+#ifdef MAX_SIG_DIG_PLUS
+ /* It is not necessarily the case that adding 2 to NV_DIG gets all the
+ possible digits in a NV, especially if NVs are not IEEE compliant
+ (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */
+# define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS)
+#else
+# define MAX_SIG_DIGITS (NV_DIG+2)
+#endif