I'll take a look, Paul, thanks.  It hadn't occurred to me to compare
different machines' uses.

-+- Sid

On Thu, Mar 23, 2023 at 10:29 AM Paul Koning <paulkoning@comcast.net> wrote:

>
>
> > On Mar 23, 2023, at 10:13 AM, Sid Maxwell via Gcc <gcc@gcc.gnu.org>
> wrote:
> >
> > Thanks for reaching out, Julian, I greatly appreciate your help.  Please
> > forgive and over- or under-sharing.  If I've left something out, please
> let
> > me know.
> >
> > From my pdp10.md:
> >
> > ;; JIRA sw_gcc-68.  gcc recognizes the "movmemhi" 'instruction' for
> > ;; doing block moves, as in struct assignment.  This pattern wasn't
> > ;; present, however.  I've added it, and it's companion function
> > ;; pdp10_expand_movmemhi().
> >
> > (define_expand "movmemhi"
> >   [(match_operand:BLK 0 "general_operand" "=r")
> >    (match_operand:BLK 1 "general_operand" "=r")
> >    (match_operand:SI 2 "general_operand" "=r")
> >    (match_operand:SI 3 "const_int_operand" "")
> >   ]...
>
> I don't remember that far back, but looking at current examples (like
> vax.md) that seems like an odd pattern.  vax.md has a three operand pattern
> with the first two marked as "memory_operand" and only the first one has
> the = modifier on it showing it's an output operand.
>
> What does the 4.3 version of gccint say about it?  Or the 4.3 version of
> vax.md?
>
>         paul
>
>