Experimental: use the Result class to manage the lifetime of registers...

src/virtual-frame-ia32.h

Index: src/virtual-frame-ia32.h
===================================================================
--- src/virtual-frame-ia32.h	(revision 999)
+++ src/virtual-frame-ia32.h	(working copy)
@@ -33,68 +33,6 @@
 
 namespace v8 { namespace internal {
 
-
-// The code generator's view of a frame element, when it wants to use it.
-//
-// A Result can be a register or a constant.
-class Result BASE_EMBEDDED {
- public:
-  // Construct a register Result.
-  Result(Register reg, CodeGenerator* cgen);
-
-  // Construct a Result whose value is a compile-time constant.
-  Result(Handle<Object> value, CodeGenerator * cgen) :
-      type_(CONSTANT),
-      cgen_(cgen) {
-    data_.handle_ = value.location();
-  }
-
-  ~Result() {
-    if (is_register()) {
-      Unuse();
-    }
-  }
-
-  void Unuse();
-
-  bool is_register() const { return type() == REGISTER; }
-  bool is_constant() const { return type() == CONSTANT; }
-  bool is_valid() const { return type() != INVALID; }
-
-  Register reg() const {
-    ASSERT(type() == REGISTER);
-    return data_.reg_;
-  }
-
-  Handle<Object> handle() const {
-    ASSERT(type() == CONSTANT);
-    return Handle<Object>(data_.handle_);
-  }
-
-  // Change a result to a register result.  If the result is not already
-  // in a register, allocate a register from the code generator, and emit
-  // code to move the value into that register.
-  void ToRegister();
- private:
-  enum Type {
-    REGISTER,
-    CONSTANT,
-    INVALID
-  };
-
-  Type type_;
-
-  Type type() const { return type_; }
-
-  union {
-    Register reg_;
-    Object** handle_;
-  } data_;
-
-  CodeGenerator* cgen_;
-};
-
-
 // -------------------------------------------------------------------------
 // Virtual frame elements
 //
@@ -401,6 +339,10 @@
   void Push(Register reg);
   void Push(Handle<Object> value);
 
+  // Pushing a result invalidates it (its contents become owned by the
+  // frame).
+  void Push(Result* result);
+
 #ifdef DEBUG
   bool IsSpilled();
 #endif