On 4 May 2000, Robert M. Love wrote:
> maybe im reading the thread wrong, but Cesar is saying the code
> while ((mm->swap_cnt << 2 * (i + 1) < max_cnt) && i++ < 10)
> does not guarentee that the expression to the left of && occurs prior to
> "i++" -- and he is Right,
> because the C standard does *not* specify this. proof is in K&R, where they
> explicitly mention compiler design or optimization can change compound
> statement ordering in the resulting machine code. thus, i agree an
> alternative should be considered in the kernel.
If a compiler compiles code so that the "i++" executes before the code to
the left of the && then the compiler is busted, plain and simple. This is
a feature of C sometimes referred to as "short-circuiting". I am certain
that the "compiler design or optimization" that K&R are talking about does
not apply here.
-Andrew
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