Comment by johnnyanmac

Yup, know your hardware and know problem. Dichotomic search is wonderful when your data can't fit in RAM and it starts being more efficient to cut down on number of nodes traversed.

for a problem space limited by your input size (signed 64 bit number) to a 6 entry dictionary? At best you may want to optimize some in-lining or compiler hints if your language supports it. maybe setup some batching operations if this is called hundreds of times a frame so you're not creating/desrtoying the stack frame everytime (even then, the compiler can probably optimize that).

But otherwise, just throw that few dozen byte lookup table into the registers and let the hardware chew through it. Big N notations aren't needed for data at this scale.