That's a performance optimisation which llvm is likely to do for you anyways, jump tables aren't exactly rocket science. Gazing into my crystal ball, might have to turn your enum variant Foo(u8) with possible values 0..15 into Foo0 through Foo15 (or maybe better Foo(EnumWith16Variants)) so that the compiler doesn't have to evaluate code to figure out that it doesn't need to NOP the rest of the jump range out, or bail out of generating a jump table, whatever it would do.