On Tue, 15 May 2018 12:10:46 -0500, Paul Edwards <mutazi...@gmail.com> wrote:
>On Tue, 15 May 2018 11:57:55 -0500, Tom Marchant <m42tom-ibmm...@yahoo.com> >wrote: > >>>There are multiple ways of guaranteeing 0. The >>>best is IBM guaranteeing it on entry to a program, >>>as another RFE. In the single test that I requested, >>>the high bits seem to be 0 already. I just want to >>>formalize that. >> >>IBM cannot guarantee that. A basic principle in MVS is that any program >>can be called by another program. You don't know how a program that >>calls you might use the 64-bit registers. > >I don't see anything wrong with "LINK" being >updated to save the high 32-bits (or more, >in future) of registers and then zeroing them so >that called 32-bit programs can run in AM64 or >AM128 or AM256. Who will be affected? "LINK" >can be updated to accept an AM64 caller at the >same time. And so it grows. You want GETMAIN updated (though the key z/OS designers have already said that won't happen). You probably want z/OS storage layout changed, so you can acquire more storage. And now you want LINK changed to manage registers differently. What additional changes will you need next in z/OS in order to support this addressing mode that IBM hasn't seen a need for? How are you planning to justify all this work to IBM? How much additional money in terms of hardware purchases or software purchases will the writers of AM(32) modules be spending with IBM, to justify all the development and testing resources that your growing list of changes will require? -- Walt ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
