With GCC specifics, you can define MAX as a macro without calling the function twice. #define max(a,b) \ ({ typeof (a) _a = (a); \ typeof (b)

With GCC specifics, you can define MAX as a macro without calling the function twice. #define max(a,b) \ ({ typeof (a) _a = (a); \ typeof (b) _b = (b); \ _a > _b ? _a : _b; })