LINKAGE=SYSTEM was all that STORAGE provided when it was introduced in MVS/ESA. The other LINKAGE options were added in z/OS 1.6.
My measurement program says that type 1 SVC linkage is faster than PC for these services. STORAGE SVC: 01.363189 PC: 02.147400 DELTA: 00.784211 POST SVC: 00.525115 PC: 00.766294 DELTA: 00.241179 WAIT SVC: 00.490125 PC: 01.052126 DELTA: 00.562001 ESTAE SVC: 01.184268 PC: 01.992566 DELTA: 00.808298 Jim Mulder -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Seymour J Metz Sent: Sunday, October 20, 2024 6:22 AM To: [email protected] Subject: Re: z/OS macros with ARCHLVL=7 Using literals is okay if they are likely to be shared, and an L is shorter than an LAY OR IILF, and is massively better than the CNOP/B/DC/L sequence I was complaining about. Does STORAGE still do that in the current z/OS release? BTW, what was the rationale for defaulting STORAGE to LINKAGE=SYSTEM? Is the PC interface faster? -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Peter Relson <[email protected]> Sent: Saturday, October 19, 2024 8:20 AM To: [email protected] Subject: Re: z/OS macros with ARCHLVL=7 Caution: This email did not originate from George Mason’s mail system. Do not click links or open attachments unless you recognize the sender and know the content is safe. In the alternate reality of unlimited resources and time, those sort of expansion might be done. The only thing that was felt justified was to avoid needing a register to base your code so that you could use relative branch better. IBM macros for the most part require addressability to your static data (so that using literals is felt OK). You can, of course, compare the expansion shown to what you'd get without the specification of SYSSTATE ARCHLVL. Now that is the S/360 version. As to "R form" of freemain (or getmain), we intentionally put no work into that path, as it should probably never be used any longer. Peter Relson z/OS Core Technology Design ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
