Optimization of variables

[Marcus Clyne <maccaday@xxxxxxxxx>]

Hi,

Will the following C code :

int y;
{
   int   x1, x2;

   x1 = 3;
   x2 = 4;

   y = x1 + x2;
}

be compiled as :

int y = 7;

automatically, without creating the extra variables on the stack and 
performing the addition calculation?

Is this true of all code, or only with certain optimizations (e.g. -O2).

Thanks,

Marcus.