Just my uninformed opinion, but it's hard for me to see how an MVC loop could be faster. Both are interruptible. (MVC is not but an MVC *loop* is.) Both update registers (okay, three versus four).
I know microcode is not magic but gee, if MVC were faster than whatever MVCL does, wouldn't the microcode writers just have used an MVC loop instead of what they did use for MVCL? My uninformed opinion is that MVCL worst case should be no slower than an MVC loop for indeterminate length moves of possibly more than 256 bytes (and as a side benefit, it is a heck of a lot easier to use in that situation, unless you happen to be very short on spare registers). Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Mike Schwab Sent: Tuesday, May 31, 2011 1:35 PM To: [email protected] Subject: Re: What is the current feeling for MVC loop vs. MVCL? How about a macro to replace MVCL with a loop using the same registers but using MVC? Anyone ever write one? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
