You could load a vector register with FOUR =PL4'0' values and 26 VST's would initialize all 104 fields, load 2 vector registers and do 13 VSTM's. or 3 vector registers with 6 VSTM's and a MVFI. All the VSTMs can execute in parallel.
Robert Ngan DXC Luxoft -----Original Message----- From: IBM Mainframe Assembler List <[email protected]> On Behalf Of Steve Smith Sent: Monday, December 1, 2025 10:10 To: [email protected] Subject: Re: quick way to initialize Packed fields? I do think that this premature optimization is a bit much for initialization code. Making it simple is more important. That said, I think my first idea would be a JXLE loop, using ST R0,field(ix), which is clear, simple, and may well be faster than anything proposed so far. sas On Mon, Dec 1, 2025 at 8:17 AM Robin Vowels < [email protected]> wrote: > Since the initialization is performed only once, how much time is this > likely to take? > If each instruction took 1 microsecond, that's a total of 104 > microseconds. > Could you measure it? > >
