[turbofan] Move replacements out of virtual object

src/compiler/escape-analysis.h

 // Copyright 2015 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_ESCAPE_ANALYSIS_H_
 #define V8_COMPILER_ESCAPE_ANALYSIS_H_
 
 #include "src/base/flags.h"
 #include "src/compiler/graph.h"
 
@@ skipping 89 matching lines @@
 
 // EscapeObjectAnalysis simulates stores to determine values of loads if
 // an object is virtual and eliminated.
 class EscapeAnalysis {
  public:
   EscapeAnalysis(Graph* graph, CommonOperatorBuilder* common, Zone* zone);
   ~EscapeAnalysis();
 
   void Run();
 
-  Node* GetReplacement(Node* at, NodeId id);
+  Node* GetReplacement(NodeId id);

[Michael Starzinger, 2015/12/14 13:38:32]

nit/suggestion: For the public interface it might make sense to pass in a
"Node*" instead of the "NodeId". The fact that node ids are used internally to
establish the mapping as an implementation detail. It also might make call-sites
slightly easier to read. WDYT? Both is fine with me, it's up to you.

[sigurds, 2015/12/14 13:48:00]

I agree, I changed the interface.

   bool IsVirtual(Node* node);
   bool IsEscaped(Node* node);
 
  private:
   void RunObjectAnalysis();
   bool Process(Node* node);
   void ProcessLoadField(Node* node);
   void ProcessStoreField(Node* node);
   void ProcessLoadElement(Node* node);
   void ProcessStoreElement(Node* node);
   void ProcessAllocationUsers(Node* node);
   void ProcessAllocation(Node* node);
   void ProcessFinishRegion(Node* node);
   void ProcessCall(Node* node);
   void ProcessStart(Node* node);
   bool ProcessEffectPhi(Node* node);
   void ProcessLoadFromPhi(int offset, Node* from, Node* node,
                           VirtualState* states);
 
   void ForwardVirtualState(Node* node);
 
   bool IsEffectBranchPoint(Node* node);
   bool IsDanglingEffectNode(Node* node);
   int OffsetFromAccess(Node* node);
 
   VirtualObject* GetVirtualObject(Node* at, NodeId id);
+  VirtualObject* ResolveVirtualObject(VirtualState* state, Node* node);
+  Node* GetReplacementIfSame(ZoneVector<VirtualObject*>& objs);
 
   bool SetEscaped(Node* node);
+  Node* replacement(NodeId id);
+  Node* replacement(Node* node);
+  Node* ResolveReplacement(Node* node);
+  bool SetReplacement(Node* node, Node* rep);
+  bool UpdateReplacement(VirtualState* state, Node* node, Node* rep);
 
   void DebugPrint();
   void DebugPrintState(VirtualState* state);
   void DebugPrintObject(VirtualObject* state, NodeId id);
 
   Graph* graph() const { return graph_; }
   CommonOperatorBuilder* common() const { return common_; }
   Zone* zone() const { return zone_; }
 
   Graph* const graph_;
   CommonOperatorBuilder* const common_;
   Zone* const zone_;
   ZoneVector<VirtualState*> virtual_states_;
+  ZoneVector<Node*> replacements_;
   EscapeStatusAnalysis escape_status_;
   MergeCache cache_;
 
   DISALLOW_COPY_AND_ASSIGN(EscapeAnalysis);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ESCAPE_ANALYSIS_H_