They are very useful for avoiding branches. However, the STORE ON CONDITION is a PITA, as it may update (and backout?) the target field even if the condition is not matched. So don't use STOC/STOCG unless you know you have write access to the target field. This means you cannot load and test a pointer value, and do a STOCNZ to the pointer location as that will generate a S0C4 for storing to address zero even though STOCNZ should never do the store.
Robert Ngan DXC Luxoft -----Original Message----- From: IBM Mainframe Assembler List <[email protected]> On Behalf Of Phil Smith III Sent: Thursday, October 23, 2025 16:26 To: [email protected] Subject: Re: LOAD ON CONDITION Jeebus. Assembler instructions should be able to fit on a licens plate!!! -----Original Message----- From: IBM Mainframe Assembler List <[email protected]> On Behalf Of Ed Jaffe Sent: Thursday, October 23, 2025 4:28 PM To: [email protected] Subject: LOAD ON CONDITION I just coded this and it was kinda fun: LOCGHINP R6,1 Set to 1 if not positive -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://www.phoenixsoftware.com/ -------------------------------------------------------------------------------- This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use.
