What would be the best way to accomplish this If-else check?

I have an if-else statement in a php class, which works perfectly. I want to know if there could be an any better or faster way to accomplish this?

if( !empty($  value_1) && empty($  value_2)){     function_1(){ } } elseif( !empty($  value_2) && empty($  value_1) ){     function_2(){ } } elseif (!empty($  value_1) || !empty($  value_2)){     function_3(){ } } else {     function_default(){ } }