A standard application job will have an AX of zero. On Tue, 14 Jan 2025 11:02:01 -0500 Tony Thigpen <[email protected]> wrote:
:>All, :> :>This instruction might just help me with a software product issue on VSEn. :> :>Can someone post an example the correct setup for R2 (the EAX) in a TAP :>test, as used on z/OS? :> :> :>Tony Thigpen :> :>John Dravnieks wrote on 1/14/25 2:38 AM: :>> Hello :>> :>> I have come across some usage of the Test Access instruction (TAR) in a problem state program - given that TAR is documented in Chapter 10 of Pop (usually the supervisor state instructions generally only of use to the operating system) I am concerned that TAR is being used incorrectly :>> :>> The code correctly loads an access register into AR7 and then has this: :>> TAR R7,R0 Valid access register? :>> JP AOK Yes :>> :>> The second operand R0 refers to general register 0, which has a positive value of 32768 or less - so bits 32-47 of gpr0 will be zero so the effective EAX used by TAR will be zero. :>> :>> My question is is this a valid way to test the validity of an access register? And should it also be checking for a condition code of 1 as well ? :>> :>> Kind regards :>> John Dravnieks, 21CS Software :>> (posted here at suggestion of Binyamin Dissen) -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
