When encoding and decoding bit planes, a decision is made in the clean up
pass if zero coding or run length coding should be performed. Embodiments
of the invention provide a zero coding or run length coding decision
instruction. The instruction will determine whether significance state
variables associated with selected coefficients bits and their immediate
neighbors are zero. If all the significance states are determined to be
zero, then run length coding is performed. Else, zero coding is
performed.