1. A method, comprising: performing, by a processor: receiving a basis vector, an operand vector, a selection vector, and a control vector; and generating a result vector; wherein each of the basis vector, the operand vector, the selection vector, the control vector, and the result vector respectively includes a set of N elements that occupy N ordered element positions; wherein generating the result vector comprises: evaluating the selection vector to identify a first active element position of the selection vector; selecting an element of the basis vector as an initial basis value dependent upon the first active element position and outputting the initial basis value at a corresponding element position of the result vector; and for one or more element positions including or subsequent to the first active element position of the selection vector, conditionally updating the initial basis value from the operand vector dependent upon the control vector and outputting a conditionally updated basis value at one or more corresponding element positions of the result vector.