AIX regression due to DFA scheduler merge

[David Edelsohn]

>>>>> law  writes:

Jeff> OK.  I've got a little code which puts the handling of libcall groups into
Jeff> sched_analyze_insn in a manner similar to how we handle post call groups.

Jeff> I'm pretty sure it does the right thing with nested libcalls, with post call
Jeff> groups or cc0 stuff that intersects libcalls, etc.

	I was working on resurrecting my old sched_analyze_1 patch, so I
will be interested to see what you implemented.  BTW, moving the libcall
test to the beginning of sched_analyze at least bootstraps better than the
previously tested version of the patch.

	While working on my version of the patch, I was pondering whether
we should handle bare CLOBBERs while we're fixing this.  In other words.

  if (!reload_completed && GET_CODE (PATTERN (insn)) == CLOBBER)
    {
      if (LIBCALL)
        create_sched_group_for_libcall;
      else
        if (set = single_set (NEXT_INSN (insn)) != 0
            && SET_DEST (set) == XEXP (PATTERN (insn), 0))
	  create_sched_group_for_set;
    }

David