+#define HASH_DEPTH 6
+
+#define HASH_ROW(x) do { \
+ if (isupper((unsigned char)(x))) \
+ (x) -= 65; \
+ else \
+ (x) -= 97; \
+ (x) *= HASH_DEPTH; \
+ } while (/* CONSTCOND */ 0)
+
+/*
+ * Lookup table is indexed first by lower-case first letter (plus one
+ * for the period, which is stored in the last row), then by lower or
+ * uppercase second letter. Buckets correspond to the index of the
+ * macro (the integer value of the enum stored as a char to save a bit
+ * of space).
+ */
+static unsigned char table[26 * HASH_DEPTH];