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Groups > comp.lang.c > #120322
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Something C might need |
| Date | 2017-09-25 12:29 -0700 |
| Organization | None to speak of |
| Message-ID | <lnefqu1ssa.fsf@kst-u.example.com> (permalink) |
| References | (3 earlier) <oq8qbp$9n4$1@dont-email.me> <2s2hscl99m82tj6h2bkgis6c1i7fa2dpun@4ax.com> <0c235d98-b91e-3a2e-1936-c87b035bea6d@verizon.net> <87o9py1v5h.fsf@bsb.me.uk> <31ab7483-b29f-4a65-5631-52ffb12a4f28@verizon.net> |
"James R. Kuyper" <jameskuyper@verizon.net> writes:
> On 2017-09-25 14:38, Ben Bacarisse wrote:
>> "James R. Kuyper" <jameskuyper@verizon.net> writes:
>> <snip>
>>> Support for uint_fast128_t is optional, but it should be available on
>>> any platform where your u128 is - a statement I'll stick with even
>>> though it fails in the only place I can easily test. Some
>>> experimenting shows that the gcc I'm using supports __int128, but
>>> neither __uint128, nor uint_least128_t. That strikes me as quite odd.
>>
>> I suspect that this is, in part, because the gcc people did not want
>> intmax_t to be 128 bits. That would force preprocessor arithmetic to
>> done in 128 bits.
>
> That seems counter-intuitive. If I'm writing code that relies upon 128
> bit integers, I would both want and expect [u]intmax_t to be a 128 bit
> type, with all of the corresponding inefficiency (which, in the case of
> pre-processor arithmetic, would only occur at compile time, which
> matters very little to me).
As someone else mentioned, gcc's unsigned 128-bit type is called
"unsigned __int128". Apparently __int128 is treated as a type
specifier, not as a typedef.
As for not defining [u]intmax_t to be 128 bits, gcc's __int128 and
unsigned __int128 types are not treated as integer types, not even as
extended integer types. The rationale, as I understand it, is that it
making [u]intmax_t 128 bits would directly or indirectly break some
APIs. Note in particular that a compiler and runtime library have to
agree on the width of intmax_t so that the "%jd" and "%ju" printf
formats will work correctly. I suppose some other functions (outside
the C standard library might use [u]intmax and could break if it were
changed.
https://stackoverflow.com/q/29927562/827263
--
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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Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-21 20:50 -0700
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-22 01:15 -0500
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-22 01:21 -0500
Re: Something C might need fir <profesor.fir@gmail.com> - 2017-09-22 00:44 -0700
Re: Something C might need Noob <root@127.0.0.1> - 2017-09-22 11:02 +0200
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-22 12:35 -0500
Re: Something C might need Richard Damon <Richard@Damon-Family.org> - 2017-09-22 13:46 -0400
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-22 11:47 -0700
Re: Something C might need supercat@casperkitty.com - 2017-09-22 12:16 -0700
Re: Something C might need Richard Damon <Richard@Damon-Family.org> - 2017-09-22 18:10 -0400
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-22 15:24 -0700
Re: Something C might need supercat@casperkitty.com - 2017-09-22 15:52 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-23 12:29 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-23 08:29 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-23 18:06 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-24 12:28 +0200
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-22 16:17 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-22 18:20 -0700
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-22 22:45 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-23 12:22 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-23 11:29 +0100
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-23 10:25 -0400
Re: Something C might need Reinhardt Behm <rbehm@hushmail.com> - 2017-09-24 22:09 +0800
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 15:32 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-24 13:17 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 21:53 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-24 14:54 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 23:10 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-24 16:14 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-25 01:04 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-24 17:23 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 08:48 +0200
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-25 11:50 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 21:59 +0200
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-25 14:25 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-26 09:39 +0200
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-26 11:50 -0700
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-25 15:44 -0500
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-24 18:57 -0400
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-25 00:08 +0100
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-24 20:51 -0400
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-25 02:10 +0100
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-24 22:22 -0400
Re: Something C might need Thiago Adams <thiago.adams@gmail.com> - 2017-09-25 06:35 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 16:16 +0200
Re: Something C might need Thiago Adams <thiago.adams@gmail.com> - 2017-09-25 07:47 -0700
Re: Something C might need Thiago Adams <thiago.adams@gmail.com> - 2017-09-25 13:38 -0700
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-24 23:29 -0500
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-25 17:40 -0500
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-24 23:30 -0500
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-25 08:58 -0400
Re: Something C might need supercat@casperkitty.com - 2017-09-23 08:41 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-23 17:32 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-23 11:32 -0700
Re: Something C might need Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-09-25 14:43 +0000
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 22:07 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-25 13:34 -0700
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-26 10:04 +1300
Re: Something C might need Jorgen Grahn <grahn+nntp@snipabacken.se> - 2017-09-26 14:31 +0000
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-27 08:38 +1300
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-23 17:49 -0700
Re: Something C might need gordonb.w32iq@burditt.org (Gordon Burditt) - 2017-09-23 21:21 -0500
Re: Something C might need supercat@casperkitty.com - 2017-09-24 11:27 -0700
Re: Something C might need gordonb.woyvd@burditt.org (Gordon Burditt) - 2017-09-25 01:08 -0500
Re: Something C might need supercat@casperkitty.com - 2017-09-25 09:38 -0700
Re: Something C might need supercat@casperkitty.com - 2017-09-25 10:00 -0700
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-23 11:32 +0100
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-23 12:29 -0700
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-23 20:38 +0100
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-23 15:25 -0700
Re: Something C might need Richard Damon <Richard@Damon-Family.org> - 2017-09-23 20:36 -0400
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-24 01:42 +0100
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-23 18:03 -0700
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-23 22:47 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 12:03 -0700
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-24 15:10 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 16:20 -0700
Re: Something C might need David Kleinecke <dkleinecke@gmail.com> - 2017-09-24 16:44 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 09:00 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-24 16:51 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 09:11 +0200
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 09:04 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-23 22:10 +0100
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-24 10:19 +1300
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-24 01:38 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 02:14 +0100
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-23 18:41 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 11:16 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 11:41 +0100
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 12:15 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 12:23 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-24 14:03 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 13:59 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 16:08 +0100
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-24 21:50 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 21:40 +0100
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 09:28 +0200
Re: Something C might need luser droog <luser.droog@gmail.com> - 2017-09-26 06:28 -0700
Re: Something C might need supercat@casperkitty.com - 2017-09-26 07:47 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-27 08:26 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-27 07:22 -0700
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-27 09:01 -0700
Re: Something C might need supercat@casperkitty.com - 2017-09-27 09:42 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-28 10:42 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-27 19:22 +0100
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-28 10:48 +0200
Re: Something C might need scott@slp53.sl.home (Scott Lurndal) - 2017-09-28 17:31 +0000
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-24 22:09 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 22:44 +0100
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-25 01:57 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-25 02:02 +0100
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 19:10 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-27 16:27 +0100
Re: Something C might need Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-09-27 09:26 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-28 10:53 +0200
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-27 10:52 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-27 19:20 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-27 11:44 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-28 10:57 +0200
Re: Something C might need James Kuyper <jameskuyper@verizon.net> - 2017-09-24 14:49 -0400
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-24 22:06 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 20:09 +0100
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-24 12:12 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-24 20:46 +0100
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 09:41 +0200
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-24 21:05 +0100
Re: Something C might need gordonb.r273i@burditt.org (Gordon Burditt) - 2017-09-23 21:34 -0500
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-24 09:01 +0100
Re: Something C might need Noob <root@127.0.0.1> - 2017-09-24 19:34 +0200
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-24 23:53 -0500
Re: Something C might need "James R. Kuyper" <jameskuyper@verizon.net> - 2017-09-25 12:27 -0400
Re: Something C might need Noob <root@127.0.0.1> - 2017-09-25 20:33 +0200
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-25 15:52 -0500
Re: Something C might need Noob <root@127.0.0.1> - 2017-09-25 23:23 +0200
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-25 15:15 -0700
Re: Something C might need Robert Wessel <robertwessel2@yahoo.com> - 2017-09-25 17:49 -0500
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-26 09:46 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-26 07:32 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-26 21:50 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-26 14:32 -0700
Re: Something C might need Noob <root@127.0.0.1> - 2017-09-26 22:34 +0200
Re: Something C might need supercat@casperkitty.com - 2017-09-26 14:39 -0700
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-25 19:38 +0100
Re: Something C might need "James R. Kuyper" <jameskuyper@verizon.net> - 2017-09-25 15:00 -0400
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-25 12:29 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-25 22:12 +0200
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-22 11:38 +0100
Re: Something C might need Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2017-09-22 04:21 -0700
Re: Something C might need David Brown <david.brown@hesbynett.no> - 2017-09-22 14:54 +0200
Re: Something C might need Keith Thompson <kst-u@mib.org> - 2017-09-22 08:02 -0700
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 06:49 -0700
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-22 20:24 +0100
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 12:45 -0700
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-23 09:00 +1200
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 17:34 -0400
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-23 10:49 +1200
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 19:25 -0400
Re: Something C might need "James R. Kuyper" <jameskuyper@verizon.net> - 2017-09-22 19:35 -0400
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-23 11:52 +1200
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 18:25 -0700
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-23 13:36 +1200
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 20:20 -0700
Rick says C is a dying language. (Was: Something C might need) gazelle@shell.xmission.com (Kenny McCormack) - 2017-09-23 09:15 +0000
Re: Rick says C is a dying language. (Was: Something C might need) "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-23 04:40 -0700
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-23 13:00 +0100
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-23 10:28 -0400
Re: Something C might need James Kuyper <jameskuyper@verizon.net> - 2017-09-22 23:22 -0400
Re: Something C might need Ian Collins <ian-news@hotmail.com> - 2017-09-23 18:01 +1200
Re: Something C might need Jerry Stuckle <jstucklex@attglobal.net> - 2017-09-22 20:31 -0400
Re: Something C might need jladasky@itu.edu - 2017-09-22 16:27 -0700
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 16:34 -0700
Re: Something C might need scott@slp53.sl.home (Scott Lurndal) - 2017-09-26 21:44 +0000
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-26 14:53 -0700
Re: Something C might need Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-09-23 02:14 +0100
Re: Something C might need bartc <bc@freeuk.com> - 2017-09-22 21:31 +0100
Re: Something C might need supercat@casperkitty.com - 2017-09-22 14:02 -0700
Re: Something C might need "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-09-22 17:29 -0400
Re: Something C might need supercat@casperkitty.com - 2017-09-22 09:12 -0700
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