And that's better than the obvious MVC of 'JESSE' because? Because with MVCIN 'JESSE' does not appear in the literal pool and make it masquerade as the control block?
I find it hard to accept that this method's obscurity would be outweighed by its usefulness. Looks to me like a convoluted solution in search of a problem. I believe in eschewing obfuscation, especially in assembler code. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Ed Jaffe Sent: Tuesday, September 1, 2020 8:23 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Architectural Level Sets On 9/1/2020 6:36 PM, Jesse 1 Robinson wrote: > As for a vanishing instruction, I once wrote some code using the Move Inverse > (MVCIN) instruction, which greatly simplified scanning data for a terminating > character. Apparently MVCIN was introduced on the 4341 (?) but not carried > forward to subsequent models. So S0C1. A rude shock for a clever programmer > looking for ingenious solutions. MVCIN is a standard part of z/Architecture. We use it *heavily* for setting control block eyecatchers e.g.: MVCIN CBlockEyeCatch,=C' ESSEJ'+5 Set eyecatcher to 'JESSE ' ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
