Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #59123

Re: Code for strtol/strtoul

From Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups comp.lang.c
Subject Re: Code for strtol/strtoul
Date 2015-03-28 11:33 +0000
Organization A noiseless patient Spider
Message-ID <87ego98igi.fsf@bsb.me.uk> (permalink)
References <mejjh4$i17$1@speranza.aioe.org> <cnncb9Foba2U1@mid.individual.net>

Show all headers | View raw

Ian Collins <ian-news@hotmail.com> writes:

> jacob navia wrote:
>
>> What to do with weird cases? For instance the sequence
>>
>> strtol(
>> "56724399879677657653445435435456765675755435435432223444465444565466654666ULL",
>> &endptr,10);
>>
>> I developed a formula for calculating the maximum number of digits to
>> read for a number base N. Is that formula correct?
>
> That calculation appears to be impacting the performance of your routine.
>
> Being a another quiet weekend, I got bored and wrote a test wrapper
> that creates an array of 1000 random number strings and then cycles
> them 10000 times to perform enough conversions for a decent elapsed
> time.
>
> Compiled with gcc -O3, your version takes ~9.9 seconds, my version
> ~6.4 seconds.  Considering the only significant difference is I don't
> bother calculating the maximum number of digits, it probably isn't a
> good thing to do.

But at least in your case, the code does not correctly scan the whole
string of digits, so that might be another difference depending on how
many ling strings your test includes.

(I didn't check Jacob's version, and I can't currently find the post, so
they may bit the same in this respect.)

-- 
Ben.

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-21 12:09 +0100
  Re: Code for strtol/strtoul Bartc <bc@freeuk.com> - 2015-03-21 11:33 +0000
    Re: Code for strtol/strtoul Bartc <bc@freeuk.com> - 2015-03-21 11:47 +0000
    Re: Code for strtol/strtoul Greg Martin <greg.at.softsprocket@dot.com> - 2015-03-21 15:58 +0000
  Re: Code for strtol/strtoul Lőrinczy Zsigmond <nospam@for.me> - 2015-03-21 16:10 +0100
    Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-21 16:34 +0100
      Re: Code for strtol/strtoul Kaz Kylheku <kaz@kylheku.com> - 2015-03-21 16:10 +0000
    Re: Code for strtol/strtoul James Kuyper <jameskuyper@verizon.net> - 2015-03-21 12:53 -0400
    Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-21 14:18 -0700
      Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-21 22:46 +0100
        Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-21 15:23 -0700
          Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-21 23:42 +0100
            Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-21 16:06 -0700
              Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-22 00:29 +0100
                Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-21 20:18 -0700
      Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-21 15:54 -0700
        Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-22 08:34 +0100
        Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 19:42 -0700
          Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-25 10:40 -0700
            Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 16:17 -0700
              Re: Code for strtol/strtoul Keith Thompson <kst-u@mib.org> - 2015-03-25 20:27 -0700
                Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 09:08 -0700
  Re: Code for strtol/strtoul Greg Martin <greg.at.softsprocket@dot.com> - 2015-03-21 15:53 +0000
    Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 21:50 -0700
      Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-25 06:54 +0100
        Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-25 19:18 +1300
          Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-25 09:57 +0100
            Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-26 07:07 +1300
              Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-26 14:22 +1300
                Re: Code for strtol/strtoul asetofsymbols@gmail.com - 2015-03-26 00:17 -0700
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-28 12:07 +1300
                Re: Code for strtol/strtoul asetofsymbols@gmail.com - 2015-03-28 02:53 -0700
        Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 08:19 -0700
        Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 16:13 -0700
      Re: Code for strtol/strtoul Greg Martin <greg.at.softsprocket@dot.com> - 2015-03-25 13:42 +0000
        Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 17:20 -0700
          Re: Code for strtol/strtoul Kaz Kylheku <kaz@kylheku.com> - 2015-03-26 04:16 +0000
            Re: Code for strtol/strtoul asetofsymbols@gmail.com - 2015-03-26 00:27 -0700
              Re: Code for strtol/strtoul Kaz Kylheku <kaz@kylheku.com> - 2015-03-26 13:44 +0000
                Re: Code for strtol/strtoul fir <profesor.fir@gmail.com> - 2015-03-26 07:13 -0700
                Re: Code for strtol/strtoul asetofsymbols@gmail.com - 2015-03-26 08:30 -0700
                Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-03-29 15:13 +0000
            Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 09:47 -0700
          Re: Code for strtol/strtoul Greg Martin <greg.at.softsprocket@dot.com> - 2015-03-26 15:00 +0000
            Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-27 07:12 +1300
              Re: Code for strtol/strtoul Bartc <bc@freeuk.com> - 2015-03-26 19:11 +0000
                Re: Code for strtol/strtoul Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-26 15:09 -0700
                Re: Code for strtol/strtoul Richard Heathfield <rjh@cpax.org.uk> - 2015-03-26 22:13 +0000
                Re: Code for strtol/strtoul Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-26 15:20 -0700
                Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-03-30 09:59 +0000
                Re: Code for strtol/strtoul Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-03-30 06:38 -0700
                Re: Code for strtol/strtoul Richard Heathfield <rjh@cpax.org.uk> - 2015-03-30 14:41 +0100
                Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-04-06 12:52 +0000
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-27 18:07 +1300
                Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-03-29 15:17 +0000
                Re: Code for strtol/strtoul Kaz Kylheku <kaz@kylheku.com> - 2015-03-29 15:26 +0000
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-30 07:09 +1300
                Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-03-30 10:02 +0000
                Re: Code for strtol/strtoul Bartc <bc@freeuk.com> - 2015-03-29 18:53 +0100
            Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 15:38 -0700
  Re: Code for strtol/strtoul Robert Wessel <robertwessel2@yahoo.com> - 2015-03-21 16:48 -0500
  Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-22 20:45 +1300
    Re: Code for strtol/strtoul Ike Naar <ike@iceland.freeshell.org> - 2015-03-23 09:40 +0000
      Re: Code for strtol/strtoul Richard Heathfield <rjh@cpax.org.uk> - 2015-03-23 09:46 +0000
        Re: Code for strtol/strtoul Reinhardt Behm <rbehm@hushmail.com> - 2015-03-23 18:44 +0800
        Re: Code for strtol/strtoul Les Cargill <lcargill99@comcast.com> - 2015-03-23 20:29 -0500
          Re: Code for strtol/strtoul Richard Heathfield <rjh@cpax.org.uk> - 2015-03-24 08:12 +0000
      Re: Code for strtol/strtoul Robert Wessel <robertwessel2@yahoo.com> - 2015-03-23 05:27 -0500
      Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-24 07:03 +1300
        Re: Code for strtol/strtoul Ike Naar <ike@iceland.freeshell.org> - 2015-03-23 22:40 +0000
          Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-24 17:17 +1300
            Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 21:42 -0700
              Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-25 17:55 +1300
                Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 08:43 -0700
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-26 14:15 +1300
                Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-28 14:53 -0700
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-29 11:04 +1300
                Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-30 12:34 -0700
                Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-31 21:20 +1300
  Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-24 22:31 -0700
    Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-25 19:30 +1300
      Re: Code for strtol/strtoul Tim Rentsch <txr@alumni.caltech.edu> - 2015-03-25 08:24 -0700
  Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-25 22:43 +0100
    Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-27 19:18 +1300
    Re: Code for strtol/strtoul Steve Thompson <stevet810@gmail.com> - 2015-03-27 15:02 +0000
      Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-27 16:10 +0100
        Re: Code for strtol/strtoul Steve Thompson <stevet810@gmail.com> - 2015-03-27 22:44 +0000
        Re: Code for strtol/strtoul raltbos@xs4all.nl (Richard Bos) - 2015-03-29 15:18 +0000
          Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-29 17:35 +0200
    Re: Code for strtol/strtoul Robert Wessel <robertwessel2@yahoo.com> - 2015-03-28 03:57 -0500
      Re: Code for strtol/strtoul jacob navia <jacob@jacob.remcomp.fr> - 2015-03-28 14:09 +0100
  Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-28 22:58 +1300
    Re: Code for strtol/strtoul Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-03-28 11:33 +0000
      Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-29 08:49 +1300
        Re: Code for strtol/strtoul Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-03-28 22:11 +0000
          Re: Code for strtol/strtoul Ian Collins <ian-news@hotmail.com> - 2015-03-29 11:30 +1300

csiph-web