On Apr 15, 2022, at 21:30:35, Robin Vowels wrote: >>> >> R0 doesn't count because no one else uses it. > > nonsense! > (That was sarcasm.)
> On Apr 15, 2022, at 21:28:55, Robin Vowels wrote: > > MVCL will do what you want. > Yes. > and MVCL will even deal with zero lengths. > It must, in order to deal with interruptions during padding. > The most common use of MVCL is to move some text to a destination > area, and to pad that area with a given character (commonly blank, > not zero), if required. > To set an area to zeros is not something that's done frequently. > I would say, almost never. > To preset storage after GETMAIN? But it might suffice to set counters to zero and leave buffers undefined. The length is probably a constant, but may exceed 256. I suspect MVCL is highly optimized in microcode or silicon; I could imagine special treatment of cache faults, etc. -- gil
