1. A data processing apparatus comprising: an instruction store operable to store a sequence of instructions including at least one multiple iteration instruction; a processing unit operable to execute the sequence of instructions, the processing unit comprising at least a first processing path and a second processing path to enable at least two instructions of the sequence to be executed in parallel, when executing instructions in parallel, the first processing path being operable to execute an instruction which is earlier in the sequence than the instruction executed in the second processing path; the processing unit being operable when executing the at least one multiple iteration instruction to allow a first iteration of the multiple iteration instruction to be executed in either the first processing path or the second processing path but to cause all remaining iterations of the multiple iteration instruction to executed in the first processing path.