+#if GENCGC_CARD_BYTES > USHRT_MAX
+# if GENCGC_CARD_BYTES > UINT_MAX
+# error "GENCGC_CARD_BYTES unexpectedly large."
+# else
+# define PAGE_BYTES_FMT "u"
+ typedef unsigned int page_bytes_t;
+# endif
+#else
+# define PAGE_BYTES_FMT "hu"
+ typedef unsigned short page_bytes_t;
+#endif
+