No, it's not a waste of resources. There is a valid use case regardless of whether you can conceive of it.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of John McKown <[email protected]> Sent: Tuesday, November 12, 2019 8:13 AM To: [email protected] Subject: Re: Questionable Instructions in Obtaining EAX documentation On Tue, Nov 12, 2019 at 6:56 AM Peter Relson <[email protected]> wrote: > <snip> > What if R9 is not supposed to be zero? Maybe the code is looking at the > PSA > of another processor. > </snip> > > The normal way to accomplish that is > USING PSA,R9 > rather than leaving a time-bomb for those who come after by using "0". > I cannot fathom the reason to use _any_ base for the PSA other than GPR0. It is simply wasteful of a scarce resource. > > Peter Relson > z/OS Core Technology Design > -- People in sleeping bags are the soft tacos of the bear world. Maranatha! <>< John McKown
