flow.c:verify_local_live_at_start patch (Was: 1 GCC regressions, 1 new, with your patch on 2000-11-02T22:05:00Z)

[Joern Rennecke]

All right, so how about this patch:

Fri Nov  3 20:51:51 2000  J"orn Rennecke <amylaar@redhat.com>

	* flow.c (verify_local_live_at_start): Back out last change.
	* combine.c (distribute_notes): When parts of a hard reg are
	neither set nor referenced in PLACE, search backwards for a
	place to put a REG_UNUSED note; if none found, ask for flow
	info refresh.

Index: flow.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/flow.c,v
retrieving revision 1.346
diff -p -r1.346 flow.c
*** flow.c	2000/11/03 05:43:09	1.346
--- flow.c	2000/11/03 20:51:46
*************** verify_local_live_at_start (new_live_at_
*** 2888,2911 ****
  
        EXECUTE_IF_SET_IN_REG_SET (new_live_at_start, 0, i,
  	{
!           /* No pseudo registers should die.  */
  	  if (REGNO_REG_SET_P (bb->global_live_at_start, i))
! 	    {
! 	      /* But hard regs can reasonably die, e.g. when we combine
! 		 (insn 6 30 7 (set (reg/v:DI 83)
! 				   (reg:DI 5 r5)) (nil)
! 		     (expr_list:REG_DEAD (reg:DI 5 r5) (nil)))
! 		 ... and ...
! 		 (insn 17 15 18 (set (reg:SI 5 r5)
! 				(subreg:SI (reg/v:DI 83) 1)) (insn_list 6 (nil))
! 		     (expr_list:REG_DEAD (reg/v:DI 83) (nil))) .  */
! 
! 	      if (i >= FIRST_PSEUDO_REGISTER)
! 		abort ();
! 	    }
! 	  else
! 	    /* Verify that the now-live register is wider than word_mode.  */
! 	    verify_wide_reg (i, bb->head, bb->end);
  	});
      }
  }
--- 2888,2898 ----
  
        EXECUTE_IF_SET_IN_REG_SET (new_live_at_start, 0, i,
  	{
!           /* No registers should die.  */
  	  if (REGNO_REG_SET_P (bb->global_live_at_start, i))
! 	    abort ();
!           /* Verify that the now-live register is wider than word_mode.  */
! 	  verify_wide_reg (i, bb->head, bb->end);
  	});
      }
  }
Index: combine.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/combine.c,v
retrieving revision 1.160
diff -p -r1.160 combine.c
*** combine.c	2000/11/02 22:02:21	1.160
--- combine.c	2000/11/03 20:51:50
*************** distribute_notes (notes, from_insn, i3, 
*** 12499,12504 ****
--- 12499,12505 ----
  			   i += HARD_REGNO_NREGS (i, reg_raw_mode[i]))
  			{
  			  rtx piece = gen_rtx_REG (reg_raw_mode[i], i);
+ 			  basic_block bb = BASIC_BLOCK (this_basic_block);
  
  			  if (! dead_or_set_p (place, piece)
  			      && ! reg_bitfield_target_p (piece,
*************** distribute_notes (notes, from_insn, i3, 
*** 12510,12515 ****
--- 12511,12544 ----
  			      distribute_notes (new_note, place, place,
  						NULL_RTX, NULL_RTX, NULL_RTX);
  			    }
+ 			  else if (! refers_to_regno_p (i, i + 1,
+ 							PATTERN (place), 0)
+ 				   && ! find_regno_fusage (place, USE, i))
+ 			    for (tem = PREV_INSN (place); ;
+ 				 tem = PREV_INSN (tem))
+ 			      {
+ 				if (! INSN_P (tem))
+ 				  {
+ 				    if (tem == bb->head)
+ 				      {
+ 					SET_BIT (refresh_blocks,
+ 						 this_basic_block);
+ 					need_refresh = 1;
+ 					break;
+ 				      }
+ 				    continue;
+ 				  }
+ 				if (dead_or_set_p (tem, piece)
+ 				    || reg_bitfield_target_p (piece,
+ 							      PATTERN (tem)))
+ 				  {
+ 				    REG_NOTES (tem)
+ 				      = gen_rtx_EXPR_LIST (REG_DEAD, piece,
+ 							   REG_NOTES (tem));
+ 				    break;
+ 				  }
+ 			      }
+ 
  			}
  
  		      place = 0;