Why can't CSE recognize const_int's in HIGH LO_SUM pair?

[law@redhat.com]

  In message < 20010910095948.A8881@redhat.com >you write:
  > The thing I like about exposing the split early is that
  > gcse gets to move these expressions around.  If you expose
  > the split later, nothing is going to move the parts around
  > as aggressively.
True.  But with the way things are currently implemented I don't think
we actually lose anything on the PA by not exposing the subexpressions
to gcse.  Instead of commonizing the HIGH and LO_SUM parts with other
idential ones elsewhere, we end up commonizing (set (reg) (const_int))


jeff