[zozbot234]

> Isn't RISC-V continually adding new complexity as it attempts to scale up

On the contrary, some extensions are pretty clearly designed for simplicity. For example the original 'M' extension implemented both multiply and divide insns, but it was found that the latter were not always useful and required large area. So a multiply-only extension was created. The basic set of integer instructions is the one thing that's anywhere close to immutable about "RISC-V", anything else is potentially open to replacement with something better, though of course with the cost of some incompatibility.

And actually, even the base set is not totally unchangeable as shown by the RV-E variant, halving the number of integer registers to 16.

[kllrnohj]

Reducing the register count is not a "RISC" move. It probably makes sense for the target die size of a given product, but it's definitely not something "RISC" related which was, at the time, about doing the exact opposite - increasing the register count relative to CISC CPUs.

Similarly divide wasn't removed. It's still there. Instead a second extension was added that introduced multiply-only variants. Total complexity was increased, not reduced.