Optimize the multiplication of two 32-bit unsigned integers.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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 7068 matching lines @@
   Token::Kind op_kind() const { return op_kind_; }
 
   bool can_overflow() const { return can_overflow_; }
   void set_can_overflow(bool value) { can_overflow_ = value; }
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
   virtual bool CanDeoptimize() const {
     return FLAG_throw_on_javascript_int_overflow
         || (can_overflow() && ((op_kind() == Token::kADD) ||
-                               (op_kind() == Token::kSUB)));
+                               (op_kind() == Token::kSUB)))
+        || (op_kind() == Token::kMUL);  // Deopt if inputs are not int32.
   }
 
   virtual Representation representation() const {
     return kUnboxedMint;
   }
 
   virtual Representation RequiredInputRepresentation(intptr_t idx) const {
     ASSERT((idx == 0) || (idx == 1));
     return kUnboxedMint;
   }
@@ skipping 1468 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_