Edward E. Jaffe wrote:
Steve Comstock wrote:
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.
Whaaatt???!!! LDF has _nothing whatsoever_ to do with branches!!! You're
thinking of the immediate & relative facility, which was around long
before z/Architecture. I suggest a perusal of "Principles of Operation"
may be in order ...
Yeah. One of these days I've got to stop shooting from the hip.
Went back and looked at my own course; LDF introduced with z990,
supports 20-bit displacement instead of 12; and, you're right
again: I was thinking of Immediate & Relative Facility when I
pulled that trigger.
Thanks for the catch.
Kind regards,
-Steve Comstock
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