re PR rtl-optimization/23837 (Wrong code with REG_NO_CONFLICT notes (caused by combine))

	PR rtl-optimization/23837
	*  optabs.c (no_conflict_move_test): Don't set must_stay for a
	clobber / clobber match between dest and p->first.

From-SVN: r104562

gcc/ChangeLog

@@ -3,6 +3,10 @@
 	* final.c (insn_default_length, insn_min_length): In !HAVE_ATTR_length
 	case, define as macros.
 
+	PR rtl-optimization/23837
+	*  optabs.c (no_conflict_move_test): Don't set must_stay for a
+	clobber / clobber match between dest and p->first.
+
 2005-09-22  Ranjit Mathew  <rmathew@gcc.gnu.org>
 
 	* doc/install.texi: Update URL for Jacks.

gcc/optabs.c

@@ -3021,7 +3021,8 @@ no_conflict_move_test (rtx dest, rtx set, void *p0)
     return;
   /* If this insn sets / clobbers a register that feeds one of the insns
      already in the list, this insn has to stay too.  */
-  else if (reg_mentioned_p (dest, PATTERN (p->first))
+  else if (reg_overlap_mentioned_p (dest, PATTERN (p->first))
+	   || (CALL_P (p->first) && (find_reg_fusage (p->first, USE, dest)))
 	   || reg_used_between_p (dest, p->first, p->insn)
 	   /* Likewise if this insn depends on a register set by a previous
 	      insn in the list.  */