I believe those are all z Architecture instructions and should work on any z Architecture machine.
NIHF might be your best bet for clearing the high half of a register: no storage access. Requires the extended-immediate facility, available on a z9. You could avoid the storage references on the AG's if you had a spare register. You could LHI R0,1/SLLG R0,R0,32/AGR r,R0 for example. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:[email protected]] On Behalf Of retired mainframer Sent: Saturday, October 28, 2017 1:27 AM To: [email protected] Subject: Re: Using the High Halfs of registers According to the 2004 POO (SA22-7832-03), which I believe predates z9, you can: Simulate an LA to clear the high half contents of a register with ICMH Rx,15,=XL4(00) or NG Rx,=XL8(FFFFFFFF) Simulate an LA to increment the count in the high half with AG Rx,=XL8(100000000) Simulate a BCTR to decrement the count in the high half with AG Rx,=X(FFFFFFFF00000000)
