EX is independent of the format of the target instruction. You can EX anything (except EX). It just plugs that second byte of the target instruction. You can EX an LR and vary which registers get copied.
ZAP has L1/L2 so you want to load your EX register with (L1 * 16) + L2 (where L1 and L2 are base 0, and a shift might be a better choice than an actual multiply). Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Dave Clark Sent: Friday, February 11, 2022 2:03 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Executing a ZAP Instruction How do (can?) you EXecute a ZAP instruction? I have a packed number in plain character format that can vary in length from 1 to 16 bytes. I need to move that into a 16-byte formal packed work field in order to make the variable-length character data into recognizable packed-decimal data. The normal EXecute (ORs but effectively) replaces bits 8 to 15 of the target instruction with bits 56 to 63 of general register R1. But a ZAP instruction has an L1 field in bits 8 to 11 of the instruction and an L2 field in bits 12 to 15 of the instruction. Does that mean ZAP can't be EXecuted? Do I have to clear and align my variable-length character data in my 16-byte packed work field myself? Or is it feasible to manipulate the content of general register R1 so that bits 56 to 63 contain the correct L1 and L2 values? Sincerely, Dave Clark -- int.ext: 91078 direct: (937) 531-6378 home: (937) 751-3300 Winsupply Group Services 3110 Kettering Boulevard Dayton, Ohio 45439 USA (937) 294-5331 **************************************************************************** ***************** This email message and any attachments is for use only by the named addressee(s) and may contain confidential, privileged and/or proprietary information. If you have received this message in error, please immediately notify the sender and delete and destroy the message and all copies. All unauthorized direct or indirect use or disclosure of this message is strictly prohibited. No right to confidentiality or privilege is waived or lost by any error in transmission. **************************************************************************** *****************
