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| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: More physical source files |
| Date | 2015-07-05 09:18 -0700 |
| Organization | None to speak of |
| Message-ID | <lnh9piwpbl.fsf@kst-u.example.com> (permalink) |
| References | (12 earlier) <71c62ee8-0007-446b-9004-c6def341205a@googlegroups.com> <lnpp47ww8j.fsf@kst-u.example.com> <d5e66ec9-845a-4dd4-8df0-ad913b4d2adb@googlegroups.com> <lnlhevwnna.fsf@kst-u.example.com> <16b6aa6b-f1df-4e3b-8278-47349d71602c@googlegroups.com> |
Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
> On Saturday, July 4, 2015 at 11:42:27 PM UTC+1, Keith Thompson wrote:
>> Malcolm McLean <malcolm.mclean5@btinternet.com> writes:
>>
>> #include <stdio.h>
>> int main(void) {
>> if (1.0 + 1.0 > 1.0) puts("ok");
>> else puts("OOPS");
>> }
>>
>> is probably not strictly conforming, given that the accuracy of
>> floating-point "+" is implementation-defined (N1570 5.2.4.2.2p6).
>> On the other hand, I would argue that if the program prints "OOPS",
>> then the implementation violates N1570 6.5.6p5:
>>
>> The result of the binary + operator is the sum of the operands.
>>
>> But there's no good way to define how much of an error would render
>> an implementation non-conforming.
>>
> if(1 + x > 1)
>
> is actually a special case. DBL_EPSILON is the smallest value of x for which
> the expression holds true.
How is that relevant? I was specifically referring to the expression
`1.0 + 1.0 > 1.0`, which is obviously true mathematically, but whose
result is in principle implementation-defined because the precision of
"+" is implementation-defined. Replacing 1.0 by DBL_EPSILON just
weakens the point.
--
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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More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-06-27 11:19 -0700
Re: More physical source files Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-06-27 11:54 -0700
Re: More physical source files Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-27 21:20 +0100
Re: More physical source files Bartc <bc@freeuk.com> - 2015-06-27 20:24 +0100
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-06-29 07:14 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-06-29 08:16 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-06-30 08:24 -0700
Re: More physical source files Robert Wessel <robertwessel2@yahoo.com> - 2015-06-30 12:15 -0500
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-06-30 15:14 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-01 08:38 -0700
Re: More physical source files glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-01 16:43 +0000
Re: More physical source files Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-01 18:52 +0100
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-01 11:21 -0700
Re: More physical source files glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-01 18:36 +0000
Re: More physical source files Richard Damon <Richard@Damon-Family.org> - 2015-07-01 22:33 -0400
Re: More physical source files glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-02 19:11 +0000
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-01 11:08 -0700
Re: More physical source files Richard Damon <Richard@Damon-Family.org> - 2015-07-01 22:30 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-02 08:29 -0700
Re: More physical source files Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-07-02 17:56 +0100
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-02 13:21 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-03 08:54 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-04 12:23 -0400
Re: More physical source files Martin Shobe <martin.shobe@yahoo.com> - 2015-07-04 11:36 -0500
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-02 16:42 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-03 08:54 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-03 10:05 -0700
Re: More physical source files glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-03 21:57 +0000
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-04 00:30 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-04 08:08 -0700
Re: More physical source files Richard Damon <Richard@Damon-Family.org> - 2015-07-04 12:21 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-05 09:22 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-05 09:49 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-05 18:16 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-06 08:37 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-06 12:56 -0400
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-06 11:59 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-06 15:45 -0400
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-06 13:14 -0700
Re: More physical source files Philip Lantz <prl@canterey.us> - 2015-07-07 01:10 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-07 08:00 -0700
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-07 07:55 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-07 13:13 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-08 08:35 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-08 12:31 -0400
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-09 08:50 -0700
Re: More physical source files Richard Heathfield <rjh@cpax.org.uk> - 2015-07-09 16:56 +0100
Re: More physical source files Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-09 13:31 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-09 15:03 -0700
Re: More physical source files Ian Collins <ian-news@hotmail.com> - 2015-07-10 10:54 +1200
Re: More physical source files David Kleinecke <dkleinecke@gmail.com> - 2015-07-10 09:52 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-09 14:32 -0400
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-05 13:41 -0400
Re: More physical source files Richard Damon <Richard@Damon-Family.org> - 2015-07-05 14:17 -0400
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-04 12:36 -0700
Re: More physical source files Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-04 15:19 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-04 15:42 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-04 19:04 -0400
Re: More physical source files Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-05 03:25 -0700
Re: More physical source files Keith Thompson <kst-u@mib.org> - 2015-07-05 09:18 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-05 14:11 -0400
Re: More physical source files Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-05 13:41 -0700
Re: More physical source files Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-10 19:00 -0700
Re: More physical source files Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-10 18:57 -0700
Re: More physical source files James Kuyper <jameskuyper@verizon.net> - 2015-07-04 12:50 -0400
Re: More physical source files Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 08:39 -0700
Re: More physical source files Bartc <bc@freeuk.com> - 2015-06-29 17:20 +0100
Re: More physical source files Rosario19 <Ros@invalid.invalid> - 2015-06-28 11:57 +0200
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