Abstract: A vector processing system for executing vector instructions, each instruction defining multiple pairs of values, an operation to be executed on each of said value pairs and a scalar modifier, the vector processing system comprising a plurality of parallel processing units, each arranged to receive one of said pairs of values and to implement the defined operation on said value pair to generate a respective result; and a scalar result unit for receiving the results of the parallel processing units and for using said results in a manner defined by the scalar modifier to generate a single output value for said instruction.