On Sun, 10 Nov 2019 09:30:30 -0500, Peter Relson wrote: ><snip> >Yes it's documented and legit, but it's a change in behaviour over the >last few z/OS releases. In IIRC z/OS 1.x, WTO did not clobber AR15, >and STORAGE OBTAIN did not change the high half of R1. ></snip> > >You have no way of knowing if that is true or not. All that you could >possibly say is that you did not encounter such a case. The environment >that could cause such a case might even not have been under your control >and might be uncommon. ... > I.e. the user, or even an ISV, was depending on undocumented behavior's remaining unchanged.
>The statement is not correct about STORAGE OBTAIN. The high half of R1 has >been changed on STORAGE OBTAIN ever since high halves existed. ... > Does code written at a time before "high halves existed", or perhaps even before ARs existed, and depending only on OS behavior documented at such a time, continue to operate correctly? If so, a user has no ground for a complaint. If it fails now, IBM should graciously apologize and move on. The pertinent aphorism is, "You can't make an omelet without breaking eggs." -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
