Re: Hints for coding JES2 exit routines (z/OS JES2 Documentation)
No! It all depends. I don't think you can magically code such that added or deleted flags will not affect your logic. What flag was added or deleted? How does it affect your intended business logic? I would think generally one would not want to change mask equates. Doing so would be a booby trap for others, or even for yourself. Charles -Original Message- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Janko Kalinic Sent: Monday, December 13, 2021 10:24 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Hints for coding JES2 exit routines (z/OS JES2 Documentation) Assembler instructions - All TM (test-under-mask) instructions should use BO/BOR/BNO/BNOR/BM/BMR branch instructions rather than BZ/BZR/BNZ/BNZR branch instructions. If this technique is used, the logic of the branch instruction does not have to be modified when adding or deleting flags in the instruction mask. Is everyone in agreement on the above branch instruction recommendation? Regards, John K
Re: Hints for coding JES2 exit routines (z/OS JES2 Documentation)
It could be that they were trying to give stylistic recommendations: only branch if the bit(s) in question are set or not set, otherwise fall through to the next instruction. But if they are going so far as to recommend specific acceptable instructions, one would think they would mention the fall-thru case. I'm not sure the conclusion is valid "the logic of the branch instruction does not have to be modified when adding or deleting flags in the instruction mask." If the mask is for one bit and I add another bit, I not sure that BO or BNO will still be what the correct instruction. On 2021-12-13 2:54 p.m., Seymour J Metz wrote: Is everyone in agreement on the above branch instruction recommendation? In agreement with each other? Yes. In agreement with you? No. There are three possible CC values after TM, not just two. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 Gary Weinhold Senior Application Architect DATAKINETICS | Data Performance & Optimization Phone:+1.613.523.5500 x216 Email: weinh...@dkl.com Visit us online at www.DKL.com E-mail Notification: The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system. From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Janko Kalinic [the.pds.comm...@gmail.com] Sent: Monday, December 13, 2021 1:24 PM To:ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Hints for coding JES2 exit routines (z/OS JES2 Documentation) Assembler instructions - All TM (test-under-mask) instructions should use BO/BOR/BNO/BNOR/BM/BMR branch instructions rather than BZ/BZR/BNZ/BNZR branch instructions. If this technique is used, the logic of the branch instruction does not have to be modified when adding or deleting flags in the instruction mask. Is everyone in agreement on the above branch instruction recommendation? Regards, John K
Re: Hints for coding JES2 exit routines (z/OS JES2 Documentation)
> Is everyone in agreement on the above branch instruction recommendation? In agreement with each other? Yes. In agreement with you? No. There are three possible CC values after TM, not just two. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 From: IBM Mainframe Assembler List [ASSEMBLER-LIST@LISTSERV.UGA.EDU] on behalf of Janko Kalinic [the.pds.comm...@gmail.com] Sent: Monday, December 13, 2021 1:24 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Hints for coding JES2 exit routines (z/OS JES2 Documentation) Assembler instructions - All TM (test-under-mask) instructions should use BO/BOR/BNO/BNOR/BM/BMR branch instructions rather than BZ/BZR/BNZ/BNZR branch instructions. If this technique is used, the logic of the branch instruction does not have to be modified when adding or deleting flags in the instruction mask. Is everyone in agreement on the above branch instruction recommendation? Regards, John K
Re: Hints for coding JES2 exit routines (z/OS JES2 Documentation)
That's nonsense, so I doubt many would agree. sas On Mon, Dec 13, 2021 at 1:24 PM Janko Kalinic wrote: > Assembler instructions > >- All TM (test-under-mask) instructions should use >BO/BOR/BNO/BNOR/BM/BMR branch instructions rather than BZ/BZR/BNZ/BNZR >branch instructions. If this technique is used, the logic of the branch >instruction does not have to be modified when adding or deleting flags > in >the instruction mask. > > > Is everyone in agreement on the above branch instruction recommendation? > > Regards, > John K >
Hints for coding JES2 exit routines (z/OS JES2 Documentation)
Assembler instructions - All TM (test-under-mask) instructions should use BO/BOR/BNO/BNOR/BM/BMR branch instructions rather than BZ/BZR/BNZ/BNZR branch instructions. If this technique is used, the logic of the branch instruction does not have to be modified when adding or deleting flags in the instruction mask. Is everyone in agreement on the above branch instruction recommendation? Regards, John K
