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 >
