Ensure that all phis inserted by load optimizer have consistent representation.

runtime/vm/compiler.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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
@@ skipping 427 matching lines @@
       optimizer.EliminateEnvironments();
 
       // Attempt to sink allocations of temporary non-escaping objects to
       // the deoptimization path.
       AllocationSinking* sinking = NULL;
       if (FLAG_allocation_sinking) {
         sinking = new AllocationSinking(flow_graph);
         sinking->Optimize();
       }
 
+      // Ensure that all phis inserted by optimization passes have consistent
+      // representations.
+      optimizer.UnboxPhis();
+
       if (optimizer.Canonicalize()) {
         // To fully remove redundant boxing (e.g. BoxDouble used only in
         // environments and UnboxDouble instructions) instruction we
         // first need to replace all their uses and then fold them away.
         // For now we just repeat Canonicalize twice to do that.
         // TODO(vegorov): implement a separate representation folding pass.
         optimizer.Canonicalize();
       }
       DEBUG_ASSERT(flow_graph->VerifyUseLists());
 
@@ skipping 409 matching lines @@
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart