-#define OP_FLAGS(pc) op_flags[((pc) - (base_pc)) / 2]
-#define OF_DELAY_OP (1 << 0)
-#define OF_TARGET (1 << 1)
+/* op_flags */
+#define OF_DELAY_OP (1 << 0)
+#define OF_BTARGET (1 << 1)
+#define OF_T_SET (1 << 2) // T is known to be set
+#define OF_T_CLEAR (1 << 3) // ... clear