Todd Burch wrote:
Certainly I can do that. And, when I do that, I have absolutely no need for
the LDF instructions.
The purpose of the Long Displacement Facility is to provide relief for base
register constraint. Coding a "LAY R1" to get around a macro expansion, and
taking up a base register to do that, doesn't buy me diddly squat in terms
of "base register relief".
Todd
Well, it does. R1 is generally reserved for program linkages
anyway, so at the very least you haven't lost anything, and
you don't need to tie up a non-reserved register for the base
to reference the data item.
What LDF gives is relief in tying up base registers for
branches, nothing more. You don't have to have a base
established for your target address. You still need a
register to move, store, and load data in memory.
Kind regards,
-Steve Comstock
The Trainer's Friend, Inc.
http://www.trainersfriend.com
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