Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.c++ > #94129
| From | "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c++ |
| Subject | Re: What does this code print ? |
| Date | 2023-10-19 14:45 -0700 |
| Organization | A noiseless patient Spider |
| Message-ID | <ugs82g$j12c$2@dont-email.me> (permalink) |
| References | (10 earlier) <ugnhvc$1t8hq$1@i2pn2.org> <ugrqok$fto1$1@dont-email.me> <20231019110532.810@kylheku.com> <ugrrh1$fto1$4@dont-email.me> <20231019120451.638@kylheku.com> |
On 10/19/2023 12:20 PM, Kaz Kylheku wrote:
> On 2023-10-19, Bonita Montero <Bonita.Montero@gmail.com> wrote:
>> Am 19.10.2023 um 20:06 schrieb Kaz Kylheku:
>>
>>> Can you point to any documentation (MSDN?) that would give us confidence
>>> that all which happened is a committed, robust feature that will work
>>> across different versions of MSVC, with different code generation
>>> options?
>>
>> Which option do you think would make MSVC drop the optimization barrier
>> of volatile function pointers? The only volatile compiler option is
>> ISO or MSVC volatile behaviour.
>
> Possibly, options that turn off optimization entirely, so that the barrier is not
> considered.
>
> It's the wrong question. What piece of documentation specifies that
> there is such an optimization barrier? Not just the optimization
> barrier, but an optimization barrier that causes calling convention
> attributes from a pointer to regenerate the called function body.
>
> Where did you get this belief?
>
> It is really weird. It similar to a situation like:
>
> struct foo { int x; int y } foo_obj = { 1, 2 };
> struct bar { int y; int x };
>
> bar *volatile bar_ptr = (struct bar *) &foo_obj;
^^^^^^^^^^^^^^^^^
Nasal demons regardless of volatile?
>
> printf("%d\n", bar_ptr->x); // unexpectedly prints 1
>
> Wee, the compiler fixed up the ->x reference to the correct offset
> through the wrong type.
>
> The code looks flatly wrong in the abstract semantics, because a
> function not defined with any calling convention attributes (and thus
> "__cdecl") is being called with incompatible calling conventions.
>
> In the abstract semantics without optimization, of course we expect real
> function calls to be attempted.
>
> A plausible explanation for the observed behavior is that the
> function got inlined first, and then due to the volatile, it was
> de-inlined, and this happened in such a way that the calling conventions
> from the pointer influenced the code generation.
>
> Where is that aspect of it documented?
>
Back to comp.lang.c++ | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-11 05:30 +0200
Re: What does this code print ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-11 14:03 +0100
Re: What does this code print ? gazelle@shell.xmission.com (Kenny McCormack) - 2023-10-11 13:12 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-11 19:22 +0200
Re: What does this code print ? scott@slp53.sl.home (Scott Lurndal) - 2023-10-11 17:41 +0000
Re: What does this code print ? Bo Persson <bo@bo-persson.se> - 2023-10-11 20:24 +0200
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-13 05:24 +0200
Re: What does this code print ? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-10-13 17:53 +0100
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-14 15:50 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-13 12:12 -0400
Re: What does this code print ? scott@slp53.sl.home (Scott Lurndal) - 2023-10-13 17:27 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-14 15:52 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-14 11:26 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 09:08 +0200
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-15 12:55 -0700
Re: What does this code print ? Richard Damon <news.x.richarddamon@xoxy.net> - 2023-10-15 22:19 -0400
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-18 20:58 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-11 19:21 +0200
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-11 12:41 -0700
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-11 12:43 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-13 05:25 +0200
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-12 20:50 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-13 08:50 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-13 12:15 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-14 15:53 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-14 11:26 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 09:00 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-15 13:15 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-17 07:47 +0200
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-17 11:34 -0700
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-13 16:34 +0000
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-13 13:12 -0700
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-14 02:36 +0000
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-13 20:44 -0700
Re: What does this code print ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-10-14 11:51 +0300
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-17 11:35 -0700
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-17 20:06 +0000
Re: What does this code print ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-10-18 11:43 +0300
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-18 17:29 +0000
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-18 11:31 -0700
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-19 14:43 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-14 15:54 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-14 18:05 +0000
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-14 14:58 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 08:58 +0200
Re: What does this code print ? Richard Damon <news.x.richarddamon@xoxy.net> - 2023-10-14 12:47 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 09:07 +0200
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 09:12 +0200
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 09:16 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-15 13:35 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-17 07:48 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-17 23:04 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-19 19:58 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-19 14:39 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-19 19:58 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-19 18:06 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-19 20:11 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-19 19:20 +0000
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-19 16:06 -0400
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-19 14:45 -0700
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-19 23:26 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-20 09:19 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-20 05:47 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-20 17:59 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-20 19:16 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-21 08:02 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-21 08:38 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-21 19:40 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-21 10:54 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-21 20:34 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-21 12:45 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-22 04:18 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-21 19:28 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-22 06:53 +0200
Re: What does this code print ? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2023-10-22 09:59 +0000
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-22 07:12 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-23 19:05 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-23 10:40 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 16:03 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-24 07:28 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 17:01 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-24 08:28 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 18:27 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-24 10:05 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 19:08 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-24 10:39 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 20:25 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-24 19:48 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-25 10:54 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 08:43 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-25 17:57 +0200
Re: What does this code print ? Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2023-10-24 16:40 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 19:07 +0200
Re: What does this code print ? scott@slp53.sl.home (Scott Lurndal) - 2023-10-24 15:25 +0000
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-24 08:34 -0700
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-24 16:34 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-24 19:05 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-20 14:50 +0000
Re: What does this code print ? Bo Persson <bo@bo-persson.se> - 2023-10-20 17:34 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-20 15:59 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-20 18:00 +0200
Re: What does this code print ? Kaz Kylheku <864-117-4973@kylheku.com> - 2023-10-20 16:06 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-20 18:40 +0200
Re: What does this code print ? gazelle@shell.xmission.com (Kenny McCormack) - 2023-10-20 20:07 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-21 08:04 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-15 13:35 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-17 07:50 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-17 23:08 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-19 20:02 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-19 14:43 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-19 20:02 +0200
Re: What does this code print ? scott@slp53.sl.home (Scott Lurndal) - 2023-10-15 14:36 +0000
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-15 18:15 +0200
Re: What does this code print ? Richard Damon <news.x.richarddamon@xoxy.net> - 2023-10-15 22:23 -0400
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-17 07:51 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-17 23:08 -0400
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-15 13:25 -0400
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-14 11:33 -0700
Re: What does this code print ? Paavo Helde <eesnimi@osa.pri.ee> - 2023-10-14 21:54 +0300
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-14 11:56 -0700
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-24 15:53 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-25 15:07 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 08:43 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-25 18:01 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 09:21 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-25 18:24 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 11:23 -0700
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-25 15:02 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-26 07:13 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 23:09 -0700
Re: What does this code print ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-10-25 23:55 -0400
Re: What does this code print ? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-10-25 15:01 -0700
Re: What does this code print ? Bonita Montero <Bonita.Montero@gmail.com> - 2023-10-26 07:15 +0200
Re: What does this code print ? Richard Damon <richard@damon-family.org> - 2023-10-25 23:12 -0700
csiph-web