Re: gcc failure (optimised/non-optimised)

From	Robert Wessel <robertwessel2@yahoo.com>
Newsgroups	comp.lang.c
Subject	Re: gcc failure (optimised/non-optimised)
Message-ID	<80pbiclia7p09gga84uc9i2eetsrl3h0ef@4ax.com> (permalink)
References	(6 earlier) <ofadk9$9tt$1@dont-email.me> <udhhhc910cbfqjhbh8migkdverspv3crc4@4ax.com> <a4177340-0bad-4fb6-995f-885c295c39c8@googlegroups.com> <mgpshc16hk6u5v8p1h9neq74tb4d0iqrgf@4ax.com> <08edccbb-aa66-4533-a666-e06659d672c2@googlegroups.com>
Organization	Forte - www.forteinc.com
Date	2017-05-24 14:51 -0500

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On Fri, 19 May 2017 00:30:56 -0700 (PDT), joel.rees@gmail.com wrote:

>On Friday, May 19, 2017 at 12:28:52 PM UTC+9, robert...@yahoo.com wrote:
>> On Thu, 18 May 2017 06:17:22 -0700 (PDT), joel.rees@somewhere wrote:
>> 
>> >On Monday, May 15, 2017 at 6:05:02 AM UTC+9, robert...@somewhere wrote:
>> >> On Sun, 14 May 2017 13:14:11 -0700, "Chris M. Thomasson"
>> >> <invalid@invalid.invalid> wrote:
>> >> 
>> >> >On 5/12/2017 7:30 AM, joel.rees@somewhere wrote:
>> >> >> On Friday, May 12, 2017 at 5:55:20 PM UTC+9, David Brown wrote:
>> >> >>> On 11/05/17 23:43, Chris M. Thomasson wrote:
>> >> >>>> On 5/11/2017 1:45 AM, David Brown wrote:
>> >> >>>>> On 11/05/17 06:56, Chris M. Thomasson wrote:
>> >> >>>>>> On 5/10/2017 9:26 AM, supercat@somewhere wrote:
>> >> >>>>>>> On Wednesday, May 10, 2017 at 7:22:45 AM UTC-5, David Brown wrote:
>> >> >[...]
>> >> >
>> >> > > And we get spinlocks, whose very name indicates what's wrong with
>> >> > > them, instead of proper primitives for managing threads of
>> >> > > execution.
>> >> >
>> >> >Why do you think we need spinlocks on Intel processors? We can code a 
>> >> >diverse array of non-blocking algorithms on Intel cpus.
>> >
>> >Because Intel's CPUs make it so hard to build a proper atomic
>> >
>> >... all in the name of hyperthreading. 
>> 
>> 
>> How is it harder than a "real" multi-core situation with x86?
>
>It's the focus on trying to keep the CPU from stalling, really.
>
>Optimizing the wrong things.


Which really doesn't answer the question.


>> >> The only reason I brought up spinlocks is that they're a sufficient
>> >> primitive to allow the building of all the atomic functions in C. That
>> >> many processors provide better ways to implement many of those atomics
>> >> is nice, but not really pertinent to the original point.
>> >
>> >Oh, yes, they are sufficient for building all the atomic functions in C.
>> >
>> >If you ignore the time domain. 
>> 
>> 
>> The standard more-or-less ignores the time domain as regards the
>> atomics.
>
>Which is a problem.


Perhaps, but not, as near as I can tell, the one being discussed.

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Re: gcc failure (optimised/non-optimised) joel.rees@gmail.com - 2017-05-18 06:17 -0700
  Re: gcc failure (optimised/non-optimised) supercat@casperkitty.com - 2017-05-18 07:51 -0700
  Re: gcc failure (optimised/non-optimised) Robert Wessel <robertwessel2@yahoo.com> - 2017-05-18 22:28 -0500
    Re: gcc failure (optimised/non-optimised) joel.rees@gmail.com - 2017-05-19 00:30 -0700
      Re: gcc failure (optimised/non-optimised) Robert Wessel <robertwessel2@yahoo.com> - 2017-05-24 14:51 -0500

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