1. A data processing device reading in and executing instructions in a certain sequence, the data processing device comprising: a fetch portion for reading in a computational instruction; a decoding portion for decoding the computational instruction that has been read in; an execution portion for executing the decoded computational instruction; and an instruction overriding control circuit that overrides, of one or a plurality of subsequent instructions that follow the computational instruction in said sequence and are associated with the computational instruction, all but one of the subsequent instructions, in accordance with an execution result of the computational instruction.