[Isolates] Merge (7083,7111] from bleeding_edge.

src/hydrogen.h

Index: src/hydrogen.h
diff --git a/src/hydrogen.h b/src/hydrogen.h
index 510ba70dd7108900c304a76b0544db330f304fd7..8d7780282c99b7afc20864106bf15806109e7601 100644
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -192,40 +192,13 @@ class HLoopInformation: public ZoneObject {
 };
 
 
-class HSubgraph: public ZoneObject {
- public:
-  explicit HSubgraph(HGraph* graph)
-      : graph_(graph),
-        entry_block_(NULL),
-        exit_block_(NULL) {
-  }
-
-  HGraph* graph() const { return graph_; }
-  HBasicBlock* entry_block() const { return entry_block_; }
-  HBasicBlock* exit_block() const { return exit_block_; }
-  void set_exit_block(HBasicBlock* block) {
-    exit_block_ = block;
-  }
-
-  void Initialize(HBasicBlock* block) {
-    ASSERT(entry_block_ == NULL);
-    entry_block_ = block;
-    exit_block_ = block;
-  }
-
- protected:
-  HGraph* graph_;  // The graph this is a subgraph of.
-  HBasicBlock* entry_block_;
-  HBasicBlock* exit_block_;
-};
-
-
-class HGraph: public HSubgraph {
+class HGraph: public ZoneObject {
  public:
   explicit HGraph(CompilationInfo* info);
 
   const ZoneList<HBasicBlock*>* blocks() const { return &blocks_; }
   const ZoneList<HPhi*>* phi_list() const { return phi_list_; }
+  HBasicBlock* entry_block() const { return entry_block_; }
   HEnvironment* start_environment() const { return start_environment_; }
 
   void InitializeInferredTypes();
@@ -295,12 +268,15 @@ class HGraph: public HSubgraph {
   void InsertRepresentationChangeForUse(HValue* value,
                                         HValue* use,
                                         Representation to);
-  void InsertRepresentationChanges(HValue* current);
+  void InsertRepresentationChangesForValue(HValue* current,
+                                           ZoneList<HValue*>* value_list,
+                                           ZoneList<Representation>* rep_list);
   void InferTypes(ZoneList<HValue*>* worklist);
   void InitializeInferredTypes(int from_inclusive, int to_inclusive);
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
 
   int next_block_id_;
+  HBasicBlock* entry_block_;
   HEnvironment* start_environment_;
   ZoneList<HBasicBlock*> blocks_;
   ZoneList<HValue*> values_;
@@ -312,8 +288,6 @@ class HGraph: public HSubgraph {
   SetOncePointer<HConstant> constant_false_;
   SetOncePointer<HArgumentsObject> arguments_object_;
 
-  friend class HSubgraph;
-
   DISALLOW_COPY_AND_ASSIGN(HGraph);
 };
 
@@ -404,7 +378,7 @@ class HEnvironment: public ZoneObject {
   void ClearHistory() {
     pop_count_ = 0;
     push_count_ = 0;
-    assigned_variables_.Clear();
+    assigned_variables_.Rewind(0);
   }
 
   void SetValueAt(int index, HValue* value) {
@@ -640,7 +614,7 @@ class HGraphBuilder: public AstVisitor {
         ast_context_(NULL),
         break_scope_(NULL),
         graph_(NULL),
-        current_subgraph_(NULL),
+        current_block_(NULL),
         inlined_count_(0) {
     // This is not initialized in the initializer list because the
     // constructor for the initial state relies on function_state_ == NULL
@@ -652,14 +626,11 @@ class HGraphBuilder: public AstVisitor {
 
   // Simple accessors.
   HGraph* graph() const { return graph_; }
-  HSubgraph* subgraph() const { return current_subgraph_; }
   BreakAndContinueScope* break_scope() const { return break_scope_; }
   void set_break_scope(BreakAndContinueScope* head) { break_scope_ = head; }
 
-  HBasicBlock* current_block() const { return subgraph()->exit_block(); }
-  void set_current_block(HBasicBlock* block) {
-    subgraph()->set_exit_block(block);
-  }
+  HBasicBlock* current_block() const { return current_block_; }
+  void set_current_block(HBasicBlock* block) { current_block_ = block; }
   HEnvironment* environment() const {
     return current_block()->last_environment();
   }
@@ -750,10 +721,6 @@ class HGraphBuilder: public AstVisitor {
                             HBasicBlock* exit_block,
                             HBasicBlock* continue_block);
 
-  void AddToSubgraph(HSubgraph* graph, ZoneList<Statement*>* stmts);
-  void AddToSubgraph(HSubgraph* graph, Statement* stmt);
-  void AddToSubgraph(HSubgraph* graph, Expression* expr);
-
   HValue* Top() const { return environment()->Top(); }
   void Drop(int n) { environment()->Drop(n); }
   void Bind(Variable* var, HValue* value) { environment()->Bind(var, value); }
@@ -791,7 +758,6 @@ class HGraphBuilder: public AstVisitor {
 #undef DECLARE_VISIT
 
   HBasicBlock* CreateBasicBlock(HEnvironment* env);
-  HSubgraph* CreateEmptySubgraph();
   HBasicBlock* CreateLoopHeaderBlock();
 
   // Helpers for flow graph construction.
@@ -884,10 +850,6 @@ class HGraphBuilder: public AstVisitor {
                                                  HValue* val,
                                                  Expression* expr);
 
-  HCompare* BuildSwitchCompare(HSubgraph* subgraph,
-                               HValue* switch_value,
-                               CaseClause* clause);
-
   HValue* BuildContextChainWalk(Variable* var);
 
   void AddCheckConstantFunction(Call* expr,
@@ -910,7 +872,7 @@ class HGraphBuilder: public AstVisitor {
   BreakAndContinueScope* break_scope_;
 
   HGraph* graph_;
-  HSubgraph* current_subgraph_;
+  HBasicBlock* current_block_;
 
   int inlined_count_;