[turbofan] Run DeadCodeElimination as part of the generic lowering phase.

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 633 matching lines @@
     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) {
-    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 21 matching lines @@
                        loop_tree->outer_loops()[0], temp_zone);
     }
   }
 };
 
 
 struct GenericLoweringPhase {
   static const char* phase_name() { return "generic lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    JSGenericLowering generic(data->info()->is_typing_enabled(),
-                              data->jsgraph());
-    SelectLowering select(data->jsgraph()->graph(), data->jsgraph()->common());
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
+    DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
+                                              data->common());
+    CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
+                                         data->common(), data->machine());
+    JSGenericLowering generic_lowering(data->info()->is_typing_enabled(),
+                                       data->jsgraph());
+    SelectLowering select_lowering(data->jsgraph()->graph(),
+                                   data->jsgraph()->common());
     TailCallOptimization tco(data->common(), data->graph());
-    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
-    AddReducer(data, &graph_reducer, &generic);
-    AddReducer(data, &graph_reducer, &select);
+    AddReducer(data, &graph_reducer, &dead_code_elimination);
+    AddReducer(data, &graph_reducer, &common_reducer);
+    AddReducer(data, &graph_reducer, &generic_lowering);
+    AddReducer(data, &graph_reducer, &select_lowering);
     // TODO(turbofan): TCO is currently limited to stubs.
     if (data->info()->IsStub()) AddReducer(data, &graph_reducer, &tco);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct ComputeSchedulePhase {
   static const char* phase_name() { return "scheduling"; }
 
@@ skipping 380 matching lines @@
     // Optimize control flow.
     if (FLAG_turbo_cf_optimization) {
       Run<ControlFlowOptimizationPhase>();
       RunPrintAndVerify("Control flow optimized");
     }
 
     // Lower changes that have been inserted before.
     Run<ChangeLoweringPhase>();
     // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
     RunPrintAndVerify("Lowered changes", true);
-
-    Run<LateControlReductionPhase>();
-    RunPrintAndVerify("Late Control reduced");
   } else {
     if (info()->is_osr()) {
       Run<OsrDeconstructionPhase>();
       if (info()->bailout_reason() != kNoReason) return Handle<Code>::null();
       RunPrintAndVerify("OSR deconstruction", true);
     }
   }
 
   // Lower any remaining generic JSOperators.
   Run<GenericLoweringPhase>();
@@ skipping 247 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8