Rerunning CSE after GCSE

[Jeffrey A Law]

  In message < 10102200216.AA19911@vlsi1.ultra.nyu.edu >you write:
  >     Yea, it worked by keeping state for each block and re-using that to spe
  > ed
  >     up skip-blocks, follow-jumps, etc etc if I recall.
  > 
  > I would like to see if we still *need* skip-blocks and follow-jumps now
  > that we have gcse.
That's a good question.  And I don't have an answer.

However, consider that cse.c has more code to handle costing, more
simplifications, etc than gcse.c  Also consider that gcse.c doesn't work
at all on hard regs -- it seems them and gives up.

jeff