With XR/STH, the STH will have to wait for the XR to complete, so it may not be faster
On February 9, 2026 9:57:43 PM GMT+02:00, Seymour J Metz <[email protected]> wrote: >If I had to do it on an old machine before MVHHI then I'D use XC for clarity. >I suspect that the XR/STH is the fastest of your three. > >-- >Shmuel (Seymour J.) Metz >http://mason.gmu.edu/~smetz3 >עַם יִשְׂרָאֵל חַי >נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר > > > > >________________________________________ >From: IBM Mainframe Assembler List <[email protected]> on behalf >of David Clark <[email protected]> >Sent: Monday, February 9, 2026 1:48 PM >To: [email protected] <[email protected]> >Subject: Half-word Counter in Storage -- Best Practice > > >External Message: Use Caution > > >If a half-word counter has to be in storage (to save on registers) and must >start at zero, which is better or which would you prefer to do as a best >practice? > >...simply clear storage? > >XC STRGLEN,STRGLEN FOR USED STRING LENGTH COUNTER > >...or clear a register and save to storage? > >XR R5,R5 STARTING AT ZERO >STH R5,STRGLEN SET USED STRING LENGTH COUNTER > >...or use an immediate value and save to storage? > >LHI R5,0 STARTING AT ZERO >STH R5,STRGLEN SET USED STRING LENGTH COUNTER > >Sincerely, > >Dave Clark >-- >int.ext: 91078 >direct: (937) 531-6378 >home: (937) 751-3300 > >Winsupply Group Services >3110 Kettering Boulevard >Dayton, Ohio 45439 USA >(937) 294-5331 > >
