In a computer system, a method and apparatus for dispatching and executing
multi-cycle and complex instructions. The method results in maximum
performance for such without impacting other areas in the processor such
as decode, grouping or dispatch units. This invention allows multi-cycle
and complex instructions to be dispatched to one port but executed in
multiple execution pipes without cracking the instruction and without
limiting it to a single execution pipe. Some control signals are
generated in the dispatch unit and dispatched with the instruction to the
Fixed Point Unit (FXU). The FXU logic then execute these instructions on
the available FXU pipes. This method results in optimum performance with
little or no other complications. The presented technique places the
flexibility of how these instructions will be executed in the FXU, where
the actual execution takes place, instead of in the instruction decode or
dispatch units or cracking by the compiler.