VM: Avoid repeated deoptimizations from hoisted array bounds checks.

runtime/vm/flow_graph_optimizer.cc

 // 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 5028 matching lines @@
 
 void LICM::Hoist(ForwardInstructionIterator* it,
                  BlockEntryInstr* pre_header,
                  Instruction* current) {
   if (current->IsCheckClass()) {
     current->AsCheckClass()->set_licm_hoisted(true);
   } else if (current->IsCheckSmi()) {
     current->AsCheckSmi()->set_licm_hoisted(true);
   } else if (current->IsCheckEitherNonSmi()) {
     current->AsCheckEitherNonSmi()->set_licm_hoisted(true);
+  } else if (current->IsCheckArrayBound()) {
+    current->AsCheckArrayBound()->set_licm_hoisted(true);
   }
-  // TODO(fschneider): Avoid repeated deoptimization when
-  // speculatively hoisting checks.
   if (FLAG_trace_optimization) {
     OS::Print("Hoisting instruction %s:%" Pd " from B%" Pd " to B%" Pd "\n",
               current->DebugName(),
               current->GetDeoptId(),
               current->GetBlock()->block_id(),
               pre_header->block_id());
   }
   // Move the instruction out of the loop.
   current->RemoveEnvironment();
   if (it != NULL) {
@@ skipping 5045 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, alloc->cls(), *slots);
   }
 }
 
 
 }  // namespace dart