re PR middle-end/49220 (ICE in create_pre_exit, at mode-switching.c:401)

	PR middle-end/49220
	* mode-switching.c (create_pre_exit): Set short_block if there
	are no copy insns.

From-SVN: r193289

gcc/ChangeLog

+2012-11-07  Kaz Kojima  <kkojima@gcc.gnu.org>
+
+	PR middle-end/49220
+	* mode-switching.c (create_pre_exit): Set short_block if there
+	are no copy insns.
+
 2012-11-07  Martin Jambor  <mjambor@suse.cz>
 
 	* lto-cgraph.c: Include tree-pass.h.

gcc/mode-switching.c

@@ -322,7 +322,14 @@ create_pre_exit (int n_entities, int *entity_map, const int *num_modes)
 			     && GET_CODE (SUBREG_REG (copy_reg)) == REG)
 		      copy_start = REGNO (SUBREG_REG (copy_reg));
 		    else
-		      break;
+		      {
+			/* When control reaches end of non-void function,
+			   there are no return copy insns at all.  This
+			   avoids an ice on that invalid function.  */
+			if (ret_start + nregs == ret_end)
+			  short_block = 1;
+			break;
+		      }
 		    if (copy_start >= FIRST_PSEUDO_REGISTER)
 		      {
 			last_insn = return_copy;