I agree. Of course, you still need base+displacement in two cases that I can think of: (1) desire for an index register; and (2) to access dynamic storage (STORAGE OBTAIN or LOADed module).
As an example of (1), I quite often do: CALL PROGRAM,(PARM1,PARM2),VL CHI R15,=Y(MAXENTRIES) JH INVALID_RC B *+4(R15) START J RC0 J RC4 J RC8 MAXENTRIES EQU *-START/4 Of course, this ASSuMEs that R15 is a multiple of 4. I should possibly test for that somehow. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * john.mck...@healthmarkets.com * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > -----Original Message----- > From: IBM Mainframe Assembler List [mailto:ASSEMBLER- > l...@listserv.uga.edu] On Behalf Of John Gilmore > Sent: Friday, August 24, 2012 3:08 PM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: which instructions should I use? > > The comments are essential, and they should motivate (instead of > describing) an instruction sequence. > > On the other hand, familiar instruction sequences don't have much > charm for me. They are, I think, more likely to lull readers to sleep > than to be 'more comprehensible'. I, at least, sit up when I see an > unfamiliar instruction sequence. > > I strongly prefer jumps to branches for all of the obvious reasons. > Retrofitting them into existing branch-based code is, as I have said > before, a bootless undertaking; but new code should use them all but > exclusively. The whole base-register-displacement scheme and its > limitations should be chucked out, except in the very few special > cases in which it is still needed. > > Elegance and brevity are finally more important than parsimony, and > relative displacements are neater and cleaner than the old > alternatives to them. > > --jg