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Groups > comp.lang.c > #98466

Re: micro-architectural details

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.lang.c
Subject Re: micro-architectural details
Date 2016-12-09 10:27 +0100
Organization A noiseless patient Spider
Message-ID <o2dtba$bvi$1@dont-email.me> (permalink)
References (11 earlier) <o29tdp$nbl$1@dont-email.me> <o2a39e$c8b$1@dont-email.me> <o2cg6d$mo0$1@dont-email.me> <o2cl1i$8c8$1@dont-email.me> <o2cmht$dkt$1@dont-email.me>

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On 08/12/16 23:25, Noob wrote:
> On 08/12/2016 22:59, BartC wrote:
>> On 08/12/2016 20:36, Noob wrote:
>>> On 07/12/2016 23:44, jacobnavia wrote:
>>
>>> OK, mister smarty pants. How do you implement your proposed
>>> overflow detection scheme on the Itanium?
>>>
>>> http://www.intel.com/content/dam/doc/manual/itanium-architecture-vol-1-2-3-4-reference-set-manual.pdf
>>
>> Start by writing an emulator for x86?
> 
> In fact, Intel built an x86 "emulator" for IA-64.
> https://en.wikipedia.org/wiki/IA-32_Execution_Layer
> 
>>> IMO, writing a compiler targeting a few arches does not make
>>> one qualified to dismiss 30 years of engineering compromises
>>> by WG14 et al. Especially if one doesn't offer an honest
>>> assessment of the pros and cons of one's proposal.
>>
>> How many years did it take to agree on binary literals? (That's if they 
>> have agreed yet.)
> 
> You're not allowed to discuss C if you can't even bother to check
> the standard at least once in a blue moon.

To save anyone checking, binary literals of the form 0b0101 are in
C++11, but not C11 (or any other C standard).

> 
>> There are many things that are no-brainers yet which 
>> haven't made it into the language, despite their 30 years' experience.
> 
> Many things such as... Binary constants? What else?
> 
> I wasn't aware that they are allowed as a gcc extension.
> https://gcc.gnu.org/onlinedocs/gcc/Binary-constants.html

It has been a gcc extension for a /long/ time now.  This was sufficient
"precedence and utility" to get binary literals included in the C++
standards, but not in the C standards.  The C standards folks are always
more conservative than the C++ standards folks (and that is a good thing
for both languages).  Personally, I think the C folks were /too/
conservative in rejecting 0b0101 literals in C11, but that's their decision.

> 
> There are also clever macro hacks to support binary constants.
> http://embeddedgurus.com/barr-code/2009/09/binary-literals-in-c/

"Clever", or "ugly".  I can't say I use binary literals very often, even
though I work in small embedded systems, but when I need them I am glad
they are supported directly by my compiler and that I don't need such hacks.

> 
> I haven't made a careful costs/benefits assessment for such
> a feature. Apparently, WG14 rejected them for C99.
> 
> http://www.open-std.org/jtc1/sc22/wg14/www/C99RationaleV5.10.pdf
> 
> "A proposal to add binary constants was rejected due to lack of
> precedent and insufficient utility."
> 
> Perhaps after a few decades of gcc, clang, and icc having that
> particular extension, WG14 will accept it?

gcc has had them for years, and other embedded compilers have had them
even longer.  To be fair, some of those older embedded compilers used a
different format for binary literals (I can't think why - 0b0101 is the
obvious choice for consistency with 0x literals).

> 
> Regards.
>

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"Let’s Stop Bashing C" Lynn McGuire <lynnmcguire5@gmail.com> - 2016-12-05 19:57 -0600
  Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 02:34 +0000
    Re: "Let’s Stop Bashing C" BGB <cr88192@hotmail.com> - 2016-12-06 00:13 -0600
      Re: "Let’s Stop Bashing C" BartC <bc@freeuk.com> - 2016-12-06 23:15 +0000
        Re: "Let’s Stop Bashing C" BGB <cr88192@hotmail.com> - 2016-12-06 21:16 -0600
    Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 11:54 +0000
    Re: "Let’s Stop Bashing C" BartC <bc@freeuk.com> - 2016-12-06 12:07 +0000
      Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 12:25 +0000
        Re: "Let’s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-06 14:07 +0100
          Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 13:40 +0000
        Re: "Let’s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 19:40 +0100
          Re: "Lete2��s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-06 13:55 -0500
            Re: "Lete2��s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 19:13 +0000
              Re: "Lete2��s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-06 11:51 -0800
                Re: "Lete2��s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 12:22 -0800
            Re: "Lete2��s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 20:16 +0100
            Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 11:20 -0800
              Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 22:15 +0100
                Re: "Lete2�™s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-06 16:49 -0500
                Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 14:24 -0800
                Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:07 +0100
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-07 22:04 +0100
                Re: micro-architectural details jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 23:44 +0100
                Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-07 23:02 +0000
                Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-07 15:28 -0800
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 21:36 +0100
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 12:56 -0800
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:03 +0100
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 14:21 -0800
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:36 +0100
                Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-08 21:59 +0000
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:25 +0100
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 14:34 -0800
                Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:59 +0100
                Re: micro-architectural details Melzzzzz <mel@zzzzz.com> - 2016-12-09 00:18 +0100
                Re: micro-architectural details fir <profesor.fir@gmail.com> - 2016-12-09 00:06 -0800
                Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-09 11:35 +0000
                Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-09 12:12 +0000
                Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-09 13:33 +0100
                Re: micro-architectural details Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-09 15:41 -0800
                Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-10 09:28 -0800
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-10 09:58 -0800
                Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 22:53 -0800
                Re: micro-architectural details Robert Wessel <robertwessel2@yahoo.com> - 2016-12-11 03:10 -0600
                Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-11 13:48 +0000
                Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-11 14:43 +0000
                Re: micro-architectural details Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 16:23 +0000
                Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-11 12:53 -0800
                Re: micro-architectural details Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 21:27 +0000
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-11 08:46 -0800
                Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:14 -0800
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-15 08:25 -0800
                Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:11 -0800
                Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-15 14:28 +0000
                Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-11 18:38 +0100
                Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-15 00:25 -0800
                Re: micro-architectural details supercat@casperkitty.com - 2016-12-09 07:42 -0800
                Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-09 11:54 -0800
                Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-09 10:27 +0100
                Re: other missing features (no-brainers) Noob <root@127.0.0.1> - 2016-12-09 17:05 +0100
                Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-09 09:51 +0000
                Re: "Lete2�™s Stop Bashing C" Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-06 20:42 -0500
                Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 14:16 -0800
                Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:31 +0100
                Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-06 15:55 -0800
                Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 01:01 +0100
                Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 16:42 -0800
                Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 01:55 +0100
                Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-07 07:11 -0800
                Re: "Lete2??s Stop Bashing C" Ike Naar <ike@iceland.freeshell.org> - 2016-12-06 23:05 +0000
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:43 +0100
                Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-07 03:06 +0000
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:47 +0100
                Re: "Lete2??s Stop Bashing C" Thiago Adams <thiago.adams@gmail.com> - 2016-12-07 03:10 -0800
                Re: "Lete2??s Stop Bashing C" Thiago Adams <thiago.adams@gmail.com> - 2016-12-07 03:13 -0800
                Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-07 11:47 +0000
                Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-07 12:08 +0000
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-07 23:45 +0100
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 00:22 +0100
                Re: "Lete2??s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 15:32 -0800
                Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 01:25 +0100
                Re: "Let's Stop Bashing C" supercat@casperkitty.com - 2016-12-07 16:36 -0800
                Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 17:09 -0800
                Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 10:28 +0100
                Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-08 08:34 -0800
                Re: "Let's Stop Bashing C" Gareth Owen <gwowen@gmail.com> - 2016-12-08 20:08 +0000
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 10:24 +0100
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 15:49 +0100
                Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 15:23 +0000
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 16:58 +0100
                Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 18:57 +0000
                Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 15:29 +0000
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 17:09 +0100
                Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 16:41 +0000
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 17:04 +0100
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 17:15 +0100
                Re: "Lete2??s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-08 11:34 -0500
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 18:40 +0100
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 10:00 -0800
                Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 19:05 +0000
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 19:58 +0100
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 08:22 -0800
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 20:12 +0100
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 11:40 -0800
                Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-10 02:44 -0600
                Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 16:22 +0000
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 20:14 +0100
                Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-10 02:19 -0600
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 07:44 -0800
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 22:05 +0100
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 22:14 +0100
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-09 10:39 +0100
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 13:33 -0800
                Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-09 11:13 +0100
                Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-07 06:27 -0600
                Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-07 07:17 -0800
                Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-07 23:43 -0600
                Re: "Lete2??s Stop Bashing C" Ike Naar <ike@iceland.freeshell.org> - 2016-12-07 07:41 +0000
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:45 +0100
                Re: "Lete2??s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 09:22 -0800
                Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:49 +0100
                Re: "Lete2??s Stop Bashing C" Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-07 09:28 -0500
            Re: "Lete2��s Stop Bashing C" "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-06 14:22 -0500
            Re: Subject field encoding Noob <root@127.0.0.1> - 2016-12-07 21:40 +0100
              Re: Subject field encoding Keith Thompson <kst-u@mib.org> - 2016-12-07 13:01 -0800
              Re: Subject field encoding Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-07 16:02 -0500
            Re: "Lete2�™s Stop Bashing C" asetofsymbols@gmail.com - 2016-12-08 15:50 -0800
          Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 19:07 +0000
    Re: "Let€™s Stop Bashing C" Xcott Craver <nospam@nospam.invalid> - 2016-12-07 16:48 -0500
      Re: "Let's Stop Bashing C" Noob <root@127.0.0.1> - 2016-12-07 23:29 +0100
  Re: "Let’s Stop Bashing C" "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-12-06 12:06 +0800

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