Backward insn combination?

[Jeffrey A Law]

  In message < 199906301252.NAA22892@sun52.NIS.cambridge >you write:
  > But the LOG_LINKS on C point back to A, which is how the code in 
  > combine_instructions works. 
Right.  I never disputed that.

  > So by combining B and D and restarting after where B was we find C
  > which points us back to A.
Hmmm, good point.  Actually, I thought we already did this (restarted
at the point there we delete the insn).  Hmmm, worth someone's time
to investigate.
jeff