padl-2.1 published

[Mark S. Miller <mark>]

Date: Wed, 23 Aug 89 19:49:22 PDT
   From: tribble (Eric Dean Tribble)

   Roger and Hugh and I were discussing multiple inheritance briefly and
   someone pointed out that the translation of a message-send in 2.0 is
   more complicated because of multiple inheritance.  Is that true?!
   Hugh suggested the fix that apple made: Have all subclasses of a
   particular class use the single inheritance model of programming.  We
   could get Nat to do this, I expect.

The question isn't "is it more complicated?" (it is), but "is it
significantly less efficient?".  I don't know.  I propose we don't
worry about this until we're in the post-Beta tuning stage.  For the
effort it would take to deal with this, I suspect there's more to be
gained by spending that effort further tuning our algorithms.  (On the
other hand, the effort would be Nat's, which is modularly separable).

Note that the first part of tuning is to avoid virtual and use inlines
in many many places where we are now using virtual.  We don't know yet
the degree to which our bottlenecks will involve virtual.