Revert r20998.

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/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/hash_map.h"
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/resolver.h"
 #include "vm/scopes.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, array_bounds_check_elimination, true,
     "Eliminate redundant bounds checks.");
+// TODO(srdjan): Enable/remove flag once it works.
+DEFINE_FLAG(bool, inline_getter_with_guarded_cid, false,
+    "Inline implict getter using guarded cid");
 DEFINE_FLAG(bool, load_cse, true, "Use redundant load elimination.");
 DEFINE_FLAG(int, max_polymorphic_checks, 4,
     "Maximum number of polymorphic check, otherwise it is megamorphic.");
 DEFINE_FLAG(bool, remove_redundant_phis, true, "Remove redundant phis.");
 DEFINE_FLAG(bool, trace_constant_propagation, false,
     "Print constant propagation and useless code elimination.");
 DEFINE_FLAG(bool, trace_optimization, false, "Print optimization details.");
 DEFINE_FLAG(bool, trace_range_analysis, false, "Trace range analysis progress");
 DEFINE_FLAG(bool, truncating_left_shift, true,
     "Optimize left shift to truncate if possible");
@@ skipping 1155 matching lines @@
 
   if (InstanceCallNeedsClassCheck(call)) {
     AddReceiverCheck(call);
   }
   LoadFieldInstr* load = new LoadFieldInstr(
       new Value(call->ArgumentAt(0)),
       field.Offset(),
       AbstractType::ZoneHandle(field.type()),
       field.is_final());
   if (field.guarded_cid() != kIllegalCid) {
-    Field* the_field = &Field::ZoneHandle(field.raw());
     if (!field.is_nullable() || (field.guarded_cid() == kNullCid)) {
       load->set_result_cid(field.guarded_cid());
-      guarded_fields_->Add(the_field);
     }
-    load->set_field(the_field);
+    load->set_field(&Field::ZoneHandle(field.raw()));
   }
   load->set_field_name(String::Handle(field.name()).ToCString());
 
   // Discard the environment from the original instruction because the load
   // can't deoptimize.
   call->RemoveEnvironment();
   ReplaceCall(call, load);
 
-  if (load->result_cid() != kDynamicCid) {
-    // Reset value types if guarded_cid was used.
-    for (Value::Iterator it(load->input_use_list());
-         !it.Done();
-         it.Advance()) {
-      it.Current()->SetReachingType(NULL);
+  if (FLAG_inline_getter_with_guarded_cid) {
+    if (load->result_cid() != kDynamicCid) {
+      // Reset value types if guarded_cid was used.
+      for (Value::Iterator it(load->input_use_list());
+           !it.Done();
+           it.Advance()) {
+        it.Current()->SetReachingType(NULL);
+      }
     }
   }
 }
 
 
 void FlowGraphOptimizer::InlineArrayLengthGetter(InstanceCallInstr* call,
                                                  intptr_t length_offset,
                                                  bool is_immutable,
                                                  MethodRecognizer::Kind kind) {
   AddReceiverCheck(call);
@@ skipping 3500 matching lines @@
   if (changed) {
     // We may have changed the block order and the dominator tree.
     flow_graph->DiscoverBlocks();
     GrowableArray<BitVector*> dominance_frontier;
     flow_graph->ComputeDominators(&dominance_frontier);
   }
 }
 
 
 }  // namespace dart