I was kind of disappointed when IBM initially gave the list of services that could be called from AMODE 64.(as long as the parameters were below the bar). I mentioned that the hardware does all the work for a PC from a 64 bit caller, so stating "support" really didn't require any code changes. All my PC routines equally supported 64bit callers.
On Mon, 13 Jun 2016 10:48:54 -0700 Ed Jaffe <edja...@phoenixsoftware.com> wrote: :>On 6/13/2016 10:12 AM, Andre Schoeman wrote: :>>> Since the documentation for IEAMSCHD says that AMODE 64 is not supported, :>>> you are taking a risk that your code might at any point stop behaving :>>> properly. That is your choice, but it is your (and your users') risk. Is :>>> there any plan to do so in the immediate future? Not that I know of. Would :>>> any such plan be announced? Probably not. :>> I accept what the current state of the documentation says. However, when :>> z/OS is touted as 64-bit capable, shouldn't a continous effort be driven whereby :>> all invoked system system services eventually are AMODE(64) capable ?? :>> (disregard the restricted location of certain control blocks for now .... I'm :>> merely referring to invoking a service whilst running in AMODE(64)) :> :>I have stated before (possibly in other forums -- certainly at TDMs) :>that our approach is to try to help IBM and the z/OS community identify :>existing system services that don't work for AMODE(64) callers. IBM has :>only limited manpower to test z/OS services, so we test them for them by :>invoking them in real-world AMODE(64) code. :> :>That means we completely disregard documentation that states a service :>requires 31-bit mode and rely solely on the results our own empirical :>testing. (Of course, we limit AMODE(64) invocations to SVC and PC-based :>services and never even try to invoke LINKAGE=BRANCH services in :>AMODE(64) because we know that won't work.) :> :>What we've discovered is that _nearly all_ SVC and PC-based services :>work just fine so long as you pass the parameters below the bar. The :>main "gotchas" are macro expansions that have not yet been updated to :>use grande instructions when SYSSTATE AMODE64=YES is in effect. Usually, :>all you must do is clear XGR 14,14 (or another register) before invoking. :> :>Is it a risk? Of course! IBM is free to change these interfaces at any :>time without warning and we're happily prepared to adapt our code as :>necessary in the event the macro expansion changes or they choose to :>support AMODE(64) callers in an incompatible way (hopefully on a release :>boundary). :> :>For us, improved performance, better code readability, and (hopefully) :>fewer changes down the road when those services finally do "officially" :>support AMODE(64) callers, are worth that risk. YM-AS-MV (Your Mileage :>-- And Sensibilities -- May Vary). -- Binyamin Dissen <bdis...@dissensoftware.com> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
