Hi, guys,
i do no understand this discussion about the code fragment
bit = ++bit % 8;
1. Since 20 years, C is my favorite programming language
2. Since some years, I give classes in C
3. The code line "bit = ++bit % 8", is fully correct.
Reason:
a) ++ has higher priority than %
b) What happens: i) bit will be incremented
ii) the modulo 8 operation is done
iii) the result will be stored in bit
4. Meaning of "bit = ++bit"??? The same does "++bit"
5. None of my C compilers (gcc or IRIX c compiler) report
any warning.
6. RESULT: The code "bit = ++bit % 8" is OK!
7. The compiler which produces the warning is buggy!
Regards
Joachim Backes
--
Joachim Backes <bac...@rhrk.uni-kl.de> | Univ. of Kaiserslautern
Computer Center, High Performance Computing | Phone: +49-631-205-2438
D-67653 Kaiserslautern, PO Box 3049, Germany | Fax: +49-631-205-3056
---------------------------------------------+------------------------
WWW: http://hlrwm.rhrk.uni-kl.de/home/staff/backes.html
On 24-Jan-2002 Karsten Festag wrote:
> Hi,
>
> I'll split
> bit = ++bit % 8;
> in the two lines
> bit = ++bit;
> bit %= 8;
>
> in microtek2.c
>
> Henning, could you do this for me in CVS?
>
> Thanks
>
> Karsten
>
> Tim Waugh schrieb:
> > On Wed, Jan 23, 2002 at 09:43:35PM +0100, Henning
> > Meier-Geinitz wrote:
> >
> > > This is with gcc-3.x? I don't get them with gcc 2.95.4.
> >
> > Yes.
> >
> > > > They
> > > > are for things like:
> > > >
> > > > bit = ++bit % 8;
> > > >
> > > > which are indeed undefined.
> > >
> > > Because it's not clear if bit should be incremented and
> > then the right
> > > side assigned to it or vice versa? Or what's the excat
> > problem?
> >
> > Yes, that's right. There is only one sequence point in
> > 'bit = ++bit %
> > 8;', at the end, and so the operations can happen in any
> > order. There
> > are two assignments to 'bit': the '=' operation and the
> > '++'
> > operation.
> >
> > Tim.
> > */
> >
> >
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