Bum

 BUM 1. v. To make highly efficient, either in time or space, often at
       the expense of clarity. The object of the verb is usually what was
       removed ("I managed to bum three more instructions.") but
       can be the program being changed ("I bummed the inner loop down
       to seven microseconds.") 2. n. A small change to an algorithm to
       make it more efficient.