Re: Limitations and workarounds to expressions defining size of an array

From	James Kuyper <jameskuyper@verizon.net>
Newsgroups	comp.lang.c
Subject	Re: Limitations and workarounds to expressions defining size of an array
Date	2012-09-05 17:23 -0400
Organization	A noiseless patient Spider
Message-ID	<5047C2B8.2040609@verizon.net> (permalink)
References	(3 earlier) <k25qj3$n5k$1@dont-email.me> <k25rm5$e1$9@dont-email.me> <k25rv3$e1$10@dont-email.me> <50467585.7090105@verizon.net> <k28dl4$irb$5@dont-email.me>

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On 09/05/2012 04:45 PM, army1987 wrote:
> On Tue, 04 Sep 2012 17:41:25 -0400, James Kuyper wrote:
> 
>> On 09/04/2012 05:31 PM, army1987 wrote:
...
>>> BTW, I'm shocked by the result. It optimizes away the call to strspn
>>> but it actually calls printf with arguments "%d\n" and 3? WTF?
>>
>> The only printf() calls explicitly mentioned in this thread so far were
>> in my example program, which used "%zu", not "%d", so you're presumably
>> referring to some other program. What does the source code look like?
> 
> #include <stdio.h>
> int main(void)
> {
>     printf("%d\n", (int)strspn("BartC", "abcdefghijklmnopqrsBCuvwxyz"));
>     return 0;
> }

OK, that's roughly what I expected, but I wanted to be sure. In
particular, your "WTF?" left me wondering whether you thought the
optimization was invalid. I'm mildly impressed by that optimization, but
not nearly as much as you were, apparently.

Thread

Limitations and workarounds to expressions defining size of an array Francois Grieu <fgrieu@gmail.com> - 2012-09-04 19:14 +0200
  Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-04 14:08 -0400
    Re: Limitations and workarounds to expressions defining size of an array Francois Grieu <fgrieu@gmail.com> - 2012-09-05 09:56 +0200
      Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-05 07:33 -0400
        Re: Limitations and workarounds to expressions defining size of an array Francois Grieu <fgrieu@gmail.com> - 2012-09-05 23:39 +0200
          Re: Limitations and workarounds to expressions defining size of an array Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-09-05 18:11 -0400
    Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-05 07:17 -0400
  Re: Limitations and workarounds to expressions defining size of an array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-04 19:18 +0100
  Re: Limitations and workarounds to expressions defining size of an array Kaz Kylheku <kaz@kylheku.com> - 2012-09-04 18:41 +0000
    Re: Limitations and workarounds to expressions defining size of an array "BartC" <bc@freeuk.com> - 2012-09-04 20:22 +0100
      Re: Limitations and workarounds to expressions defining size of an array Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-09-04 17:07 -0400
        Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-04 17:25 -0400
          Re: Limitations and workarounds to expressions defining size of an array Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-09-04 18:24 -0400
            Re: Limitations and workarounds to expressions defining size of an array Keith Thompson <kst-u@mib.org> - 2012-09-04 17:29 -0700
        Re: Limitations and workarounds to expressions defining size of an array army1987 <army1987@ask-for-it.invalid> - 2012-09-04 21:26 +0000
          Re: Limitations and workarounds to expressions defining size of an array army1987 <army1987@ask-for-it.invalid> - 2012-09-04 21:31 +0000
            Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-04 17:41 -0400
              Re: Limitations and workarounds to expressions defining size of an array army1987 <army1987@ask-for-it.invalid> - 2012-09-05 20:45 +0000
                Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-05 17:23 -0400
                Re: Limitations and workarounds to expressions defining size of an array army1987 <army1987@ask-for-it.invalid> - 2012-09-05 21:30 +0000
                Re: Limitations and workarounds to expressions defining size of an array Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-09-05 23:04 +0100
                Re: Limitations and workarounds to expressions defining size of an array Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-09-05 18:17 -0400
                Re: Limitations and workarounds to expressions defining size of an array James Kuyper <jameskuyper@verizon.net> - 2012-09-05 18:29 -0400
            Re: Limitations and workarounds to expressions defining size of an array Kaz Kylheku <kaz@kylheku.com> - 2012-09-04 21:44 +0000
      Re: Limitations and workarounds to expressions defining size of an array Kaz Kylheku <kaz@kylheku.com> - 2012-09-04 21:39 +0000
        Re: Limitations and workarounds to expressions defining size of an array "BartC" <bc@freeuk.com> - 2012-09-04 22:58 +0100
          Re: Limitations and workarounds to expressions defining size of an array Kaz Kylheku <kaz@kylheku.com> - 2012-09-04 22:12 +0000
          Re: Limitations and workarounds to expressions defining size of an array Lowell Gilbert <lgusenet@be-well.ilk.org> - 2012-09-04 18:55 -0400
      Re: Limitations and workarounds to expressions defining size of an array Keith Thompson <kst-u@mib.org> - 2012-09-04 16:51 -0700
        Re: Limitations and workarounds to expressions defining size of an array Eric Sosman <esosman@ieee-dot-org.invalid> - 2012-09-04 20:58 -0400
          Re: Limitations and workarounds to expressions defining size of an array Francois Grieu <fgrieu@gmail.com> - 2012-09-05 10:04 +0200
          Re: Limitations and workarounds to expressions defining size of an array Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 04:47 -0700
            Re: Limitations and workarounds to expressions defining size of an array Keith Thompson <kst-u@mib.org> - 2012-09-07 14:04 -0700
              Re: Limitations and workarounds to expressions defining size of an array Casey Carter <casey_at_carter_dot_net@nospam.invalid> - 2012-09-07 16:40 -0500
              Re: Limitations and workarounds to expressions defining size of an array Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 19:54 -0700
                Re: Limitations and workarounds to expressions defining size of an array Keith Thompson <kst-u@mib.org> - 2012-09-08 14:15 -0700
                Re: Limitations and workarounds to expressions defining size of an array lawrence.jones@siemens.com - 2012-09-17 12:09 -0400
        Re: Limitations and workarounds to expressions defining size of an array Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 04:53 -0700
          Re: Limitations and workarounds to expressions defining size of an array "BartC" <bc@freeuk.com> - 2012-09-07 13:07 +0100
            Re: Limitations and workarounds to expressions defining size of an array Keith Thompson <kst-u@mib.org> - 2012-09-07 14:08 -0700
            Re: Limitations and workarounds to expressions defining size of an array Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 19:41 -0700
  Re: Limitations and workarounds to expressions defining size of an array "BartC" <bc@freeuk.com> - 2012-09-04 20:26 +0100
  Re: Limitations and workarounds to expressions defining size of an array Barry Schwarz <schwarzb@dqel.com> - 2012-09-04 14:14 -0700
  Re: Limitations and workarounds to expressions defining size of an array Tim Rentsch <txr@alumni.caltech.edu> - 2012-09-07 04:41 -0700
  Re: Limitations and workarounds to expressions defining size of an array army1987 <army1987@ask-for-it.invalid> - 2012-09-07 13:32 +0000

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