Re: [avr-gcc-list] Tip: handling volatile operands

[Dave N6NZ]

Dave Hansen wrote:

>    switch (ioport)
>    {
>     case 1: ...
>     case 2: ...
>     case 99: ...
>    }
>
> This is (IMHO) a closer abstraction of what you actually want done.  

But there is no general guarantee that the compiler won't turn a switch 
into an if..then..else if... chain.  It would be an interesting test of 
the volatile keyword to see if declaring the switch variable volatile 
has the effect of forcing a jump table.

It appears to me that this whole discussion is about is trying to cheap 
out on critical sections by looking for locks that come for free under 
specific circumstances with particular releases of the optimizer.  Maybe 
it is better to document the places where it isn't obvious that you need 
a lock?

-dave