On Sun, 6 May 2018 15:45:31 -0400, Tony Thigpen <[email protected]> wrote:
>Just for starters. > >1) I am looking at the registers at abend. Is it a 31 bit address with >the high-bit on, or is it a 32 bit address? If you don't want to debug 32-bit programs that have 4 GiB of memory available to them, then simply don't code it. There's no reason to stop other people from using the full 4 GiB. You also can't tell whether an address is 31-bit or a 24-bit address with crud in the top 8 bits. That's no reason for the 24-bit bar from being there for eternity. >2) The programmer uses GETMAIN LOC=32 forgetting that he is passing an >address that is in that area to a subprogram that is not 32bit. Oops. Same as calling an AM24 subroutine from an AM31 caller. No reason to stick with AM24 for eternity. >3) I am looking at a parameter list with 4 parms. The 2nd and the 4th >have the high-bit on. Is the 2nd parm the last parm or is not but >instead it is a 32 bit address and the 4th parm the last parm? If you don't want to be confused by parameter lists then simply never use LOC=32 addresses in the parameter lists. Use LOC=32 memory for internal use only. >I am a vendor that writes system software that is called by application >programmers. I am not sure how I would validate that a 32 bit address >was 32 bit and not 31 bit. Or, the reverse. You can't differentiate between an AM24 or AM31 address either. It is up to the caller to provide data in the expected AMODE. >IBM has the same problem when somebody calls their services. That is why >the BAR exists. IBM services that can't accept an AM64 caller are already documented as such. As far as I can tell, the BAR exists for the same reasons that 16 MiB LINE exists - historical curiosity. No reason to be stuck with that forever. Most other 32-bit programming environments allow access to the full 4 GiB and z/Arch is capable of delivering the same functionality to z/OS users. BFN. Paul. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
