+/*
+ * We're only looking at 7 bits of the address; everything is
+ * aligned to 4, lots of things are aligned to greater powers
+ * of 2. Shift right by 8, i.e. drop the bottom 256 worth.
+ */
+#define TABLESIZE 128
+#define LOOKUP(x) (((int)(x) >> 8) & (TABLESIZE - 1))