CLOS Speed

[Brad.Myers@a.gp.cs.cmu.edu]

Our project is using the February 3rd, 1988 version of PCL (CLOS).  I
am trying to convince our group to continue to use CLOS, but the problem
is that the speed of slot access and method call is so slow that we are
thinking of using a home-brewed object system.  Our measurements show
that using CLOS is between 3 to 5 times slower than using structs and
procedure calls on CMU Common Lisp on an IBM-RT.  The times we are getting
are:
	Simple CLOS Slot access:	17   microseconds
	Simple struct access:		 4.7   "
	Method call:			56     "
	Procedure call:			20     "

Are these numbers close to what other people observe?  Can we expect
to see a (significantly) faster version of CLOS?  If so, how much
faster, and when will it be available?  I would like to stick with
the CLOS standard, but we need resonable performance in our application.

Thanks,

Brad A. Myers
Research Computer Scientist
Computer Science Department
Carnegie Mellon University
Pittsburgh, PA  15213
(412) 268-5150
bam@a.gp.cs.cmu.edu