+#ifdef PERL_MEM_LOG
+/* Enough space for the reserved byte, 1 for a potential leading 0, then enough
+ * for the longest representable integer plus an extra, the 3 flag characters,
+ * and NUL */
+PERLVARA(I, mem_log, 1 + 1 + TYPE_DIGITS(UV) + 1 + 3 + 1, char);
+#endif