I agree with Gerhard; I was taught and use label DS 0H
for labels instead of EQU. Mike Shaw MVS/QuickRef Support Group Chicago-Soft, Ltd. On Mon, Jun 1, 2020 at 4:46 PM Gerhard adam <[email protected]> wrote: > > > > > Even though it may not happen often the EQU can point to an odd > address and cause the label to be referenced when it is filled with binary > zeroes (S0C1) > The use of 0H always forces boundary alignment for instructions > > > > Get Outlook for iOS > > > > > > > On Mon, Jun 1, 2020 at 1:43 PM -0700, "Schmitt, Michael" < > [email protected]> wrote: > > > > > > > > > > > In John R. Ehrman's SHARE presentations on tips for modernizing IBM > z/Architecture assembler programs (such as > https://share.confex.com/share/120/webprogram/Handout/Session12522/modrnasm.pdf), > he says that important advice from experienced assembler programmers is to: > > _Don't_ use EQU for statement-label creation > > Can anyone venture a guess as to the reason for this advice? I've been > coding MVS assembler for 30 years and this is the first I've heard of this > guideline. > > One thing I'm wondering is if the suggestion is to avoid stand alone > statement labels entirely (such as LABEL EQU * or LABEL DS 0H) in favor of > putting the label on the next instruction? Or is there something about EQU > * that makes it a bad alternative to DS 0H? > > __ > Michael Schmitt | DXC.technology > > > DXC Technology Company - Headquarters: 1775 Tysons Boulevard, Tysons, > Virginia 22102, USA. > DXC Technology Company -- This message is transmitted to you by or on > behalf of DXC Technology Company or one of its affiliates. It is intended > exclusively for the addressee. The substance of this message, along with > any attachments, may contain proprietary, confidential or privileged > information or information that is otherwise legally exempt from > disclosure. Any unauthorized review, use, disclosure or distribution is > prohibited. If you are not the intended recipient of this message, you are > not authorized to read, print, retain, copy or disseminate any part of this > message. If you have received this message in error, please destroy and > delete all copies and notify the sender by return e-mail. Regardless of > content, this e-mail shall not operate to bind DXC Technology Company or > any of its affiliates to any order or other contract unless pursuant to > explicit written agreement or government initiative expressly permitting > the use of e-mail for such purpose. --. >
