Thank you!!! This is exactly what I was looking for. I had thought the limit was a single byte, but I tried this and it works perfectly. In initial testing it seems to load quite a bit faster. I'm going to add some code to compare the two (before and after) for CPU overhead. But this seems to be pretty good. It's definitely a lot less code to go through.
On Sat, 29 Nov 2025 23:30:39 -0500, Steve Smith <[email protected]> wrote: >MVC "ripple" initialization isn't limited to 1-byte. > ZAP P1,=P'0' > MVC P2(256),P1 Init P2-P65 > MVC P66(156),P65 Init P66-P104 > >Check my math... better yet use EQU and DC to do the math. > >sas > >On Sat, Nov 29, 2025 at 10:35 PM Brian Westerman < >[email protected]> wrote: > >> Hi, >> >> I have a program in which I have 104 PL4 fields tht are used for various >> counters, and when the program starts it spends a significant amount of >> time initializing all of those fields to zero. >> >> we used to use ZAP field,=PL4'0' and then I found an entry (on the web) >> that said it would be "slightly" faster to use MVC, so I changed it to 104 >> MVC filed,=PL4'0'. >> >> Is there not a quicker way to do this? I know that I can ripple the first >> byte of a field for up to 256 bytes with a single instruction, but can that >> same type of thing be done with a 4 byte packed field? >> >> If not, is there a quicker way to initialize these fields without doing >> each one separately? >> >> Thanks for any tips. >> >> Brian >>
