Teaching expression() to treat some operations specially

[Dmitry Selyutin]

On Tue, Jul 12, 2022 at 1:44 PM Jan Beulich <jbeulich@suse.com> wrote:
> why again can't you deal with *
> there (converting the thing to an X_md<N> expression)?

Actually this is what we already do. :-)
https://git.libre-soc.org/?p=binutils-gdb.git;a=blob;f=gas/config/tc-ppc.c;h=989d1a29a56a364cdfcce6b670f7466ff8eaaeea;hb=refs/heads/svp64-ng#l4238

There are two issues:
1. Handle register names in macros in a uniform way.
2. Handle unary * operator.

The thread became a bit confusing due to these questions being
somewhat related (e.g. whether these should be parsed in the same
place).
My point was, since * is indeed an unary operator, it's kind of
natural for it to be handled at md_operator.
However, we can stick to md_operand, no problems; so the second
question is already solved.
As for the first one, I'm now preparing a patch for it (it's also
about md_operand, anyway).
I attempt to make the code somewhat more straightforward and generic,
and also handle X_md stuff at port's side.
I'll update on this. Thank you for your help and advice!

-- 
Best regards,
Dmitry Selyutin