[turbofan] Move replacements out of virtual object

src/compiler/escape-analysis.h

Index: src/compiler/escape-analysis.h
diff --git a/src/compiler/escape-analysis.h b/src/compiler/escape-analysis.h
index 1ba86da6a48614cc4ad08ca25889da664463e0ba..fef78308dfb73cc57e05736e96c65ce210a443c2 100644
--- a/src/compiler/escape-analysis.h
+++ b/src/compiler/escape-analysis.h
@@ -107,7 +107,7 @@ class 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);
 
@@ -134,8 +134,15 @@ class EscapeAnalysis {
   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);
@@ -149,6 +156,7 @@ class EscapeAnalysis {
   CommonOperatorBuilder* const common_;
   Zone* const zone_;
   ZoneVector<VirtualState*> virtual_states_;
+  ZoneVector<Node*> replacements_;
   EscapeStatusAnalysis escape_status_;
   MergeCache cache_;