Refactor building of lazy bailouts in AstGraphBuilder.

BUG=
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/464033002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23096 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/ast-graph-builder.h

@@ -171,8 +171,18 @@ class AstGraphBuilder : public StructuredGraphBuilder, public AstVisitor {
   // Dispatched from VisitForInStatement.
   void VisitForInAssignment(Expression* expr, Node* value);
 
-  void BuildLazyBailout(Node* node, BailoutId ast_id);
-  void BuildLazyBailoutWithPushedNode(Node* node, BailoutId ast_id);
+  // Flag that describes how to combine the current environment with
+  // the output of a node to obtain a framestate for lazy bailout.
+  enum OutputFrameStateCombine {
+    PUSH_OUTPUT,   // Push the output on the expression stack.
+    IGNORE_OUTPUT  // Use the frame state as-is.
+  };
+
+  // Builds deoptimization for a given node.
+  void PrepareFrameState(Node* node, BailoutId ast_id,
+                         OutputFrameStateCombine combine = IGNORE_OUTPUT);
+
+  OutputFrameStateCombine StateCombineFromAstContext();
 
   DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
   DISALLOW_COPY_AND_ASSIGN(AstGraphBuilder);
@@ -282,10 +292,15 @@ class AstGraphBuilder::AstContext BASE_EMBEDDED {
   bool IsValue() const { return kind_ == Expression::kValue; }
   bool IsTest() const { return kind_ == Expression::kTest; }
 
+  // Determines how to combine the frame state with the value
+  // that is about to be plugged into this AstContext.
+  AstGraphBuilder::OutputFrameStateCombine GetStateCombine() {
+    return IsEffect() ? IGNORE_OUTPUT : PUSH_OUTPUT;
+  }
+
   // Plug a node into this expression context.  Call this function in tail
   // position in the Visit functions for expressions.
   virtual void ProduceValue(Node* value) = 0;
-  virtual void ProduceValueWithLazyBailout(Node* value) = 0;
 
   // Unplugs a node from this expression context.  Call this to retrieve the
   // result of another Visit function that already plugged the context.
@@ -295,8 +310,7 @@ class AstGraphBuilder::AstContext BASE_EMBEDDED {
   void ReplaceValue() { ProduceValue(ConsumeValue()); }
 
  protected:
-  AstContext(AstGraphBuilder* owner, Expression::Context kind,
-             BailoutId bailout_id);
+  AstContext(AstGraphBuilder* owner, Expression::Context kind);
   virtual ~AstContext();
 
   AstGraphBuilder* owner() const { return owner_; }
@@ -308,8 +322,6 @@ class AstGraphBuilder::AstContext BASE_EMBEDDED {
   int original_height_;
 #endif
 
-  BailoutId bailout_id_;
-
  private:
   Expression::Context kind_;
   AstGraphBuilder* owner_;
@@ -320,11 +332,10 @@ class AstGraphBuilder::AstContext BASE_EMBEDDED {
 // Context to evaluate expression for its side effects only.
 class AstGraphBuilder::AstEffectContext V8_FINAL : public AstContext {
  public:
-  explicit AstEffectContext(AstGraphBuilder* owner, BailoutId bailout_id)
-      : AstContext(owner, Expression::kEffect, bailout_id) {}
+  explicit AstEffectContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kEffect) {}
   virtual ~AstEffectContext();
   virtual void ProduceValue(Node* value) V8_OVERRIDE;
-  virtual void ProduceValueWithLazyBailout(Node* value) V8_OVERRIDE;
   virtual Node* ConsumeValue() V8_OVERRIDE;
 };
 
@@ -332,11 +343,10 @@ class AstGraphBuilder::AstEffectContext V8_FINAL : public AstContext {
 // Context to evaluate expression for its value (and side effects).
 class AstGraphBuilder::AstValueContext V8_FINAL : public AstContext {
  public:
-  explicit AstValueContext(AstGraphBuilder* owner, BailoutId bailout_id)
-      : AstContext(owner, Expression::kValue, bailout_id) {}
+  explicit AstValueContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kValue) {}
   virtual ~AstValueContext();
   virtual void ProduceValue(Node* value) V8_OVERRIDE;
-  virtual void ProduceValueWithLazyBailout(Node* value) V8_OVERRIDE;
   virtual Node* ConsumeValue() V8_OVERRIDE;
 };
 
@@ -344,11 +354,10 @@ class AstGraphBuilder::AstValueContext V8_FINAL : public AstContext {
 // Context to evaluate expression for a condition value (and side effects).
 class AstGraphBuilder::AstTestContext V8_FINAL : public AstContext {
  public:
-  explicit AstTestContext(AstGraphBuilder* owner, BailoutId bailout_id)
-      : AstContext(owner, Expression::kTest, bailout_id) {}
+  explicit AstTestContext(AstGraphBuilder* owner)
+      : AstContext(owner, Expression::kTest) {}
   virtual ~AstTestContext();
   virtual void ProduceValue(Node* value) V8_OVERRIDE;
-  virtual void ProduceValueWithLazyBailout(Node* value) V8_OVERRIDE;
   virtual Node* ConsumeValue() V8_OVERRIDE;
 };
 

src/compiler/graph-builder.cc

@@ -30,6 +30,8 @@ StructuredGraphBuilder::StructuredGraphBuilder(Graph* graph,
 
 Node* StructuredGraphBuilder::MakeNode(Operator* op, int value_input_count,
                                        Node** value_inputs) {
+  DCHECK(op->InputCount() == value_input_count);
+
   bool has_context = OperatorProperties::HasContextInput(op);
   bool has_control = OperatorProperties::GetControlInputCount(op) == 1;
   bool has_effect = OperatorProperties::GetEffectInputCount(op) == 1;