jump.c (duplicate_loop_exit_test): Strip REG_WAS_0 notes off all insns we're going to copy.

	* jump.c (duplicate_loop_exit_test): Strip REG_WAS_0 notes off all
	insns we're going to copy.
	* regclass.c (reg_scan_mark_refs): Don't test X for NULL_RTX.

From-SVN: r22887

gcc/ChangeLog

@@ -21,6 +21,10 @@ Wed Oct  7 02:27:52 1998  Jeffrey A Law  (law@cygnus.com)
 	
 Wed Oct  7 01:08:43 1998  Bernd Schmidt <crux@Pool.Informatik.RWTH-Aachen.DE>
 
+	* jump.c (duplicate_loop_exit_test): Strip REG_WAS_0 notes off all
+	insns we're going to copy.
+	* regclass.c (reg_scan_mark_refs): Don't test X for NULL_RTX.
+
 	* loop.c (count_one_set): Add prototype.
 
 	* caller-save.c (restore_referenced_regs): Lose mode argument.

gcc/jump.c

@@ -480,12 +480,9 @@ jump_optimize (f, cross_jump, noop_moves, after_regscan)
 				remove_death (dreg, trial);
 				break;
 			      }
-#ifdef PRESERVE_DEATH_INFO_REGNO_P
-			/* Deleting insn could lose a death-note for SREG
-			   so don't do it if final needs accurate
-			   death-notes.  */
-			if (PRESERVE_DEATH_INFO_REGNO_P (sreg)
-			    && (trial = find_regno_note (insn, REG_DEAD, sreg)))
+
+			/* Deleting insn could lose a death-note for SREG.  */
+			if ((trial = find_regno_note (insn, REG_DEAD, sreg)))
 			  {
 			    /* Change this into a USE so that we won't emit
 			       code for it, but still can keep the note.  */
@@ -497,7 +494,6 @@ jump_optimize (f, cross_jump, noop_moves, after_regscan)
 			    XEXP (trial, 1) = NULL_RTX;
 			  }
 			else
-#endif
 			  delete_insn (insn);
 		      }
 		  }
@@ -2434,8 +2430,7 @@ duplicate_loop_exit_test (loop_start)
 	 has a REG_RETVAL or REG_LIBCALL note (hard to adjust)
 	 is a NOTE_INSN_LOOP_BEG because this means we have a nested loop
 	 is a NOTE_INSN_BLOCK_{BEG,END} because duplicating these notes
-	      are not valid
-	    
+	      is not valid.
 
      We also do not do this if we find an insn with ASM_OPERANDS.  While
      this restriction should not be necessary, copying an insn with
@@ -2480,6 +2475,10 @@ duplicate_loop_exit_test (loop_start)
 	  break;
 	case JUMP_INSN:
 	case INSN:
+	  /* The code below would grossly mishandle REG_WAS_0 notes,
+	     so get rid of them here.  */
+	  while ((p = find_reg_note (insn, REG_WAS_0, NULL_RTX)) != 0)
+	    remove_note (insn, p);
 	  if (++num_insns > 20
 	      || find_reg_note (insn, REG_RETVAL, NULL_RTX)
 	      || find_reg_note (insn, REG_LIBCALL, NULL_RTX)

gcc/regclass.c

@@ -1995,13 +1995,6 @@ reg_scan_mark_refs (x, insn, note_flag, min_regno)
   register rtx dest;
   register rtx note;
 
-  /* This can happen when scanning insns referenced by certain notes.
-
-     It is unclear if we should be scanning such insns; until someone can
-     say for sure this seems like the safest fix.  */
-  if (x == NULL_RTX)
-    return;
-
   code = GET_CODE (x);
   switch (code)
     {