[lederhosen]

qsort(3) is quite slow because it can not inline the compare function. If you created a 'generic' bubble sort that take a compare function pointer and no LTO optimization (or use an inlined c++ sort), the quick sort algorithm might be faster even on 50 elements.

[krylon]

I had suspected that might be a factor.

Either way, at 50 elements, if the difference in performance between qsort and bubblesort has significant impact on overall performance, there is probably something very wrong. ;-)