re PR bootstrap/43681 (bootstrap fails with "unused" var message for an apparently used var.)

	PR bootstrap/43681
	* expr.c (block_move_libcall_safe_for_call_parm): Avoid
	set but not used variable warning.

From-SVN: r158111

gcc/ChangeLog

+2010-04-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR bootstrap/43681
+	* expr.c (block_move_libcall_safe_for_call_parm): Avoid
+	set but not used variable warning.
+
 2010-04-08  Wei Guozhi  <carrot@google.com>
 
 	PR target/41653

gcc/expr.c

@@ -1262,6 +1262,9 @@ block_move_libcall_safe_for_call_parm (void)
      an outgoing argument.  */
 #if defined (REG_PARM_STACK_SPACE)
   fn = emit_block_move_libcall_fn (false);
+  /* Avoid set but not used warning if *REG_PARM_STACK_SPACE doesn't
+     depend on its argument.  */
+  (void) fn;
   if (OUTGOING_REG_PARM_STACK_SPACE ((!fn ? NULL_TREE : TREE_TYPE (fn)))
       && REG_PARM_STACK_SPACE (fn) != 0)
     return false;