Re: Possible CSE quirk involving SUBREG on the i386

[Jeffrey A Law <law at cygnus dot com>]

  In message <199807010559.WAA27729@dm.cobaltmicro.com>you write:
  > However, it is really a workaround for the core problem.
Yes.  But the core problem (IMHO) is rather difficult to solve.

  > But, I'm concerned that increasing the number of patterns combine
  > looks at in one go will increase compile time considerably.
I haven't seen this behavior yet, though I'm not adding lots of these
patterns :-)  The H8 port has one "bridge" pattern.  I think the
mn102 port has 2 or 3.

  > The next question arises as to what a good number would be, perhaps
  > the code in combine can be made generic enough that a target header
  > define can tell it the max number of patterns to ever try to coalesce
  > at once?
I'd be suprised if we could make combine do 4->3 without a lot of
work -- which then begs the question are the benefits enough to
justify the work considering the other things we could be working
on?

jeff