[Libre-soc-dev] LD/ST Elwidth Overrides

[Jacob Lifshay]

On Thu, Sep 2, 2021, 10:52 lkcl <luke.leighton at gmail.com> wrote:

>
>
> On September 2, 2021 5:26:52 PM UTC, Jacob Lifshay <
> programmerjake at gmail.com> wrote:
> >How about this: ffirst works in all vector addressing modes (including
> >strided, gather, unit stride, etc.) but it stops the first time it
> >tries to
> >access more than 1 page (or some other small spec-determined number
> >such as
> >2 or 4) regardless if that would cause a page fault or not.
>
> the hardware is already entirely at liberty to be implemented that way and
> that freedom DOES NOT require making it entirely mandatory and does not
> require the spec to state that because it is up to the implementor to
> choose what to do and what design criteria to take into account.
>

ok, in that case I think we should re-allow ffirst for all modes and have a
note stating that hw implementers *should* limit it to avoid massive page
probing, suggesting the above algorithm.

Jacob