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Groups > comp.lang.c > #110095
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: https://github.com/bartg/langs/tree/master/bccproj |
| Date | 2017-05-15 15:20 -0700 |
| Organization | None to speak of |
| Message-ID | <lnbmqt4v9c.fsf@kst-u.example.com> (permalink) |
| References | (15 earlier) <4ff88e50-f208-411e-8d69-e0710a03bec2@googlegroups.com> <kfnziefqlck.fsf@x-alumni2.alumni.caltech.edu> <34bdc6a9-a31a-4051-be03-de6b3158d44e@googlegroups.com> <lno9uu3q8a.fsf@kst-u.example.com> <2dd541b4-20f1-4f5e-bf0d-44897f7e9e9a@googlegroups.com> |
supercat@casperkitty.com writes:
> On Monday, May 15, 2017 at 1:54:52 PM UTC-5, Keith Thompson wrote:
>> supercat writes:
>> [...]
>> > On the other hand, I see no evidence that allowances for integer
>> > treatments other than silent-wraparound or silent (and not
>> > necessarily consistent) promotion were intended for any purpose
>> > other than to either facilitate implementations on hardware whose
>> > underlying semantics were inconsistent with those, or to allow for
>> > implementations that would affirmatively trap integer overflow *in
>> > documented fashion*. I am aware of *ZERO* twentieth- century
>> > evidence that anyone of note thought that quality implementations
>> > for two's-complement hardware should not be expected to either
>> > yield some possibly-meaningless result, trap in documented fashion,
>> > or choose in Unspecified fashion between those two behaviors.
>>
>> The phrase "the behavior is undefined" in C90 6.3, 5th paragraph,
>> is not sufficient evidence for you?
>
> They no doubt expected that quality implementations *for hardware that did
> not use silent-wraparound two's-complement overflow semantics* might behave
> in fashions other than the above. That alone would be sufficient reason for
> them to classify the behavior as Undefined, whether or not they expected that
> quality implementations targeting silent-wraparound two's-complement
> hardware would ever do anything other than the above.
>
> Given that the decision to have short unsigned types promote to signed int
> was predicated in some measure on the way that silent-wraparound two's-
> complement platforms--i.e. the majority of (then) current implementations--
> behaved in cases where the Standard imposed no requirements, I would say
> the rationale given would make no sense unless the authors expected that
> such behaviors would continue to be commonplace for most kinds of
> implementations.
If the committee had wanted to mention that expectation in the
standard, either in a non-normative footnote or in a "Recommended
Practice" sections, they could easily have done so. You seem
unwilling to draw any conclusion from the fact that they didn't.
Meanwhile, the standard says the behavior of signed overflow is
undefined, and compiler writers take it at its word.
--
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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https://github.com/bartg/langs/tree/master/bccproj jacobnavia <jacob@jacob.remcomp.fr> - 2017-04-24 23:33 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-24 23:14 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-25 00:31 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-04-25 14:46 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-25 17:05 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-26 01:32 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-26 11:32 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-04-26 12:09 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Tim Rentsch <txr@alumni.caltech.edu> - 2017-04-27 14:32 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-04-28 06:23 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-04-28 14:26 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-04-28 11:04 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-04-28 18:26 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-04-28 12:59 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-04-28 20:29 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-28 17:35 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-04-28 13:21 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-28 22:35 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-01 05:16 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-01 13:47 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-03 05:16 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-05 18:46 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-06 12:00 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj David Kleinecke <dkleinecke@gmail.com> - 2017-05-06 12:01 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-06 12:15 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Kleinecke <dkleinecke@gmail.com> - 2017-05-06 14:03 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 05:53 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 14:26 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 07:10 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 15:36 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 15:43 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj David Kleinecke <dkleinecke@gmail.com> - 2017-05-08 12:06 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 11:02 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 19:46 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 12:23 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 21:08 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-08 13:26 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-05-08 13:32 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-08 13:40 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 21:33 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 13:30 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 22:00 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-05-08 22:18 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-08 18:12 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-09 07:04 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Ian Collins <ian-news@hotmail.com> - 2017-05-10 07:50 +1200
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-09 13:31 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Ian Collins <ian-news@hotmail.com> - 2017-05-10 08:58 +1200
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-09 14:25 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Philip Lantz <prl@canterey.us> - 2017-05-18 05:45 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-05-18 14:02 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-18 07:22 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Robert Wessel <robertwessel2@yahoo.com> - 2017-05-18 22:27 -0500
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-19 08:29 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-05-10 14:32 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj raltbos@xs4all.nl (Richard Bos) - 2017-05-10 10:19 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-10 09:51 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-05-10 17:37 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-10 10:53 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Tim Rentsch <txr@alumni.caltech.edu> - 2017-05-14 12:39 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-15 07:58 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-05-15 11:54 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-15 12:25 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-05-15 15:20 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-15 15:43 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Tim Rentsch <txr@alumni.caltech.edu> - 2017-05-16 04:38 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-16 12:48 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Tim Rentsch <txr@alumni.caltech.edu> - 2017-05-24 08:12 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-24 09:10 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Ian Collins <ian-news@hotmail.com> - 2017-05-25 07:22 +1200
Re: https://github.com/bartg/langs/tree/master/bccproj Tim Rentsch <txr@alumni.caltech.edu> - 2017-05-27 06:03 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-05-27 11:42 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj raltbos@xs4all.nl (Richard Bos) - 2017-05-15 12:34 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-05-15 08:02 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-05-08 18:24 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-10 05:32 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Thiago Adams <thiago.adams@gmail.com> - 2017-05-06 12:04 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-28 09:53 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-28 19:47 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-28 11:56 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-04-28 12:21 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-28 13:07 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-28 22:23 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-28 14:03 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-04-28 14:57 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-28 15:57 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-04-28 11:49 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj jacobnavia <jacob@jacob.remcomp.fr> - 2017-04-26 13:31 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-26 15:14 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-26 15:10 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-26 16:36 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-04-26 08:49 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-26 20:44 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-26 21:02 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-26 22:07 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-26 22:56 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-27 11:16 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj Richard Heathfield <rjh@cpax.org.uk> - 2017-04-27 10:53 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-27 12:56 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-27 04:13 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj bartc <bc@freeuk.com> - 2017-04-27 12:27 +0100
Re: https://github.com/bartg/langs/tree/master/bccproj "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-27 06:05 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Ian Collins <ian-news@hotmail.com> - 2017-04-27 09:38 +1200
Re: https://github.com/bartg/langs/tree/master/bccproj David Kleinecke <dkleinecke@gmail.com> - 2017-04-26 17:40 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Geoff <geoff@invalid.invalid> - 2017-04-26 22:22 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-04-27 01:45 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Geoff <geoff@invalid.invalid> - 2017-04-26 21:55 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj David Brown <david.brown@hesbynett.no> - 2017-04-27 11:25 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj "James R. Kuyper" <jameskuyper@verizon.net> - 2017-04-27 12:59 -0400
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-27 15:03 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj scott@slp53.sl.home (Scott Lurndal) - 2017-04-27 13:27 +0000
Re: https://github.com/bartg/langs/tree/master/bccproj GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-04-26 01:29 +0200
Re: https://github.com/bartg/langs/tree/master/bccproj Philip Lantz <prl@canterey.us> - 2017-04-26 10:14 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj supercat@casperkitty.com - 2017-04-26 12:25 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj Keith Thompson <kst-u@mib.org> - 2017-04-24 15:26 -0700
Re: https://github.com/bartg/langs/tree/master/bccproj jacobnavia <jacob@jacob.remcomp.fr> - 2017-04-26 11:36 +0200
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