Restrict immediate operands to smi where only smis are supported.

runtime/vm/flow_graph_optimizer.cc

 // 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 14 matching lines @@
 DECLARE_FLAG(bool, trace_type_check_elimination);
 DEFINE_FLAG(bool, use_cha, true, "Use class hierarchy analysis.");
 DEFINE_FLAG(bool, load_cse, true, "Use redundant load elimination.");
 DEFINE_FLAG(bool, trace_range_analysis, false, "Trace range analysis progress");
 DEFINE_FLAG(bool, trace_constant_propagation, false,
     "Print constant propagation and useless code elimination.");
 DEFINE_FLAG(bool, array_bounds_check_elimination, true,
     "Eliminate redundant bounds checks.");
 DEFINE_FLAG(int, max_polymorphic_checks, 4,
     "Maximum number of polymorphic check, otherwise it is megamorphic.");
-DEFINE_FLAG(bool, remove_redundant_phis, false,
-    "Remove redundant phis (disabled as causes incorrect code).");
+DEFINE_FLAG(bool, remove_redundant_phis, true, "Remove redundant phis.");
 
 
 void FlowGraphOptimizer::ApplyICData() {
   VisitBlocks();
 }
 
 
 // Attempts to convert an instance call (IC call) using propagated class-ids,
 // e.g., receiver class id.
 void FlowGraphOptimizer::ApplyClassIds() {
@@ skipping 3686 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart