> Yes, there is one in the proposed "B" extension. Not good enough: it won't be in the smaller chips, or even in the biggest ones for a good while. The lowRISC

> Yes, there is one in the proposed "B" extension. Not good enough: it won't be in the smaller chips, or even in the biggest ones for a good while. The lowRISC Ibex core which I work on and whilst not the smallest core is definitely at the small end has full bitmanip extension support: https://github.com/lowrisc/ibex https://github.com/lowrisc/ibex Yes the extension isn't finalised yet but we're not expecting much change so we can tweak the implementation to match the ratified standard when it appears. I'd also note bitmanip is broken up into subgroups so it's possible smaller cores will only implement the simple stuff (e.g. Popcount) to avoid the overhead of the full implementation.