Addressability of instructions and the addressing of data ranges are extended. One or more operands obtained from fields explicitly specified by an instruction are overridden (i.e., ignored), and instead, an address based on the instruction (e.g., an instruction address) is substituted for the one or more operands. This provides an address having more bits than allowed by the operand being overridden, thereby extending addressability of the instruction and extended data range addressing. Further, in one aspect, additional bits may be added to one or more immediate fields of the instruction, thereby extending addressability of the instructions and extending data range addressing.