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Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?)

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KP2 KP2 <jungletrain@outlook.com> wrote:
> On Sunday, July 17, 1988 at 11:40:08 AM UTC-7, Daniel R. Levy wrote:
> > In article <880712162...@explorer.dgp.toronto.edu>, fl...@dgp.toronto.edu (Alan J Rosenthal) writes:
> > > [a certain MS-DOS C compiler can't compile an array larger than a segment]
> > > MS-DOS C compilers seem only to accept a subset
> > > of the C language because it allows them to compile certain benchmarks
> > > into faster code.
> > Accepting a "subset of the C language," as you put it, might make it EASIER
> > to write a PC compiler in order to compiler "certain benchmarks" faster, etc.,
> > but it's not NECESSARY. In the example you cited, there's nothing that would
> > theoretically keep the compiler from having the smarts to generate fast code to
> > do well by the small arrays in benchmarks and slower but working code for
> > larger, multi-segment arrays. Now the COMPILER might then be slower, but
> > that's another story.
> > -- 
> > |------------Dan Levy------------| THE OPINIONS EXPRESSED HEREIN ARE MINE ONLY
> > | AT&T Data Systems Group | AND ARE NOT TO BE IMPUTED TO AT&T.
> > | Skokie, Illinois | 
> > |-----Path: att!ttbcad!levy-----|
> How is it today?

a) Dan Levy was wrong.  In C arrays are closely tied to pointers
   and typically supported separate compilation.  Given that it
   is impossible to enlarge some arrays without giving the same
   treatment to all non-local arrays, that is slowing down most
   (or all) array operations.  One could try better handling
   whole program at once, essentially rewriting program into
   more efficient one.  IIUC there were several attempts to
   do things in this spirit (not limited to DOS array problem),
   but nothing working come out.
b) DOS compilers had "memory models". "Huge" memory model allowed
   arrays bigger than segment.  I am not sure when huge memory model
   was available first, but I suspect that before 1988.
c) We have standard now.  Standard allows limit on size of "objects".
   IIUC if only "trouble" with compiler is limit on size of arrays,
   then it is standard compiliant now (so no talk about "subset").
d) DOS segments is now history/computer archeology.
e) There are small machines (MCU-s) and C compilers targeting them.
   If machine has 64kB memory you can make compiler that meets
   standard requirements on size of "objects" (it is likely that
   you will have to run compiler on different, bigger machine).

-- 
                              Waldek Hebisch

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Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) KP2 KP2 <jungletrain@outlook.com> - 2022-12-10 13:06 -0800
  Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-10 20:57 -0600
    Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-10 22:57 -0600
    Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) antispam@math.uni.wroc.pl - 2022-12-11 20:31 +0000
      Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Robert Latest <boblatest@yahoo.com> - 2022-12-12 14:39 +0000
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) antispam@math.uni.wroc.pl - 2022-12-13 12:15 +0000
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-13 16:23 +0000
      Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-26 05:20 -0800
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-26 14:37 +0000
          Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-26 10:30 -0800
            Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-27 16:45 +0000
              Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-27 19:38 -0800
                Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-12-29 02:09 +0000
                Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-29 19:56 -0800
  Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) antispam@math.uni.wroc.pl - 2022-12-11 20:12 +0000
    Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-12 14:33 -0600
      Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) scott@slp53.sl.home (Scott Lurndal) - 2022-12-12 21:12 +0000
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-12-12 16:09 -0800
  Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Jack Lemmon <invalid@invalid.net> - 2022-12-12 20:30 +0000
    Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lynn McGuire <lynnmcguire5@gmail.com> - 2022-12-12 15:20 -0600
    Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-12 21:28 +0000
      Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) scott@slp53.sl.home (Scott Lurndal) - 2022-12-12 22:39 +0000
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2022-12-12 22:49 +0000
          Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) "minf...@arcor.de" <minforth@arcor.de> - 2022-12-31 04:01 -0800
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-12-12 15:56 -0800
          Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) scott@slp53.sl.home (Scott Lurndal) - 2022-12-13 14:55 +0000
            Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) David Brown <david.brown@hesbynett.no> - 2022-12-13 16:26 +0100
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) David Brown <david.brown@hesbynett.no> - 2022-12-13 14:50 +0100
        Re: Limitation of MS-DOS C compiler? (was Re: Should I convert FORTRAN code to C?) Anton Shepelev <anton.txt@g{oogle}mail.com> - 2022-12-13 18:56 +0300

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