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From: scs@athena.mit.edu (Steve Summit)
Newsgroups: comp.lang.c
Subject: Re: DEFINITE bug in Turbo C 2.0
Summary: Enough, already
Message-ID: <1990Mar24.000455.24060@athena.mit.edu>
Date: 24 Mar 90 00:04:55 GMT
References: <802@zeusa.UUCP> <451@wattres.UUCP> <1990Mar23.074526.8286@ncsuvx.ncsu.edu> <946@lectroid.sw.stratus.com> <16259@haddock.ima.isc.com> <1990Mar23.073923.6425@cs.eur.nl>
Sender: scs@adam.mit.edu (Steve Summit)
Reply-To: scs@adam.mit.edu (Steve Summit)
Organization: not likely
Lines: 30

In article <451@wattres.UUCP> steve@wattres.UUCP (Steve Watt) writes:
>Some more votes:
...
>Interesting...
>...but I can sure understand most of the others, except for cc under Ultrix...

In article <1990Mar23.074526.8286@ncsuvx.ncsu.edu> dks@shumv1.ncsu.edu (D. K. Smith) writes:
>...I decided 
>to compare the results of the above code on my THINK C 3.02 compiler...

It has already been explained that the referenced code yields
undefined, compiler-dependent behavior.  Investigate it further
if you must, but please don't post the results here.  Which
"answer" a particular compiler gives is simply not useful (nor
particularly interesting).

In article <1990Mar23.073923.6425@cs.eur.nl> reino@cs.eur.nl (Reino de Boer) writes:
>I think the point made was not that the results should be the same, but
>that... both computations [should] leave (11 * 12) in "x".

Don't make the common mistake of believing that x++ increments x
just after yielding its former value, but before doing anything
else in the expression.  The incrementation merely happens later,
sometime before the following _statement_ is executed (formally,
before the next "sequence point"), but it need not happen before
the next use of x in the same expression.  (The "relative
precedence of '++' and '*'" doesn't really enter into it.)

                                            Steve Summit
                                            scs@adam.pika.mit.edu