Generating a hashed value of the program counter in a data processing system. The hashed value can be used for prefetching in the data processing system. In some examples, the hashed value is used to identify whether a load instruction associated with the hashed value has an address that is part of a strided stream in an address stream. In some examples, the hashed value is a subset of bits of the bits of the program counter. In other examples, the hashed value may be derived in other ways from the program counter.