[NDS32] Look into LO_SUM's operand to determine whether it is a valid address.

gcc/
	* config/nds32/nds32.c (nds32_legitimate_address_p): For LO_SUM,
	we need to look into its operand to determine whether it is a valid
	address.

From-SVN: r217904

gcc/ChangeLog

 2014-11-21  Chung-Ju Wu  <jasonwucj@gmail.com>
 
+	* config/nds32/nds32.c (nds32_legitimate_address_p): For LO_SUM,
+	we need to look into its operand to determine if it is a valid
+	address.
+
+2014-11-21  Chung-Ju Wu  <jasonwucj@gmail.com>
+
 	* config/nds32/nds32.c (nds32_emit_stack_push_multiple): Add new
 	vaarg_p argument and create correct CFI info.
 	(nds32_expand_prologue): Pass true or false to

gcc/config/nds32/nds32.c

@@ -2041,8 +2041,14 @@ nds32_legitimate_address_p (machine_mode mode, rtx x, bool strict)
 	return false;
 
     case LO_SUM:
-      if (!TARGET_GP_DIRECT)
-	return true;
+      /* (mem (lo_sum (reg) (symbol_ref))) */
+      /* (mem (lo_sum (reg) (const))) */
+      gcc_assert (REG_P (XEXP (x, 0)));
+      if (GET_CODE (XEXP (x, 1)) == SYMBOL_REF
+	  || GET_CODE (XEXP (x, 1)) == CONST)
+	return nds32_legitimate_address_p (mode, XEXP (x, 1), strict);
+      else
+	return false;
 
     default:
       return false;