I have read many times that insertion sort has tight code and hence the hidden constant factor in its asymptotic complexity is smaller. I just read yesterday that quick sort has tight code just like insertion sort so it also has smaller hidden constant factor. It is one of the reasons it is considered best among the
O(n lg n) sorting algorithms.
I don't understand what does it mean when someone says that this algorithm's code is tight. What does that mean exactly and how does it lead to improvement in the efficiency of the algorithm (the smaller hidden constant factor in asymptotic complexity)?