expr.c (store_field): Do nothing except elaborate side-effects if zero-bit field.

	* expr.c (store_field): Do nothing except elaborate side-effects if
	zero-bit field.

From-SVN: r41763

gcc/ChangeLog

+Wed May  2 13:09:36 2001  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
+
+	* expr.c (store_field): Do nothing except elaborate side-effects if
+	zero-bit field.
+
 2001-05-02  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* c-lex.c: NULL_PTR -> NULL.

gcc/expr.c

@@ -5131,6 +5131,11 @@ store_field (target, bitsize, bitpos, mode, exp, value_mode,
   if (TREE_CODE (exp) == ERROR_MARK)
     return const0_rtx;
 
+  /* If we have nothing to store, do nothing unless the expression has
+     side-effects.  */
+  if (bitsize == 0)
+    return expand_expr (exp, const0_rtx, VOIDmode, 0);
+
   if (bitsize < HOST_BITS_PER_WIDE_INT)
     width_mask = ((HOST_WIDE_INT) 1 << bitsize) - 1;