[turbofan] Proper dead code elimination as regular reducer.

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"
 #include "src/base/platform/elapsed-timer.h"
 #include "src/compiler/ast-graph-builder.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/basic-block-instrumentor.h"
 #include "src/compiler/change-lowering.h"
 #include "src/compiler/code-generator.h"
 #include "src/compiler/common-operator-reducer.h"
 #include "src/compiler/control-flow-optimizer.h"
-#include "src/compiler/control-reducer.h"
+#include "src/compiler/dead-code-elimination.h"
 #include "src/compiler/frame-elider.h"
 #include "src/compiler/graph-replay.h"
 #include "src/compiler/graph-trimmer.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/greedy-allocator.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/instruction-selector.h"
 #include "src/compiler/js-builtin-reducer.h"
 #include "src/compiler/js-context-specialization.h"
 #include "src/compiler/js-generic-lowering.h"
@@ skipping 370 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->DeadValue(),
-                     jsgraph->DeadControl()) {}
+      : 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 211 matching lines @@
     AddReducer(data, &graph_reducer, &machine_reducer);
     AddReducer(data, &graph_reducer, &common_reducer);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct EarlyControlReductionPhase {
   static const char* phase_name() { return "early control reduction"; }
   void Run(PipelineData* data, Zone* temp_zone) {
-    ControlReducer::ReduceGraph(temp_zone, data->jsgraph(), 0);
+    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 LateControlReductionPhase {
   static const char* phase_name() { return "late control reduction"; }
   void Run(PipelineData* data, Zone* temp_zone) {
-    ControlReducer::ReduceGraph(temp_zone, data->jsgraph(), 0);
+    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);
@@ skipping 702 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8