Maybe you should add a default: case. That may eliminate the warning.
J M Sharath Bharadwaj bharadwaj wrote:
hi Andrew,
I was talking about warning option called -Wuninitialized
Here in the below code, compiler gives warning like " might be used
uninitialized in this function" for x ,
{
int x;
switch (y)
{
case 1: x = 1;
break;
case 2: x = 4;
break;
case 3: x = 5;
}
foo (x);
}
If the value code{y} is always 1, 2 or 3, then code{x} is
always initialized, but GCC doesn't know this. So it emits a warning.
My question was, if I am going to initialize the variable x to some
value. is that going to help for the compiler to perform better
optimization, without giving ant warnings
Sharath.
On Fri, Jul 11, 2008 at 7:19 PM, Andrew Haley <aph@xxxxxxxxxx> wrote:
J M Sharath Bharadwaj bharadwaj wrote:
hi All,
Is GCC going to perform a better optimization, if I am going to
initialize the variable explicitly. I am asking this because I was
reading the GCC online doc for warning options like as in
http://www.cs.cmu.edu/cgi-bin/info2www?(gcc.info)Warning%20Options
This is a strange question.
If you read an uninitialized variable your program contains undefined
behaviour, and optimization is going to be the least of your problems.
If you don't read from an uninitialized variable it doesn't matter.
Andrew.
