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Groups > comp.lang.c > #129477
| From | Keith Thompson <kst-u@mib.org> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: stdcbench benchmark |
| Date | 2018-04-19 16:05 -0700 |
| Organization | None to speak of |
| Message-ID | <lnsh7qkda9.fsf@kst-u.example.com> (permalink) |
| References | (16 earlier) <H6FBC.478231$0g.141253@fx06.am4> <pb78io$3e0$1@dont-email.me> <NL5CC.658974$Oy5.533339@fx11.am4> <fjsbc0Fcse1U1@mid.individual.net> <9Q8CC.663606$%a5.321093@fx21.am4> |
bartc <bc@freeuk.com> writes:
> On 19/04/2018 21:07, Ian Collins wrote:
>> On 04/20/2018 07:05 AM, bartc wrote:
>>> I said the way C++ is used is complicated - true or not?
>>
>> That applies to any language and depends on the user, doesn't at?
>
> This is in the context of the the example application that slows down
> dramatically when not optimised. Apparently there were no other
> explanations.
Let's restore some context to this discussion. The following text is
quoted from articles earlier in this thread.
David Brown:
For some real C code - yes, that is exactly what happens.
And the efficiency of the generated code matters little in
such cases. For other real C code, it is a different situation.
Scott Lurndal:
Indeed. The application I'm currently working on has between 6
and 96 threads running flat-out, 100%. No I/O. Might block
infrequently waiting for a mutex, very infrequently, the
threads are pretty much independent. Every cycle matters,
so work goes into looking at L1/L2 cache behavior, data
layout wrt cache-lines, compiler optimzations, and inline
micro-optimizations (e.g. avoiding blocking operations like
mutexes when possible by using atomics instead)
bartc:
How much difference would it make if you left all that in place,
but switched off compiler optimisations?
Scott Lurndal:
It runs 20 to 40 times slower.
Then, several followups later, David Brown:
Good software design will involve a lot of functions - often
small ones. If Scott's code is C++ rather than C, that will
likely be even more true. Inlining is disabled in gcc at -O0,
even for functions marked "inline" (since the C/C++ keyword
"inline" does not force function inlining). This can easily
make a massive difference, especially as inlining opens up new
possibilities for other optimisations (constant propagation,
strength reduction, dead code elimination, etc.). gcc does a
lot of that kind of thing.
Scott has not posted in this thread since then.
So this entire argument about C++ (which, I'll point out, is not
the topic of this newsgroup) was based on David Brown's speculation
that Scott's application *might* be C++.
The fact that an application runs 20 to 40 times slower without
optimization is somewhat interesting. I see no reason to doubt
Scott's word on the matter, or to speculate further on the reasons
behind it without more information from Scott (who is, of course,
under no obligation to provide it).
--
Keith Thompson (The_Other_Keith) kst-u@mib.org <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
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stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-15 10:38 +0200
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-15 02:31 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-15 13:42 +0100
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-15 18:00 +0100
Re: stdcbench benchmark Melzzzzz <Melzzzzz@zzzzz.com> - 2018-04-15 18:11 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-15 19:30 +0100
Re: stdcbench benchmark Melzzzzz <Melzzzzz@zzzzz.com> - 2018-04-15 18:52 +0000
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-15 20:15 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-15 20:42 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-15 22:31 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-15 23:29 +0100
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-16 07:48 +0200
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-15 23:22 -0700
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-16 11:52 +0200
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-16 09:56 +0200
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-16 01:58 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 10:08 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 11:37 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-16 22:42 +1200
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 12:54 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 13:02 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 14:39 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 14:53 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 16:32 +0200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 14:41 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 15:56 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 17:21 +0200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 15:43 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 17:00 +0100
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 16:09 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 17:22 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 09:35 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 11:42 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 14:14 +0200
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-17 15:49 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 18:45 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 23:00 +0200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-17 21:18 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 23:20 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 09:27 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 11:30 +0100
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-18 03:43 -0700
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-18 22:58 +1200
Re: stdcbench benchmark mark.bluemel@gmail.com - 2018-04-18 04:01 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 12:39 +0100
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-18 06:52 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 13:59 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 06:14 -0700
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-19 07:39 +1200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 06:14 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 16:31 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 08:00 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 17:26 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 08:37 -0700
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-18 16:12 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 18:15 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 04:01 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 13:01 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 04:15 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 13:41 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-18 05:35 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 12:26 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 13:58 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 22:29 +0100
Re: stdcbench benchmark Keith Thompson <kst-u@mib.org> - 2018-04-18 10:34 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 22:34 +0200
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 22:35 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-19 20:05 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-20 08:07 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-19 23:34 +0100
Re: stdcbench benchmark Keith Thompson <kst-u@mib.org> - 2018-04-19 16:05 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 00:18 +0100
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-25 23:12 +0000
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-20 16:15 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 11:39 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-20 23:46 +1200
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-20 05:04 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 13:27 +0100
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-20 06:06 -0700
Re: stdcbench benchmark supercat@casperkitty.com - 2018-04-20 13:05 -0700
Re: stdcbench benchmark mark.bluemel@gmail.com - 2018-04-20 01:23 -0700
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-20 01:40 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 12:04 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-20 04:16 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 13:48 +0100
Re: stdcbench benchmark Tim Rentsch <txr@alumni.caltech.edu> - 2018-04-23 11:53 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-23 20:33 +0100
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-26 01:00 -0700
Re: stdcbench benchmark Keith Thompson <kst-u@mib.org> - 2018-04-20 09:17 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 19:25 +0100
Re: stdcbench benchmark Keith Thompson <kst-u@mib.org> - 2018-04-20 11:58 -0700
Re: stdcbench benchmark supercat@casperkitty.com - 2018-04-20 12:30 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 21:03 +0100
Re: stdcbench benchmark Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-20 22:16 +0100
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 23:09 +0100
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 14:42 +0100
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-20 09:30 -0700
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-21 07:24 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 20:43 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-21 07:59 +1200
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-21 08:01 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 21:18 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-21 09:17 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-20 23:15 +0100
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 02:14 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 09:54 +0200
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-18 01:21 -0700
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 11:40 +0100
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-18 11:26 +1200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-18 01:48 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-18 09:58 +0200
Re: stdcbench benchmark Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-04-16 16:45 +0000
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 17:31 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 18:53 +0100
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 17:55 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 19:01 +0100
Re: stdcbench benchmark Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-04-16 20:28 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-16 21:57 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 09:45 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 12:24 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 14:31 +0200
Re: stdcbench benchmark Robert Wessel <robertwessel2@yahoo.com> - 2018-04-16 16:59 -0500
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 01:02 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 09:47 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 13:16 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 14:38 +0200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-17 13:18 +0000
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 14:37 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 06:44 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 15:58 +0200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-17 15:43 +0000
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-17 08:47 -0700
Re: stdcbench benchmark Ian Collins <ian-news@hotmail.com> - 2018-04-17 08:04 +1200
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 20:30 +0000
Re: stdcbench benchmark Melzzzzz <Melzzzzz@zzzzz.com> - 2018-04-16 16:31 +0000
Re: stdcbench benchmark Keith Thompson <kst-u@mib.org> - 2018-04-20 14:22 -0700
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-17 00:42 -0700
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-16 07:00 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-16 16:35 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-16 09:28 -0700
Re: stdcbench benchmark scott@slp53.sl.home (Scott Lurndal) - 2018-04-16 17:42 +0000
Re: stdcbench benchmark Robert Wessel <robertwessel2@yahoo.com> - 2018-04-16 17:07 -0500
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 02:50 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 12:42 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 11:58 +0100
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-17 14:01 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 13:40 +0100
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-17 15:41 +0200
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 14:46 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 06:09 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 16:07 +0200
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 14:43 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 15:26 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 07:42 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 16:51 +0200
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 08:07 -0700
Re: stdcbench benchmark Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-17 08:16 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 23:17 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 17:12 +0100
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 23:26 +0200
Re: stdcbench benchmark bartc <bc@freeuk.com> - 2018-04-17 23:38 +0100
Re: stdcbench benchmark Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-04-17 05:52 -0700
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 16:10 +0200
Re: stdcbench benchmark David Brown <david.brown@hesbynett.no> - 2018-04-17 10:02 +0200
Re: stdcbench benchmark Philipp Klaus Krause <pkk@spth.de> - 2018-04-15 23:20 +0200
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