calls.c (load_register_parameters): Move check for zero sized items so that only the call to ...

	* calls.c (load_register_parameters): Move check for zero
	sized items so that only the call to 
	mem_overlaps_already_clobbered_arg_p () is protected.

From-SVN: r162402

gcc/ChangeLog

+2010-07-22  Iain Sandoe  <iains@gcc.gnu.org>
+
+	* calls.c (load_register_parameters): Move check for zero
+	sized items so that only the call to 
+	mem_overlaps_already_clobbered_arg_p () is protected.
+
 2010-07-22  Jan Hubicka  <jh@suse.cz>
 
 	* ipa-pure-const.c (varying_state): Break out from ...

gcc/calls.c

@@ -1668,15 +1668,16 @@ load_register_parameters (struct arg_data *args, int num_actuals,
 	      emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
 			      args[i].aligned_regs[j]);
 
-	  else if ((partial == 0 || args[i].pass_on_stack)
-		   && size != 0)
+	  else if (partial == 0 || args[i].pass_on_stack)
 	    {
 	      rtx mem = validize_mem (args[i].value);
 
-	      /* Check for overlap with already clobbered argument area.  */
+	      /* Check for overlap with already clobbered argument area,
+	         providing that this has non-zero size.  */
 	      if (is_sibcall
-		  && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
-							   size))
+		  && (size == 0
+		      || mem_overlaps_already_clobbered_arg_p 
+					   (XEXP (args[i].value, 0), size)))
 		*sibcall_failure = 1;
 
 	      /* Handle a BLKmode that needs shifting.  */