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Groups > comp.lang.c > #400344 > unrolled thread

Prioritize Performance over Correctness

Started byJanis Papanagnou <janis_papanagnou+ng@hotmail.com>
First post2026-07-22 01:38 +0200
Last post2026-07-23 11:18 +0200
Articles 20 on this page of 186 — 20 participants

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Contents

  Prioritize Performance over Correctness Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-07-22 01:38 +0200
    Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-21 17:26 -0700
      Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-22 01:50 +0000
        Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-21 20:25 -0700
          Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-22 17:37 +0000
        Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-22 13:26 -0700
      Re: Prioritize Performance over Correctness Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-07-22 07:33 +0200
        Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-07-22 10:41 +0200
          Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-22 18:08 -0500
            Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-07-23 10:31 +0200
              Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-23 14:31 -0700
                Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-23 14:48 -0700
                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-23 15:11 -0700
                    Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-07-24 09:23 +0200
                      Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-24 03:14 -0700
                      Re: Prioritize Performance over Correctness scott@slp53.sl.home (Scott Lurndal) - 2026-07-24 14:56 +0000
                      Re: Prioritize Performance over Correctness antispam@fricas.org (Waldek Hebisch) - 2026-07-25 16:30 +0000
                        Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-27 09:33 -0400
                          Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 00:22 +0800
                            Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-27 12:58 -0700
                              Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-27 15:37 -0500
                                Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-27 17:13 -0400
                                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-27 15:17 -0700
                                    Re: Prioritize Performance over Correctness scott@slp53.sl.home (Scott Lurndal) - 2026-07-28 01:18 +0000
                                      Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 15:40 +0800
                                        Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 14:18 +0000
                                          Multics( Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 22:48 +0800
                                            Re: Multics( Re: Prioritize Performance over Correctness) scott@slp53.sl.home (Scott Lurndal) - 2026-07-28 15:08 +0000
                                              Re: Multics( Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 23:30 +0800
                                                Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 19:08 +0000
                                                  Re: Multics( Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 04:08 +0800
                                                    Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 22:15 +0000
                                                    Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 22:26 +0000
                                                      Re: Multics( Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 06:41 +0800
                                                        Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 23:23 +0000
                                                          Picture of Organicks' book Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 16:01 +0800
                                                            Re: Picture of Organicks' book cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-29 13:46 +0000
                                                              Re: Picture of Organicks' book R Kym Horsell <kymhorsell@gmail.com> - 2026-07-29 16:54 +0000
                                                          Re: Multics( Re: Prioritize Performance over Correctness) Cóilín Nioclásín Glostéir <thanks-to@Taf.com> - 2026-07-29 23:22 +0000
                                              Re: Multics( Re: Prioritize Performance over Correctness) Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-08-15 15:55 -0700
                                            Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 18:58 +0000
                                              Re: Multics( Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 04:10 +0800
                                                Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 22:20 +0000
                                                  Re: Multics( Re: Prioritize Performance over Correctness) scott@slp53.sl.home (Scott Lurndal) - 2026-07-29 14:44 +0000
                                                    Re: Multics( Re: Prioritize Performance over Correctness) cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-30 02:08 +0000
                                    Re: Prioritize Performance over Correctness Tim Rentsch <tr.17687@z991.linuxsc.com> - 2026-08-16 07:59 -0700
                              Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-27 17:59 -0700
                                Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 15:42 +0800
                                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-28 03:22 -0700
                                    Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 19:21 +0800
                                      Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-28 13:02 +0100
                                        Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 20:18 +0800
                                          Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-28 14:17 +0100
                                            Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-28 16:02 -0500
                                            Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 16:45 +0800
                                              Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-29 12:03 +0100
                                                Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 19:32 +0800
                                                  Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-29 13:42 +0100
                                                    Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 20:49 +0800
                                                      Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-29 16:01 +0100
                                                Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-29 12:53 -0700
                                                Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-31 14:21 -0400
                                                  Re: Prioritize Performance over Correctness bart <bc@freeuk.com> - 2026-07-31 20:07 +0100
                                                    Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-31 13:00 -0700
                                                    Re: Prioritize Correctness Over Performance Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-01 02:34 +0000
                                        Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-28 16:08 -0700
                                          Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 23:28 +0000
                                      Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 14:22 +0000
                                      Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-28 13:51 -0700
                                      Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-28 20:32 -0400
                                    Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-28 14:20 +0000
                                  Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-28 13:54 -0700
                                    Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 05:00 +0800
                                      Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-28 20:25 -0400
                                        Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-29 14:55 -0700
                                      Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-28 20:31 -0400
                                        Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-28 21:26 -0700
                                          Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-29 14:57 -0700
                                            Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-29 15:33 -0700
                                              Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-29 16:22 -0700
                                              Re: Prioritize Performance over Correctness Richard Harnden <richard.nospam@gmail.invalid> - 2026-07-30 07:40 +0100
                                                Re: Prioritize Correctness over Performance Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-30 06:48 +0000
                                                  Re: Prioritize Correctness over Performance James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-30 06:50 -0400
                                                  Re: Prioritize Correctness over Performance Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-30 03:54 -0700
                                                    Re: Prioritize Correctness over Performance James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-30 08:24 -0400
                                                      Re: Prioritize Correctness over Performance Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-30 14:40 -0700
                                                  Re: Prioritize Correctness over Performance "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-30 19:39 -0700
                                                Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-30 06:44 -0400
                                                  Re: Prioritize Performance over Correctness Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-30 21:00 +0000
                                                    Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-30 14:38 -0700
                                                    Re: Prioritize Performance over Correctness Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-30 21:53 +0000
                                                      Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-30 15:10 -0700
                                                    Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-30 19:40 -0700
                                                      Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-07-31 02:43 +0000
                                                        Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-30 19:44 -0700
                                                          Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-30 19:58 -0700
                                                          Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-01 01:25 -0700
                                                            Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-08-02 23:14 +0200
                                                              Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-02 14:37 -0700
                                                                Re: Prioritize Performance over Correctness Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-02 22:51 +0000
                                                                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-08-02 16:43 -0700
                                                                  Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 12:03 -0700
                                                                    Re: Prioritize Correctness Over Performance Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-03 23:49 +0000
                                                                      Re: Prioritize Correctness Over Performance "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 19:35 -0700
                                                                MS-DOS memory models (was: Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-03 08:08 +0800
                                                                Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-08-03 10:16 +0200
                                                                  Re: Prioritize Performance over Correctness Richard Harnden <richard.nospam@gmail.invalid> - 2026-08-03 10:41 +0100
                                                                    Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-08-03 12:28 +0200
                                                                      Malicious Computer Architecture (was: Re: Prioritize Performance over Correctness) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-03 19:23 +0800
                                                                        Re: Malicious Computer Architecture David Brown <david.brown@hesbynett.no> - 2026-08-03 14:01 +0200
                                                                          Re: Malicious Computer Architecture Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-03 22:52 +0800
                                                                            Re: Malicious Computer Architecture David Brown <david.brown@hesbynett.no> - 2026-08-03 19:41 +0200
                                                                              Re: Malicious Computer Architecture "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 13:13 -0700
                                                                            Re: Malicious Computer Architecture "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 13:10 -0700
                                                                        Re: Malicious Computer Architecture (was: Re: Prioritize Performance over Correctness) scott@slp53.sl.home (Scott Lurndal) - 2026-08-03 14:29 +0000
                                                                        Johnny Depp prevention [Windows 11 etc...] (Was: Malicious Computer Architecture) Mild Shock <janburse@fastmail.fm> - 2026-08-03 18:10 +0200
                                                                          But how can you deploy. when its ROM? (Was: Johnny Depp prevention [Windows 11 etc...]) Mild Shock <janburse@fastmail.fm> - 2026-08-03 18:15 +0200
                                                                            GPU Elasticity: Collective Communications Libraries (Was: But how can you deploy. when its ROM?) Mild Shock <janburse@fastmail.fm> - 2026-08-07 14:37 +0200
                                                                              What are Flits and Phits? [Network on a Chip] (Re: GPU Elasticity: Collective Communications Libraries) Mild Shock <janburse@fastmail.fm> - 2026-08-07 18:07 +0200
                                                                                Cristallina: Thank you for the Beam (Re: What are Flits and Phits? [Network on a Chip]) Mild Shock <janburse@fastmail.fm> - 2026-08-09 21:22 +0200
                                                                                  Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Mild Shock <janburse@fastmail.fm> - 2026-08-18 16:26 +0200
                                                                                    How to shoot yourself in the foot (Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Mild Shock <janburse@fastmail.fm> - 2026-08-18 16:50 +0200
                                                                                      Re: How to shoot yourself in the foot (Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-19 03:24 +0800
                                                                                    Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-19 03:21 +0800
                                                                                      Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Aidan Kehoe <kehoea@parhasard.net> - 2026-08-18 21:13 +0100
                                                                                        Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-18 22:49 +0000
                                                                                          Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-19 08:32 +0800
                                                                                        Re: Loderunner Enemy AI better than SWI-Prolog? [Prolog Education Group] Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-19 08:27 +0800
                                                                                The Mac Neo is a Budget Monster [GPU Channels] (Re: What are Flits and Phits? [Network on a Chip]) Mild Shock <janburse@fastmail.fm> - 2026-08-11 16:27 +0200
                                                                                  The luminaries of duct-tape engineering [Sweeney and Torvald] (Was: The Mac Neo is a Budget Monster [GPU Channels]) Mild Shock <janburse@fastmail.fm> - 2026-08-11 16:51 +0200
                                                                        Re: Malicious Computer Architecture Aidan Kehoe <kehoea@parhasard.net> - 2026-08-03 19:51 +0100
                                                                          Re: Malicious Computer Architecture Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-05 00:22 +0800
                                                                            Re: Malicious Computer Architecture Richard Harnden <richard.nospam@gmail.invalid> - 2026-08-04 19:10 +0100
                                                                              Re: Malicious Computer Architecture Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-05 03:21 +0800
                                                                            Re: Malicious Computer Architecture Kaz Kylheku <046-301-5902@kylheku.com> - 2026-08-06 21:55 +0000
                                                                              Re: Malicious Computer Architecture Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-08-07 06:31 +0800
                                                                            Re: Malicious Computer Architecture Aidan Kehoe <kehoea@parhasard.net> - 2026-08-06 23:01 +0100
                                                                        A Case for Impurity: The Applied Pi Calculus (Re: Malicious Computer Architecture) Mild Shock <janburse@fastmail.fm> - 2026-08-04 14:58 +0200
                                                                          The Sandcastle of Paul Taraus Interactors (Re: A Case for Impurity: The Applied Pi Calculus) Mild Shock <janburse@fastmail.fm> - 2026-08-04 15:10 +0200
                                                                    Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-08-03 05:34 -0700
                                                                    Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 13:04 -0700
                                                                      Re: Prioritize Correctness Over Performance Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-04 00:52 +0000
                                                                        Re: Prioritize Correctness Over Performance scott@slp53.sl.home (Scott Lurndal) - 2026-08-04 14:22 +0000
                                                                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-08-03 05:25 -0700
                                                                    Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-08-03 15:10 +0200
                                                                    Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-08-03 13:16 -0700
                                                            Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-08-03 20:29 -0400
                                                              Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-08-03 17:55 -0700
                                                                Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-08-04 09:12 +0200
                                                    Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-08-02 19:01 -0700
                                                      Re: Prioritize Performance over Correctness cross@spitfire.i.gajendra.net (Dan Cross) - 2026-08-03 19:59 +0000
                                                Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-30 03:50 -0700
                                      Re: Prioritize Performance over Correctness "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2026-07-29 15:09 -0700
                              Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-28 08:14 +0800
                                Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 05:54 +0800
                                  Re: Prioritize Performance over Correctness steveo@panix.com (Steven M. O'Neill) - 2026-07-31 20:34 +0000
                                Re: Prioritize Performance over Correctness James Kuyper <jameskuyper@alumni.caltech.edu> - 2026-07-28 19:40 -0400
                            Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-27 15:36 -0500
                              Re: Prioritize Performance over Correctness Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-29 04:56 +0800
                Re: Prioritize Performance over Correctness Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-07-24 14:47 +0200
                  Re: Prioritize Performance over Correctness David Brown <david.brown@hesbynett.no> - 2026-07-24 16:27 +0200
                  Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-25 00:52 +0800
                    Re: Resources for Amateur Compiler Writers bart <bc@freeuk.com> - 2026-07-24 23:08 +0100
                      Re: Resources for Amateur Compiler Writers BGB <cr88192@gmail.com> - 2026-07-24 18:50 -0500
                      Re: Resources for Amateur Compiler Writers Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-25 01:54 +0000
                        Re: Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-25 15:20 +0800
                          Re: Resources for Amateur Compiler Writers Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-25 07:24 +0000
                            Re: Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-25 15:30 +0800
                              Re: Resources for Amateur Compiler Writers David Brown <david.brown@hesbynett.no> - 2026-07-25 10:37 +0200
                                Re: Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-27 00:35 +0800
                                  Re: Resources for Amateur Compiler Writers BGB <cr88192@gmail.com> - 2026-07-26 12:39 -0500
                                    Re: Resources for Amateur Compiler Writers bart <bc@freeuk.com> - 2026-07-26 22:27 +0100
                                      Re: Resources for Amateur Compiler Writers BGB <cr88192@gmail.com> - 2026-07-26 18:02 -0500
                              Re: Resources for Amateur Compiler Writers Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-07-25 22:32 +0000
                                Re: Resources for Amateur Compiler Writers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-25 15:58 -0700
                      Re: Resources for Amateur Compiler Writers David Brown <david.brown@hesbynett.no> - 2026-07-25 10:23 +0200
                    Re: Resources for Amateur Compiler Writers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-24 16:29 -0700
                      Re: Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-25 15:25 +0800
                        Re: Resources for Amateur Compiler Writers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-25 15:33 -0700
                          Re: Resources for Amateur Compiler Writers Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-07-27 00:38 +0800
                            Re: Resources for Amateur Compiler Writers Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-26 17:06 -0700
                    Re: Resources for Amateur Compiler Writers Cóilín Nioclásín Glostéir <thanks-to@Taf.com> - 2026-07-26 17:03 +0000
                  Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-24 16:50 -0500
                  Re: Prioritize Performance over Correctness Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-07-24 16:13 -0700
              Re: Prioritize Performance over Correctness BGB <cr88192@gmail.com> - 2026-07-26 15:26 -0500
          Re: Prioritize Performance over Correctness Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-07-23 11:18 +0200

Page 5 of 10 — ← Prev page 1 … 3 4 [5] 6 7 … 10  Next page →


#400576

FromRichard Harnden <richard.nospam@gmail.invalid>
Date2026-07-30 07:40 +0100
Message-ID<114erk4$1gduv$1@dont-email.me>
In reply to#400571
On 29/07/2026 23:33, Keith Thompson wrote:
> "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> writes:
>> On 7/28/2026 9:26 PM, Keith Thompson wrote:
>>> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
>>>> On 2026-07-28 17:00, Johann 'Myrkraverk' Oskarsson wrote:
>>>>> On 29/07/2026 4:54 AM, Chris M. Thomasson wrote:
>>>> ...>> say NULL is (void*)0xDEADBEEF, or whatever, for a system. Then for a
>>>> NULL is required to be a null pointer constant, for which there are only
>>>> two options,
>>>> 1) an integer constant expression with a value of 0.
>>>> or
>>>> 2) such an expression converted to (void*)
>>>
>>> As of C23, a null pointer constant can be an integer constant
>>> expression with the value 0, such an expression cast to void*, or the
>>> predefined constant nullptr.  (POSIX imposes some additional
>>> requirements.)  `(void*)nullptr` is guaranteed to evaluate to a null
>>> pointer, but it's not a null pointer constant.  Note that `(void*)0`
>>> is a null pointer constant, but it doesn't qualify as a definition of
>>> the NULL macro.  7.1.2 requires any definition of an object-like
>>> macro in the standard library to "expand to code that is fully
>>> protected by parentheses where necessary, so that it groups in an
>>> arbitrary expression as if it were a single identifier".
>>>
>>> Any of `0`, `((void*)0)`, or `nullptr` would be a reasonable
>>> expansion for NULL.  Unreasonable but valid definitions include:
>>>
>>>       #define NULL ('/'/'/'-'/'/'/')
>>>       #define NULL (1+1==3)
>>>
>>>> Since 0xDEADBEEF doesn't have a value of 0, it doesn't qualify.
>>>
>>> Right.  It's easy (but incorrect) to assume a correlation between
>>> the fact that a constant 0 (in source code) is a null pointer
>>> constant, and the fact that all-bits-zero (during execution)
>>> is very commonly a representation for a null pointer.  There are
>>> historical reasons, but the language is careful does not require
>>> any particular representation for a runtime null pointer.
>>> [...]
>>
>> The bits of the raw NULL does not have to be 0.
> 
> You're restating something that was already clearly stated in this
> thread, and you're doing it incorrectly.
> 
> The NULL macro is a source code construct.  It doesn't have "bits",
> unless you count the bits making up the characters 'N', 'U', 'L',
> 'L' (in the source character set, which needn't match the execution
> character set).
> 
> The thing whose bits don't have to be 0 is a null pointer *value*,
> something that exists during execution and can result from an
> occurence of NULL in the source code.
> 
> The point from upthread is that your suggested (void*)0xDEADBEEF
> is not a null pointer constant, and therefore is not a valid
> expansion of the NULL macro, *even if* 0xDEADBEEF matches the
> run-time representation of a null pointer.
> 
> (I normally ignore your posts, but I made an arbitrary exception
> in this case.)
> 

Can a pointer have a value of zero, but not be a null pointer?

This, for example, thinks that p ends up as a null pointer.
But there is no constant 0.

Probably I'm confused.

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
     char *p = malloc(1);

     printf("p = %p\n", (void*) p);

     do
     {
         p--;
         printf("p is%s null, p = %p\n", p ? " not" : "", (void*) p);
     }
     while (p);

     return 0;
}

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#400577 — Re: Prioritize Correctness over Performance

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-07-30 06:48 +0000
SubjectRe: Prioritize Correctness over Performance
Message-ID<114es4e$1gg4f$1@dont-email.me>
In reply to#400576
On Thu, 30 Jul 2026 07:40:04 +0100, Richard Harnden wrote:

> Can a pointer have a value of zero, but not be a null pointer?

C doesn’t define any special pointer values, other than the null
pointer. The null pointer can be compared for equality with (a
suitable cast of) the integer literal 0 (I’m not sure, it might be
that arbitrary integer expressions evaluating to 0 are not allowed),
but that is not considered grounds for concluding/requiring that the
bit pattern for the null pointer is actually equal to the integer
value 0.

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#400581 — Re: Prioritize Correctness over Performance

FromJames Kuyper <jameskuyper@alumni.caltech.edu>
Date2026-07-30 06:50 -0400
SubjectRe: Prioritize Correctness over Performance
Message-ID<114fa9e$1mred$1@dont-email.me>
In reply to#400577
On 2026-07-30 02:48, Lawrence D’Oliveiro wrote:
> On Thu, 30 Jul 2026 07:40:04 +0100, Richard Harnden wrote:
> 
>> Can a pointer have a value of zero, but not be a null pointer?
> 
> C doesn’t define any special pointer values, other than the null
> pointer. The null pointer can be compared for equality with (a
> suitable cast of) the integer literal 0 (I’m not sure, it might be
> that arbitrary integer expressions evaluating to 0 are not allowed),

True. Only integer constant expressions with a value of 0 qualify as
null pointer constants. If an integer variable named zero had a value of
zero, then "zero" is an integer expression with a value of zero, but
because it's not a constant expression, conversion of "zero" to a
pointer type is not guaranteed to produce a null pointer constant.
However, on most implementations, especially those where a pointer
object with all-bits-0 does represent a null pointer, that conversion is
likely to produce one. You just need to remember that it's not required
to do so.
However, any integer constant expression, regardless of type, does
qualify as a null pointer constant, even

	1LL-'\001'

> but that is not considered grounds for concluding/requiring that the
> bit pattern for the null pointer is actually equal to the integer
> value 0.

Correct.

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#400582 — Re: Prioritize Correctness over Performance

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-07-30 03:54 -0700
SubjectRe: Prioritize Correctness over Performance
Message-ID<114fahd$1mrbt$2@kst.eternal-september.org>
In reply to#400577
Lawrence D’Oliveiro <ldo@nz.invalid> writes:
> On Thu, 30 Jul 2026 07:40:04 +0100, Richard Harnden wrote:
>> Can a pointer have a value of zero, but not be a null pointer?
>
> C doesn’t define any special pointer values, other than the null
> pointer. The null pointer can be compared for equality with (a
> suitable cast of) the integer literal 0 (I’m not sure, it might be
> that arbitrary integer expressions evaluating to 0 are not allowed),
> but that is not considered grounds for concluding/requiring that the
> bit pattern for the null pointer is actually equal to the integer
> value 0.

Correct.

The only integer expressions that are null pointer constants are
constant integer expressions with the value 0, but they can be
arbitrarily complex (1-1, 1+1==3, '/'/'/'-'/'/'/').  A non-constant
integer expression that happens to yield 0 is not guaranteed to yield a
null pointer when converted to a pointer type.  These:

    void *np = (void*)0; // the cast isn't actually needed
    int zero = 0;
    void *fake_np = (void*)0;

can even assign different values to np and to fake_np.  (That's
likely to happen only on implementations where a null pointer
is not represented as all-bits-zero; such an implementation would
have to treat constant expressions specially.)

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#400583 — Re: Prioritize Correctness over Performance

FromJames Kuyper <jameskuyper@alumni.caltech.edu>
Date2026-07-30 08:24 -0400
SubjectRe: Prioritize Correctness over Performance
Message-ID<114ffq0$1otmb$1@dont-email.me>
In reply to#400582
On 2026-07-30 06:54, Keith Thompson wrote:
...>     void *np = (void*)0; // the cast isn't actually needed
>     int zero = 0;
>     void *fake_np = (void*)0;

I suspect that you intended that to be (void*)zero.

> can even assign different values to np and to fake_np.

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#400616 — Re: Prioritize Correctness over Performance

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-07-30 14:40 -0700
SubjectRe: Prioritize Correctness over Performance
Message-ID<114ggc3$25jib$2@kst.eternal-september.org>
In reply to#400583
James Kuyper <jameskuyper@alumni.caltech.edu> writes:
> On 2026-07-30 06:54, Keith Thompson wrote:
> ...>     void *np = (void*)0; // the cast isn't actually needed
>>     int zero = 0;
>>     void *fake_np = (void*)0;
>
> I suspect that you intended that to be (void*)zero.

I did indeed.  Thanks.

>> can even assign different values to np and to fake_np.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#400623 — Re: Prioritize Correctness over Performance

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-07-30 19:39 -0700
SubjectRe: Prioritize Correctness over Performance
Message-ID<114h1ta$2b0po$1@dont-email.me>
In reply to#400577
On 7/29/2026 11:48 PM, Lawrence D’Oliveiro wrote:
> On Thu, 30 Jul 2026 07:40:04 +0100, Richard Harnden wrote:
> 
>> Can a pointer have a value of zero, but not be a null pointer?
> 
> C doesn’t define any special pointer values, other than the null
> pointer. The null pointer can be compared for equality with (a
> suitable cast of) the integer literal 0 (I’m not sure, it might be
> that arbitrary integer expressions evaluating to 0 are not allowed),
> but that is not considered grounds for concluding/requiring that the
> bit pattern for the null pointer is actually equal to the integer
> value 0.

Yup.

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#400579

FromJames Kuyper <jameskuyper@alumni.caltech.edu>
Date2026-07-30 06:44 -0400
Message-ID<114f9up$1mm0c$1@dont-email.me>
In reply to#400576
On 2026-07-30 02:40, Richard Harnden wrote:
> On 29/07/2026 23:33, Keith Thompson wrote:
...>> The NULL macro is a source code construct.  It doesn't have "bits",
>> unless you count the bits making up the characters 'N', 'U', 'L',
>> 'L' (in the source character set, which needn't match the execution
>> character set).
>>
>> The thing whose bits don't have to be 0 is a null pointer *value*,
>> something that exists during execution and can result from an
>> occurence of NULL in the source code.
>>
>> The point from upthread is that your suggested (void*)0xDEADBEEF
>> is not a null pointer constant, and therefore is not a valid
>> expansion of the NULL macro, *even if* 0xDEADBEEF matches the
>> run-time representation of a null pointer.
>>
>> (I normally ignore your posts, but I made an arbitrary exception
>> in this case.)
>>
> 
> Can a pointer have a value of zero, but not be a null pointer?

No, the value of a pointer is the location that it points at. It's value
is never a number. It's representation, if misinterpreted as an integer
type (which would require type punning), can be 0. On most
implementations that representation would represent a null pointer, but
it is entirely permitted for it to not be a null pointer, so long as
there is some other representation that does represent a null pointer.

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#400613

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-07-30 21:00 +0000
Message-ID<114ge0v$24ndu$2@dont-email.me>
In reply to#400579
On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:

> ... the value of a pointer is the location that it points at. It's
> value is never a number.

In C, its value is never *directly compatible* with a number.

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#400615

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-07-30 14:38 -0700
Message-ID<114gg7o$25jib$1@kst.eternal-september.org>
In reply to#400613
Lawrence D’Oliveiro <ldo@nz.invalid> writes:
> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>> ... the value of a pointer is the location that it points at. It's
>> value is never a number.
>
> In C, its value is never *directly compatible* with a number.

Was that meant to be a clarification?  It's true and clear
that the value of a pointer is never a number.  I don't even know
what "directly compatible" is supposed to mean.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#400617

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-07-30 21:53 +0000
Message-ID<114gh4v$24ndu$10@dont-email.me>
In reply to#400613
On Thu, 30 Jul 2026 21:00:15 -0000 (UTC), I wrote:

> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>
>> ... the value of a pointer is the location that it points at. It's
>> value is never a number.
>
> In C, its value is never *directly compatible* with a number.

Except integer 0, of course.

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#400619

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-07-30 15:10 -0700
Message-ID<114gi5b$25jib$5@kst.eternal-september.org>
In reply to#400617
Lawrence D’Oliveiro <ldo@nz.invalid> writes:
> On Thu, 30 Jul 2026 21:00:15 -0000 (UTC), I wrote:
>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>> ... the value of a pointer is the location that it points at. It's
>>> value is never a number.
>>
>> In C, its value is never *directly compatible* with a number.
>
> Except integer 0, of course.

For certain values of "directly compatible", I suppose, though I
still don't know what you mean by that.  (The C standard uses the word
"compatible" for types, not for values.)

0 is not a pointer value.  The constant 0 is a null pointer constant,
which can be converted, implicitly or explicitly, to a pointer value,
yielding a null pointer.  Any integer expression can be converted
to a pointer type, yielding an implementation-defined result (or
a null pointer if the expression is an NPC).

James's original statement that a pointer value is never a number
was both clear and correct.  What information or clarity are you
trying to add?

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#400624

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-07-30 19:40 -0700
Message-ID<114h1v7$2b0po$2@dont-email.me>
In reply to#400613
On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
> 
>> ... the value of a pointer is the location that it points at. It's
>> value is never a number.
> 
> In C, its value is never *directly compatible* with a number.

Well, uintptr_t?

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#400625

Fromcross@spitfire.i.gajendra.net (Dan Cross)
Date2026-07-31 02:43 +0000
Message-ID<114h24r$9nm$1@reader1.panix.com>
In reply to#400624
In article <114h1v7$2b0po$2@dont-email.me>,
Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>> 
>>> ... the value of a pointer is the location that it points at. It's
>>> value is never a number.
>> 
>> In C, its value is never *directly compatible* with a number.
>
>Well, uintptr_t?

That's a type, not a value.

	- Dan C.

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#400626

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-07-30 19:44 -0700
Message-ID<114h26m$2b0po$3@dont-email.me>
In reply to#400625
On 7/30/2026 7:43 PM, Dan Cross wrote:
> In article <114h1v7$2b0po$2@dont-email.me>,
> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>> On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>>
>>>> ... the value of a pointer is the location that it points at. It's
>>>> value is never a number.
>>>
>>> In C, its value is never *directly compatible* with a number.
>>
>> Well, uintptr_t?
> 
> That's a type, not a value.
Afait uintptr_t can be set to the NULL and any pointer? Then compared?

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#400627

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-07-30 19:58 -0700
Message-ID<114h30s$2bbo8$1@dont-email.me>
In reply to#400626
On 7/30/2026 7:44 PM, Chris M. Thomasson wrote:
> On 7/30/2026 7:43 PM, Dan Cross wrote:
>> In article <114h1v7$2b0po$2@dont-email.me>,
>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>> On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>>>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>>>
>>>>> ... the value of a pointer is the location that it points at. It's
>>>>> value is never a number.
>>>>
>>>> In C, its value is never *directly compatible* with a number.
>>>
>>> Well, uintptr_t?
>>
>> That's a type, not a value.
> Afait uintptr_t can be set to the NULL and any pointer? Then compared?

  uintptr_t can be set to NULL, but I am not sure what bit pattern its 
going to get. The lower level does.

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#400686

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-08-01 01:25 -0700
Message-ID<114kain$3erqe$1@dont-email.me>
In reply to#400626
On 7/30/2026 7:44 PM, Chris M. Thomasson wrote:
> On 7/30/2026 7:43 PM, Dan Cross wrote:
>> In article <114h1v7$2b0po$2@dont-email.me>,
>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>> On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>>>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>>>
>>>>> ... the value of a pointer is the location that it points at. It's
>>>>> value is never a number.
>>>>
>>>> In C, its value is never *directly compatible* with a number.
>>>
>>> Well, uintptr_t?
>>
>> That's a type, not a value.
> Afait uintptr_t can be set to the NULL and any pointer? Then compared?

I think, humm... uintptr_t can be set to a function pointer as well?

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#400716

FromDavid Brown <david.brown@hesbynett.no>
Date2026-08-02 23:14 +0200
Message-ID<114oc02$qbqp$1@dont-email.me>
In reply to#400686
On 01/08/2026 10:25, Chris M. Thomasson wrote:
> On 7/30/2026 7:44 PM, Chris M. Thomasson wrote:
>> On 7/30/2026 7:43 PM, Dan Cross wrote:
>>> In article <114h1v7$2b0po$2@dont-email.me>,
>>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>>> On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>>>>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>>>>
>>>>>> ... the value of a pointer is the location that it points at. It's
>>>>>> value is never a number.
>>>>>
>>>>> In C, its value is never *directly compatible* with a number.
>>>>
>>>> Well, uintptr_t?
>>>
>>> That's a type, not a value.
>> Afait uintptr_t can be set to the NULL and any pointer? Then compared?
> 
> I think, humm... uintptr_t can be set to a function pointer as well?

You are not making sense here.

Any pointer (object pointer or function pointer) can be converted to any 
integer type.  Whether or not the resulting integer value can be 
converted back to the same pointer is implementation dependent, as is 
the way the conversions are done.

But /if/ any void* pointer can be converted to an integer type without 
loss of information, then uintptr_t and intptr_t are unsigned and signed 
types that can be used for the task.  They may or may not be able to 
represent function pointers.  In practice, on most systems, uintptr_t 
works for any data or function pointer.  But you have to explicitly 
convert pointers to the uintptr_t integer type.

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#400718

From"Chris M. Thomasson" <chris.m.thomasson.1@gmail.com>
Date2026-08-02 14:37 -0700
Message-ID<114odai$qp0b$1@dont-email.me>
In reply to#400716
On 8/2/2026 2:14 PM, David Brown wrote:
> On 01/08/2026 10:25, Chris M. Thomasson wrote:
>> On 7/30/2026 7:44 PM, Chris M. Thomasson wrote:
>>> On 7/30/2026 7:43 PM, Dan Cross wrote:
>>>> In article <114h1v7$2b0po$2@dont-email.me>,
>>>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>>>> On 7/30/2026 2:00 PM, Lawrence D’Oliveiro wrote:
>>>>>> On Thu, 30 Jul 2026 06:44:41 -0400, James Kuyper wrote:
>>>>>>
>>>>>>> ... the value of a pointer is the location that it points at. It's
>>>>>>> value is never a number.
>>>>>>
>>>>>> In C, its value is never *directly compatible* with a number.
>>>>>
>>>>> Well, uintptr_t?
>>>>
>>>> That's a type, not a value.
>>> Afait uintptr_t can be set to the NULL and any pointer? Then compared?
>>
>> I think, humm... uintptr_t can be set to a function pointer as well?
> 
> You are not making sense here.
> 
> Any pointer (object pointer or function pointer) can be converted to any 
> integer type.  Whether or not the resulting integer value can be 
> converted back to the same pointer is implementation dependent, as is 
> the way the conversions are done.

uintptr_t can help us here. They are very useful.


> But /if/ any void* pointer can be converted to an integer type without 
> loss of information, then uintptr_t and intptr_t are unsigned and signed 
> types that can be used for the task.

right.


>  They may or may not be able to 
> represent function pointers.  In practice, on most systems, uintptr_t 
> works for any data or function pointer.  But you have to explicitly 
> convert pointers to the uintptr_t integer type.
> 

Can void* always hold a function pointer? I think not. So, that means 
that uintptr_t cannot always hold a function pointer... Right?

However, uintptr_t can always hold a void*

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#400725

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-08-02 22:51 +0000
Message-ID<114ohks$rsgh$2@dont-email.me>
In reply to#400718
On Sun, 2 Aug 2026 14:37:20 -0700, Chris M. Thomasson wrote:

> Can void* always hold a function pointer? I think not.

Even on architectures with separate instruction/data spaces, I would
say it is reasonable to require that void* can indeed hold a function
pointer.

This is because you are likely to need a pointer to some environment
context for the function to execute in anyway, so the function pointer
won’t point directly to the code, but to a descriptor that contains
the pointer to the code.

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