I doubt that PC was ever intended as a replacement for, e.g., BASR. How does its performance stack up against SVC?
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Christopher Y. Blaicher <[email protected]> Sent: Wednesday, August 28, 2019 12:19 PM To: [email protected] Subject: Re: Assembler :- PC Instruction PC and BAKR, which is another stacking type instruction, are not cheap. You can do a BASR and STORAGE OBTAIN, STORAGE RELEASE and BR in less time than a BAKR. I do not know for sure, but I would guess that 99% of what PC, BAKR and PR do is millicode, and they do a lot. Chris Blaicher Technical Architect Syncsort, Inc. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of scott Ford Sent: Wednesday, August 28, 2019 11:21 AM To: [email protected] Subject: Re: Assembler :- PC Instruction I feel it’s important how to use the instruction and it’s pros and cons. I am not sure how important speed of instructions or width , halfword or full word are that pressing of an issue with today’s processors, but that’s my opinion. Scott On Wed, Aug 28, 2019 at 11:18 AM scott Ford <[email protected]> wrote: > Charles, > > Exactly, what is being done under the covers, i.e; microcode etc .. > > Scott > > On Wed, Aug 28, 2019 at 10:49 AM Tony Harminc <[email protected]> wrote: > >> On Wed, 28 Aug 2019 at 09:59, Charles Mills <[email protected]> wrote: >> >> > In answer to your question, I guess the answer is no. There is a >> > DAT >> "facility" (some of us remember when there was a DAT box!) but no, >> there is no named "PC facility" any more than there is a "BAL >> facility." It's just part of the processors. >> >> It's arguable that ASN translation is (usually) the part of the >> architecture that corresponds best to DAT in the context of PC and PR >> instruction processing. But not all PCs invoke ASN translation, and >> those that do do it a bit differently than how it is described in >> Chapter 3. >> >> But really, as Binyamin said, the excruciating details of what PC >> *does* are covered in the POPS, both under the PC instruction itself, >> and in Chapter 5 in the section "Stacking Process" under "Linkage >> Stack Operations". >> >> Tony H. >> >> --------------------------------------------------------------------- >> - For IBM-MAIN subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO >> IBM-MAIN >> > -- > Scott Ford > IDMWORKS > z/OS Development > -- Scott Ford IDMWORKS z/OS Development ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
