Speculate on bitwise operators.

runtime/vm/redundancy_elimination.cc

 // Copyright (c) 2016, 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.
 
 #include "vm/redundancy_elimination.h"
 
 #include "vm/bit_vector.h"
 #include "vm/flow_graph.h"
 #include "vm/hash_map.h"
 #include "vm/il_printer.h"
@@ skipping 985 matching lines @@
 
     return false;
   }
 
   // Check if any use of the definition can create an alias.
   // Can add more objects into aliasing_worklist_.
   bool AnyUseCreatesAlias(Definition* defn) {
     for (Value* use = defn->input_use_list(); use != NULL;
          use = use->next_use()) {
       Instruction* instr = use->instruction();
-      if (instr->IsPushArgument() ||
+      if (instr->IsPushArgument() || instr->IsCheckedSmiOp() ||
+          instr->IsCheckedSmiComparison() ||

[Vyacheslav Egorov (Google), 2016/11/15 21:58:34]

We should consider making this a flag / function on a Instruction. 

If we decide to add a new instruction with a slow path that can call arbitrary
Dart code we might forget to add a rule here again.

           (instr->IsStoreIndexed() &&
            (use->use_index() == StoreIndexedInstr::kValuePos)) ||
           instr->IsStoreStaticField() || instr->IsPhi()) {
         return true;
       } else if ((instr->IsAssertAssignable() || instr->IsRedefinition()) &&
                  AnyUseCreatesAlias(instr->AsDefinition())) {
         return true;
       } else if ((instr->IsStoreInstanceField() &&
                   (use->use_index() !=
                    StoreInstanceFieldInstr::kInstancePos))) {
@@ skipping 2356 matching lines @@
         join->phis_ = NULL;
       } else {
         join->phis_->TruncateTo(to_index);
       }
     }
   }
 }
 
 
 }  // namespace dart