Re: hii
Ganga wrote:
> Please, will anyone explain me difference between 'register' and
Register keyword for a variable will force the compiler backend to give
register.
so by this compiler can acess the variable without store
instruction(i.e it can use mov instruction).
> 'volatile' variables
Volatile Keyword for a variable will prevent variable from
optimization.
i.e
main()
{
int i=2,j=3,a,b;
a=i+j;
b=i+j;
return a+b;
}
For above code the compiler try to optimize the code.
i.e
main()
{
int i=2,j=3,a,b
t=i+j; //where t is the temproray variable which is interal generated
by compiler.
a=t;//a & b are automatic variable.
b=t;
// by this we can save one addition.
return a+b;
}
main()
{
volatile int i=2,j=3,a,b;
a=i+j;
b=i+j;
return a+b;
}
but in the case volatile.it prevents variables(i,j) from optimization.
so above code remain same.
.
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