Only infer int32 in HBoundsCheck if input is double or int32.

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 1129 matching lines @@
     stream->Add(" + %d) >> %d)", offset(), scale());
   }
   if (skip_check()) {
     stream->Add(" [DISABLED]");
   }
 }
 
 
 void HBoundsCheck::InferRepresentation(HInferRepresentation* h_infer) {
   ASSERT(CheckFlag(kFlexibleRepresentation));
-  Representation r;
   HValue* actual_index = index()->ActualValue();
   HValue* actual_length = length()->ActualValue();
   Representation index_rep = actual_index->representation();
-  if (!actual_length->representation().IsSmiOrTagged()) {
-    r = Representation::Integer32();
-  } else if ((index_rep.IsTagged() && actual_index->type().IsSmi()) ||
-      index_rep.IsSmi()) {
-    // If the index is smi, allow the length to be smi, since it is usually
-    // already smi from loading it out of the length field of a JSArray.  This
-    // allows for direct comparison without untagging.
-    r = Representation::Smi();
-  } else {
+  Representation length_rep = actual_length->representation();
+  if (index_rep.IsTagged()) index_rep = Representation::Smi();
+  if (length_rep.IsTagged()) length_rep = Representation::Smi();
+  Representation r = index_rep.generalize(length_rep);
+  if (r.is_more_general_than(Representation::Integer32())) {
     r = Representation::Integer32();
   }
   UpdateRepresentation(r, h_infer, "boundscheck");
 }
 
 
 bool HBoundsCheckBaseIndexInformation::IsRelationTrueInternal(
     NumericRelation relation,
     HValue* related_value,
     int offset,
@@ skipping 2682 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