isnan(double_value)),
       int32_value_(DoubleToInt32(double_value)),
       double_value_(double_value) {
   has_smi_value_ = has_int32_value_ && Smi::IsValid(int32_value_);
   Initialize(r);
 }
 
 
 void HConstant::Initialize(Representation r) {
   if (r.IsNone()) {
-    if (has_int32_value_) {
+    if (has_smi_value_) {
+      r = Representation::Smi();
+    } else if (has_int32_value_) {
       r = Representation::Integer32();
     } else if (has_double_value_) {
       r = Representation::Double();
     } else {
       r = Representation::Tagged();
     }
   }
   set_representation(r);
   SetFlag(kUseGVN);
   if (representation().IsInteger32()) {
@@ skipping 1614 matching lines @@
     case kBackingStore:
       if (!name_.is_null()) stream->Add(*String::cast(*name_)->ToCString());
       stream->Add("[backing-store]");
       break;
   }
 
   stream->Add("@%d", offset());
 }
 
 } }  // namespace v8::internal