Re: Computer architects leaving Intel...

In article <vc4mgj$1khmk$1@dont-email.me>,
Thomas Koenig  <tkoenig@netcologne.de> wrote:

Kent Dickey <kegs@provalid.com> schrieb:
>

When you write code working on signed numbers and do something like:
>
(a < 0) || (a >= max)
>
Then the compiler realizes if you treat 'a' as unsigned, this is just:
>
(unsigned)a >= max

>
For which definition of a and max exactly?
>
It coertainly does not do so for
>
_Bool foo(int a, int max)
{
   return (a < 0) || (a >= max);
}

Sorry, I should have made it clear for max >= 0 (but not necessarily an
unsigned variable), and for my code, a constant, which is how the
compiler knows it's positive .  I have this in my code all the time to
validate function inputs--a negative number is bad, and a number beyond
a certain reasonable value is bad.  And I let the compiler optimize the
check to (unsigned)a >= (unsigned)max.

Kent