That's not my dog; it comes from Michael Stein. My code did not have a PTR opcode and had a DC at the end, after the second ..., and yes, if the DC were in a full page rsect then it would fail.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of CM Poncelet [ponce...@bcs.org.uk] Sent: Tuesday, February 9, 2021 12:22 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: LINK vs LOAD/CALL https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.3.0/com.ibm.zos.v2r3.ieab100/reus.htm BTW Your 'refreshable' ... PTR DC A(0) label L R15,PTR LTR R15,R15 BNZ CALLIT ... ... Code that always leaves the same value in R15 ST R15,PTR CALLIT BALR R14,R15 ... would not assemble with a CC=00 if coded as an *RSECT* methinks. Chris Poncelet (retired etc.) On 08/02/2021 22:47, Seymour J Metz wrote: > That "therefore" is incorrect. Nor would refreshing my example cause an > incorrect branch. If you'll give me the URL I'll submit a RCF. > > There's now way that z/OS will refresh anything smaller than a page, much > less smaller than a word. > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > ________________________________________ > From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of > Michael Stein [m...@zlvfc.com] > Sent: Monday, February 8, 2021 5:33 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: LINK vs LOAD/CALL > >>> This is refreshable, and even runs on S/360 >> PTR DC A(0) >> label L R15,PTR >> LTR R15,R15 >> BNZ CALLIT >> ... ... Code that always leaves the same value in R15 >> ST R15,PTR >> CALLIT BALR R14,R15 > According to the manual no. > > refreshable: > all or part of the module can be replaced at any time without notice > by the operating system. *therefore* must not modify itself in > any way. > > So if part of your address got refreshed (to 0) you would then branch > to some wrong address... > > Most likely the way it is/would be implemented it wouldn't just refresh > a part of a fullword on a fullword boundary. But that's not the what > the manual says it might do. > > The first I saw of REFR was OS/MVT 360. Aactual refreshing was only > mentioned as action by the machine check handler for storage errors in > parts of the nucleus. > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
