Lpc2000

At 11:31 AM 4/9/05 +0000, charlesgrenz wrote:
>When ever you use a global variable, you have to specify it as a
>volatile to tell the compiler not to opitmize the variable out of the
>equation when working with any ANSI C compiler.

Um, no.  The C compiler MUST assume that any global variable can change 
across a function call if it can't trace the call (ie if it's in a separate 
module).  Once a call is made outside of the compiler 'sight' all globals 
have to be considered changed by the compiler.

Now once a routine has read a global it can assume it's unchanged until 
it's made a function call unless it's declared as volatile.  But in this 
case volatile will make no difference.

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,   be 
they legal, genetic, or physical.  If you don't believe me, try to chew a 
radio signal. "  -- Kelvin Throop, III
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