64 bit addressing execution is faster if less access to real memory is required to fetch the next instruction. This is what quadword promise, is'It? the "performance gain" is also depend on the logic of the program (if commands sequenced well with less brunch instructions).
ITschak On Wed, Jan 22, 2014 at 5:30 AM, Jim Mulder <[email protected]> wrote: > >One caveat to that statement is as follows, from the POps: > >"The performance of CDSG on some models may > >be significantly slower than that of CSG. WHEN > >QUADWORD CONSISTENCY IS NOT REQUIRED BY THE PROGRAM, > >alternate code sequences should be used." > >(my caps) > > CDSG was implemented in millicode on the z900, z800, z990, z890, > and z9 machines. It was moved to hardware on the z10 and later > machines. > > Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
