scheduling problems again

[Mike Stump]

> To: mrs@wrs.com (Mike Stump)
> cc: egcs@cygnus.com
> Date: Wed, 28 Jan 1998 00:05:22 -0700
> From: Jeffrey A Law <law@hurl.cygnus.com>

> I'd just change it to ignore REG_DEAD notes after reload instead of
> aborting.  There's still cases where it would be useful if it
> ignored such notes.

Oops, my last patch was incomplete and not as optimal as it could be,
try this instead:

The genattrtab.c patch is so that genattrtab can link.  It doesn't
actually use dead_or_set_p currently (I checked), but if in the future
it does, the semantics will be that the REG_DEAD notes (if any are
found) are reliable.  That seemed like a reasonable default.

1998-01-28  Mike Stump  <mrs@wrs.com>

	* rtlanal.c (dead_or_set_regno_p): Ignore REG_DEAD notes after
	reload completes, as REG_DEAD notes are not maintained after
	reload completes and may be inaccurate.
	* genattrtab.c (reload_completed): Define so that if
	dead_or_set_p is ever called, REG_DEAD notes are treated as
	valid.

Doing diffs in genattrtab.c.~1~:
*** genattrtab.c.~1~	Mon Jan 19 12:21:17 1998
--- genattrtab.c	Wed Jan 28 10:32:33 1998
*************** static rtx true_rtx, false_rtx;
*** 348,353 ****
--- 348,358 ----
  
  static char *alternative_name;
  
+ /* Indicate that REG_DEAD notes are valid if dead_or_set_p is ever
+    called.  */
+ 
+ int reload_completed = 0;
+ 
  /* Simplify an expression.  Only call the routine if there is something to
     simplify.  */
  #define SIMPLIFY_TEST_EXP(EXP,INSN_CODE,INSN_INDEX)	\
--------------
Doing diffs in rtlanal.c.~1~:
*** rtlanal.c.~1~	Thu Jan 15 17:20:49 1998
--- rtlanal.c	Wed Jan 28 10:23:32 1998
*************** dead_or_set_regno_p (insn, test_regno)
*** 1157,1175 ****
    int regno, endregno;
    rtx link;
  
!   /* See if there is a death note for something that includes TEST_REGNO.  */
!   for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
      {
!       if (REG_NOTE_KIND (link) != REG_DEAD || GET_CODE (XEXP (link, 0)) != REG)
! 	continue;
  
!       regno = REGNO (XEXP (link, 0));
!       endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
! 		  : regno + HARD_REGNO_NREGS (regno,
! 					      GET_MODE (XEXP (link, 0))));
  
!       if (test_regno >= regno && test_regno < endregno)
! 	return 1;
      }
  
    if (GET_CODE (insn) == CALL_INSN
--- 1157,1186 ----
    int regno, endregno;
    rtx link;
  
!   /* REG_READ notes are not normally maintained after reload, so we
!      ignore them if the are invalid.  */
!   if (! reload_completed
! #ifdef PRESERVE_DEATH_INFO_REGNO_P
!       || PRESERVE_DEATH_INFO_REGNO_P (test_regno)
! #endif
!       )
      {
!       /* See if there is a death note for something that includes
!          TEST_REGNO.  */
!       for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
! 	{
! 	  if (REG_NOTE_KIND (link) != REG_DEAD
! 	      || GET_CODE (XEXP (link, 0)) != REG)
! 	    continue;
  
! 	  regno = REGNO (XEXP (link, 0));
! 	  endregno = (regno >= FIRST_PSEUDO_REGISTER ? regno + 1
! 		      : regno + HARD_REGNO_NREGS (regno,
! 						  GET_MODE (XEXP (link, 0))));
  
! 	  if (test_regno >= regno && test_regno < endregno)
! 	    return 1;
! 	}
      }
  
    if (GET_CODE (insn) == CALL_INSN
--------------