Remove class HSubgraph.

Review URL: http://codereview.chromium.org/6647018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7100 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -557,13 +557,15 @@ void HBasicBlock::FinishExit(HControlInstruction* instruction) {
 
 
 HGraph::HGraph(CompilationInfo* info)
-    : HSubgraph(this),
-      next_block_id_(0),
+    : next_block_id_(0),
+      entry_block_(NULL),
       blocks_(8),
       values_(16),
       phi_list_(NULL) {
   start_environment_ = new HEnvironment(NULL, info->scope(), info->closure());
   start_environment_->set_ast_id(info->function()->id());
+  entry_block_ = CreateBasicBlock();
+  entry_block_->SetInitialEnvironment(start_environment_);
 }
 
 
@@ -785,11 +787,11 @@ void HGraph::EliminateUnreachablePhis() {
 
 
 bool HGraph::CollectPhis() {
-  const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
-  phi_list_ = new ZoneList<HPhi*>(blocks->length());
-  for (int i = 0; i < blocks->length(); ++i) {
-    for (int j = 0; j < blocks->at(i)->phis()->length(); j++) {
-      HPhi* phi = blocks->at(i)->phis()->at(j);
+  int block_count = blocks_.length();
+  phi_list_ = new ZoneList<HPhi*>(block_count);
+  for (int i = 0; i < block_count; ++i) {
+    for (int j = 0; j < blocks_[i]->phis()->length(); ++j) {
+      HPhi* phi = blocks_[i]->phis()->at(j);
       phi_list_->Add(phi);
       // We don't support phi uses of arguments for now.
       if (phi->CheckFlag(HValue::kIsArguments)) return false;
@@ -2080,36 +2082,6 @@ void TestContext::BuildBranch(HValue* value) {
   } while (false)
 
 
-// 'thing' could be an expression, statement, or list of statements.
-#define ADD_TO_SUBGRAPH(graph, thing)       \
-  do {                                      \
-    AddToSubgraph(graph, thing);            \
-    if (HasStackOverflow()) return;         \
-  } while (false)
-
-
-class HGraphBuilder::SubgraphScope BASE_EMBEDDED {
- public:
-  SubgraphScope(HGraphBuilder* builder, HSubgraph* new_subgraph)
-      : builder_(builder) {
-    old_subgraph_ = builder_->current_subgraph_;
-    subgraph_ = new_subgraph;
-    builder_->current_subgraph_ = subgraph_;
-  }
-
-  ~SubgraphScope() {
-    builder_->current_subgraph_ = old_subgraph_;
-  }
-
-  HSubgraph* subgraph() const { return subgraph_; }
-
- private:
-  HGraphBuilder* builder_;
-  HSubgraph* old_subgraph_;
-  HSubgraph* subgraph_;
-};
-
-
 void HGraphBuilder::Bailout(const char* reason) {
   if (FLAG_trace_bailout) {
     SmartPointer<char> name(info()->shared_info()->DebugName()->ToCString());
@@ -2161,13 +2133,10 @@ void HGraphBuilder::VisitExpressions(ZoneList<Expression*>* exprs) {
 
 
 HGraph* HGraphBuilder::CreateGraph() {
-  ASSERT(subgraph() == NULL);
   graph_ = new HGraph(info());
-
   {
     HPhase phase("Block building");
-    graph()->Initialize(CreateBasicBlock(graph()->start_environment()));
-    current_subgraph_ = graph();
+    current_block_ = graph()->entry_block();
 
     Scope* scope = info()->scope();
     if (scope->HasIllegalRedeclaration()) {
@@ -2245,25 +2214,6 @@ HGraph* HGraphBuilder::CreateGraph() {
 }
 
 
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph, Statement* stmt) {
-  SubgraphScope scope(this, graph);
-  Visit(stmt);
-}
-
-
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph, Expression* expr) {
-  SubgraphScope scope(this, graph);
-  VisitForValue(expr);
-}
-
-
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph,
-                                  ZoneList<Statement*>* stmts) {
-  SubgraphScope scope(this, graph);
-  VisitStatements(stmts);
-}
-
-
 HInstruction* HGraphBuilder::AddInstruction(HInstruction* instr) {
   ASSERT(current_block() != NULL);
   current_block()->AddInstruction(instr);

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();
@@ -304,6 +277,7 @@ class HGraph: public HSubgraph {
   void CheckForBackEdge(HBasicBlock* block, HBasicBlock* successor);
 
   int next_block_id_;
+  HBasicBlock* entry_block_;
   HEnvironment* start_environment_;
   ZoneList<HBasicBlock*> blocks_;
   ZoneList<HValue*> values_;
@@ -315,8 +289,6 @@ class HGraph: public HSubgraph {
   SetOncePointer<HConstant> constant_false_;
   SetOncePointer<HArgumentsObject> arguments_object_;
 
-  friend class HSubgraph;
-
   DISALLOW_COPY_AND_ASSIGN(HGraph);
 };
 
@@ -643,7 +615,7 @@ 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
@@ -655,14 +627,11 @@ 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();
   }
@@ -753,10 +722,6 @@ 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); }
@@ -908,7 +873,7 @@ class HGraphBuilder: public AstVisitor {
   BreakAndContinueScope* break_scope_;
 
   HGraph* graph_;
-  HSubgraph* current_subgraph_;
+  HBasicBlock* current_block_;
 
   int inlined_count_;
 

src/x64/lithium-codegen-x64.h

@@ -77,7 +77,6 @@ class LCodeGen BASE_EMBEDDED {
   Handle<Object> ToHandle(LConstantOperand* op) const;
   Operand ToOperand(LOperand* op) const;
 
-
   // Try to generate code for the entire chunk, but it may fail if the
   // chunk contains constructs we cannot handle. Returns true if the
   // code generation attempt succeeded.