> > Do you need to save/restore the vector configuration before and after > > clearing the vector registers? If so, that seems to be missing. If > > not, it seems like a comment explaining why would be useful. > > I'll add some comments in the code and want to explain here first. > We need not save/restore the vector configurations. Because, by design, > the RVV requires vsetvl when using vector instructions. When users want to > use the RVV insns next, they should have to issue vsetvl first.
I think one keypoint here is -fzero-call-used-regs=* emit zeroing instruction before return, that means there won't be any vector operations between return and zeroing instructions, so we don't need to restore the vcsr after zeroing.
