Re: Compiler stress test

From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.lang.c
Subject	Re: Compiler stress test
Date	2019-02-06 14:10 +1300
Message-ID	<gbuqfgFfhg9U10@mid.individual.net> (permalink)
References	(1 earlier) <Ncf6E.180775$nC1.50518@fx04.am4> <gbubouFfhg9U9@mid.individual.net> <fFn6E.260179$IF1.167829@fx03.am4> <q3d699$sns$1@dont-email.me> <Hqp6E.929682$Sj4.791671@fx15.am4>

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On 06/02/2019 12:58, Bart wrote:
> On 05/02/2019 23:29, David Brown wrote:
>> On 05/02/2019 22:57, Bart wrote:
>>> On 05/02/2019 20:59, Ian Collins wrote:
> 
>>>> There must be something strange (slow) with Windows gcc builds.
>>>> N=20,000:
>>>>
>>>> $ time gcc -c zz.c
>>>>
>>>> real    0m6.427s
>>>> user    0m6.236s
>>>> sys    0m0.184s
>>>>
>>>> $ time clang -c zz.c
>>>>
>>>> real    0m3.186s
>>>> user    0m3.083s
>>>> sys    0m0.076s
>>>
>>>
>>> Not really. Your clang is 2x as fast as gcc, while my clang is 3x as
>>> fast as gcc. There's little in it.
>>>
>>> Obviously your machine is somewhat faster than mine, but enough other
>>> factors can be at play (eg. different compiler versions, different OS,
>>> faster storage or faster file functions) to account for the 1.5x
>>> discrepancy.
>>>
>>
>> I believe your gcc version is quite old - while Ian's is quite new.
>> There have been significant improvements in the compilation of large
>> files in recent versions.
> 
>     C:\mapps>clang --version
>     clang version 7.0.0 (tags/RELEASE_700/final)
>     Target: x86_64-pc-windows-msvc
> 
>     C:\mapps>gcc --version
>     gcc (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 8.1.0
> 
> Is gcc 8.1.0 that old?
> 
> However, if I run the tests again, gcc isn't any faster, but clang is:
> 
>     C:\c>timeit "gcc -c c.c"
>       gcc -c c.c 34.13
> 
>     C:\c>timeit "gcc -c c.c"
>       gcc -c c.c 33.65
> 
>     C:\c>timeit "clang -c c.c"
>     clang -c c.c 6.37
> 
>     C:\c>timeit "clang -c c.c"
>     clang -c c.c 6.40
> 
> Now gcc takes 5 times as long as clang.

So there is a problem with gcc builds for Windows.

-- 
Ian.

Thread

Compiler stress test jacobnavia <jacob@jacob.remcomp.fr> - 2019-02-05 10:30 +0100
  Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-05 22:50 +1300
    Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-05 22:56 +1300
      strict aliasing rule on buffers slacked.misha@gmail.com - 2019-02-05 13:33 +0100
        Re: strict aliasing rule on buffers Richard Damon <Richard@Damon-Family.org> - 2019-02-05 08:13 -0500
        Re: strict aliasing rule on buffers Barry Schwarz <schwarzb@dqel.com> - 2019-02-05 06:00 -0800
        Re: strict aliasing rule on buffers David Brown <david.brown@hesbynett.no> - 2019-02-05 15:33 +0100
        Re: strict aliasing rule on buffers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2019-02-05 14:36 +0000
        Re: strict aliasing rule on buffers James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-02-05 07:27 -0800
    Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-07 08:28 +1300
      Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-06 19:48 +0000
      Re: Compiler stress test jacobnavia <jacob@jacob.remcomp.fr> - 2019-02-06 22:11 +0100
        Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-07 00:34 +0100
          Re: Compiler stress test jacobnavia <jacob@jacob.remcomp.fr> - 2019-02-07 07:13 +0100
            Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-07 08:32 +0100
              Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-07 12:06 +0000
                Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-07 14:08 +0100
                Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-07 13:49 +0000
                Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-07 17:01 +0100
                Re: Compiler stress test jacobnavia <jacob@jacob.remcomp.fr> - 2019-02-07 22:26 +0100
                Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-07 23:24 +0100
                Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-07 23:20 +0000
                Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-08 10:42 +0100
                Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-08 16:37 +1300
                Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-08 12:30 +0100
                Re: Compiler stress test Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2019-02-08 08:18 -0800
                Re: Compiler stress test scott@slp53.sl.home (Scott Lurndal) - 2019-02-08 16:04 +0000
                Re: Compiler stress test Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-02-11 20:34 +0000
                Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-08 16:30 +1300
  Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-05 12:20 +0000
    Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-06 09:59 +1300
      Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-05 21:57 +0000
        Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-06 00:29 +0100
          Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-05 23:58 +0000
            Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-06 14:10 +1300
              Re: Compiler stress test Bart <bc@freeuk.com> - 2019-02-06 01:16 +0000
                Re: Compiler stress test Ian Collins <ian-news@hotmail.com> - 2019-02-06 14:21 +1300
                Re: Compiler stress test Paul <nospam@needed.invalid> - 2019-02-06 01:28 -0500
                Re: Compiler stress test Paul <nospam@needed.invalid> - 2019-02-08 03:51 -0500
            Re: Compiler stress test David Brown <david.brown@hesbynett.no> - 2019-02-06 08:13 +0100
      Re: Compiler stress test BGB <cr88192@hotmail.com> - 2019-02-06 13:13 -0600

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