X'B040' is only on a quad-word boundary if the contents of R11 are already on a quad-word boundary. It's not just the displacement, but the contents of the base register plus the displacement (i.e., the effective address) that must be quad-word aligned.
HTH Peter -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Donald Likens Sent: Monday, February 25, 2013 12:40 PM To: [email protected] Subject: I do not understand S0C6 on CDSG I am missing something: The Principles of Operations states: COMPARE DOUBLE AND SWAP (CDSG) must be designated on a quadword boundary. The R1 and R2 fields for COMPARE DOUBLE AND SWAP must each designate an even-numbered register. Otherwise, a specification exception is recognized. I think the following instruction meets all of these requirements but I am getting an S0C6? EB42 B040 003E CDSG R4,R2,SEG Am I correct is saying B040 is a quadword boundary? Is there a good way in assembler to insure a double word starts on a quadword boundary? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN This message and any attachments are intended only for the use of the addressee and may contain information that is privileged and confidential. If the reader of the message is not the intended recipient or an authorized representative of the intended recipient, you are hereby notified that any dissemination of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail and delete the message and any attachments from your system. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
