There's another macro exercise. Given MYBLKHDR,'EYECATCH' to generate MVI MYBLKHDR,C'E'/MVC MYBLKHDR+1(L'MYBLKHDR-1),=C'YECATCH'
An immediate instructions also "solves" my eyecatcher compare query, lamenting the lack of "CLCIN." CLI for the first character followed by a CLC for the remainder would have the advantage that probably more than 9 times out of 10 the CLI would be sufficient. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Jonathan Scott Sent: Saturday, October 24, 2020 8:13 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Reversed string macro I do hope no-one is taking this thread too seriously. The use of MVCIN to set a data area eyecatcher is incredibly inefficient. If you really think that there it is important to ensure that data area eyecatchers aren't found in the code which creates them, you can copy the convention used internally by much of CICS, which is to move in a prefix character followed by the rest, so the prefix character is normally set with MVI and the rest with MVC. I've just compared a MVI, MVC sequence with a MVCIN instruction and it was more than 10 times faster on this machine.
