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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Efficiency of code generated by Ada compilers
Newsgroups: comp.lang.ada
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Date: Sun, 8 Aug 2010 20:11:44 +0200
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On Sun, 8 Aug 2010 10:13:51 -0700, Charles H. Sampson wrote:

> 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?

Sometimes it has to be that way because modular types do not support
non-static bounds. E.g.:

procedure Foo (N : Positive) is
   type M is mod 2**N; -- You cannot do that!

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de