Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.c > #155501
| From | Keith Thompson <Keith.S.Thompson+u@gmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Trick to knowing hex address alignment? |
| Date | 2020-10-10 15:42 -0700 |
| Organization | None to speak of |
| Message-ID | <87lfgd7leh.fsf@nosuchdomain.example.com> (permalink) |
| References | <5%6gH.106678$tL.55004@fx15.iad> <rlsnk5$1ndm$1@gioia.aioe.org> |
Christian Hanné <the.hanne@gmail.com> writes:
>> Is there a trick to quickly figuring the alignment?
>
> Do a sprintf and identify the 16-bit-aligned adresses by checking if
> the last digit is 0, the 32-bit-aligned addresses by checking if the
> last digit is 0 and the second last digit is even. That's the most
> efficient solution.
I'm not going to say that's the *least* efficient solution, but I
can't think of one that's less efficent without being deliberately
contrived.
Convert to unintptr_t and check the low-order bits. This isn't
completely portable (I've worked on systems where it wouldn't work),
but it's likely to work on most implementations. Add a comment
acnowledging the portability issues.
The standard guarantees that converting a void* value to [u]intptr_t
and back again yields the original value. If there is no integer
type for which it can make that guarantee, it won't define
[u]intptr_t. It says nothing about how pointers are represented,
so you can't portably assume that the low-order bits mean what you
think they do, but implementations where they don't are rare.
--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 20:11 -0400
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-09 18:43 -0600
Re: Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 22:14 -0400
Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-10 01:10 +0000
Re: Trick to knowing hex address alignment? dfs <nospam@dfs.com> - 2020-10-09 22:15 -0400
Re: Trick to knowing hex address alignment? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-10-10 01:30 -0400
Re: Trick to knowing hex address alignment? BGB <cr88192@gmail.com> - 2020-10-10 01:30 -0500
Re: Trick to knowing hex address alignment? "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2020-10-12 16:58 -0400
Re: Trick to knowing hex address alignment? BGB <cr88192@gmail.com> - 2020-10-14 16:04 -0500
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-10 18:31 +0200
Re: Trick to knowing hex address alignment? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-10-10 09:46 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-10 19:50 +0200
Re: Trick to knowing hex address alignment? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-10-10 18:45 +0000
Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-10 15:05 -0400
Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-10 12:34 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 08:10 +0200
Re: Trick to knowing hex address alignment? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-10-11 02:29 -0700
Re: Trick to knowing hex address alignment? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-10-11 12:08 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 13:13 +0200
Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-11 15:06 -0400
Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-11 15:27 -0400
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:18 +0200
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 08:19 +0200
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 00:43 -0700
Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 12:03 +0200
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 13:14 +0200
Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-12 08:33 -0400
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:21 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:07 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:58 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 00:10 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 09:53 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:25 -0700
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:31 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 10:34 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 01:47 -0700
Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-13 15:39 +0000
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 16:16 -0700
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:32 +0000
Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-12 07:13 -0700
Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 19:16 +0200
Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-12 21:26 +0100
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:08 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:50 +0200
Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-11 21:16 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:18 +0200
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:44 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:21 +0200
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 13:18 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:19 +0200
Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-11 14:12 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:20 +0200
Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-12 07:09 -0700
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:35 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:37 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 15:51 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 17:07 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 16:45 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 17:47 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-12 17:05 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:46 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:19 -0700
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:48 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:22 +0200
Re: Trick to knowing hex address alignment? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2020-10-13 06:25 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:20 +0200
Re: Trick to knowing hex address alignment?, speciall Richard Damon <Richard@Damon-Family.org> - 2020-10-13 12:38 -0400
Re: Trick to knowing hex address alignment?, speciall James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-13 12:51 -0400
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-12 11:11 -0600
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 18:50 +0000
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-12 13:03 -0600
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 19:30 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:47 +0200
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:52 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:23 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 14:43 +0100
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 08:57 -0600
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:21 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 17:38 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:03 +0200
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 11:20 -0600
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:23 +0200
Re: Trick to knowing hex address alignment? Bart <bc@freeuk.com> - 2020-10-13 18:28 +0100
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:30 +0200
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-14 09:24 +0000
Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-14 09:35 -0400
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-15 09:29 +0200
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-13 10:24 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 19:31 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-13 14:47 -0700
Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-12 21:48 -0400
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 06:49 +0200
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-13 15:24 +0000
Re: Trick to knowing hex address alignment? Richard Damon <Richard@Damon-Family.org> - 2020-10-13 12:32 -0400
Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-13 21:55 +0100
Re: Trick to knowing hex address alignment? Vir Campestris <vir.campestris@invalid.invalid> - 2020-10-13 22:00 +0100
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-13 14:13 -0700
Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-14 13:13 +0200
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-14 15:59 +0000
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-14 11:31 -0600
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-14 19:03 +0000
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-13 09:50 -0600
Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-13 17:41 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 20:07 +0200
Re: Trick to knowing hex address alignment? Kaz Kylheku <793-849-0957@kylheku.com> - 2020-10-15 00:38 +0000
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-14 21:23 -0600
Re: Trick to knowing hex address alignment? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-10-12 11:20 +0100
Re: Trick to knowing hex address alignment? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-10-12 10:19 -0400
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-10 15:42 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-11 13:14 +0200
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-11 14:11 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 07:20 +0200
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 00:42 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 13:16 +0200
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 07:22 -0700
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:23 +0200
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-12 14:35 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-12 16:40 +0200
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-12 14:09 -0700
Re: Trick to knowing hex address alignment? David Brown <david.brown@hesbynett.no> - 2020-10-12 08:26 +0200
Re: Trick to knowing hex address alignment? Öö Tiib <ootiib@hot.ee> - 2020-10-12 03:19 -0700
Re: Trick to knowing hex address alignment? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-10-12 07:22 -0700
Re: Trick to knowing hex address alignment? arnold@hooterville.invalid (Arnold Ziffel) - 2020-10-13 11:59 +0000
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 14:25 +0200
Re: Trick to knowing hex address alignment? scott@slp53.sl.home (Scott Lurndal) - 2020-10-13 15:26 +0000
Re: Trick to knowing hex address alignment? DFS <nospam@dfs.com> - 2020-10-13 11:33 -0400
Re: Trick to knowing hex address alignment? Christian Hanné <the.hanne@gmail.com> - 2020-10-13 18:23 +0200
Re: Trick to knowing hex address alignment? Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-10-11 09:47 -0600
Re: Trick to knowing hex address alignment? Elias Schwerdtfeger <nachtwaechter@tamagothi.de> - 2020-10-10 18:45 +0200
Re: Trick to knowing hex address alignment? Barry Schwarz <schwarzb@delq.com> - 2020-10-10 10:32 -0700
Re: Trick to knowing hex address alignment? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-10-10 14:01 -0700
csiph-web