Experimental: thread live register references to deferred code....

src/codegen.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 26 matching lines @@
 // of Visitor and that the following methods are available publicly:
 // CodeGenerator::MakeCode
 // CodeGenerator::SetFunctionInfo
 // CodeGenerator::AddDeferred
 // CodeGenerator::masm
 //
 // These methods are either used privately by the shared code or implemented as
 // shared code:
 // CodeGenerator::CodeGenerator
 // CodeGenerator::~CodeGenerator
+// CodeGenerator::SetFrame
 // CodeGenerator::ProcessDeferred
 // CodeGenerator::GenCode
 // CodeGenerator::BuildBoilerplate
 // CodeGenerator::ComputeCallInitialize
 // CodeGenerator::ComputeCallInitializeInLoop
 // CodeGenerator::ProcessDeclarations
 // CodeGenerator::DeclareGlobals
 // CodeGenerator::CheckForInlineRuntimeCall
 // CodeGenerator::GenerateFastCaseSwitchStatement
 // CodeGenerator::GenerateFastCaseSwitchCases
@@ skipping 17 matching lines @@
 //       moment, this doesn't work for the extensions in Google3,
 //       and we can only run the tests with --nolazy.
 
 
 // Deferred code objects are small pieces of code that are compiled
 // out of line. They are used to defer the compilation of uncommon
 // paths thereby avoiding expensive jumps around uncommon code parts.
 class DeferredCode: public ZoneObject {
  public:
   explicit DeferredCode(CodeGenerator* generator);
-  virtual ~DeferredCode() { }
+  virtual ~DeferredCode() {}
 
   virtual void Generate() = 0;
 
   MacroAssembler* masm() const { return masm_; }
   CodeGenerator* generator() const { return generator_; }
 
-  JumpTarget* enter() { return &enter_; }
-  JumpTarget* exit() { return &exit_; }
+  // Emit a conditional branch to the code entry.
+  void BranchTo(Condition cc);
+
+  // Bind the exit target of the code.
+  void BindExit();
+
+  // Emit an exit from the code if the exit target is bound.
+  void ExitIfBound();
+
+  Label* enter() { return &enter_; }
+
+  VirtualFrame* frame() { return frame_; }
+  void clear_frame() { frame_ = NULL; }
+
+  RegisterFile* registers() { return &registers_; }
 
   int statement_position() const { return statement_position_; }
   int position() const { return position_; }
 
 #ifdef DEBUG
   void set_comment(const char* comment) { comment_ = comment; }
   const char* comment() const { return comment_; }
 #else
   inline void set_comment(const char* comment) { }
   const char* comment() const { return ""; }
 #endif
 
  protected:
   // The masm_ field is manipulated when compiling stubs with the
   // BEGIN_STUB and END_STUB macros. For that reason, it cannot be
   // constant.
   MacroAssembler* masm_;
 
  private:
   CodeGenerator* const generator_;
-  JumpTarget enter_;
+
+  // The entry is a label, paired with a known frame and a known global
+  // register file.  It is not a jump target because it doesn't use any of
+  // the jump target's branch or bind machinery.
+  Label enter_;
+  VirtualFrame* frame_;
+  RegisterFile registers_;
+
+  // The exit target is a regular jump target.
   JumpTarget exit_;
+
   int statement_position_;
   int position_;
 #ifdef DEBUG
   const char* comment_;
 #endif
   DISALLOW_COPY_AND_ASSIGN(DeferredCode);
 };
 
 
 // RuntimeStub models code stubs calling entry points in the Runtime class.
@@ skipping 156 matching lines @@
     PrintF("ArgumentsAccessStub (type %d)\n", type_);
   }
 #endif
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODEGEN_H_