Stop overallocating feedback vector slots.

src/ast-numbering.cc

 // Copyright 2012 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.
 
 #include "src/ast.h"
 #include "src/ast-numbering.h"
 #include "src/scopes.h"
 
 namespace v8 {
 namespace internal {
 
 class AstNumberingVisitor final : public AstVisitor {
  public:
-  explicit AstNumberingVisitor(Isolate* isolate, Zone* zone)
+  AstNumberingVisitor(Isolate* isolate, Zone* zone)
       : AstVisitor(),
         next_id_(BailoutId::FirstUsable().ToInt()),
         properties_(zone),
         ic_slot_cache_(4),
         dont_optimize_reason_(kNoReason) {
     InitializeAstVisitor(isolate, zone);
   }
 
   bool Renumber(FunctionLiteral* node);
 
  private:
 // AST node visitor interface.
 #define DEFINE_VISIT(type) virtual void Visit##type(type* node) override;
   AST_NODE_LIST(DEFINE_VISIT)
 #undef DEFINE_VISIT
 
   bool Finish(FunctionLiteral* node);
 
+  void VisitVariableProxyReference(VariableProxy* node);
+  void VisitPropertyReference(Property* node);
+  void VisitReference(Expression* expr);
+
   void VisitStatements(ZoneList<Statement*>* statements) override;
   void VisitDeclarations(ZoneList<Declaration*>* declarations) override;
   void VisitArguments(ZoneList<Expression*>* arguments);
   void VisitObjectLiteralProperty(ObjectLiteralProperty* property);
 
   int ReserveIdRange(int n) {
     int tmp = next_id_;
     next_id_ += n;
     return tmp;
   }
@@ skipping 95 matching lines @@
   node->set_base_id(ReserveIdRange(Literal::num_ids()));
 }
 
 
 void AstNumberingVisitor::VisitRegExpLiteral(RegExpLiteral* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(RegExpLiteral::num_ids()));
 }
 
 
+void AstNumberingVisitor::VisitVariableProxyReference(VariableProxy* node) {
+  IncrementNodeCount();
+  if (node->var()->IsLookupSlot()) {
+    DisableCrankshaft(kReferenceToAVariableWhichRequiresDynamicLookup);
+  }
+  node->set_base_id(ReserveIdRange(VariableProxy::num_ids()));
+}
+
+
 void AstNumberingVisitor::VisitVariableProxy(VariableProxy* node) {
-  IncrementNodeCount();
-  if (node->var()->IsLookupSlot()) {
-    DisableCrankshaft(kReferenceToAVariableWhichRequiresDynamicLookup);
-  }
+  VisitVariableProxyReference(node);
   ReserveFeedbackSlots(node);
-  node->set_base_id(ReserveIdRange(VariableProxy::num_ids()));
 }
 
 
 void AstNumberingVisitor::VisitThisFunction(ThisFunction* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(ThisFunction::num_ids()));
 }
 
 
 void AstNumberingVisitor::VisitSuperPropertyReference(
@@ skipping 132 matching lines @@
 
 void AstNumberingVisitor::VisitTryFinallyStatement(TryFinallyStatement* node) {
   IncrementNodeCount();
   DisableOptimization(kTryFinallyStatement);
   node->set_base_id(ReserveIdRange(TryFinallyStatement::num_ids()));
   Visit(node->try_block());
   Visit(node->finally_block());
 }
 
 
+void AstNumberingVisitor::VisitPropertyReference(Property* node) {
+  IncrementNodeCount();
+  node->set_base_id(ReserveIdRange(Property::num_ids()));
+  Visit(node->key());
+  Visit(node->obj());
+}
+
+
+void AstNumberingVisitor::VisitReference(Expression* expr) {
+  DCHECK(expr->IsProperty() || expr->IsVariableProxy());
+  if (expr->IsProperty())

[Benedikt Meurer, 2015/07/30 06:32:22]

Nit: if { ... } else { ... }

+    VisitPropertyReference(expr->AsProperty());
+  else
+    VisitVariableProxyReference(expr->AsVariableProxy());
+}
+
+
 void AstNumberingVisitor::VisitProperty(Property* node) {
-  IncrementNodeCount();
+  VisitPropertyReference(node);
   ReserveFeedbackSlots(node);
-  node->set_base_id(ReserveIdRange(Property::num_ids()));
-  Visit(node->key());
-  Visit(node->obj());
 }
 
 
 void AstNumberingVisitor::VisitAssignment(Assignment* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(Assignment::num_ids()));
   if (node->is_compound()) VisitBinaryOperation(node->binary_operation());
-  Visit(node->target());
+  VisitReference(node->target());
   Visit(node->value());
   ReserveFeedbackSlots(node);
 }
 
 
 void AstNumberingVisitor::VisitBinaryOperation(BinaryOperation* node) {
   IncrementNodeCount();
   node->set_base_id(ReserveIdRange(BinaryOperation::num_ids()));
   Visit(node->left());
   Visit(node->right());
@@ skipping 213 matching lines @@
 }
 
 
 bool AstNumbering::Renumber(Isolate* isolate, Zone* zone,
                             FunctionLiteral* function) {
   AstNumberingVisitor visitor(isolate, zone);
   return visitor.Renumber(function);
 }
 }  // namespace internal
 }  // namespace v8