On Sep 18, 17:16, Derek Peschel wrote:
> On Wed, Sep 18, 2002 at 08:05:27AM +0000, Pete Turnbull wrote:
> > Well, I'd say the "right thing to do" is to use absolute addressing
modes.
> > What modes 6/7 do is generate references which are relative to the
>
> Sorry, I meant "the right thing for MACRO to do". Jerome and you didn't
> seem to like the output format as it currently stands. How would you
> change it? Jerome apparently wants to add some kind of warning lines.
> Would you distinguish between ordinary relocation and PIC?
>
> I'm really asking what the situations are (what the loader is capable of,
> how you would define "relocatable" on the -11, tec.) as well as what
> algorithms make sense to you.
I'm not sure what LINK does, and what input it needs. It's a long time
since I used MACRO-11, but I'd have expected it to generate the "correct"
values, for a start. What Pat's output showed was:
7 001000 012767 000110 177566' MOV #110,XBUF
but if you were entering that in ODT, what you'd want would be
7 001000 012767 000110 176552' MOV #110,XBUF
In other words, you'd want MACRO to do the calculation for you, and have
LINK adjust that if the eventual loading address was other than 001000.
If I were redesigning MACRO from scratch, I'd have it mark the PC-relative
addresses more obviously, perhaps something like this:
7 001000 012767 000110 [176552] MOV #110,XBUF
but then it would be more reasonable to put the target address, 177566, in
the listing, rather than the offset, 176552. Maybe it could do both, but
it gets a bit clumsy:
7 001000 012767 000110 [177566] (+176552) MOV #110,XBUF
This is just for the listing, obviously; what it puts in the .OBJ file
would not change. However, I imagine any such changes would bring howls of
protest from generations of MACRO programmers :-)
> I tried the real MACRO (under RSX-11M) and it adds an apostrophe to the
> initial setting of . (which is what I'd expect, since . was never given
> a numeric value, only incremented from its default) but still no
apostrophes
> after the addresses later in the listing.
I don't have any listing readily to hand. Were the addresses shown as the
target addresses, or the offsets required to reach those tagets?
--
Pete Peter Turnbull
Network Manager
University of York
Received on Thu Sep 19 2002 - 02:42:00 BST