--- gcc/config/xm-hp800.h	2018/04/24 17:51:35	1.1.1.1
+++ gcc/config/xm-hp800.h	2018/04/24 17:54:30	1.1.1.2
@@ -31,6 +31,7 @@ the Free Software Foundation, 675 Mass A
 #define bcmp(a,b,c) memcmp (a,b,c)
 
 #else /* hpux */
+#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 extern int errno;
 #endif /* hpux */