Temporarily patch HCompareIDAndBranch to accept Smi.

src/hydrogen.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 9666 matching lines @@
   HValue* left = Pop();
   HInstruction* instr = BuildBinaryOperation(expr, left, right);
   instr->set_position(expr->position());
   return ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 // TODO(rossberg): this should die eventually.
 Representation HOptimizedGraphBuilder::ToRepresentation(TypeInfo info) {
   if (info.IsUninitialized()) return Representation::None();
+  // TODO(verwaest): Return Smi rather than Integer32.
   if (info.IsSmi()) return Representation::Integer32();
   if (info.IsInteger32()) return Representation::Integer32();
   if (info.IsDouble()) return Representation::Double();
   if (info.IsNumber()) return Representation::Double();
   return Representation::Tagged();
 }
 
 
 Representation HOptimizedGraphBuilder::ToRepresentation(Handle<Type> type) {
   if (type->Is(Type::None())) return Representation::None();
@@ skipping 213 matching lines @@
     return ast_context()->ReturnControl(result, expr->id());
   } else {
     if (combined_rep.IsTagged() || combined_rep.IsNone()) {
       HCompareGeneric* result =
           new(zone()) HCompareGeneric(context, left, right, op);
       result->set_observed_input_representation(1, left_rep);
       result->set_observed_input_representation(2, right_rep);
       result->set_position(expr->position());
       return ast_context()->ReturnInstruction(result, expr->id());
     } else {
+      // TODO(verwaest): Remove once ToRepresentation properly returns Smi when
+      // the IC measures Smi.
+      if (left_type->Is(Type::Integer31())) left_rep = Representation::Smi();
+      if (right_type->Is(Type::Integer31())) right_rep = Representation::Smi();
       HCompareIDAndBranch* result =
           new(zone()) HCompareIDAndBranch(left, right, op);
       result->set_observed_input_representation(left_rep, right_rep);
       result->set_position(expr->position());
       return ast_context()->ReturnControl(result, expr->id());
     }
   }
 }
 
 
@@ skipping 1684 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal