[turbofan] Sparse representation for state values

src/compiler/state-values-utils.h

Index: src/compiler/state-values-utils.h
diff --git a/src/compiler/state-values-utils.h b/src/compiler/state-values-utils.h
index 14b1b9e59963755c2b0e543becb3c46f3220e994..dc643137e050bed90e4188e06e36f542517443d8 100644
--- a/src/compiler/state-values-utils.h
+++ b/src/compiler/state-values-utils.h
@@ -33,10 +33,11 @@ class V8_EXPORT_PRIVATE StateValuesCache {
   struct StateValuesKey : public NodeKey {
     // ValueArray - array of nodes ({node} has to be nullptr).
     size_t count;
+    uint32_t mask;
     Node** values;
 
-    StateValuesKey(size_t count, Node** values)
-        : NodeKey(nullptr), count(count), values(values) {}
+    StateValuesKey(size_t count, uint32_t mask, Node** values)
+        : NodeKey(nullptr), count(count), mask(mask), values(values) {}
   };
 
   class ValueArrayIterator;
@@ -48,7 +49,7 @@ class V8_EXPORT_PRIVATE StateValuesCache {
   Node* BuildTree(ValueArrayIterator* it, size_t max_height);
   NodeVector* GetWorkingSpace(size_t level);
   Node* GetEmptyStateValues();
-  Node* GetValuesNodeFromCache(Node** nodes, size_t count);
+  Node* GetValuesNodeFromCache(Node** nodes, size_t count, uint32_t mask);
 
   Graph* graph() { return js_graph_->graph(); }
   CommonOperatorBuilder* common() { return js_graph_->common(); }
@@ -86,17 +87,17 @@ class V8_EXPORT_PRIVATE StateValuesAccess {
     MachineType type();
     bool done();
     void Advance();
+    void MoveToNextSibling();
+    void EnsureValid();
 
     struct StatePos {
       Node* node;
+      uint32_t mask;
       int index;
-
-      explicit StatePos(Node* node) : node(node), index(0) {}
-      StatePos() {}
     };
 
     StatePos* Top();
-    void Push(Node* node);
+    void Push(Node* node, uint32_t mask);
     void Pop();
 
     static const int kMaxInlineDepth = 8;