On 11 April 2012 04:26, <[email protected]> wrote: > Edward Jaffe <[email protected]> wrote > >> On 4/10/2012 11:31 AM, McKown, John wrote: >>> But that made me wonder why the z/Architecture does not specify that the >>> contents of the AR register associated with the link register in any of >>> the "branch and link" type instructions: BALR, BASR, BRAS, BRASL, and >>> BASSM will be set to 0? >>> >>> Anybody have any idea why these type of instructions don't set the AR? >> >> Unnecessary. Instruction fetch is always from the primary address space. > > No, in Home-space mode instructions are fetched from the HASN.
Maybe better just to say that instruction fetch addresses are never qualified by an access register. This of course includes instructions fetched by Execute. Tony H.
