@TechReport{	  it:2000-029,
  author	= {Mikael Pettersson},
  title		= {A staged tag scheme for {E}rlang},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Computing Science Division},
  year		= {2000},
  number	= {2000-029},
  month		= nov,
  abstract	= {The runtime systems in Ericsson's implementations of the
		  Erlang programming language, up to and including release
		  R6B, use a simple tag scheme which allows for fast
		  computation of an object's type. However, the tag scheme
		  also restricts all Erlang objects to a 28- or 30-bit
		  address space. This is problematic when Erlang is ported to
		  new systems, and reduces reliability for applications
		  needing large amounts of memory.
		  
		  This paper describes the development of a new \emph{staged}
		  tag scheme, which was designed to \emph{not} restrict the
		  range of pointers, and thus eliminate the source of the
		  abovementioned problems. Secondary benefits also followed:
		  the staged tag scheme is more flexible, and, perhaps
		  surprisingly, is actually more efficient.
		  
		  The staged tag scheme has been integrated into Ericsson's
		  Erlang code, and is a standard feature starting with
		  release R7A. }
}