From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeffrey A Law <law@chunks.cygnus.com>
To: egcs@cygnus.com
Subject: Re: Some Haifa scheduler bugs
Date: Fri, 22 Aug 1997 15:24:57 -0000
Message-ID: <9708221140.AA11211@issan.informatik.uni-dortmund.de>
In-reply-to: Some Haifa scheduler bugs
X-SW-Source: 1997-08/0295.html
Message-ID: <19970822152457.JKIuT_nXaLew60nxHSI6wk2splchNSJbKXD-_2BpLJ0@z>

  In message <Pine.SOL.3.90.970821173718.733B-100000@maigret.informatik.rwth-aa
chen.de>you write:
  > I've thought about something like this, but this code won't work, I think.
  > It will call reemit_notes twice for the last insn in the SCHED_GROUP and
  > not at all for the first one.
OK.  Let's use the same example again:

Consider if we have Z <-A <-B <-C, all with SCHED_GROUP_P set on A B & C,
but not Z.



  insn = C
  We start the while loop (SCHED_GROUP_P (C) == 1)
    prev = B
    move_insn1 (C, last)
    insn = B
   2nd iteration (SCHED_GROUP_P (B) == 1)
    prev = A
    move_insn1 (B, last)
    insn = A
   3rd iteration (SCHED_GROUP_P (A) == 1)
    prev = Z
    move_insn_1 (A, last)
    insn = Z
   loop terminates (SCHED_GROUP_P (Z) == 0)

  move_insn1 (Z, last)
  reemit_notes (Z, Z)


So the problem here is we don't call reemit_notes for A B & C.


So, how about this:

static rtx
move_insn (insn, last)
     rtx insn, last;
{
  while (SCHED_GROUP_P (insn))
    {
      rtx prev = PREV_INSN (insn);
      move_insn1 (insn, last);
      reemit_notes (insn, insn);
      insn = prev;
    }

  move_insn1 (insn, last);
  return reemit_notes (insn, insn);
}



  insn = C
  We start the while loop (SCHED_GROUP_P (C) == 1)
    prev = B
    move_insn1 (C, last)
    reemit_notes (C, C)
    insn = B
   2nd iteration (SCHED_GROUP_P (B) == 1)
    prev = A
    move_insn1 (B, last)
    reemit_notes (B, B)
    insn = A
   3rd iteration (SCHED_GROUP_P (A) == 1)
    prev = Z
    move_insn1 (A, last)
    reemit_notes (A, A)
    insn = Z
   loop terminates (SCHED_GROUP_P (Z) == 0)


  move_insn1 (Z, last)
  reemit_notes (Z, Z)


Jeff