On Tue, 15 May 2018 13:07:10 -0500, Tom Marchant <[email protected]> wrote:
>>>any program can be called by another program. >> >>I don't see anything wrong with "LINK" being >>updated to save the high 32-bits > >"CALL" is not the same as "LINK". > >The operating system does not get involved in any way on a CALL. Oh sure. A 64-bit program doing a CALL to a 32-bit routine will be required to save and clear the high 32 bits of registers. Or do it the other way around and a 32-bit routine is able to protect itself from dirty upper bits. I would suggest that the first option is better as only a 64-bit program is required to have knowledge of and manipulate 64-bit registers. BFN. Paul. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
