Revert of [turbofan] Run DeadCodeElimination together with the advanced reducers.

src/compiler/pipeline.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/pipeline.h"
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
 
 #include "src/base/adapters.h"
@@ skipping 389 matching lines @@
   Reducer* const reducer_;
   SourcePositionTable* const table_;
 
   DISALLOW_COPY_AND_ASSIGN(SourcePositionWrapper);
 };
 
 
 class JSGraphReducer final : public GraphReducer {
  public:
   JSGraphReducer(JSGraph* jsgraph, Zone* zone)
-      : GraphReducer(zone, jsgraph->graph(), jsgraph->Dead()) {}
+      : GraphReducer(zone, jsgraph->graph(), jsgraph->TheHoleConstant(),
+                     jsgraph->Dead()) {}
   ~JSGraphReducer() final {}
 };
 
 
 void AddReducer(PipelineData* data, GraphReducer* graph_reducer,
                 Reducer* reducer) {
   if (data->info()->is_source_positions_enabled()) {
     void* const buffer = data->graph_zone()->New(sizeof(SourcePositionWrapper));
     SourcePositionWrapper* const wrapper =
         new (buffer) SourcePositionWrapper(reducer, data->source_positions());
@@ skipping 136 matching lines @@
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct TypedLoweringPhase {
   static const char* phase_name() { return "typed lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common());
     LoadElimination load_elimination(&graph_reducer);
     JSBuiltinReducer builtin_reducer(&graph_reducer, data->jsgraph());
     JSTypedLowering typed_lowering(&graph_reducer, data->jsgraph(), temp_zone);
     JSIntrinsicLowering intrinsic_lowering(
         &graph_reducer, data->jsgraph(),
         data->info()->is_deoptimization_enabled()
             ? JSIntrinsicLowering::kDeoptimizationEnabled
             : JSIntrinsicLowering::kDeoptimizationDisabled);
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
-    AddReducer(data, &graph_reducer, &dead_code_elimination);
     AddReducer(data, &graph_reducer, &builtin_reducer);
     AddReducer(data, &graph_reducer, &typed_lowering);
     AddReducer(data, &graph_reducer, &intrinsic_lowering);
     AddReducer(data, &graph_reducer, &load_elimination);
     AddReducer(data, &graph_reducer, &common_reducer);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct SimplifiedLoweringPhase {
   static const char* phase_name() { return "simplified lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     SimplifiedLowering lowering(data->jsgraph(), temp_zone,
                                 data->source_positions());
     lowering.LowerAllNodes();
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common());
     ValueNumberingReducer vn_reducer(temp_zone);
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
-    AddReducer(data, &graph_reducer, &dead_code_elimination);
     AddReducer(data, &graph_reducer, &vn_reducer);
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct ControlFlowOptimizationPhase {
   static const char* phase_name() { return "control flow optimization"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     ControlFlowOptimizer optimizer(data->graph(), data->common(),
                                    data->machine(), temp_zone);
     optimizer.Optimize();
   }
 };
 
 
 struct ChangeLoweringPhase {
   static const char* phase_name() { return "change lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
-    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
-                                              data->common());
     ValueNumberingReducer vn_reducer(temp_zone);
     ChangeLowering lowering(data->jsgraph());
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
-    AddReducer(data, &graph_reducer, &dead_code_elimination);
     AddReducer(data, &graph_reducer, &vn_reducer);
     AddReducer(data, &graph_reducer, &lowering);
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);
     graph_reducer.ReduceGraph();
   }
 };
+
+
+struct LateControlReductionPhase {
+  static const char* phase_name() { return "late control reduction"; }
+  void Run(PipelineData* data, Zone* temp_zone) {
+    GraphReducer graph_reducer(temp_zone, data->graph());
+    DeadCodeElimination dce(&graph_reducer, data->graph(), data->common());
+    CommonOperatorReducer common(&graph_reducer, data->graph(), data->common(),
+                                 data->machine());
+    graph_reducer.AddReducer(&dce);
+    graph_reducer.AddReducer(&common);
+    graph_reducer.ReduceGraph();
+  }
+};
 
 
 struct EarlyGraphTrimmingPhase {
   static const char* phase_name() { return "early graph trimming"; }
   void Run(PipelineData* data, Zone* temp_zone) {
     GraphTrimmer trimmer(temp_zone, data->graph());
     NodeVector roots(temp_zone);
     data->jsgraph()->GetCachedNodes(&roots);
     trimmer.TrimGraph(roots.begin(), roots.end());
   }
@@ skipping 697 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8