Re: The bug

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From	Keith Thompson <kst-u@mib.org>
Newsgroups	comp.lang.c
Subject	Re: The bug
Date	Tue, 13 Feb 2018 11:44:13 -0800
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jacobnavia <jacob@jacob.remcomp.fr> writes:
> Le 08/02/2018 à 22:50, jacobnavia a écrit :
>> Consider this program:
[snip]
>> Compiled without any optimizations, this program outputs nothing. Gcc 
>> with -O2 will print "bug".
>> 
>> Why is this happening?
>> 
>
> I found the root cause: gcc/clang will assume that there is no "UB" i.e. 
> no overflow. Then, a multiplication of two unsigned values into a signed 
> result can't be negative.

*You* found the root cause?  I posted the explanation last Thursday.

If you've killfiled me, you're free to do so, but I'd like to know about
it so I don't waste my time.

Can someone post a followup to this so jacob sees it?  I'll also mention
that I recently posted an lcc-win bug report in comp.compilers.lcc;
jacob might have missed that as well.

-- 
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"

Thread

The bug jacobnavia <jacob@jacob.remcomp.fr> - 2018-02-08 22:50 +0100
  Re: The bug Keith Thompson <kst-u@mib.org> - 2018-02-08 14:15 -0800
  Re: The bug jacobnavia <jacob@jacob.remcomp.fr> - 2018-02-13 10:25 +0100
    Re: The bug David Brown <david.brown@hesbynett.no> - 2018-02-13 10:51 +0100
      Re: The bug jacobnavia <jacob@jacob.remcomp.fr> - 2018-02-13 11:19 +0100
        Re: The bug David Brown <david.brown@hesbynett.no> - 2018-02-13 12:23 +0100
      Re: The bug Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2018-02-13 08:19 -0800
        Re: The bug David Brown <david.brown@hesbynett.no> - 2018-02-15 10:52 +0100
    Re: The bug Noob <root@127.0.0.1> - 2018-02-13 16:19 +0100
      Re: The bug Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-19 12:11 -0800
        Re: The bug supercat@casperkitty.com - 2018-02-19 16:31 -0800
          Re: The bug Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-21 23:03 -0800
            Re: The bug supercat@casperkitty.com - 2018-02-23 16:40 -0800
              Re: The bug Richard Damon <Richard@Damon-Family.org> - 2018-02-24 05:57 -0500
              Re: The bug Tim Rentsch <txr@alumni.caltech.edu> - 2018-02-24 13:11 -0800
                Re: The bug Anton Shepelev <anton.txt@gmail.com> - 2018-02-25 00:15 +0300
    Re: The bug Keith Thompson <kst-u@mib.org> - 2018-02-13 11:44 -0800
      Re: The bug asetofsymbols@gmail.com - 2018-02-13 12:13 -0800
      Re: The bug Noob <root@127.0.0.1> - 2018-02-15 09:45 +0100

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