1. Method for storing a vector of process data elements that have a size of n bits from a register file into a memory, the memory being arranged for storage of a vector of storage data elements in locations having a size of m bits, wherein m>n, the method comprising: exchanging bits between process data elements in the vector stored in mutually subsequent register elements, the exchanging resulting in a vector of modified data elements, shuffling groups of k subsequent bits in the resulting vector, storing the resulting shuffled vector of modified data elements as a vector of storage data elements in the memory.