I believe it has been the intention of the MVS team over the past several years to make all of the basic assembler macro-invoked services independent of the caller's R13. I recall that once upon a time most of them required a save area off R13, and were so documented. I think now that most or all of them do not, and if a macro is not documented as requiring a user save area (actually, in this case, is affirmatively documented as not requiring one) then I think it is a pretty safe guess that it does not require one.
Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Peter Hunkeler Sent: Thursday, December 22, 2016 2:48 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Do the Name/Token Pair callable services need R13 to point to save area? I'm thinking of using a Name/Token pair to keep the address of "my" storage area, and X'00' to mean I first need to obtain the storage. This is in RENT code. When I get control, R13 points to a save area, which my code will use, but I do not yet have storage for another save area before calling IEANTRT, so I cannot change R13. The book says I do *not* have to place anything special into any register before calling the Name/Token Pair callable services. From this I conclude that the callable service routines will *not* use the save area pointed to by R13 (and work with only R0, R1, and R15 which are documented as being used). ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
