There are faster instruction that the older compilers didn't have available, such as relative addressing instead of base register / offset. https://www.ibm.com/products/automatic-binary-optimizer-zos can copy the load module and replace binary instructions with newer instructions for testing and implementation without recompiling. SMF and program analysis to pick the most cost savings programs to convert.
On Mon, Mar 27, 2023 at 9:31 AM Schmitt, Michael <michael.schm...@dxc.com> wrote: > > The last time we mass-converted and recompiled our COBOL was from OS/VS COBOL > to VS COBOL II in 1992. Since then we've migrated our 7 million lines of > COBOL code... > > - 1998 Language Environment > - 2000 COBOL for MVS & VM > - 2003 COBOL for OS/390 & VM > - 2004 COBOL for z/OS & OS/390 3.2 > - 2005 3.3 > - 2006 3.4 > - 2011 4.2 > - 2020 6.2 > > By doing... nothing. > > The hardest part of going to IBM Enterprise COBOL for z/OS 6 was the PDSE > requirement for load modules. > > > So, in my experience, we don't need to know when our COBOL programs were last > used. And we already have tools that give us the compile date and version, > both from IBM and home grown. > > We still have a large number of programs that haven't been recompiled since > the VS COBOL II migration. They coexist just fine. > > (You may have to *relink* to pick up the Language Environment bootstrap > programs) > > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > Steve Pryor > Sent: Friday, March 24, 2023 1:39 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: A question or two on zOS issues > > There are a couple of pressing issues in z/OS that I'm sure many folks are > aware of but about which there doesn't seem to be much being done. I'm > curious as to what other IBM-MAINer's thoughts might be. Specifically, I'm > talking about: > > 1.) migration to IBM's latest COBOL release, and > > 2.) the not-really-that-far-off issue of Year 2042 > > I've been asked several times recently whether we (a z/OS ISV) should > consider developing products to address these issues. Frankly, though, I live > in an ivory tower and while I sometime *think* I know what installations > problems and needs are, I'm usually surprised to find that reality is quite > different. So I'd like to throw a couple of questions out to the list for > comment: > > 1.) Would a reporting utility that determined which COBOL programs were > executed (and which ones weren't), and what release and options they were > compiled with be significantly helpful in a COBOL migration? What other > features would be nice to have? Or is this a low priority for most > installations, who are perhaps trying to justify keeping the mainframe alive > and/or conducting business as usual, let alone doing a COBOL migration > project? > > 2.) It's rather shocking that 2042 is so close and not much seems to be > happening. We are one of the vendors that have a date-simulation utility, but > we don’t know if data centers have any near-term plans for 2042. Would it be > worthwhile to have a 2042 date-simulation product now, or is everyone going > to cross their fingers and try to use a test LPAR once the operating system > fully supports 2042 dates? > > Thanks for any comments and insight the IBM-MAIN hive mind might have. > > Steve Pryor > CTO > DTS Software, LLC > > ---------------------------------------------------------------------- > 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 -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
