[Interpreter] Local flow control in the bytecode graph builder.

src/interpreter/control-flow-builders.h

Index: src/interpreter/control-flow-builders.h
diff --git a/src/interpreter/control-flow-builders.h b/src/interpreter/control-flow-builders.h
index c9be6dcdc73ef57a59de53f78aaac99b227f80f2..1f5196861a4edca17ccc2eb6c9f1e1bf297bbf35 100644
--- a/src/interpreter/control-flow-builders.h
+++ b/src/interpreter/control-flow-builders.h
@@ -44,6 +44,7 @@ class BreakableControlFlowBuilder : public ControlFlowBuilder {
   // SetBreakTarget is called.
   void Break() { EmitJump(&break_sites_); }
   void BreakIfTrue() { EmitJumpIfTrue(&break_sites_); }
+  void BreakIfFalse() { EmitJumpIfFalse(&break_sites_); }
   void BreakIfUndefined() { EmitJumpIfUndefined(&break_sites_); }
   void BreakIfNull() { EmitJumpIfNull(&break_sites_); }
 
@@ -52,6 +53,8 @@ class BreakableControlFlowBuilder : public ControlFlowBuilder {
   void EmitJump(ZoneVector<BytecodeLabel>* labels, int index);
   void EmitJumpIfTrue(ZoneVector<BytecodeLabel>* labels);
   void EmitJumpIfTrue(ZoneVector<BytecodeLabel>* labels, int index);
+  void EmitJumpIfFalse(ZoneVector<BytecodeLabel>* labels);
+  void EmitJumpIfFalse(ZoneVector<BytecodeLabel>* labels, int index);
   void EmitJumpIfUndefined(ZoneVector<BytecodeLabel>* labels);
   void EmitJumpIfNull(ZoneVector<BytecodeLabel>* labels);
 
@@ -64,7 +67,6 @@ class BreakableControlFlowBuilder : public ControlFlowBuilder {
 
 // A class to help with co-ordinating break and continue statements with
 // their loop.
-// TODO(oth): add support for TF branch/merge info.
 class LoopBuilder final : public BreakableControlFlowBuilder {
  public:
   explicit LoopBuilder(BytecodeArrayBuilder* builder)
@@ -72,9 +74,12 @@ class LoopBuilder final : public BreakableControlFlowBuilder {
         continue_sites_(builder->zone()) {}
   ~LoopBuilder();
 
-  // This methods should be called by the LoopBuilder owner before
-  // destruction to update sites that emit jumps for continue.
-  void SetContinueTarget(const BytecodeLabel& continue_target);
+  void LoopHeader() { builder()->Bind(&loop_header_); }
+  void Condition() { builder()->Bind(&condition_); }
+  void Next() { builder()->Bind(&next_); }
+  void JumpToHeader() { builder()->Jump(&loop_header_); }
+  void JumpToHeaderIfTrue() { builder()->JumpIfTrue(&loop_header_); }
+  void LoopEnd();
 
   // This method is called when visiting continue statements in the AST.
   // Inserts a jump to a unbound label that is patched when the corresponding
@@ -85,6 +90,13 @@ class LoopBuilder final : public BreakableControlFlowBuilder {
   void ContinueIfNull() { EmitJumpIfNull(&continue_sites_); }
 
  private:
+  void SetContinueTarget(const BytecodeLabel& continue_target);
+
+  BytecodeLabel loop_header_;
+  BytecodeLabel condition_;
+  BytecodeLabel next_;
+  BytecodeLabel loop_end_;
+
   // Unbound labels that identify jumps for continue statements in the code.
   ZoneVector<BytecodeLabel> continue_sites_;
 };