Revert of [turbofan] Combine GenericLoweringPhase and ChangeLoweringPhase.

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 704 matching lines @@
   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());
+    SimplifiedOperatorReducer simple_reducer(data->jsgraph());
+    ValueNumberingReducer value_numbering(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, &simple_reducer);
+    AddReducer(data, &graph_reducer, &value_numbering);
+    AddReducer(data, &graph_reducer, &lowering);
+    AddReducer(data, &graph_reducer, &machine_reducer);
+    AddReducer(data, &graph_reducer, &common_reducer);
+    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 27 matching lines @@
 struct GenericLoweringPhase {
   static const char* phase_name() { return "generic lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     JSContextRelaxation context_relaxing;
     DeadCodeElimination dead_code_elimination(&graph_reducer, data->graph(),
                                               data->common());
     CommonOperatorReducer common_reducer(&graph_reducer, data->graph(),
                                          data->common(), data->machine());
-    SimplifiedOperatorReducer simple_reducer(data->jsgraph());
-    ValueNumberingReducer value_numbering(temp_zone);
-    ChangeLowering change_lowering(data->jsgraph());
-    MachineOperatorReducer machine_reducer(data->jsgraph());
     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());
     AddReducer(data, &graph_reducer, &context_relaxing);
     AddReducer(data, &graph_reducer, &dead_code_elimination);
     AddReducer(data, &graph_reducer, &common_reducer);
-    if (data->info()->is_typing_enabled()) {
-      AddReducer(data, &graph_reducer, &simple_reducer);
-      AddReducer(data, &graph_reducer, &value_numbering);
-      AddReducer(data, &graph_reducer, &change_lowering);
-      AddReducer(data, &graph_reducer, &machine_reducer);
-    }
     AddReducer(data, &graph_reducer, &generic_lowering);
     AddReducer(data, &graph_reducer, &select_lowering);
     AddReducer(data, &graph_reducer, &tco);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct ComputeSchedulePhase {
   static const char* phase_name() { return "scheduling"; }
@@ skipping 371 matching lines @@
     RunPrintAndVerify("Lowered simplified");
 
     Run<BranchEliminationPhase>();
     RunPrintAndVerify("Branch conditions eliminated");
 
     // 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);
   }
 
-  // Lower changes inserted earlier and any remaining generic JSOperators.
+  // Lower any remaining generic JSOperators.
   Run<GenericLoweringPhase>();
   // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
   RunPrintAndVerify("Lowered generic", true);
 
   Run<LateGraphTrimmingPhase>();
   // TODO(jarin, rossberg): Remove UNTYPED once machine typing works.
   RunPrintAndVerify("Late trimmed", true);
 
   BeginPhaseKind("block building");
 
@@ skipping 287 matching lines @@
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 Isolate* Pipeline::isolate() const { return info()->isolate(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8