Vectorization and scalarization of methods are provided. A plurality of node webs is constructed based on traversing an intermediate representation of a program. Transitive closure of the plurality of node webs is performed to form a set of final node webs. It is determined that each respective node in the set of final node webs can be converted into one of vector operation code or a sequence of scalar operation codes based on at least one node including a specified vector length and only one vector length value being specified within the set of final node webs. Each respective node in the set of final node webs is converted into one of corresponding vector operation code or a corresponding sequence of scalar operation codes to accelerate execution of supported and unsupported methods of the program.