AFAIK, RXY format instructions support negative offsets just fine. LHY 5,-1(0,12)
On Sun, 24 Oct 2021, 7:55 am Peter Relson, <rel...@us.ibm.com> wrote: > Eric R posted (from the PoP): > <snip> > When, during the generation of the address, an > address is obtained that exceeds the value allowed > for the address size (2^24 - 1, 2^31 - 1, or 2^64 - 1), one of > the following two actions is taken: > > 1. The carry out of the high-order bit position of the > address is ignored. This handling of an address > of excessive size is called wraparound. > > 2. An interruption condition is recognized. > > ... > > Addresses generated by the CPU that may be virtual > addresses always wrap. > </snip> > > That post omitted this phrase from the PoP that follows shortly after: > > For CPU table entries that are addressed by real or absolute addresses, it > is unpredictable > whether the address wraps or an addressing exception is recognized. > > Paul G wrote: > <snip> > An interrupt condition is *never* recognized "during generation of [an] > address." > </snip> > > Therefore we conclude that this statement is not correct for the case of > CPU table entries addressed by real or absolute addresses. > (I don't know exactly what a "CPU table entry" is in this context.) > > Peter Relson > z/OS Core Technology Design > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
