Re: Efficiency of code generated by Ada compilers

[csampson@inetworld.net (Charles H. Sampson)]

Robert A Duff <bobduff@shell01.TheWorld.com> wrote:

> Gene <gene.ressler@gmail.com> writes:
> 
> > In some cases, a built-in Ada construct will generate better code than
> > a "hand-coded" equivalent in C++.  An example I ran into recently was
> > incrementing a modular type.  In Ada, you say I := I + 1;, and the
> > compiler takes care of "wrapping" to zero.  In C++, I've frequently
> > seen people write i = (i + 1) % n; to simulate the same operation in
> > the absence of modular types.
> 
> You will see me writing "I := (I + 1) mod N;" (for signed
> integer I) in Ada.  ;-)
>
     I'm surprised, Bob.  Are you saying that you signed integers in
preference to a modular type for a variable that cycles?  I use
modular-typed variables and, if I've got my engineer's hat on, write

     I := I + 1;  -- Modular variable.  Wraps.

but I have to admit that in the heat of battle the comment might be
omitted.  Even in that case, the variable name probably indicates that
wrapping should be expected.

                        Charlie
-- 
All the world's a stage, and most 
of us are desperately unrehearsed.  Sean O'Casey