A processor executes an instruction set including instructions in which a register specifier is implicitly derived, based on another register specifier. One technique for implicitly deriving a register specifier is to add or subtract one from a specifically-defined register specifier. Implicit derivation...http://www.google.de/patents/US7117342?utm_source=gb-gplus-sharePatent US7117342 - Implicitly derived register specifiers in a processor
