An example device includes a first register storing a first vector comprised of a set of vector elements; a second register having a set of lanes and configured to store a second vector; and a storage that stores a set of control elements. Each such control element corresponds to a respective one of the vector elements of the set of vector elements in the first register. In addition, each control element of the set of control elements has a first portion that specifies, for the corresponding vector element of the set of vector elements, a lane of the set of lanes of the second register, and a second portion that specifies whether the corresponding vector element of the set of vector elements is to be routed to the lane specified by the first portion. The example device further includes processing circuitry to, based on an instruction that specifies the first register and the second register, generate the second vector based on the set of control elements.