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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Sequence points and commit to memory |
| Date | 2015-05-14 12:58 -0700 |
| Organization | None to speak of |
| Message-ID | <87iobvc4nx.fsf@kst-u.example.com> (permalink) |
| References | <mj1u70$r5d$1@dont-email.me> <chine.bleu-804F61.08350514052015@news.eternal-september.org> <928a9f76-7417-4e84-81b1-a92f71517ab0@googlegroups.com> <chine.bleu-754459.10443214052015@news.eternal-september.org> <2921f8f5-64e5-461f-9dd0-092ba73bcb1e@googlegroups.com> |
David Kleinecke <dkleinecke@gmail.com> writes:
[...]
> "Register" only has optional meaning. If a machine has no actual registers
> all declaring a variable as "register" means is that you are forbidding
> yourself from taking its address etc.
Right.
> This is something I assume - if there
> are no real registers - you would not want to do.
Why not? There's probably not much advantage in using the "register"
keyword (even for machines that do have registers), but it should be
mostly harmless.
The standard's description of "register" doesn't even mention CPU
registers; it merely "suggests that access to the object be as fast as
possible". That could have some effect even on a registerless CPU. Or
it could have no effect.
> So if you do use the "register" storage class you are making your program
> less portable (surely not by a great deal but somewhat).
No, it's no less portable; why would it be?
"register" is intended as a way for the programmer to give information
to the compiler about how an object is used. If that information is
incorrect it might hurt performance, but it shouldn't affect
correctness.
> Fortunately I haven't seen any software for years (except stuff I dredge
> up from the archives) that uses "register" (or "auto").
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 11:43 +0100
Re: Sequence points and commit to memory Richard Heathfield <rjh@cpax.org.uk> - 2015-05-14 12:02 +0100
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-14 13:39 +0200
Re: Sequence points and commit to memory Richard Heathfield <rjh@cpax.org.uk> - 2015-05-14 13:18 +0100
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-14 23:11 +0200
Re: Sequence points and commit to memory Stephen Sprunk <stephen@sprunk.org> - 2015-05-14 09:06 -0500
Re: Sequence points and commit to memory Siri Cruz <chine.bleu@yahoo.com> - 2015-05-14 08:35 -0700
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-14 10:23 -0700
Re: Sequence points and commit to memory Siri Cruz <chine.bleu@yahoo.com> - 2015-05-14 10:44 -0700
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-14 11:09 -0700
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-14 12:58 -0700
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-14 16:31 -0500
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-14 17:24 -0700
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-14 20:18 -0500
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-15 09:34 +0200
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-15 10:18 -0500
Re: 'register' attribute (was: Sequence points and commit to memory) Morris Dovey <mrdovey@iedu.com> - 2015-05-16 01:26 -0500
Re: 'register' attribute David Brown <david.brown@hesbynett.no> - 2015-05-17 00:02 +0200
Re: 'register' attribute Morris Dovey <mrdovey@iedu.com> - 2015-05-16 19:29 -0500
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-15 09:52 -0700
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-15 13:27 -0400
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-15 10:50 -0700
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-15 12:32 -0500
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-14 23:23 +0200
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-15 09:42 -0700
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-15 13:13 -0400
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-16 08:32 -0700
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-15 10:35 -0700
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-15 11:08 -0700
Re: Sequence points and commit to memory Robert Wessel <robertwessel2@yahoo.com> - 2015-05-15 16:40 -0500
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-16 08:48 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-15 21:46 +0100
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-16 08:56 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-16 19:35 +0100
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-18 09:49 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-19 09:04 +0100
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-19 08:42 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 22:00 +0100
Re: Sequence points and commit to memory Siri Cruz <chine.bleu@yahoo.com> - 2015-05-14 14:26 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 22:33 +0100
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-14 23:38 +0200
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 23:04 +0100
Re: Sequence points and commit to memory Stephen Sprunk <stephen@sprunk.org> - 2015-05-15 13:09 -0500
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-15 21:56 +0100
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-15 17:30 -0400
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-16 07:51 +0100
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-16 22:10 -0400
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 00:25 +0200
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-18 18:55 -0400
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 09:10 +0200
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-19 12:05 -0400
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 18:42 +0200
Re: Sequence points and commit to memory Stephen Sprunk <stephen@sprunk.org> - 2015-05-16 16:33 -0500
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 00:27 +0200
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-18 19:05 -0400
Re: Sequence points and commit to memory glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-19 00:09 +0000
Re: Sequence points and commit to memory Richard Heathfield <rjh@cpax.org.uk> - 2015-05-19 01:11 +0100
Re: Sequence points and commit to memory Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-23 07:02 -0700
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-18 23:21 -0400
Re: Sequence points and commit to memory glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-19 06:25 +0000
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 08:58 +0200
Re: Sequence points and commit to memory glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-19 23:20 +0000
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-20 12:31 +0200
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-19 12:10 -0400
Re: Sequence points and commit to memory glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-05-19 23:24 +0000
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 09:05 +0200
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-19 08:37 -0700
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-19 12:14 -0400
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 19:02 +0200
Re: Sequence points and commit to memory Robert Wessel <robertwessel2@yahoo.com> - 2015-05-15 16:46 -0500
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-17 00:20 +0200
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-17 18:19 +0100
Re: Sequence points and commit to memory Philip Lantz <prl@canterey.us> - 2015-05-17 16:11 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-18 08:30 +0100
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-18 10:31 -0700
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-18 11:11 -0700
Re: Sequence points and commit to memory David Kleinecke <dkleinecke@gmail.com> - 2015-05-19 09:37 -0700
Re: Sequence points and commit to memory Ian Collins <ian-news@hotmail.com> - 2015-05-19 17:40 +1200
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-19 01:31 -0500
Re: Sequence points and commit to memory Ian Collins <ian-news@hotmail.com> - 2015-05-19 20:38 +1200
Re: Sequence points and commit to memory Morris Dovey <mrdovey@iedu.com> - 2015-05-19 10:50 -0500
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 00:46 +0200
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 00:35 +0200
Re: Sequence points and commit to memory Robert Wessel <robertwessel2@yahoo.com> - 2015-05-15 16:42 -0500
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-16 07:58 +0100
Re: Sequence points and commit to memory Robert Wessel <robertwessel2@yahoo.com> - 2015-05-16 02:18 -0500
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-16 08:36 +0100
Re: Sequence points and commit to memory Robert Wessel <robertwessel2@yahoo.com> - 2015-05-17 04:31 -0500
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-17 18:24 +0100
Re: Sequence points and commit to memory David Brown <david.brown@hesbynett.no> - 2015-05-19 00:55 +0200
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-14 11:26 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 22:07 +0100
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-14 14:22 -0700
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-14 22:36 +0100
Re: Sequence points and commit to memory Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-22 08:16 -0700
Re: Sequence points and commit to memory Keith Thompson <kst-u@mib.org> - 2015-05-22 11:31 -0700
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-15 00:05 -0400
Re: Sequence points and commit to memory "James Harris" <james.harris.1@gmail.com> - 2015-05-15 22:25 +0100
Re: Sequence points and commit to memory James Kuyper <jameskuyper@verizon.net> - 2015-05-15 17:56 -0400
Re: Sequence points and commit to memory Nobody <nobody@nowhere.invalid> - 2015-05-17 10:04 +0100
Re: Sequence points and commit to memory Tim Rentsch <txr@alumni.caltech.edu> - 2015-05-24 08:11 -0700
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