GCC warnings for unused global variables

[Mike Stump]

On Friday, May 2, 2003, at 07:56 AM, Gabriel Dos Reis wrote:
> They can be optimized out if the program cannot tell the difference.

Disagree.  I think the above is probably either confusing, or wrong.  
We can better well what you mean if you tell us if, in:

Given:

extern volatile int i;
int main() {
	i = 1;
	i = 2;
}

can the program tell the difference?  If you say no, then I think your 
statement is wrong, otherwise, if you mean if and only if and not just 
if above, then I think your statement is confusing.