In theory the branch relative is easier on the pipeline. An old base-displacement branch is dependent on the value of some register, which in theory may be subject to the machinations of the fixed point arithmetic unit. A relative jump is only dependent on the instruction counter and the contents of the instruction itself.
Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Seymour J Metz Sent: Friday, March 4, 2022 10:40 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Jump vs. Branch I don't know why he uses the term indirect; if anything, they're more direct then the old branches. I wouldn't expect them to be more efficient, but if you use them for all branches then you can save a register, which can avoid otherwise extraneous saves and restores. Unless I have to run on a really old box, I'd use the jump instructions all the time.