[Turbofan] Make GenericLowering operate concurrently.

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 <memory>
 #include <sstream>
 
@@ skipping 961 matching lines @@
 };
 
 struct LoopExitEliminationPhase {
   static const char* phase_name() { return "loop exit elimination"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     LoopPeeler::EliminateLoopExits(data->graph(), temp_zone);
   }
 };
 
+struct GenericLoweringPrepPhase {
+  static const char* phase_name() { return "generic lowering prep"; }
+
+  void Run(PipelineData* data, Zone* temp_zone) {
+    // Make sure we cache these code stubs.
+    data->jsgraph()->CEntryStubConstant(1);
+    data->jsgraph()->CEntryStubConstant(2);
+    data->jsgraph()->CEntryStubConstant(3);
+  }
+};
+
 struct GenericLoweringPhase {
   static const char* phase_name() { return "generic lowering"; }
 
   void Run(PipelineData* data, Zone* temp_zone) {
     JSGraphReducer graph_reducer(data->jsgraph(), temp_zone);
     JSGenericLowering generic_lowering(data->jsgraph());
     AddReducer(data, &graph_reducer, &generic_lowering);
     graph_reducer.ReduceGraph();
   }
 };
@@ skipping 566 matching lines @@
   //      selection due to the way we handle truncations; if we'd want to look
   //      at types afterwards we'd essentially need to re-type (large portions
   //      of) the graph.
   //
   // In order to catch bugs related to type access after this point we remove
   // the types from the nodes at this point (currently only in Debug builds).
   Run<UntyperPhase>();
   RunPrintAndVerify("Untyped", true);
 #endif
 
-  // Run generic lowering pass.
-  Run<GenericLoweringPhase>();
-  RunPrintAndVerify("Generic lowering", true);
+  // Do some hacky things to prepare generic lowering.
+  Run<GenericLoweringPrepPhase>();
 
   data->EndPhaseKind();
 
   return true;
 }
 
 bool PipelineImpl::OptimizeGraph(Linkage* linkage) {
   PipelineData* data = this->data_;
 
+  // Run generic lowering pass.
+  Run<GenericLoweringPhase>();
+  RunPrintAndVerify("Generic lowering", true);
+
   data->BeginPhaseKind("block building");
 
   // Run early optimization pass.
   Run<EarlyOptimizationPhase>();
   RunPrintAndVerify("Early optimized", true);
 
   Run<EffectControlLinearizationPhase>();
   RunPrintAndVerify("Effect and control linearized", true);
 
   Run<DeadCodeEliminationPhase>();
@@ skipping 389 matching lines @@
   data->DeleteRegisterAllocationZone();
 }
 
 CompilationInfo* PipelineImpl::info() const { return data_->info(); }
 
 Isolate* PipelineImpl::isolate() const { return info()->isolate(); }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8