Currently, there is no v1.0 tag in riscv-v-spec. That is why I use the date of the commit as the draft version number. We hope v1.0 could be merged into LLVM 12. I am not sure whether it is an acceptable way to do it or not.
There are a lot of "Resolve for v1.0" issues open against the spec still. Are we sure we want to brand this as 1.0? It will end up as such in the ELF attributes and thus be deemed compatible with future "real" 1.0 binaries.
(Their problem stems from having 1.0 drafts before they've resolved all the outstanding issues and frozen the instruction set; if they didn't jump the gun then things would be saner for people implementing it)
Vector extension is under -enable-experimental-extensions in LLVM. Could we change the version number to v1.0 to align with current V specification? "Experimental v1.0" should be more consistent with "v1.0-draft" V specification. What do you think?