[Libre-soc-dev] Wishbone and House Contract Of Sale Proposition

[Richard Wilbur]

On Thu, Oct 28, 2021 at 11:40 AM lkcl <luke.leighton at gmail.com> wrote:
>
> On Thu, Oct 28, 2021 at 6:39 PM Richard Wilbur <richard.wilbur at gmail.com> wrote:
> > Why must we "drop the queue starting from this requester, and any
> > later requesters" instead of just dropping the cancelled request and
> > leaving the remainder of the queue intact?
>
> this is a hard requirement stemming from speculative execution

How does that follow?  Is there a reference on speculative execution
that I could read to help me see the connection?  Seems like
speculative execution could be more trouble than it's worth.  It
certainly doesn't save energy to compute results and throw them away
instead of putting computational units into low-power mode.  If we
guess right, it can save time--I see that much.

I guess I was looking at this initially from the perspective of a
multi-master backplane bus, such as PCI.  It sounds like we must be
talking about an on-chip bus.