conditional expression evaluation question

[John P. Nelson]

>	while (cp < end && triples < MINSKIP)
>		if ((*cp++ | *cp++ | *cp++) == 0) ++triples;
>		else triples = 0;

Assuming that bitwise OR is really what you wanted, this code fragment will
probably break several existing compilers.  As for ANSI C, they introduced
the concept of sequence-points, at which points all side effects must have
taken effect.  Sequence-points occur at && || , :? operators (and the end
of the expression).  There are no sequence points in that bitwise OR
expression.  To quote the standard (under the ++ operator):  "The side
effect of updating the stored value of the operand may be delayed until the
next sequence point is reached."

This says to me that a ANSI conforming C compiler is free to optimize all
the increments to the end of the expression if it wishes to.  The above
code would be unportable.