From: muta...@gmail.com   
      
   On Friday, November 11, 2022 at 12:33:44 AM UTC+8, Joe Monk wrote:   
   > > You need to actually do something with memory. I need to know if you   
   > > are doing ANY instructions that use the full 64 bits of a register to   
   > > address memory. If you are, it is a 64-bit program.   
   > So, by that definition, every z/Arch program is 64-bit, regardless of AMODE.   
   >   
   > All z/Arch physical memory accesses are 64-bit.   
      
   No, that's not correct. If a program only ever populates the low   
   32 bits of registers, to use as addresses, then it is a 32-bit   
   program.   
      
   Just because someone moves a properly-written 32-bit program (that   
   doesn't rely on address masking) from S/370 to z/Arch, doesn't   
   magically turn it into a 64-bit program. Life would be so simple if   
   it did. The bitness is decided at build time. ie how many address bits   
   are populated, and whether the programmer is a jackass who relied   
   on masking.   
      
   BFN. Paul.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)