In the case of iefbr14, the branch instruction could have been BCR 8,14
The condition code was set by the preceding instruction. ;-) Some might find it confusing. ...chris. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Martin Packer Sent: Friday, February 12, 2016 6:05 AM To: [email protected] Subject: Re: AW: Re: You thought IEFBR14 was bad? Try GNU's /bin/true code Thanks for spelling it out. I needed it. :-( :-) And maybe it helped the young'uns. :-) Cheers, Martin Martin Packer, zChampion, Principal Systems Investigator, Worldwide Cloud & Systems Performance, IBM +44-7802-245-584 email: [email protected] Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker From: Tom Marchant <[email protected]> To: [email protected] Date: 12/02/2016 13:37 Subject: Re: AW: Re: You thought IEFBR14 was bad? Try GNU's /bin/true code Sent by: IBM Mainframe Discussion List <[email protected]> On Fri, 12 Feb 2016 07:19:37 +0000, Martin Packer wrote: >But Unconditional being all 4 bits set was what I wanted elucidation on. >Perhaps I'm being thick, or perhaps it's a special case. Condition code has two bits, giving it four possible values, 0, 1, 2, or 3. The mask bits in the conditional branch instructions have four bits, each bit corresponds to one of the four possible condition code settings. For example, if the first bit (bit 0) in the instruction mask is 1, it means take the branch if the condition code is zero. If the second mask bit (bit 1) is set, it means take the branch if the condition code is one. If all four bits are set, it means take the branch if the value of the condition code is 0, 1, 2, or 3. Since there are no other possible values, the branch is unconditional. -- Tom Marchant ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- 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
