In these kinds of situations, O(1) means nothing; any (reasonable) approach will be O(1), but constant factors will dominate. For example, there are measurable

In these kinds of situations, O(1) means nothing; any (reasonable) approach will be O(1), but constant factors will dominate. For example, there are measurable differences in branch prediction based on whether each opcode's implementation ends with its own dispatch code or branches back to a common dispatch routine. The sequence of instructions is basically the same in both cases, but there is an icache/branch prediction tradeoff to be made. Subtle stuff (see http://repo.or.cz/w/luajit-2.0.git/blob/0ded8e82a88fadb40b4dd7e6632311781f1b2f91:/src/vm_x86.dasc#l283 http://repo.or.cz/w/luajit-2.0.git/blob/0ded8e82a88fadb40b4d...)