Refactor Scheduler to simplify construction of CFG from sea of nodes. Use PreEdge/Post as part of t…

src/compiler/scheduler.h

 // Copyright 2013 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.
 
 #ifndef V8_COMPILER_SCHEDULER_H_
 #define V8_COMPILER_SCHEDULER_H_
 
 #include <vector>
 
 #include "src/v8.h"
 
 #include "src/compiler/opcodes.h"
 #include "src/compiler/schedule.h"
 #include "src/zone-allocator.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 // Computes a schedule from a graph, placing nodes into basic blocks and
 // ordering the basic blocks in the special RPO order.
 class Scheduler {
  public:
-  // Create a new schedule and place all computations from the graph in it.
+  // The complete scheduling algorithm.
+  // Create a new schedule and place all nodes from the graph into it.
   static Schedule* ComputeSchedule(Graph* graph);
 
   // Compute the RPO of blocks in an existing schedule.
   static BasicBlockVector* ComputeSpecialRPO(Schedule* schedule);
 
+  // (Exposed for testing only)
+  // Build and connect the CFG for a node graph, but don't schedule nodes.
+  static void ComputeCFG(Graph* graph, Schedule* schedule);
+
  private:
   Zone* zone_;
   Graph* graph_;
   Schedule* schedule_;
-  NodeVector branches_;
-  NodeVector calls_;
-  NodeVector deopts_;
-  NodeVector returns_;
-  NodeVector loops_and_merges_;
   IntVector unscheduled_uses_;
   NodeVectorVector scheduled_nodes_;
   NodeVector schedule_root_nodes_;
   IntVector schedule_early_rpo_index_;
 
   Scheduler(Zone* zone, Graph* graph, Schedule* schedule);
 
   bool IsBasicBlockBegin(Node* node);
-  bool CanBeScheduled(Node* node);
   bool HasFixedSchedulePosition(Node* node);
   bool IsScheduleRoot(Node* node);
 
   int GetRPONumber(BasicBlock* block) {
     DCHECK(block->rpo_number_ >= 0 &&
            block->rpo_number_ < static_cast<int>(schedule_->rpo_order_.size()));
     DCHECK(schedule_->rpo_order_[block->rpo_number_] == block);
     return block->rpo_number_;
   }
 
   void PrepareAuxiliaryNodeData();
   void PrepareAuxiliaryBlockData();
 
-  friend class CreateBlockVisitor;
-  void CreateBlocks();
-
-  void WireBlocks();
-
-  void AddPredecessorsForLoopsAndMerges();
-  void AddSuccessorsForBranches();
-  void AddSuccessorsForReturns();
-  void AddSuccessorsForCalls();
-  void AddSuccessorsForDeopts();
-
   void GenerateImmediateDominatorTree();
   BasicBlock* GetCommonDominator(BasicBlock* b1, BasicBlock* b2);
 
   friend class ScheduleEarlyNodeVisitor;
   void ScheduleEarly();
 
   friend class PrepareUsesVisitor;
   void PrepareUses();
 
   friend class ScheduleLateNodeVisitor;
   void ScheduleLate();
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_SCHEDULER_H_