+/*----- Basic macros ------------------------------------------------------*/
+
+/* --- @MPW@ --- *
+ *
+ * Arguments: @x@ = an unsigned value
+ *
+ * Use: Expands to the value of @x@ masked and typecast to a
+ * multiprecision integer word.
+ */
+
+#define MPW(x) ((mpw)((x) & MPW_MAX))
+
+/* --- @MPWS@ --- *
+ *
+ * Arguments: @n@ = number of words
+ *
+ * Use: Expands to the number of bytes occupied by a given number of
+ * words.
+ */
+
+#define MPWS(n) ((n) * sizeof(mpw))
+