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| From | jgk@panix.com (Joe keane) |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: the loop control |
| Date | 2011-10-31 16:36 +0000 |
| Organization | Public Access Networks Corp. |
| Message-ID | <j8miq2$kh4$1@reader1.panix.com> (permalink) |
| References | <j8hrok$3cq$1@reader1.panix.com> <op.v35g1ubrlahckh@cantereyd> |
compare
int fc(int len, struct foo *fob, struct bar *bab)
{
...
for (j = 0; j < len; j++)
{
fob[j].a = bab[j].x;
fob[j].b = bab[j].y + 1;
fob[j].c = bab[j].d;
}
...
}
versus
int fd(int len, struct foo *fob, struct bar *bab)
{
...
for (j = 0; j < len; j++)
{
fop = &fob[j];
bap = &bab[j];
fop->a = bap->x;
fop->b = bap->y + 1;
fop->c = bap->d;
}
...
}
The first one looks like Pascal or Fortran. The second one looks more
like C. It says 'i don't need the array base and index, just give me
the pointer'.
All style, you should get the same machine code. But i've seen too many
cases where the code that looks 'faster' actually is! I mean it's nice
to say 'the optimizer will take care of this', but then it doesn't hurt
to help it some, by not making code more complicated than it should be.
Anyway readability is key; to me code like
ct = len;
fop = fob;
while (--ct >= 0)
{
...(fop)
fop++;
}
is so idiomatic that it's easiest.
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the loop control jgk@panix.com (Joe keane) - 2011-10-29 21:38 +0000
Re: the loop control Ian Collins <ian-news@hotmail.com> - 2011-10-30 10:48 +1300
Re: the loop control Kaz Kylheku <kaz@kylheku.com> - 2011-10-29 22:10 +0000
Re: the loop control jgk@panix.com (Joe keane) - 2011-10-31 15:21 +0000
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-10-31 11:35 -0400
Re: the loop control jgharston <jgh@arcade.demon.co.uk> - 2011-10-31 10:27 -0700
Re: the loop control Seebs <usenet-nospam@seebs.net> - 2011-10-31 18:36 +0000
Re: the loop control Robert Wessel <robertwessel2@yahoo.com> - 2011-10-31 13:49 -0500
Re: the loop control Sjouke Burry <s@b> - 2011-10-31 18:49 +0000
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-10-31 15:07 -0400
Re: the loop control Keith Thompson <kst-u@mib.org> - 2011-10-31 13:56 -0700
Re: the loop control Seebs <usenet-nospam@seebs.net> - 2011-10-31 17:18 +0000
Re: the loop control Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-01 04:35 -0700
Re: the loop control Seebs <usenet-nospam@seebs.net> - 2011-11-01 21:44 +0000
Re: the loop control Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-11-02 01:16 -0700
Re: the loop control Kaz Kylheku <kaz@kylheku.com> - 2011-10-31 19:23 +0000
Re: the loop control jgk@panix.com (Joe keane) - 2011-11-02 04:47 +0000
Re: the loop control Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-31 23:07 +0200
Re: the loop control Ike Naar <ike@sverige.freeshell.org> - 2011-11-01 00:11 +0000
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-10-31 22:01 -0400
Re: the loop control Kaz Kylheku <kaz@kylheku.com> - 2011-11-01 02:51 +0000
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-11-01 07:23 -0400
Re: the loop control Ike Naar <ike@iceland.freeshell.org> - 2011-11-01 09:51 +0000
Re: the loop control pete <pfiland@mindspring.com> - 2011-11-01 05:34 -0500
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-11-01 07:30 -0400
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-11-01 07:35 -0400
Re: the loop control Hans Vlems <hvlems@freenet.de> - 2011-11-11 00:38 -0800
Re: the loop control jgk@panix.com (Joe keane) - 2011-11-02 03:36 +0000
Re: the loop control Ian Collins <ian-news@hotmail.com> - 2011-11-02 17:09 +1300
Re: the loop control Keith Thompson <kst-u@mib.org> - 2011-11-02 03:56 -0700
Re: the loop control Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-10-31 21:38 +0000
Re: the loop control Acid Washed China Blue Jeans <chine.bleu@yahoo.com> - 2011-10-29 19:31 -0700
Re: the loop control Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2011-10-29 23:11 -0600
Re: the loop control "Philip Lantz" <prl@canterey.us> - 2011-10-29 22:47 -0700
Re: the loop control jgk@panix.com (Joe keane) - 2011-10-31 16:36 +0000
Re: the loop control Kaz Kylheku <kaz@kylheku.com> - 2011-10-31 19:30 +0000
Re: the loop control blp@cs.stanford.edu (Ben Pfaff) - 2011-10-31 12:38 -0700
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-10-31 15:51 -0400
Re: the loop control blp@cs.stanford.edu (Ben Pfaff) - 2011-10-31 13:06 -0700
Re: the loop control Keith Thompson <kst-u@mib.org> - 2011-10-31 14:17 -0700
Re: the loop control Seebs <usenet-nospam@seebs.net> - 2011-11-01 21:44 +0000
Re: the loop control Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-31 23:30 +0200
Re: the loop control jgk@panix.com (Joe keane) - 2011-11-03 21:29 +0000
Re: the loop control James Kuyper <jameskuyper@verizon.net> - 2011-11-03 18:00 -0400
Re: the loop control Kaz Kylheku <kaz@kylheku.com> - 2011-11-04 00:43 +0000
Re: the loop control jgk@panix.com (Joe keane) - 2011-11-11 02:24 +0000
Re: the loop control Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-10-31 23:20 +0200
Re: the loop control pete <pfiland@mindspring.com> - 2011-10-31 18:01 -0500
Re: the loop control Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-11-02 01:20 +0200
Re: the loop control 88888 Dihedral <dihedral88888@googlemail.com> - 2011-11-02 01:25 -0700
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