I can see why you'd say that yeah, it could probably use some trimming down of the less widely applicable instructions. But I don't otherwise think having a set

I can see why you'd say that yeah, it could probably use some trimming down of the less widely applicable instructions. But I don't otherwise think having a set of disparate, seemingly unrelated instructions is a bad thing for something like bitmanip, as long as they all pull their weight. I think they do have an official working group. I remember reading a few months ago their working GCC PoC had ~4% dynaminc instruction reduction in SPECint and some 5% perf improvement. Nothing world-shattering, but considering that the instructions are pretty lightweight to implement in hardware, the cost-benefit seems decent. (Full disclosure: I am not a RISC-V member or particularly invested in bitmanip, just some random person going off of what I remember!)