<snip> Don't expect anyone else to save it, so if you really need it after you get started then save again in your own storage before you call someone else who may or may not preserve it. </snip>
I disagree. That's what linkage conventions are for. Sure, if a callee fails to follow them (and fails to document its requirements so that the caller can know that it needs to do extra work), the caller is screwed. So fix the callee. <snip> Must a 31-bit caller not depend on both halves of R2-R13 being preserved by a 31-bit subroutine? </snip> If it is truly a "subroutine" then it is owned by the caller and it is up to the caller to decide what its own rules are. If it is something not owned by the caller, then any caller (31-bit or otherwise) must be able to depend on both halves of R2-R13 being preserved (whether the target is 31-bit or otherwise). Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
