Re: qsort() vs. std::sort

From	Bonita Montero <Bonita.Montero@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: qsort() vs. std::sort
Date	2022-04-25 13:32 +0200
Organization	A noiseless patient Spider
Message-ID	<t460se$upn$1@dont-email.me> (permalink)
References	<t4092b$des$1@dont-email.me> <18ed77e2-889f-48d1-ac35-1a16122f8d57n@googlegroups.com> <t45uug$ej4$1@dont-email.me>

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Am 25.04.2022 um 12:59 schrieb Bonita Montero:
> Am 25.04.2022 um 10:16 schrieb Öö Tiib:
>> On Saturday, 23 April 2022 at 10:15:39 UTC+3, Bonita Montero wrote:
>>> I just measured how superior C++'s std::sort is over C's qsort:
>>> These are the results on my computer (Ryzen Threadripper 3990X):
>>>
>>> 2: 279%
>>> 4: 303%
>>> 8: 531%
>>> 16: 611%
>>> 32: 543%
>>> 64: 627%
>>> 128: 536%
>>> 256: 481%
>>> 512: 402%
>>> 1024: 316%
>>> 2048: 260%
>>> 4096: 230%
>>>
>>> Up to 6,3 times faster with less coding !
>>
>> Perhaps you have biased standard library. For example that online
>> compiler <http://coliru.stacked-crooked.com/a/31e2a018eaabe85a>
>> With array sizes that matter > 1024 the sorts look about equal:
>> 2: 202%
>> 4: 420%
>> 8: 436%
>> 16: 357%
>> 32: 530%
>> 64: 675%
>> 128: 432%
>> 256: 421%
>> 512: 303%
>> 1024: 375%
>> 2048: 90%
>> 4096: 96%
>> 8192: 98%
> 
> The result is dependent on
> a) the implementation of the standard library
> b) how good the compiler optimizes and
> c) the CPU you run the code on.

And there's another significant point:
if you run the code online the CPU might be shared among others
also running or compiling some code. So you'll have to run the
code very often to get an equal distribution of that effect.

Thread

qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-23 09:15 +0200
  Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-23 09:31 +0200
  Re: qsort() vs. std::sort Juha Nieminen <nospam@thanks.invalid> - 2022-04-25 05:56 +0000
    Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-25 08:27 +0200
  Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-25 01:16 -0700
    Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-25 12:59 +0200
      Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-25 13:32 +0200
        Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-25 05:26 -0700
          Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-25 17:41 +0200
            Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-26 00:46 -0700
              Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-26 12:19 +0200
      Re: qsort() vs. std::sort Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-04-25 05:24 -0700
        Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-25 17:42 +0200
    Re: qsort() vs. std::sort Juha Nieminen <nospam@thanks.invalid> - 2022-04-26 05:26 +0000
      Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-26 00:19 -0700
      Re: qsort() vs. std::sort scott@slp53.sl.home (Scott Lurndal) - 2022-04-26 14:03 +0000
        Re: qsort() vs. std::sort Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-04-26 08:50 -0700
        Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-29 01:38 -0700
          Re: qsort() vs. std::sort Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-04-29 02:39 -0700
            Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-29 04:06 -0700
    Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-26 12:28 +0200
      Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-26 04:54 -0700
        Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-26 14:10 +0200
          Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-26 06:23 -0700
            Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-26 16:26 +0200
  Re: qsort() vs. std::sort William Ahern <william@25thandClement.com> - 2022-04-27 17:03 -0700
    Re: qsort() vs. std::sort Bonita Montero <Bonita.Montero@gmail.com> - 2022-04-28 06:58 +0200
    Re: qsort() vs. std::sort Juha Nieminen <nospam@thanks.invalid> - 2022-04-28 06:33 +0000
      Re: qsort() vs. std::sort Öö Tiib <ootiib@hot.ee> - 2022-04-28 01:08 -0700
        Re: qsort() vs. std::sort Juha Nieminen <nospam@thanks.invalid> - 2022-04-28 08:23 +0000
      Re: qsort() vs. std::sort William Ahern <william@25thandClement.com> - 2022-04-28 02:55 -0700

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