Re: [avr-gcc-list] Re: C vs. assembly performance

[Georg-Johann Lay]

Vincent Trouilliez schrieb:
> On Sat, 28 Feb 2009 19:09:13 -0700
> "Weddington, Eric" <address@hidden> wrote:
>
> > So in application code I tend to avoid switch statements for embedded systems, 
> > unless I'm writing throw-away code or the application is trivial.
>
> Oh no ! ;-)
> I have only recently got round to using switch statements, to improve
> code legibility. In my current/first embedded project, I happen to have
> a very long (25 cases, 160 lines long) switch statement.. I dread to
> think what it would like if I had to replace it (what else with ?) with
> nested if's !
> How readable would that be... not to mention that with indentation, 25
> levels of nesting would mean the last case would be 3 meters on the far
> right... ;-)
>
> Any coding tips to make all this look about readable by human
> beings ?! ;-/
You can write

if ()
{}
else if ()
{}
else if ()
{}
...
else
{}

instead of

if ()
{}
else
    if ()
    {}
    else
        if ()
        {}
           ...
                       else
                       {}

(Optionally with one more level of {} in each but the last else)
In fact, editors like emacs will indent the two sources differently, 
i.e. just in the way I indicated, even though there is absolutely no 
difference in semantic. And the first complies with coding standards 
like gnu and gcc, and maybe even others like misra etc.

Georg-Johann