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 a basis value dependent upon the first active element position; for element positions including or subsequent to the first active element position of the selection vector, conditionally updating the basis value from the operand vector dependent upon the control vector; and updating the result vector dependent upon the basis value.