IBM Mainframe Discussion List <[email protected]> wrote on 05/01/2007 08:43:03 AM:
> On Tue, 1 May 2007 07:13:52 -0400 Peter Relson <[EMAIL PROTECTED]> wrote: > > :>CVTALRS indicates that z/OS support for ASN-and-LX reuse is present. This > :>means, among other things, that you can use such things as the "LXSIZE" > :>operand of LXRES. This bit is on for all still-supported z/OS releases > :>(i.e., z/OS 1.6 and follow-on). > :> > :>CVTALR indicates that the architecture is enabled. That means that you will > :>actually get a reusable LX if you request one (and thus must meet the usage > :>requirements for that such as setting the high half of GPR 15 with the > :>proper value before using that LX in issuing a PC). And if we had actually > :>enabled ASN reuse, and if your address space were architecturally reusable, > :>you would not be able to SSAR or PT to it but would need to use SSAIR / PTI > :>if the architecture demanded it. > > To break it down: > > CVTALR is off - you cannot use SSAIR/PTI/ESTA 5 > > CVTALR is on, CVTALRS is off - the instructions SSAIR etc. can be used. Will > the high order word of the result of ESAIR/ESTA 5 be guaranteed to be safe so > that an SSAIR can be used? Or might it be garbage? > > Both on - SSAR/PT may fail. ESAR will work. > > Do I understand it? "CVTALR is on, CVTALRS is off" will never occur. CVTALRS is always on for z/OS 1.6 or higher, and never on for a lower release. CVTALR is never on for a release lower than z/OS 1.6. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
