Fix overflow check computation for Smi Phis

src/hydrogen-representation-changes.cc

 // Copyright 2013 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 109 matching lines @@
     for (HUseIterator it(phi->uses()); !it.Done(); it.Advance()) {
       // If a Phi is used as a non-truncating int32 or as a double,
       // clear its "truncating" flag.
       HValue* use = it.value();
       Representation input_representation =
           use->RequiredInputRepresentation(it.index());
       if ((phi->representation().IsInteger32() &&
            !(input_representation.IsInteger32() &&
              use->CheckFlag(HValue::kTruncatingToInt32))) ||
           (phi->representation().IsSmi() &&
-           !(input_representation.IsSmi() ||
+           !(input_representation.IsSmi() &&
              use->CheckFlag(HValue::kTruncatingToSmi)))) {
         if (FLAG_trace_representation) {
           PrintF("#%d Phi is not truncating because of #%d %s\n",
                  phi->id(), it.value()->id(), it.value()->Mnemonic());
         }
         phi->ClearFlag(HValue::kTruncatingToInt32);
         phi->ClearFlag(HValue::kTruncatingToSmi);
         worklist.Add(phi, zone());
         break;
       }
@@ skipping 32 matching lines @@
     // Process normal instructions.
     for (HInstruction* current = block->first(); current != NULL; ) {
       HInstruction* next = current->next();
       InsertRepresentationChangesForValue(current);
       current = next;
     }
   }
 }
 
 } }  // namespace v8::internal