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Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers
Date 2017-06-04 13:34 -0700
Organization None to speak of
Message-ID <lnshjflcg1.fsf@kst-u.example.com> (permalink)
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"Pascal J. Bourguignon" <pjb@informatimago.com> writes:
[...]
> Never the less, he introduces an interesting conceptualization of the
> problem, by defining the C* and "C" languages in addition to the C
> standard, and by classifying optimizations relatively to those
> languages.

It would have been nice if the author had described those languages
*correctly*.

http://www.complang.tuwien.ac.at/kps2015/proceedings/KPS_2015_submission_29.pdf

C* is;
    A language (or family of languages) where language constructs
    correspond directly to things that the hardware does. E.g., *
    corresponds to what a hardware multiply instruction does. In terms
    of the C standard, *conforming programs* are written in C*.

The author's use of the phrase "conforming programs" has nothing to do
with the way the standard defines that term.  (N1570 4p7: "A *conforming
program* is one that is acceptable to a conforming implementation.")

And the idea of mapping language constructs directly to hardware seems
frankly a bit silly.  *Which* hardware?  Is a program that uses 64-bit
integers a C* program if it runs on a 64-bit system, but not if it runs
on a 32-bit system that implements 64-bit arithmetic via a longer
sequence of instructions?

"C" is:
    The subset of C* that excludes all undefined behaviour according to
    the C standard. In C-standard terms, programs written in "C" are
    *strictly conforming programs*.

Again, the author's use of "strictly conforming programs" doesn't match
the standard's definition of that term.  A program with no undefined
behavior whose output depends on unspecified or implementation-defined
behavior is not strictly conforming.  (The use of quotation marks in the
name makes it difficult to write about, but that's a minor point.)

Criticisms of C, and of its implementation, are fine, but they should be
based on accurate information.

[...]

-- 
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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What every compiler writer should know about programmersWhat every compiler writer should know about programmers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-06-02 00:57 +0200
  Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers David Brown <david.brown@hesbynett.no> - 2017-06-02 16:07 +0200
    Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-02 09:14 -0700
      Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers David Brown <david.brown@hesbynett.no> - 2017-06-04 13:48 +0200
        Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers "Pascal J. Bourguignon" <pjb@informatimago.com> - 2017-06-04 15:59 +0200
          Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Keith Thompson <kst-u@mib.org> - 2017-06-04 13:34 -0700
            Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-04 16:18 -0700
          Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-04 16:07 -0700
        Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-05 09:12 -0700
          Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-05 17:29 +0100
            Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-05 16:56 -0700
              Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Keith Thompson <kst-u@mib.org> - 2017-06-05 17:49 -0700
              Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-06 11:52 +0100
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-06 08:00 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-06 17:21 +0100
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-06 12:40 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-11 15:59 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-12 08:48 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-13 19:25 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-14 07:18 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-14 10:07 -0700
                Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-14 13:01 -0700
    Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers already5chosen@yahoo.com - 2017-06-04 05:11 -0700
      Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers Tim Rentsch <txr@alumni.caltech.edu> - 2017-06-05 12:55 -0700
  Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers "J. Clarke" <j.clarke.873638@gmail.com> - 2017-06-10 13:08 -0400
    Re: What every compiler writer should know about programmersWhat every compiler writer should know about programmers supercat@casperkitty.com - 2017-06-10 13:23 -0700
  Re: What every compiler writer should know about programmers Noob <root@127.0.0.1> - 2017-06-10 22:13 +0200

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