This is the third newbie question I make here, but... If I put, for example: variable = 1 + 2; gcc will compile the code for the CPU add one to two and put in variable, in execution time, or will substitute and in the compiled code the equivalent of: variable = 3; would be inserted? If it evaluate expressions like this before compiling, it always is done? Or I would need some directive to ask gcc to evaluate it for me before compiling? Thank you :)