[turbofan] Allow ReplaceWithValue to kill control.

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 392 matching lines @@
   }
 
  private:
   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->TheHoleConstant(),
+                     jsgraph->DeadControl()) {}
+  ~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());
     graph_reducer->AddReducer(wrapper);
   } else {
     graph_reducer->AddReducer(reducer);
   }
@@ skipping 58 matching lines @@
     }
   }
 };
 
 
 struct ContextSpecializerPhase {
   static const char* phase_name() { return "context specializing"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     JSContextSpecializer spec(data->jsgraph());
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     AddReducer(data, &graph_reducer, &spec);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct InliningPhase {
   static const char* phase_name() { return "inlining"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     JSInliner inliner(&graph_reducer, data->info()->is_inlining_enabled()
                                           ? JSInliner::kGeneralInlining
                                           : JSInliner::kRestrictedInlining,
                       temp_zone, data->info(), data->jsgraph());
     AddReducer(data, &graph_reducer, &inliner);
     graph_reducer.ReduceGraph();
   }
 };
 
 
@@ skipping 15 matching lines @@
 
 
 struct JSTypeFeedbackPhase {
   static const char* phase_name() { return "type feedback specializing"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     Handle<Context> native_context(data->info()->context()->native_context());
     TypeFeedbackOracle oracle(data->isolate(), temp_zone,
                               data->info()->unoptimized_code(),
                               data->info()->feedback_vector(), native_context);
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     Handle<GlobalObject> global_object = Handle<GlobalObject>::null();
     if (data->info()->has_global_object()) {
       global_object =
           Handle<GlobalObject>(data->info()->global_object(), data->isolate());
     }
     // TODO(titzer): introduce a specialization mode/flags enum to control
     // specializing to the global object here.
     JSTypeFeedbackSpecializer specializer(
         &graph_reducer, data->jsgraph(), data->js_type_feedback(), &oracle,
         global_object, data->info()->is_deoptimization_enabled()
                            ? JSTypeFeedbackSpecializer::kDeoptimizationEnabled
                            : JSTypeFeedbackSpecializer::kDeoptimizationDisabled,
         data->info()->dependencies());
     AddReducer(data, &graph_reducer, &specializer);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct TypedLoweringPhase {
   static const char* phase_name() { return "typed lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     LoadElimination load_elimination;
     JSBuiltinReducer builtin_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(data->jsgraph());
     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();
     ValueNumberingReducer vn_reducer(temp_zone);
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(data->jsgraph());
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     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) {
     ValueNumberingReducer vn_reducer(temp_zone);
     ChangeLowering lowering(data->jsgraph());
     MachineOperatorReducer machine_reducer(data->jsgraph());
     CommonOperatorReducer common_reducer(data->jsgraph());
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     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 EarlyControlReductionPhase {
@@ skipping 28 matching lines @@
 
 
 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());
     TailCallOptimization tco(data->common(), data->graph());
-    GraphReducer graph_reducer(data->graph(), temp_zone);
+    JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     AddReducer(data, &graph_reducer, &generic);
     AddReducer(data, &graph_reducer, &select);
     // TODO(turbofan): TCO is currently limited to stubs.
     if (data->info()->IsStub()) AddReducer(data, &graph_reducer, &tco);
     graph_reducer.ReduceGraph();
   }
 };
 
 
 struct ComputeSchedulePhase {
@@ skipping 640 matching lines @@
     tcf << AsC1VRegisterAllocationData("CodeGen",
                                        data->register_allocation_data());
   }
 
   data->DeleteRegisterAllocationZone();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8