There have been compilers for more than half a century that produced better code for complex instructions than most programmers. Further, what is optimal for one processor might be slow on another. So best practice for assembler is to code for readability and maintainability, document well, and encapsulate any tricky optimization of frequently used functions in centralized macros, again well documented.
Don't C, COBOL and PL/I all use the same compiler back end these days? -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Tony Thigpen <t...@vse2pdf.com> Sent: Sunday, January 13, 2019 6:06 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Unreadable code (Was: Concurrent Server Task Dispatch issue multitasking issue) I have seen some reports that current C compilers, which understand the z-hardware pipeline, can actually produce object that is faster running than an assembler. Mainly because no sane assembler programmer would produce great pipe-line code because it would be un-maintanable. I am an assembler programmer, not a C programmer, so I view the reports with some speciesism. Tony Thigpen scott Ford wrote on 1/12/19 1:33 PM: > I am speaking in terms of development cycle. > > On Sat, Jan 12, 2019 at 1:32 PM scott Ford <idfli...@gmail.com> wrote: > >> David and Zman, >> >> Both good points, C is certainly faster than Assembler or maybe PL/S >> >> On Sat, Jan 12, 2019 at 2:17 AM David Crayford <dcrayf...@gmail.com> >> wrote: >> >>> On 12/01/2019 4:08 am, Seymour J Metz wrote: >>>> despite being used frequently for the purpose, it's really not >>> particularly suited for writing operating systems >>> >>> LOL! That's absurd! C has been ported to just about every architecture >>> worth mentioning and is well suited to low-level programming. It's also >>> incredibly >>> efficient and has a mature and well established tool chain for >>> debugging, profiling, code correctness etc. What do you consider a good >>> language for >>> writing operating systems? >>> >>> ---------------------------------------------------------------------- >>> For IBM-MAIN subscribe / signoff / archive access instructions, >>> send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN >>> >> -- >> Scott Ford >> IDMWORKS >> z/OS Development >> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
