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| From | Ken Brody <kenbrody@spamcop.net> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Pointer Arithmetic & UB |
| Date | 2012-12-12 14:24 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <kaalki$3uf$1@dont-email.me> (permalink) |
| References | <ka559a$hdg$1@speranza.aioe.org> <e4659f49-c39e-4367-bbad-c2724a3ebd13@googlegroups.com> <50C6461E.40208@verizon.net> |
On 12/10/2012 3:29 PM, James Kuyper wrote: > On 12/10/2012 03:04 PM, Prathamesh Kulkarni wrote: >> Instead, of i and j >> would *(a + 20 - 15) still have >> undefined behaviour ? Probably any C compiler >> will evaluate 20 - 15 during translation, but >> does the standard require constant expression >> to be evaluated during translation >> even if it is a sub-expression >> as in the above case ? > > No, it does not. It would be an unusual compiler that failed to do so, > but it is not required. When I went to college, there was a FORTRAN compiler aimed specifically at teaching FORTRAN programming. Since it was expected that there would be more time spent compiling (and recompiling, after fixing errors) the program than in running it (the resulting program would in all likelihood be run only once), there was zero optimization done on the resulting code. This made the compiler itself "lean and mean", allowing it to finish compiling (or getting to the errors) faster. It didn't make sense to spend X amount of time optimizing a program, only to save less than X time once the program actually ran the one time it would be run. I could see such an implementation of C being developed.
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Pointer Arithmetic & UB Edward Rutherford <edward.p.rutherford79@REMOVETHIS.gmail.com> - 2012-12-10 17:14 +0000
Re: Pointer Arithmetic & UB "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-12-10 09:35 -0800
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-10 12:55 -0500
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-10 13:25 -0500
Re: Pointer Arithmetic & UB falk@rahul.net (Edward A. Falk) - 2012-12-11 00:46 +0000
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-10 21:28 -0500
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-12 14:36 -0500
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-12 20:35 +0000
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-12 15:57 -0500
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-12 16:02 -0500
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-12 16:13 -0500
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-12 21:18 -0500
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-12 22:42 -0500
Re: Pointer Arithmetic & UB Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-12-17 12:04 +0200
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-17 08:47 -0500
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-17 14:58 +0000
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-17 10:59 -0500
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-17 17:26 +0000
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-17 19:33 -0500
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-20 11:00 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-20 10:03 -0800
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-20 22:02 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 13:09 -0800
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-21 22:40 +0000
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-21 23:39 -0500
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-22 06:50 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-22 00:15 -0800
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-22 10:34 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-22 09:32 -0800
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-23 09:38 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-23 09:55 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-26 13:35 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-27 09:03 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-27 21:31 -0500
Re: Pointer Arithmetic & UB Philip Lantz <prl@canterey.us> - 2012-12-28 01:55 -0800
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-29 13:43 -0800
Re: Pointer Arithmetic & UB Philip Lantz <prl@canterey.us> - 2012-12-28 01:39 -0800
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-28 11:31 +0000
Re: Pointer Arithmetic & UB Keith Thompson <kst-u@mib.org> - 2012-12-28 08:47 -0800
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-29 17:45 -0800
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-30 04:06 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2013-01-02 10:08 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-26 13:29 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-27 07:55 -0800
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-27 08:01 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-27 21:10 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-29 18:03 -0800
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-23 03:48 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-23 10:22 -0800
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-12-27 10:34 +0000
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-27 10:16 -0800
Re: Pointer Arithmetic & UB Ben Bacarisse <ben.usenet@bsb.me.uk> - 2013-01-10 17:26 +0000
Re: Pointer Arithmetic & UB Robert Wessel <robertwessel2@yahoo.com> - 2012-12-20 12:21 -0600
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-20 13:40 -0500
Re: Pointer Arithmetic & UB Robert Wessel <robertwessel2@yahoo.com> - 2012-12-20 13:32 -0600
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-20 14:58 -0500
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-20 21:54 +0000
Re: Pointer Arithmetic & UB Lanarcam <lanarcam1@yahoo.fr> - 2012-12-20 19:49 +0100
Re: Pointer Arithmetic & UB Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-12-21 02:38 +0200
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-21 14:33 -0500
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-21 03:18 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 13:16 -0800
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-21 17:57 -0500
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-21 23:52 +0000
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-21 19:47 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-21 22:54 -0800
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-22 03:31 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-22 09:16 -0800
Re: Pointer Arithmetic & UB Shao Miller <sha0.miller@gmail.com> - 2012-12-24 04:23 -0500
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-27 11:07 -0800
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 02:33 -0800
Re: Pointer Arithmetic & UB Tim Rentsch <txr@alumni.caltech.edu> - 2012-12-17 02:18 -0800
Re: Pointer Arithmetic & UB Noob <root@127.0.0.1> - 2012-12-11 11:36 +0100
Re: Pointer Arithmetic & UB "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2012-12-11 10:00 -0800
Re: Pointer Arithmetic & UB Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-12-17 12:11 +0200
Re: Pointer Arithmetic & UB Eric Sosman <esosman@comcast-dot-net.invalid> - 2012-12-11 15:27 -0500
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-11 21:09 +0000
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-12 14:30 -0500
Re: Pointer Arithmetic & UB Keith Thompson <kst-u@mib.org> - 2012-12-12 11:42 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-12 17:12 -0500
Re: Pointer Arithmetic & UB Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2012-12-17 12:16 +0200
Re: Pointer Arithmetic & UB Prathamesh Kulkarni <bilbotheelffriend@gmail.com> - 2012-12-10 12:04 -0800
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-10 15:29 -0500
Re: Pointer Arithmetic & UB Prathamesh Kulkarni <bilbotheelffriend@gmail.com> - 2012-12-10 12:44 -0800
Re: Pointer Arithmetic & UB Prathamesh Kulkarni <bilbotheelffriend@gmail.com> - 2012-12-10 12:47 -0800
Re: Pointer Arithmetic & UB James Kuyper <jameskuyper@verizon.net> - 2012-12-10 16:02 -0500
Re: Pointer Arithmetic & UB Prathamesh Kulkarni <bilbotheelffriend@gmail.com> - 2012-12-10 13:08 -0800
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-12 14:26 -0500
Re: Pointer Arithmetic & UB Greg Martin <greg@softsprocket.com> - 2012-12-10 14:55 -0800
Re: Pointer Arithmetic & UB Sjouke Burry <s@b> - 2012-12-10 21:18 +0000
Re: Pointer Arithmetic & UB falk@rahul.net (Edward A. Falk) - 2012-12-11 00:48 +0000
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-10 21:01 +0000
Re: Pointer Arithmetic & UB Ken Brody <kenbrody@spamcop.net> - 2012-12-12 14:24 -0500
Re: Pointer Arithmetic & UB Robert Wessel <robertwessel2@yahoo.com> - 2012-12-12 14:34 -0600
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-12 20:45 +0000
Re: Pointer Arithmetic & UB Robert Wessel <robertwessel2@yahoo.com> - 2012-12-12 15:29 -0600
Re: Pointer Arithmetic & UB glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2012-12-13 02:02 +0000
Re: Pointer Arithmetic & UB Malcolm McLean <malcolm.mclean5@btinternet.com> - 2012-12-17 05:57 -0800
Re: Pointer Arithmetic & UB pete <pfiland@mindspring.com> - 2012-12-10 20:20 -0500
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