On Fri, 1 Nov 2024 at 16:24, Dave Gibney < 000006fb76de82cb-dmarc-requ...@listserv.ua.edu> wrote:
> The description does not state the alignment is required. It states that > with ETF-2 installed, the table will be treated as if it was doubleword > aligned eve if it is not actually so aligned. At least that is how I read > ir. > Yes, it means that the rightmost three bits of the address of the table are ignored. So if you provide a table address of say X'12345', the address actually used will be X'12340'. This is silent - no specification exception or the like - so it will almost certainly lead to an incorrect result. And one that's hard to debug if you failed to notice the "treated as". Tony H. > -----Original Message----- > > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > > Behalf Of Tony Harminc > > Sent: Friday, November 1, 2024 1:03 PM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: Bounded string move? > > > > On Thu, 31 Oct 2024 at 08:27, Peter Relson <rel...@us.ibm.com> wrote: > > > > > Shmuel wrote: > > > TROO comes closest to doing what I want, but it has that pesky > > > alignment requirement. > > > > > > OK, I'll bite. What alignment requirement? Are you referring to this: > > > > > > From POp: > > > When the ETF2-enhancement facility is not installed, the translation > > > table is treated as being on a 4 K-byte boundary. > > > When the ETF2-enhancement facility is installed, the translation table > > > is treated as being on a doubleword boundary. > > > > > > ETF2 has been part of the architecture levelset for z/OS since z/OS > 2.1. > > > > > > > Certainly that's what Shmuel is referring to. Normally of course there's > no > > problem aligning the TRxx table to the (relaxed as of ETF2) doubleword > > boundary. But my suggested use of TROO uses the string data as the > > translation table (and a different table as the data), and such a string > can > > typically be on any byte boundary. So it's just another thing that has > to be > > tested for and perhaps adjusted, and that isn't free in terms of time or > > readability. > > > > Tony H. > > > > ---------------------------------------------------------------------- > > 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 > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
