It is probably easier to add more functionality to existing ALUs. Various instruction sets have added "free" bonus operations, but one could go a step further a

It is probably easier to add more functionality to existing ALUs. Various instruction sets have added "free" bonus operations, but one could go a step further and allow any two functions from a wide set to be combined, the intermediate value would not hit the registers, and thus save a store and a load relative to two individual instructions.