Spill arguments for a function call from the virtual frame as they are produc...

src/x64/virtual-frame-x64.h

 // Copyright 2009 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 127 matching lines @@
   // Spill all occurrences of a specific register from the frame.
   void Spill(Register reg) {
     if (is_used(reg)) SpillElementAt(register_location(reg));
   }
 
   // Spill all occurrences of an arbitrary register if possible.  Return the
   // register spilled or no_reg if it was not possible to free any register
   // (ie, they all have frame-external references).
   Register SpillAnyRegister();
 
+  // Spill the top element of the frame to memory.
+  void SpillTop() { SpillElementAt(element_count() - 1); }
+
   // Sync the range of elements in [begin, end] with memory.
   void SyncRange(int begin, int end);
 
   // Make this frame so that an arbitrary frame of the same height can
   // be merged to it.  Copies and constants are removed from the frame.
   void MakeMergable();
 
   // Prepare this virtual frame for merging to an expected frame by
   // performing some state changes that do not require generating
   // code.  It is guaranteed that no code will be generated.
@@ skipping 402 matching lines @@
 
   // Classes that need raw access to the elements_ array.
   friend class DeferredCode;
   friend class JumpTarget;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_VIRTUAL_FRAME_X64_H_