Clarification of Fractional LMUL requirements, and the storage/derivation of ELEN/SEWLMUL1MAX values
Re-reading section 3.3.2 in the documentation (link), would like to propose adding goal, constraints, steps for implementing Fraction LMUL
I think adding these would really help clarify both the VFLMUL idea and implementation. I've been having extensive discussions around this, re-reading this section a bunch, and thinking it would probably be good to add additional lines to the vspec.adoc to clarify the idea.
Sharing my tentative understanding below (and some questions on ELEN and SEWLMUL1MAX), derived mainly from looking at the spike lmul checks and 3.3.2, curious as well if this captures the main intent of the fractional-lmul or there are aspects which are missing or equations require adjustment:
Suggested edits for discussion:
Would be happy to contribute pull requests after confirming whether this understanding is correct, and clarifying questions about the SEWLMUL1MAX/ELEN derivation/storage.
All the best,