Add explicit smi checks for unary smi operations.

runtime/vm/intermediate_language.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 1914 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(BinaryDoubleOpComp);
 };
 
 
 // Handles both Smi operations: BIT_OR and NEGATE.
 class UnarySmiOpComp : public TemplateComputation<1> {
  public:
   UnarySmiOpComp(Token::Kind op_kind,
                  InstanceCallComp* instance_call,
-                Value* value)
+                 Value* value)
       : op_kind_(op_kind), instance_call_(instance_call) {
+    ASSERT((op_kind == Token::kNEGATE) || (op_kind == Token::kBIT_NOT));
     ASSERT(value != NULL);
     inputs_[0] = value;
   }
 
   Value* value() const { return inputs_[0]; }
   Token::Kind op_kind() const { return op_kind_; }
 
   InstanceCallComp* instance_call() const { return instance_call_; }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
   DECLARE_COMPUTATION(UnarySmiOp)
 
-  virtual bool CanDeoptimize() const { return true; }
+  virtual bool CanDeoptimize() const { return op_kind() == Token::kNEGATE; }
   virtual intptr_t ResultCid() const { return kSmiCid; }
 
  private:
   const Token::Kind op_kind_;
   InstanceCallComp* instance_call_;
 
   DISALLOW_COPY_AND_ASSIGN(UnarySmiOpComp);
 };
 
 
@@ skipping 1428 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_