Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.c > #162604

Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ?

From Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups comp.lang.c
Subject Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ?
Date 2021-09-03 19:10 +0100
Organization A noiseless patient Spider
Message-ID <871r65ttr3.fsf@bsb.me.uk> (permalink)
References (10 earlier) <1b0fddb0-ead0-46b7-acd6-fcd629cea2b3n@googlegroups.com> <sgsao1$ie0$1@dont-email.me> <b269912f-21e1-4c16-9bb1-efcd6954453en@googlegroups.com> <sgtdf2$g6v$1@dont-email.me> <90a43fde-5b57-48a6-ac61-c11b16f1425an@googlegroups.com>

Show all headers | View raw


"james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> writes:

> On Friday, September 3, 2021 at 11:03:12 AM UTC-4, Bonita Montero wrote:
>> Am 03.09.2021 um 15:59 schrieb james...@alumni.caltech.edu: 
>> > On Friday, September 3, 2021 at 1:10:37 AM UTC-4, Bonita Montero wrote: 
>> >> Am 02.09.2021 um 20:28 schrieb james...@alumni.caltech.edu: 
>> >> 
>> >>> The platform doesn't have pointers - that's a C concept. ... 
>> >> 
>> >> If they allow memory-addressing they know pointers. 
>> > 
>> > A platform can only be said to "know" something if it's running a program.
>> Machine-level does know pointers and architecture-depenent data-types: 
>> MOV EBX, DWORD PTR [EAX + ECX * 8] 
>> Rest of your nonsense unread.
>
> On a platform such as the one I've described, with no hardware support for
> access to any piece of memory smaller than 16 bits, and a compiler which
> chooses to set CHAR_BIT == 8, the following function:
>
>       void add_3a(unsigned char *p) { *p += 3; }
>
> Would have to be compiled into machine code which does something
> similar to:
>
>     struct _byteptr {
>         int *addr
>         int offset;
>     };

I used (as was tangentially involved in the implementation of) C on a
machine that had 16 bit words and only word addressing.  The choice made
there was to use the bottom bit to select between the two halves of the
word addressed by the pointer (shifted right by 1).

-- 
Ben.

Back to comp.lang.c | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-08-30 21:59 -0500
  Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2021-08-30 21:53 -0700
    Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2021-08-30 21:59 -0700
  Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bo Persson <bo@bo-persson.se> - 2021-08-31 09:01 +0200
    Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-08-31 23:46 -0500
      Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-01 08:19 +0200
      Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-01 15:32 +0000
        Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-01 19:20 +0200
          Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-01 19:44 +0200
            Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-01 13:17 -0500
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-01 20:32 +0200
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-01 19:00 +0000
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-01 15:06 -0500
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-01 20:14 +0000
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Michael S <already5chosen@yahoo.com> - 2021-09-01 14:04 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-01 23:44 +0000
            Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-01 20:37 +0200
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-01 12:43 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-02 05:37 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-02 11:28 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-03 07:10 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-03 06:59 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-03 17:02 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Manfred <noname@add.invalid> - 2021-09-03 19:33 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-03 19:47 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-03 17:54 +0000
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-03 20:54 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-03 20:52 +0000
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-04 12:36 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-03 10:49 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-09-03 19:10 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-03 14:20 -0400
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-09-03 19:45 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-03 16:35 -0400
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-04 13:12 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-04 09:11 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-04 11:27 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-05 04:25 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-06 16:10 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-08 19:44 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-08 11:45 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-09 19:09 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-09 10:51 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-10 10:31 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-10 10:41 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-14 04:14 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-14 07:45 -0700
            Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-01 20:34 +0100
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-09-01 13:02 -0700
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? scott@slp53.sl.home (Scott Lurndal) - 2021-09-01 20:18 +0000
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Michael S <already5chosen@yahoo.com> - 2021-09-01 14:07 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-01 22:18 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2021-09-01 18:23 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-02 13:35 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2021-09-02 05:24 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2021-09-02 14:56 -0600
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Vir Campestris <vir.campestris@invalid.invalid> - 2021-09-07 21:12 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-07 22:19 -0400
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Vir Campestris <vir.campestris@invalid.invalid> - 2021-09-12 21:23 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Michael S <already5chosen@yahoo.com> - 2021-09-09 08:36 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-01 17:46 -0500
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-01 16:53 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-02 17:11 -0500
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-09-01 16:59 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-01 17:01 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-02 01:29 +0100
              Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-02 13:29 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-02 14:19 +0100
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-02 17:10 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Michael S <already5chosen@yahoo.com> - 2021-09-02 07:28 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? David Brown <david.brown@hesbynett.no> - 2021-09-02 21:07 +0200
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Michael S <already5chosen@yahoo.com> - 2021-09-02 13:05 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-02 17:18 -0700
                Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Bart <bc@freeuk.com> - 2021-09-03 01:25 +0100
  Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Mark Bluemel <mark.bluemel@gmail.com> - 2021-09-01 03:30 -0700
    Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Mark Bluemel <mark.bluemel@gmail.com> - 2021-09-01 03:36 -0700
    Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Lynn McGuire <lynnmcguire5@gmail.com> - 2021-09-01 12:49 -0500
      Re: Examples of current platforms/architectures where sizeof(void*) > sizeof(int*) ? Mark Bluemel <mark.bluemel@gmail.com> - 2021-09-01 14:30 -0700

csiph-web